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Molybdenum(IV) bromide , also known as molybdenum tetrabromide, is the inorganic compound with the formula MoBr 4 . It is a black solid. MoBr 4 has been prepared by treatment of molybdenum(V) chloride with hydrogen bromide :
The reaction proceeds via the unstable molybdenum(V) bromide, which releases bromine at room temperature. [ 1 ]
Molybdenum(IV) bromide can also be prepared by oxidation of molybdenum(III) bromide with bromine. [ 2 ] | https://en.wikipedia.org/wiki/MoBr4 |
Molybdenum dichloride describes chemical compounds with the empirical formula MoCl 2 . At least two forms are known, and both have attracted much attention from academic researchers because of the unexpected structures seen for these compounds and the fact that they give rise to hundreds of derivatives. The form discussed here is Mo 6 Cl 12 . The other molybdenum(II) chloride is potassium octachlorodimolybdate .
Rather than adopting a close-packed structure typical of metal dihalides, e.g., cadmium chloride , molybdenum(II) chloride forms a structure based on clusters. Molybdenum(II), which is a rather large ion , prefers to form compounds with metal-metal bonds, i.e. metal clusters . In fact all "lower halides" (i.e. where halide/M ratio is <4) in the "early transition metal series (Ti, V, Cr, Mn triads) do. The species Mo 6 Cl 12 is polymeric, consisting of cubic Mo 6 Cl 8 4+ clusters interconnected by chloride ligands that bridge from cluster to cluster. This material converts readily to salts of the dianion [Mo 6 Cl 14 ] 2− . In this anion, each Mo bears one terminal chloride but is otherwise part of an Mo 6 octahedron embedded inside a cube defined by eight chloride centers. Thus, the coordination environment of each Mo is four triply bridging chloride ligands, four Mo neighbors, and one terminal Cl. The cluster has 24e − , four being provided by each Mo 2+ . [ 1 ]
Mo 6 Cl 12 is prepared by the reaction of molybdenum(V) chloride with molybdenum metal:
This reaction proceeds via the intermediacy of MoCl 3 and MoCl 4 , which also are reduced by the presence of excess Mo metal. The reaction is conducted in a tube furnace at 600–650 °C. [ 2 ]
Once isolated, Mo 6 Cl 12 undergoes many reactions with retention of the Mo 6 12+ core. Heating in concentrated HCl gives (H 3 O) 2 [Mo 6 Cl 14 ]. The terminal chloride ligands, labeled "ausser" are readily exchanged:
Under more forcing conditions, all 14 ligands can be exchanged, to giving salts of [Mo 6 Br 14 ] 2− and [Mo 6 I 14 ] 2− .
A variety of clusters are structurally related to [Mo 6 Cl 14 ] 2− . The tungsten analogue is known. Ta and Nb form related clusters where halides are bridge edges of the Ta 6 octahedron vs faces. The resulting formula is [Ta 6 Cl 18 ] 4− .
Sulfido and selenido derivatives are also well studied. [Re 6 Se 8 Cl 6 ] 4− has the same number of valence electrons as does [Mo 6 Cl 14 ] 2− . [ 3 ]
The Mo-S clusters Mo 6 S 8 L 6 , analogues of the "Chevrel phases", have been prepared by the reaction of sulfide sources with Mo 6 Cl 12 in the presence of donor ligands L. [ 4 ] | https://en.wikipedia.org/wiki/MoCl2 |
Molybdenum(III) chloride is the inorganic compound with the formula MoCl 3 . It forms purple crystals. [ 1 ]
Molybdenum(III) chloride is synthesized by the reduction of molybdenum(V) chloride with hydrogen . [ 2 ] A higher yield is produced by the reduction of pure molybdenum(V) chloride with anhydrous tin(II) chloride as the reducing agent . [ 3 ]
Molybdenum trichloride exists as two polymorphs : alpha (α) and beta (β). The alpha structure is similar to that of aluminum chloride (AlCl 3 ). In this structure, molybdenum has octahedral coordination geometry and exhibits cubic close-packing in its crystalline structure. The beta structure, however, exhibits hexagonal close packing. [ 4 ]
Molybdenum trichloride gives a ether complexes MoCl 3 (thf) 3 and MoCl 3 (Et 2 O) 3 . They are beige, paramagnetic solids. Both feature octahedral Mo centers. The diethyl ether complex is synthesized by reducing a Et 2 O solution of MoCl 5 with tin powder. [ 5 ] Older procedures involve stepwise reduction involving isolation of the Mo(IV)-thf complex. [ 6 ]
Hexa(tert-butoxy)dimolybdenum(III) is prepared by the salt metathesis reaction from MoCl 3 (thf) 3 : [ 7 ] | https://en.wikipedia.org/wiki/MoCl3 |
Molybdenum tetrachloride is the inorganic compound with the empirical formula MoCl 4 . The material exists as two polymorphs , both being dark-colored paramagnetic solids. These compounds are mainly of interest as precursors to other molybdenum complexes.
The α polymorph is a polymer. The β polymorph is a hexamer. In both polymorph, the Mo center is octahedral with two terminal chloride ligands and four doubly bridging ligands. [ 1 ] In addition to these two binary phases, a number of adducts are know with the formula MoCl 4 L 2 where L is a Lewis base .
α-Molybdenum tetrachloride can be prepared from by dechlorination of molybdenum pentachloride using tetrachloroethene : [ 2 ]
Heating α-molybdenum tetrachloride in a sealed container in the presence of molybdenum pentachloride induces conversion to the β polymorph. [ 2 ]
When heated in an open container, molybdenum tetrachloride evolves chlorine, giving molybdenum trichloride ; [ 2 ]
The acetonitrile complex adduct can be prepared by reduction of the pentachloride with acetonitrile: [ 3 ] [ 4 ]
The MeCN ligands can be exchanged with other ligands:
The pentachloride can be reduced to the ether complex MoCl 4 (Et 2 O) 2 using tin powder. It is a beige, paramagnetic solid. [ 5 ] | https://en.wikipedia.org/wiki/MoCl4 |
Molybdenum(V) chloride is the inorganic compound with the empirical formula MoCl 5 . This dark volatile solid is used in research to prepare other molybdenum compounds. It is moisture-sensitive and soluble in chlorinated solvents.
Usually called molybdenum pentachloride, it is in fact partly a dimer with the molecular formula Mo 2 Cl 10 . [ 1 ] In the dimer, each molybdenum has local octahedral symmetry and two chlorides bridge between the molybdenum centers. [ 2 ] A similar structure is also found for the pentachlorides of W, Nb and Ta. [ 3 ] In the gas phase and partly in solution, the dimers partially dissociate to give a monomeric MoCl 5 . [ 4 ] The monomer is paramagnetic, with one unpaired electron per Mo center, reflecting the fact that the formal oxidation state is +5, leaving one valence electron on the metal center.
MoCl 5 is prepared by chlorination of Mo metal but also chlorination of MoO 3 . The unstable hexachloride MoCl 6 is not produced in this way. [ 5 ]
MoCl 5 is reduced by acetonitrile to afford an orange acetonitrile complex , MoCl 4 (CH 3 CN) 2 . This complex in turn reacts with THF to give MoCl 4 (THF) 2 , a precursor to other molybdenum-containing complexes. [ 6 ]
Molybdenum(IV) bromide is prepared by treatment of MoCl 5 with hydrogen bromide :
The reaction proceeds via the unstable molybdenum(V) bromide, which releases bromine at room temperature. [ 7 ]
MoCl 5 is a good Lewis acid toward non-oxidizable ligands. It forms an adduct with chloride to form [MoCl 6 ] − . In organic synthesis , the compound finds occasional use in chlorinations , deoxygenation , and oxidative coupling reactions. [ 8 ]
MoCl 5 is reduced by acetonitrile : [ 9 ]
Although it polymerizes tetrahydrofuran , MoCl 5 is stable in diethyl ether . Reduction of such solutions with tin gives MoCl 4 ((CH 3 CH 2 ) 2 O) 2 and MoCl 3 ((CH 3 CH 2 ) 2 O) 3 , depending on conditions. [ 10 ]
MoCl 5 is an aggressive oxidant and readily hydrolyzes to release HCl. | https://en.wikipedia.org/wiki/MoCl5 |
Molybdenum hexafluoride , also molybdenum(VI) fluoride , is an inorganic compound with the formula Mo F 6 . It is the fluoride of molybdenum in its highest oxidation state of +6. It is a colourless solid that melts just below room temperature and boils at 34 °C. [ 3 ] It is one of the seventeen known binary hexafluorides .
Molybdenum hexafluoride is made by direct reaction of molybdenum metal in an excess of elemental fluorine : [ 2 ]
The compound hydrolyzes easily, [ 4 ] and typical impurities are MoO 2 F 2 and MoOF 4 . [ 5 ]
At −140 °C, it crystallizes in the orthorhombic space group Pnma . Lattice parameters are a = 9.394 Å , b = 8.543 Å, and c = 4.959 Å. There are four formula units (in this case, discrete molecules) per unit cell , giving a density of 3.50 g·cm −3 . [ 2 ] The fluorine atoms are arranged in the hexagonal close packing . [ 6 ]
In liquid and gas phase, MoF 6 adopt octahedral molecular geometry with point group O h . The Mo–F bond length is 1.817 Å. [ 2 ]
Molybdenum hexafluoride has few uses. In the nuclear industry, MoF 6 occurs as an impurity in uranium hexafluoride since molybdenum is a fission product of uranium .
The semiconductor industry constructs various integrated circuits through chemical vapor deposition of molybdenum hexafluoride. [ 4 ] In some cases, the deposited molybdenum is an impurity in the intended tungsten hexafluoride . MoF 6 can be removed by reduction of a WF 6 - MoF 6 mixture with any of a number of elements including hydrogen iodide at moderately elevated temperature. [ 7 ] [ 8 ] | https://en.wikipedia.org/wiki/MoF6 |
MoFEM (Mesh Orientated Finite Element Method) is an open source finite element analysis code developed and maintained at the University of Glasgow . MoFEM is tailored for the solution of multi-physics problems with arbitrary levels of approximation, different levels of mesh refinement and optimised for high-performance computing. MoFEM is the blend of the Boost (C++ libraries) MultiIndex containers, MOAB (Mesh Oriented Database) and PETSc (Portable, Extensible Toolkit for Scientific Computation). MoFEM is developed in C++ and it is open-source software under the GNU Lesser General Public License ( GPL ).
Building a scientific simulation environment for finite element methods is a complicated task. The longest part of finite element code development is in dealing with technical problems related to software implementation, rather than resolving the underlying physics that the code is intended to tackle.
The demand for accurate solutions of increasingly complicated real-world problems means that the underlying data structures also become increasingly complicated. This is particularly evident with multi-physics, hp-adaptivity, and/or evolving geometries (e.g. crack propagation). Established commercial software is often limited in this respect, or can be relatively slow to adopt new innovations. Working around these problems has been the main motivation for the development of MoFEM, recognising that it is increasingly necessary for engineers, scientists and mathematicians to carry out calculations using several mesh refinements, different approximation orders, multiple degrees of freedom and/or different scales.
MoFEM evolved from YAFEMS (2008), a general and open source finite element code developed at the University of Glasgow .
In 2013 YAFEMS was re-written from scratch and named MoFEM. MoFEM was initiated by two projects. EPSRC founded a project for Providing Confidence in Durable Composites (DURACOMP) [ 1 ] in a consortium of three institutions: University of Warwick , University of Glasgow , Newcastle University and several industrial partners. The second project was funded by IAA-EPSRC: Simulation of fracture in nuclear graphite: from academic setting to commercial application [ 2 ] and EDF Energy .
MoFEM is free, open source software, released under the GNU Lesser General Public License as published by the Free Software Foundation . [ 7 ] | https://en.wikipedia.org/wiki/MoFEM_JosePH |
Molybdenum dioxide is the chemical compound with the formula MoO 2 . It is a violet-colored solid and is a metallic conductor. The mineralogical form of this compound is called tugarinovite , and is only very rarely found.
It crystallizes in a monoclinic cell, and has a distorted rutile, ( TiO 2 ) crystal structure. In TiO 2 the oxide anions are close packed and titanium atoms occupy half of the octahedral interstices (holes). In MoO 2 the octahedra are distorted, the Mo atoms are off-centre, leading to alternating short and long Mo – Mo distances and Mo-Mo bonding. The short Mo – Mo distance is 251 pm which is less than the Mo – Mo distance in the metal, 272.5 pm. The bond length is shorter than would be expected for a single bond. The bonding is complex and involves a delocalisation of some of the Mo electrons in a conductance band accounting for the metallic conductivity. [ 1 ]
MoO 2 can be prepared :
Single crystals are obtained by chemical transport using iodine . Iodine reversibly converts MoO 2 into the volatile species MoO 2 I 2 . [ 3 ]
Molybdenum dioxide is a constituent of "technical molybdenum trioxide" produced during the industrial processing of MoS 2 : [ 4 ] [ 5 ]
MoO 2 has been reported as catalysing the dehydrogenation of alcohols, [ 6 ] the reformation of hydrocarbons [ 7 ] and biodiesel. [ 8 ] Molybdenum nano-wires have been produced by reducing MoO 2 deposited on graphite. [ 9 ] Molybdenum dioxide has also been suggested as possible anode material for Li-ion batteries . [ 10 ] [ 11 ] | https://en.wikipedia.org/wiki/MoO2 |
Molybdenum dichloride dioxide is the inorganic compound with the formula MoO 2 Cl 2 . It is a yellow diamagnetic solid that is used as a precursor to other molybdenum compounds. Molybdenum dichloride dioxide is one of several oxychlorides of molybdenum.
Gaseous molybdenum dichloride dioxide is a monomer, [ 1 ] but upon condensation, it polymerizes to give a coordination polymer of uncertain structure.
The compound is most easily prepared by treatment molybdenum trioxide with concentrated hydrochloric acid : [ 2 ]
MoO 2 Cl 2 can also be prepared from MoOCl 4 : [ 3 ]
It is also prepared by chlorination of molybdenum dioxide : [ 4 ]
It is also prepared by chlorination of molybdenum trixoide: [ 5 ]
Many bis adducts are known of the type MoO 2 Cl 2 ( ether ) 2 . These octahedral molecular complexes are soluble in organic solvents.
With bulky anilines , it converts to the diimido complex MoCl 2 (=N− Ar ) 2 ( dimethoxyethane ) . This complex is the precursor to the Schrock carbenes of the type Mo(OR) 2 (=N−Ar)(=CH− tBu ) . [ 4 ]
Molybdenum difluoride dioxide exists as a sublimable white solid, in contrast to the dichloride. | https://en.wikipedia.org/wiki/MoO2Cl2 |
Molybdenum trioxide describes a family of inorganic compounds with the formula MoO 3 (H 2 O) n where n = 0, 1, 2. The anhydrous compound is produced on the largest scale of any molybdenum compound since it is the main intermediate produced when molybdenum ores are purified. The anhydrous oxide is a precursor to molybdenum metal, an important alloying agent. It is also an important industrial catalyst . [ 8 ] It is a yellow solid, although impure samples can appear blue or green.
Molybdenum trioxide occurs as the rare mineral molybdite .
In the gas phase, three oxygen atoms are bonded to the central molybdenum atom. In the solid state, anhydrous MoO 3 is composed of layers of distorted MoO 6 octahedra in an orthorhombic crystal. The octahedra share edges and form chains which are cross-linked by oxygen atoms to form layers. The octahedra have one short molybdenum-oxygen bond to a non-bridging oxygen. [ 9 ] [ 10 ] Also known is a metastable (β) form of MoO 3 with a WO 3 -like structure. [ 11 ] [ 2 ]
MoO 3 is produced industrially by roasting the mineral molybdenite ( molybdenum disulfide ), the chief ore of molybdenum: [ 8 ]
Similar procedures apply to the recovery of molybdenum from spent catalysts. The resulting trioxide can be purified by sublimation.
The laboratory synthesis of the dihydrate entails acidification of aqueous solutions of sodium molybdate with perchloric acid : [ 12 ]
The dihydrate loses water readily to give the monohydrate. Both are bright yellow in color. Molybdenum trioxide dissolves slightly in water to give " molybdic acid ". In base, it dissolves to afford the molybdate anion.
Molybdenum trioxide is used to manufacture molybdenum metal:
Molybdenum trioxide is also a component of the co-catalyst used in the industrial production of acrylonitrile by the oxidation of propene and ammonia .
Because of its layered structure and the ease of the Mo(VI)/Mo(V) coupling, MoO 3 is of interest in electrochemical devices and displays. It has been described as "the most commonly used TMO [transition metal oxide] in organic electronics applications ... it is evaporated at relatively low temperature (~400 °C)." [ 13 ] It has favourable electronic and chemical properties for use as interfacing layers, p-type dopants and hole transport materials in OLEDs , organic solar cells and perovskite solar cells , [ 14 ] especially when forming an ohmic contact to organic semiconductors . [ 15 ] | https://en.wikipedia.org/wiki/MoO3 |
Molybdenum oxytetrachloride is the inorganic compound with the formula Mo O Cl 4 . This thermally unstable, dark green solid is used to prepare other complexes of molybdenum. Its molecule adopts a square pyramidal molecular geometry of C 4v symmetry . As for other Mo(VI) compounds, it is diamagnetic . It decomposes thermally to MoOCl 3 .
It is prepared by treating molybdenum pentachloride with oxygen . [ 2 ] It also arises by chlorination of molybdenum trioxide : [ 3 ] | https://en.wikipedia.org/wiki/MoOCl4 |
MoOPH , also known as oxodiperoxymolybdenum(pyridine)-(hexamethylphosphoric triamide) , is a reagent used in organic synthesis . [ 1 ] It contains a molybdenum (VI) center with multiple oxygen ligands, coordinated with pyridine and HMPA ligands, although the HMPA can be replaced by DMPU . [ 2 ] It is an electrophilic source of oxygen that reacts with enolates and related structures, and thus can be used for alpha- hydroxylation of carbonyl -containing compounds. [ 3 ] Other reagents used for alpha-hydroxylation via enol or enolate structures include Davis oxaziridine , oxygen , and various peroxyacids (see Rubottom oxidation ). This reagent was first utilized by Edwin Vedejs as an efficient alpha-hydroxylating agent in 1974 and an effective preparative procedure was later published in 1978. [ 4 ]
MoOPH is synthesized from molybdenum trioxide by oxidation with hydrogen peroxide and addition of the HMPA and pyridine ligands: [ 4 ] MoO 3 → 2. HMPA 1. H 2 O 2 MoO 5 ( H 2 O ) ( HMPA ) → 0.2 Torr MoO 5 ( HMPA ) → Pyridine MoO 5 ( HMPA ) ( pyridine ) {\displaystyle {\ce {MoO3}}\xrightarrow {\stackrel {1.{\ce {H2O2}}}{2.{\ce {HMPA}}}} {\ce {MoO5 (H2O) (HMPA)}}\xrightarrow {\text{0.2 Torr}} {\ce {MoO5 (HMPA)}}\xrightarrow {\text{Pyridine}} {\ce {MoO5(HMPA)(pyridine)}}}
Due to MoOPH's steric bulk , preferential attack at the O–O bond occurs from the less hindered enolate face in the absence of stereoelectronic factors. [ 5 ] [ 6 ] [ 7 ]
In addition, nitriles with acidic alpha protons can be converted directly to cyanohydrins ; however, in the case of branched nitriles, this reaction directly affords the ketone. [ 8 ]
In the case of sulfones, alpha-hydroxylation leads directly to the ketone or aldehyde. [ 9 ]
Common byproducts of the alpha-hydroxylation tend to include overoxidation to the corresponding dicarbonyl or intermolecular aldol reaction of the starting material. Procedures to prevent side reactions include the inverse addition of the enolate to MoOPH or careful control of the temperature (-78 to -20 °C). Notable miscellaneous reactions include MoOPH’s ability to oxidize alkylboranes directly to the alcohol with net stereo-retention. [ 10 ]
MoOPH has also been shown to oxidize N-trimethylsilyl amides directly to the hydroxamic acid. [ 11 ] | https://en.wikipedia.org/wiki/MoOPH |
hR9 , R3m , No 160 (3R) [ 5 ]
Molybdenum disulfide (or moly) is an inorganic compound composed of molybdenum and sulfur . Its chemical formula is MoS 2 .
The compound is classified as a transition metal dichalcogenide . It is a silvery black solid that occurs as the mineral molybdenite , the principal ore for molybdenum. [ 6 ] MoS 2 is relatively unreactive. It is unaffected by dilute acids and oxygen . In appearance and feel, molybdenum disulfide is similar to graphite . It is widely used as a dry lubricant because of its low friction and robustness. Bulk MoS 2 is a diamagnetic , indirect bandgap semiconductor similar to silicon , with a bandgap of 1.23 eV. [ 2 ]
MoS 2 is naturally found as either molybdenite , a crystalline mineral, or jordisite, a rare low temperature form of molybdenite. [ 7 ] Molybdenite ore is processed by flotation to give relatively pure MoS 2 . The main contaminant is carbon. MoS 2 also arises by thermal treatment of virtually all molybdenum compounds with hydrogen sulfide or elemental sulfur and can be produced by metathesis reactions from molybdenum pentachloride . [ 8 ]
All forms of MoS 2 have a layered structure, in which a plane of molybdenum atoms is sandwiched by planes of sulfide ions. These three strata form a monolayer of MoS 2 . Bulk MoS 2 consists of stacked monolayers, which are held together by weak van der Waals interactions .
Crystalline MoS 2 exists in one of two phases, 2H- MoS 2 and 3R- MoS 2 , where the "H" and the "R" indicate hexagonal and rhombohedral symmetry, respectively. In both of these structures, each molybdenum atom exists at the center of a trigonal prismatic coordination sphere and is covalently bonded to six sulfide ions. Each sulfur atom has pyramidal coordination and is bonded to three molybdenum atoms. Both the 2H- and 3R-phases are semiconducting. [ 10 ]
A third, metastable crystalline phase known as 1T- MoS 2 was discovered by intercalating 2H- MoS 2 with alkali metals . [ 11 ] This phase has trigonal symmetry and is metallic. The 1T-phase can be stabilized through doping with electron donors such as rhenium , [ 12 ] or converted back to the 2H-phase by microwave radiation. [ 13 ] The 2H/1T-phase transition can be controlled via the incorporation of sulfur (S) vacancies . [ 14 ]
Nanotube -like and buckyball -like molecules composed of MoS 2 are known. [ 15 ]
While bulk MoS 2 in the 2H-phase is known to be an indirect-band gap semiconductor, monolayer MoS 2 has a direct band gap. The layer-dependent optoelectronic properties of MoS 2 have promoted much research in 2-dimensional MoS 2 -based devices. 2D MoS 2 can be produced by exfoliating bulk crystals to produce single-layer to few-layer flakes either through a dry, micromechanical process or through solution processing.
Micromechanical exfoliation, also pragmatically called " Scotch-tape exfoliation ", involves using an adhesive material to repeatedly peel apart a layered crystal by overcoming the van der Waals forces. The crystal flakes can then be transferred from the adhesive film to a substrate. This facile method was first used by Konstantin Novoselov and Andre Geim to obtain graphene from graphite crystals. However, it can not be employed for a uniform 1-D layers because of weaker adhesion of MoS 2 to the substrate (either silicon, glass or quartz); the aforementioned scheme is good for graphene only. [ 16 ] While Scotch tape is generally used as the adhesive tape, PDMS stamps can also satisfactorily cleave MoS 2 if it is important to avoid contaminating the flakes with residual adhesive. [ 17 ]
Liquid-phase exfoliation can also be used to produce monolayer to multi-layer MoS 2 in solution. A few methods include lithium intercalation [ 18 ] to delaminate the layers and sonication in a high-surface tension solvent. [ 19 ] [ 20 ]
MoS 2 excels as a lubricating material (see below) due to its layered structure and low coefficient of friction . Interlayer sliding dissipates energy when a shear stress is applied to the material. Extensive work has been performed to characterize the coefficient of friction and shear strength of MoS 2 in various atmospheres. [ 21 ] The shear strength of MoS 2 increases as the coefficient of friction increases. This property is called superlubricity . At ambient conditions, the coefficient of friction for MoS 2 was determined to be 0.150, with a corresponding estimated shear strength of 56.0 MPa. [ 21 ] Direct methods of measuring the shear strength indicate that the value is closer to 25.3 MPa. [ 22 ]
The wear resistance of MoS 2 in lubricating applications can be increased by doping MoS 2 with Cr . Microindentation experiments on nanopillars of Cr-doped MoS 2 found that the yield strength increased from an average of 821 MPa for pure MoS 2 (at 0% Cr) to 1017 MPa at 50% Cr. [ 23 ] The increase in yield strength is accompanied by a change in the failure mode of the material. While the pure MoS 2 nanopillar fails through a plastic bending mechanism, brittle fracture modes become apparent as the material is loaded with increasing amounts of dopant. [ 23 ]
The widely used method of micromechanical exfoliation has been carefully studied in MoS 2 to understand the mechanism of delamination in few-layer to multi-layer flakes. The exact mechanism of cleavage was found to be layer dependent. Flakes thinner than 5 layers undergo homogenous bending and rippling, while flakes around 10 layers thick delaminated through interlayer sliding. Flakes with more than 20 layers exhibited a kinking mechanism during micromechanical cleavage. The cleavage of these flakes was also determined to be reversible due to the nature of van der Waals bonding. [ 24 ]
In recent years, MoS 2 has been utilized in flexible electronic applications, promoting more investigation into the elastic properties of this material. Nanoscopic bending tests using AFM cantilever tips were performed on micromechanically exfoliated MoS 2 flakes that were deposited on a holey substrate. [ 17 ] [ 25 ] The Young's modulus of monolayer flakes was 270 GPa, [ 25 ] while the thicker flakes were stiffer, with a Young's modulus of 330 GPa. [ 17 ] Molecular dynamic simulations found the in-plane Young's modulus of MoS 2 to be 229 GPa, which matches the experimental results within error. [ 26 ]
Bertolazzi and coworkers also characterized the failure modes of the suspended monolayer flakes. The strain at failure ranges from 6 to 11%. The average yield strength of monolayer MoS 2 is 23 GPa, which is close to the theoretical fracture strength for defect-free MoS 2 . [ 25 ]
The band structure of MoS 2 is sensitive to strain. [ 27 ] [ 28 ] [ 29 ]
Molybdenum disulfide is stable in air and attacked only by aggressive reagents . It reacts with oxygen upon heating forming molybdenum trioxide :
Chlorine attacks molybdenum disulfide at elevated temperatures to form molybdenum pentachloride :
Molybdenum disulfide is a host for formation of intercalation compounds . This behavior is relevant to its use as a cathode material in batteries. [ 30 ] [ 31 ] One example is a lithiated material, Li x MoS 2 . [ 32 ] With butyl lithium , the product is LiMoS 2 . [ 6 ]
Due to weak van der Waals interactions between the sheets of sulfide atoms, MoS 2 has a low coefficient of friction . MoS 2 in particle sizes in the range of 1–100 μm is a common dry lubricant . [ 34 ] Few alternatives exist that confer high lubricity and stability at up to 350 °C in oxidizing environments. Sliding friction tests of MoS 2 using a pin on disc tester at low loads (0.1–2 N) give friction coefficient values of <0.1. [ 35 ] [ 36 ]
MoS 2 is often a component of blends and composites that require low friction. For example, it is added to graphite to improve sticking. [ 33 ] A variety of oils and greases are used, because they retain their lubricity even in cases of almost complete oil loss, thus finding a use in critical applications such as aircraft engines . When added to plastics , MoS 2 forms a composite with improved strength as well as reduced friction. Polymers that may be filled with MoS 2 include nylon ( trade name Nylatron ), Teflon and Vespel . Self-lubricating composite coatings for high-temperature applications consist of molybdenum disulfide and titanium nitride , using chemical vapor deposition .
Examples of applications of MoS 2 -based lubricants include two-stroke engines (such as motorcycle engines), bicycle coaster brakes , automotive CV and universal joints , ski waxes [ 37 ] and bullets . [ 38 ]
Other layered inorganic materials that exhibit lubricating properties (collectively known as solid lubricants (or dry lubricants)) includes graphite, which requires volatile additives and hexagonal boron nitride . [ 39 ]
MoS 2 is employed as a cocatalyst for desulfurization in petrochemistry , for example, hydrodesulfurization . The effectiveness of the MoS 2 catalysts is enhanced by doping with small amounts of cobalt or nickel . The intimate mixture of these sulfides is supported on alumina . Such catalysts are generated in situ by treating molybdate/cobalt or nickel-impregnated alumina with H 2 S or an equivalent reagent. Catalysis does not occur at the regular sheet-like regions of the crystallites, but instead at the edge of these planes. [ 40 ]
MoS 2 finds use as a hydrogenation catalyst for organic synthesis . [ 41 ] As it is derived from a common transition metal , rather than a group 10 metal, MoS 2 is chosen when price or resistance to sulfur poisoning are of primary concern. MoS 2 is effective for the hydrogenation of nitro compounds to amines and can be used to produce secondary amines via reductive amination . [ 42 ] The catalyst can also effect hydrogenolysis of organosulfur compounds , aldehydes , ketones , phenols and carboxylic acids to their respective alkanes . [ 41 ] However, it suffers from low activity, often requiring hydrogen pressures above 96 MPa and temperatures above 185 °C.
MoS 2 plays an important role in condensed matter physics research. [ 43 ]
MoS 2 and related molybdenum sulfides are efficient catalysts for hydrogen evolution , including the electrolysis of water ; [ 44 ] [ 45 ] thus, are possibly useful to produce hydrogen for use in fuel cells . [ 46 ]
MoS 2 @Fe- N -C core/shell [ 47 ] nanosphere with atomic Fe-doped surface and interface ( MoS 2 /Fe- N -C) can be used as a used an electrocatalyst for oxygen reduction and evolution reactions (ORR and OER) bifunctionally because of reduced energy barrier due to Fe-N 4 dopants and unique nature of MoS 2 /Fe- N -C interface.
As in graphene , the layered structures of MoS 2 and other transition metal dichalcogenides exhibit electronic and optical properties [ 48 ] that can differ from those in bulk. [ 49 ] Bulk MoS 2 has an indirect band gap of 1.2 eV, [ 50 ] [ 51 ] while MoS 2 monolayers have a direct 1.8 eV electronic bandgap , [ 52 ] supporting switchable transistors [ 53 ] and photodetectors . [ 54 ] [ 49 ] [ 55 ]
MoS 2 nanoflakes can be used for solution-processed fabrication of layered memristive and memcapacitive devices through engineering a MoO x / MoS 2 heterostructure sandwiched between silver electrodes. [ 56 ] MoS 2 -based memristors are mechanically flexible, optically transparent and can be produced at low cost.
The sensitivity of a graphene field-effect transistor (FET) biosensor is fundamentally restricted by the zero band gap of graphene, which results in increased leakage and reduced sensitivity. In digital electronics, transistors control current flow throughout an integrated circuit and allow for amplification and switching. In biosensing, the physical gate is removed and the binding between embedded receptor molecules and the charged target biomolecules to which they are exposed modulates the current. [ 57 ]
MoS 2 has been investigated as a component of flexible circuits. [ 58 ] [ 59 ]
In 2017, a 115-transistor, 1-bit microprocessor implementation was fabricated using two-dimensional MoS 2 . [ 60 ]
MoS 2 has been used to create 2D 2-terminal memristors and 3-terminal memtransistors . [ 61 ]
Due to the lack of spatial inversion symmetry, odd-layer MoS2 is a promising material for valleytronics because both the CBM and VBM have two energy-degenerate valleys at the corners of the first Brillouin zone, providing an exciting opportunity to store the information of 0s and 1s at different discrete values of the crystal momentum. The Berry curvature is even under spatial inversion (P) and odd under time reversal (T), the valley Hall effect cannot survive when both P and T symmetries are present. To excite valley Hall effect in specific valleys, circularly polarized lights were used for breaking the T symmetry in atomically thin transition-metal dichalcogenides. [ 62 ] In monolayer MoS 2 , the T and mirror symmetries lock the spin and valley indices of the sub-bands split by the spin-orbit couplings, both of which are flipped under T; the spin conservation suppresses the inter-valley scattering. Therefore, monolayer MoS2 have been deemed an ideal platform for realizing intrinsic valley Hall effect without extrinsic symmetry breaking. [ 63 ]
MoS 2 also possesses mechanical strength, electrical conductivity, and can emit light, opening possible applications such as photodetectors. [ 64 ] MoS 2 has been investigated as a component of photoelectrochemical (e.g. for photocatalytic hydrogen production) applications and for microelectronics applications. [ 53 ]
Under an electric field MoS 2 monolayers have been found to superconduct at temperatures below 9.4 K. [ 65 ] | https://en.wikipedia.org/wiki/MoS2 |
Molybdenum trisulfide is an inorganic compound with the formula MoS 3 . [ 1 ]
This inorganic compound –related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/MoS3 |
Tetrathiomolybdate , also spelled tiomolibdate ( USAN ), is the anion of the following salts: | https://en.wikipedia.org/wiki/MoS4 |
Molybdenum diselenide ( MoSe 2 ) is an inorganic compound of molybdenum and selenium . Its structure is similar to that of MoS 2 . [ 6 ] Compounds of this category are known as transition metal dichalcogenides , abbreviated TMDCs. These compounds, as the name suggests, are made up of a transition metals and elements of group 16 on the periodic table of the elements . Compared to MoS 2 , MoSe 2 exhibits higher electrical conductivity. [ 7 ]
Like many TMDCs, MoSe 2 is a layered material with strong in-plane bonding and weak out-of-plane interactions. These interactions lead to exfoliation into two-dimensional layers of single unit cell thickness. [ 8 ]
The most common form of these TMDCs have trilayers of molybdenum sandwiched between selenium ions causing a trigonal prismatic metal bonding coordination, but it is octahedral when the compound is exfoliated . The metal ion in these compounds is surrounded by six Se 2− ions. The coordination geometry of the Mo is sometimes found as octahedral and trigonal prismatic. [ 9 ]
Synthesis of MoSe 2 involves direct reaction of molybdenum and selenium in a sealed tube at high temperature. Chemical vapor transport with a halogen (usually bromine or iodine ) is used to purify the compound at very low pressure (less than 10-6 torr) and very high temperature (600–700 °C). It has to be heated very gradually to prevent explosion due to its strong exothermic reaction. Stoichiometric layers crystallize in a hexagonal structure as the sample cools. [ 9 ] Excess selenium can be removed by sublimation under vacuum. [ 10 ] The synthesis reaction of MoSe 2 is:
Single-crystal-thick layers of MoSe 2 are produced by scotch tape exfoliation from bulk crystals or by chemical vapor deposition (CVD). [ 11 ] [ 12 ]
The electron mobility of 2D- MoSe 2 is significantly higher than that of 2D- MoS 2 . 2D MoSe 2 adopts structures reminiscent of graphene , although the latter's electron mobility is thousands of times greater still. In contrast to graphene, 2D- MoSe 2 has a direct band gap , suggesting applications in transistors and photodetectors . [ 11 ]
Molybdenum(IV) selenide occurs in the nature as the extremely rare mineral drysdallite . [ 13 ] | https://en.wikipedia.org/wiki/MoSe2 |
Molybdenum disilicide ( MoSi 2 , or molybdenum silicide ), an intermetallic compound , a silicide of molybdenum , is a refractory ceramic with primary use in heating elements . It has moderate density , melting point 2030 °C, and is electrically conductive . At high temperatures it forms a passivation layer of silicon dioxide , protecting it from further oxidation. The thermal stability of MoSi 2 alongside its high emissivity make this material, alongside WSi 2 attractive for applications as a high emissivity coatings in heat shields for atmospheric entry . [ 3 ] MoSi 2 is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. [ 4 ] It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid .
While MoSi 2 has excellent resistance to oxidation and high Young's modulus at temperatures above 1000 °C, it is brittle in lower temperatures. Also, at above 1200 °C it loses creep resistance. These properties limits its use as a structural material , but may be offset by using it together with another material as a composite material .
Molybdenum disilicide and MoSi 2 -based materials are usually made by sintering . Plasma spraying can be used for producing its dense monolithic and composite forms; material produced this way may contain a proportion of β-MoSi 2 due to its rapid cooling.
Molybdenum disilicide heating elements can be used for temperatures up to 1800 °C, in electric furnaces used in laboratory and production environment in production of glass , steel , electronics , ceramics , and in heat treatment of materials. While the elements are brittle, they can operate at high power without aging, and their electrical resistivity does not increase with operation time. Their maximum operating temperature has to be lowered in atmospheres with low oxygen content due to breakdown of the passivation layer. [ 5 ]
Molybdenum disilicide is used in microelectronics as a contact material. It is often used as a shunt over polysilicon lines to increase their conductivity and increase signal speed. | https://en.wikipedia.org/wiki/MoSi2 |
mP12 , P2 1 /m , No. 11 (β or 1T)
Molybdenum(IV) telluride , molybdenum ditelluride or just molybdenum telluride is an inorganic compound with formula MoTe 2 . It is a semiconductor, and can fluoresce . It is one of the transition metal dichalcogenides . As a semiconductor the band gap lies in the infrared region. It is a potential use as a semiconductor in electronics or an infrared detector . [ 4 ] MoTe 2 is black. [ 5 ] Although sometimes described as Mo 4+ , 2Te 2- , it is not ionic but highly covalent.
MoTe 2 can be prepared by heating the correct ratio of the elements together at 1100 °C in a vacuum. [ 6 ] Another method is via vapour deposition, where molybdenum and tellurium are volatilised in bromine gas and then deposited. [ 7 ] Using bromine results in forming an n-type semiconductor , whereas using tellurium only results in a p-type semiconductor . [ 8 ]
The amount of tellurium in molybdenum ditelluride can vary from 1.97 to 2. [ 9 ] Excess tellurium deposited during this process can be dissolved off with sulfuric acid . [ 10 ]
It can crystallise in two dimensional sheets which can be thinned down to monolayers that are flexible and almost transparent.
By annealing molybdenum film in a tellurium vapour at 850 to 870 K for several hours, a thin layer of MoTe 2 is formed. [ 11 ]
An amorphous form can be produced by sonochemically reacting molybdenum hexacarbonyl with tellurium dissolved in decalin . [ 12 ]
Molybdenum ditelluride can be formed by electrodeposition from a solution of molybdic acid (H 2 MoO 4 ) and tellurium dioxide (TeO 2 ). The product can be electroplated on stainless steel or indium tin oxide . [ 13 ]
Tellurization of thin Mo film at 650 °C by chemical vapor deposition (CVD) leads to the hexagonal, semiconducting α-form (2H-MoTe 2 ) while using MoO 3 film produces the monoclinic, semimetallic β-form (1T'-MoTe 2 ) at the same temperature of 650 °C. [ 14 ]
Very thin crystals of MoTe 2 can be made using sticky tape. When they are thin around 500 nm thick red light can be transmitted. Even thinner layers can be orange or transparent. An absorption edge occurs in the spectrum with wavelengths longer than 6720 Å transmitted and shorter wavelengths heavily attenuated. At 77 K this edge changes to 6465 Å. This corresponds to deep red. [ 15 ]
MoTe 2 reflects about 43% in the infrared band but has a peak at 234.5 cm −1 and a minimum at 245.8 cm −1 . [ 16 ]
As the temperature is lowered the absorption bands become narrower. At 77 K there are absorption peaks at 1.141, 1.230, 1.489, 1.758, 1.783, 2.049, 2.523, 2.578, and 2.805 eV. [ 17 ]
Exciton energy levels are at 1.10 eV, called A, and 1.48 eV, called B, with a difference of 0.38 eV. [ 18 ]
The Raman spectrum has four lines with wavenumbers of 25.4, 116.8, 171.4, and a double one at 232.4 and 234.5 cm −1 . [ 16 ] The peak at 234.5 cm −1 is due to E 1 2g mode, especially in nanolayers, but the thicker forms and the bulk has the second peak at 232.4 cm −1 also perhaps due to the E 2 1u phonon mode. The peak near 171.4 cm −1 comes from the A 1g . 138 and 185 cm −1 peaks may be due to harmonics. B 1 2g is assigned to a peak around 291 cm −1 in nanolayers with few layers. [ 19 ] The E 1 2g frequency increases as the number of layers decreases to 236.6 cm −1 for single layer. The A 1g mode lowers its frequency as the number of layers decreases, becoming 172.4 cm −1 for the monolayer. [ 19 ]
MoTe 2 commonly exists in three crystalline forms with rather similar layered structures: hexagonal α (2H-MoTe 2 ), monoclinic β (1T-MoTe 2 ) and orthorhombic β' (1T'-MoTe 2 ). At room temperature it crystallises in the hexagonal system similar to molybdenum disulfide . [ 6 ] Crystals are platy or flat. [ 7 ] MoTe 2 has unit cell sizes of a=3.519 Å c=13.964 Å and a specific gravity of 7.78 g·cm −3 . [ 6 ] Each molybdenum atom is surrounded by six tellurium atoms in a trigonal prism with the separation of these Mo and Te atoms being 2.73 Å. [ 6 ] This results in sublayers of molybdenum sandwiched between two sublayers of tellurium atoms, and then this three layer structure is stacked. [ 21 ] Each layer is 6.97 Å thick. [ 15 ] Within this layer two tellurium atoms in the same sublayer subtend an angle of 80.7°. The tellurium atoms on one sublayer are directly above those in the lower sublayer, and they subtend an angle of 83.1° at the molybdenum atom. The other Te-Mo-Te angle across sublayers is 136.0°. The distance between molybdenum atoms within a sublayer is 3.518 Å. This is the same as the distance between tellurium atoms in a sublayer. The distance between a tellurium atom in one sublayer and the atom in the other sublayer is 3.60 Å. [ 22 ]
The layers are only bonded together with van der Waals force . [ 23 ] The distance between tellurium atoms across the layers is 3.95 Å. [ 22 ] The tellurium atom at the bottom of one layer is aligned with the centre of a triangle of tellurium atoms on the top of the layer below. The layers are thus in two different positions. [ 22 ] The crystal is very easily cleaved on the plane between the three layer sheets. [ 21 ] The sizes change with temperature, at 100 K a=3.492 Å and at 400 K is 3.53 Å. In the same range c changes from 13.67 Å to 14.32 Å due to thermal expansion. [ 21 ] The hexagonal form is also called 2H-MoTe 2 , where "H" stands for hexagonal, and "2" means that the layers are in two different positions. Every second layer is positioned the same.
At temperatures above 900 °C MoTe 2 crystallises in the monoclinic 1T form (β–MoTe 2 ), with space group P2 1 /m with unit cell sizes of a=6.33 Å b=3.469 Å and c=13.86 Å with the angle β=93°55′. The high-temperature form has rod shaped crystals. The measured density of this polymorph is 7.5 g·cm −3 , but in theory it should be 7.67 g·cm −3 . Tellurium atoms form a distorted octahedron around the molybdenum atoms. [ 7 ] This high-temperature form, termed β–MoTe 2 can be quenched to room temperature by rapid cooling. [ 24 ] In this metastable state β-MoTe 2 can survive below 500 °C. [ 25 ] When metastable β–MoTe 2 is cooled below −20 °C, its crystal form changes to orthorhombic. This is because the monoclinic angle c changes to 90°. This form is called β' or, misleadingly, Td. [ 26 ]
The transition from α- to β-MoTe 2 happens at 820 °C, but if Te is reduced by 5% the required transition temperature increases to 880 °C. [ 25 ] K. Ueno and K. Fukushima claim that when the α form is heated in a low or high vacuum that it oxidises to form MoO 2 and that reversible phase transitions do not take place. [ 27 ]
In bulk, MoTe 2 can be produced as a single crystal with difficulty, but can also be made as a powder, as a polycrystalline form, as a thin film, as a nanolayer consisting of a few TeMoTe sheets, a bilayer consisting of two sheets or as a monolayer with one sheet.
Thin nanolayer forms of α-MoTe 2 have different symmetry depending on how many layers there are. With an odd number of layers the symmetry group is D 1 3h without inversion , but for an even number of layers, the lattice is the same if inverted and the symmetry group is D 3 3d . [ 19 ] Nanotubes with a 20–60 nm diameter can be made by heat treating amorphous MoTe 2 . [ 12 ]
N-type bulk α-MoTe 2 has an electrical conductivity of 8.3 Ω −1 cm −1 with 5×10 17 mobile electrons per cubic centimeter. P-type bulk MoTe 2 has an electrical conductivity of 0.2 Ω −1 cm −1 and a hole concentration of 3.2×10 16 cm −3 . [ 8 ] The peak electrical conductivity is around 235 K, dropping off slowly with decreasing temperatures, but also reducing to a minimum around 705 K. Above 705 K conductivity increases again with temperature. [ 5 ] Powdered MoTe 2 has a much higher resistance.
β–MoTe 2 has a much lower resistivity than α–MoTe 2 by more than a thousand times with values around 0.002 Ω·cm. [ 24 ] It is much more metallic in nature. [ 25 ] In the β form the molybdenum atoms are closer together so that the conduction band overlaps. [ 28 ] At room temperature resistivity is 0.000328 Ω·cm. [ 29 ]
Orthorhombic MoTe 2 has a resistance about 10% lower than the β form, and the resistance shows hysteresis of several degrees across the transition point around 250 K. The resistance drops roughly linearly with decreasing temperature. At 180 K resistivity is 2.52×10 −4 Ω·cm, [ 29 ] and at 120 mK the material becomes a superconductor. [ 20 ] Since orthorhombic MoTe 2 breaks spatial inversion symmetry, it exhibits ferroelectricity which can be coupled to its innate superconductivity. This coupling was leveraged to create a superconducting switch with MoTe 2 . [ 30 ] [ 31 ]
At low electric current levels the voltage is proportional to the current in the α form. With high electric currents MoTe 2 shows negative resistance, where as the current increases the voltage across the material decreases. This means there is a maximum voltage that can be applied. In the negative resistance region the current must be limited, otherwise thermal runaway will destroy the item made from the material. [ 32 ]
The Hall constant at room temperature is around 120 cm 3 /Coulomb for stochiometric α-MoTe 2 . But as Te is depleted the constant drops to close to 0 for compositions in the range MoTe 1.94 to MoTe 1.95 . [ 33 ]
The Seebeck coefficient is about 450 μV/K at room temperature for pure MoTe 2 , but this drops to 0 for MoTe 1.95 . The Seebeck coefficient increases as temperature drops. [ 33 ]
In the bulk α form of MoTe 2 the material is a semiconductor with a room temperature indirect band gap of 0.88 eV and a direct band gap of 1.02 eV. If instead of bulk forms, nanolayers are measured, the indirect band gap increases as the number of layers is reduced. α-MoTe 2 changes from an indirect to a direct band gap material in very thin slices. [ 34 ] It is a direct bandgap material when it is one or two layers (monolayer or bilayer). [ 35 ]
The band gap is reduced for tellurium-deficient MoTe 2 from 0.97 to 0.5. [ 9 ] The work function is 4.1 eV. [ 36 ]
α–MoTe 2 is diamagnetic whereas β–MoTe 2 is paramagnetic . [ 25 ]
X-ray photoelectron spectroscopy on clean MoTe 2 crystal surfaces show peaks at 231 and 227.8 eV due to molybdenum 3d 3/2 and 3d 5/2 ; with 582.9 and 572.5 due to tellurium 3d 3/2 and 3d 5/2 electrons. [ 8 ]
The X-ray K absorption edge occurs at 618.41±0.04 X units compared to molybdenum metal at 618.46 xu. [ 37 ]
Atomic force microscopy (AFM) of the van der Waals surface of α-MoTe 2 shows alternating rows of smooth balls, which are the tellurium atoms. [ 28 ] AFM images are often done on a silica (SiO 2 ) surface on silicon. A monolayer of α-MoTe 2 has its surface 0.9 nm above the silica, and each extra layer of α-MoTe 2 adds 0.7 nm. [ 19 ]
Scanning tunneling microscopy (STM) of α-MoTe 2 reveals a hexagonal grid like chicken wire, where the molybdenum atoms are contributing to the current. Higher bias voltages are required to get an image, either over 0.5 V or below −0.3 V. [ 28 ]
β-MoTe 2 surfaces examined with scanning tunneling microscopy can show either a pattern of tellurium atoms or a pattern of molybdenum atoms on different parts. When the scanning tip is further from the surface only tellurium atoms are visible. This is explained by the d z 2 orbitals from molybdenum penetrating up through the surface layer of tellurium. The molybdenum can supply a much bigger current than tellurium. But at greater distance only the p orbital from tellurium can be detected. Lower voltages than used for α form still produce atomic images. [ 28 ]
Friction force microscopy (FFM) has been used to get a slip-stick image at a resolution below that of the unit cell. [ 38 ] [ 39 ]
Heat in α-MoTe 2 is due to vibrations of the atoms. These vibrations can be resolved into phonons in which the atoms move backwards and forwards in different ways. For a monolayer twisting of the tellurium atoms within the plane is termed E″, a scissoring action where tellurium moves in the plane of the layer is termed E′. Where tellurium vibrates in opposite directions perpendicular to the layer out of the plane the phonon mode is A′ 1 and where the tellurium moves in the same direction opposite to the molybdenum the mode is called A″ 1 . Of these modes the first three are active in the Raman spectrum . In a bilayer there is an extra interaction between the atoms on the bottom of one layer and the atom on the top of the under layer. The mode symbols are modified with a suffix, "g" or "u" . In the bulk form with many layers, the modes are called A 1g (corresponding to A′ 1 in the monolayer), A 2u , B 1u B 2g , E 1g , E 1u , E 2g and E 2u . Modes E 1g , E 1 2g , E 2 2g , and A 1g are Raman active. Modes E 1 1u , E 2 1u , A 1 2u , and A 2 2u are infrared active. [ 19 ]
Molar heat of formation of α-MoTe 2 is −6 kJ/mol from β-MoTe 2 . Heat of formation of β-MoTe 2 is −84 kJ/mol. For Mo 3 Te 4 it is −185 kJ/mol. [ 40 ]
Thermal conductivity is 2 Wm −1 K −1 . [ 41 ]
Under pressure α-MoTe 2 is predicted to become a semimetal between 13 and 19 GPa. The crystal form should stay the same at pressures up to 100 GPa. [ 42 ] β-MoTe 2 is not predicted to become more metallic under pressure. [ 42 ]
MoTe 2 exhibits topological Fermi arcs . This is evidence for a new type (type-II) of Weyl fermion that arises due to the breaking of Lorentz invariance , which does not have a counterpart in high-energy physics, which can emerge as topologically protected touching between electron and hole pockets. The topological surface states are confirmed by directly observing the surface states using bulk- and surface-sensitive angle-resolved photoemission spectroscopy. [ 43 ]
Poisson ratio V ∞ =0.37. [ 41 ] Monolayer relaxed ion elastic coefficients C 11 =80 and C 12 =21. [ 41 ] Monolayer relaxed ion piezoelectric coefficient d 11 =9.13. [ 41 ]
MoTe 2 burn with a blue flame, emitting a white smoke of tellurium dioxide . [ 44 ]
MoTe 2 dissolves in dilute nitric acid with complete decomposition Hot hydrochloric does not attack MoTe 2 . [ 45 ] [ 46 ] Concentrated sulfuric acid at 261 °C completely dissolves MoTe 2 . Sodium hydroxide solution also attacks MoTe 2 . [ 47 ]
MoTe 2 gradually oxidises in air forming molybdenum dioxide (MoO 2 ). [ 6 ] Intermediates may include tellurites Te 2 MoO 7 and TeMo 5 O 16 . [ 48 ] Other oxidation products include molybdenum trioxide , tellurium, and tellurium dioxide. [ 49 ] Flakes of molybdenum ditelluride that contain many defects have lower luminescence, and absorb oxygen from the air, losing their luminescence. [ 4 ] [ 50 ]
When heated to high temperatures, tellurium evaporates from molybdenum ditelluride, producing the tellurium-deficient forms and then Mo 2 Te 3 . [ 25 ] [ 51 ] The vapour pressure of Te 2 over hot MoTe 2 is given by 10 8.398-11790/T . [ 52 ] On further heating Mo 2 Te 3 gives off Te 2 vapour. The partial pressure of Te 2 is given by 10 5.56-9879/T where T is in K and the pressure is in bars. Molybdenum metal is left behind. [ 52 ]
The surface on the flat part of the hexagonal crystal (0001) is covered in tellurium and is relatively inert. Layers of tungsten disulfide and tungsten diselenide can be grown on molybdenum ditelluride by van der Waals epitaxy (vdWE). [ 53 ] Gold also can be deposited on the cleavage surfaces of MoTe 2 . On the α form gold tends to be isotropically deposited, but on the β form it makes elongated strips along the [010] crystal direction. [ 54 ] Other substances that have been deposited on the crystal surface include indium selenide (InSe), [ 55 ] cadmium sulfide (CdS), [ 56 ] cadmium telluride (CdTe), [ 57 ] tin disulfide (SnS 2 ), tin diselenide (SnSe 2 ), [ 58 ] and tantalum diselenide (TaSe 2 ). [ 59 ]
The sheets in α-MoTe 2 can be separated and dispersed in water with a sodium cholate surfactant and sonication . It forms an olive green suspension. MoTe 2 is hydrophobic, but the surfactant coats the surface with its lipophilic tail. [ 60 ]
The sheets in α-MoTe 2 react with lithium to form intercalation compounds . Up to Li 1.6 MoTe 2 can be formed. This material has a similar X-ray diffraction pattern to α-MoTe 2 . [ 61 ] Perylene tetracarboxylic anhydride also intercalates. [ 62 ] [ 63 ]
Another molybdenum telluride has formula Mo 2 Te 3 . [ 6 ]
Yet another molybdenum telluride, hexamolybdenum octatelluride Mo 6 Te 8 forms black crystals shaped like cubes. It is formed when the elements in the correct ratio are heated together at 1000 °C for a week. It is related to the Chevrel phases . [ 64 ] It is not superconducting. [ 65 ]
Potential uses for MoTe 2 include electronics, optoelectronics or a photoelectric cell materials. Diodes have been fabricated from MoTe 2 by baking a p-type material in bromine. [ 8 ] The diode's current versus voltage plot shows very little current with reverse bias, an exponential region with dV/dln(j) of 1.6, and at higher voltages (>0.3V) a linear response due to resistance. [ 66 ] When operated as a capacitor, the capacitance varies as the inverse square of the bias, and also drops for higher frequencies. [ 66 ] Transistors have also been built from MoTe 2 . [ 67 ] MoTe 2 has potential to build low power electronics. Field effect transistors (FET) have been built from a bilayer, trilayer and thicker nanolayers. [ 68 ] An ambipolar FET has been built, and also a FET that can operate in n- or p-modes which had two top electrodes. [ 69 ]
Because MoTe 2 has two phases, devices can be constructed that mix the 2H semiconductor, and the 1T' metallic form.
A FET can be constructed with a thin layer of molybdenum ditelluride covered with a liquid gate composed of an ionic liquid or an electrolyte such as potassium perchlorate dissolved in polyethylene glycol . With low gate voltages below 2 volts, the device operates in an electrostatic mode, where the current from drain to source is proportional to the gate voltage. Above 2 volts the device enters an intermediate region where current does not increase. Above 3.5 volts current leaks through the gate, and electrolysis occurs intercalating potassium atoms in the MoTe 2 layer. The potassium intercalated molybdenum ditelluride becomes superconducting below 2.8 K. [ 36 ]
As a lubricant molybdenum ditelluride can function well in a vacuum and at temperatures up to 500 °C with a coefficient of friction below 0.1. However molybdenum disulfide has a lower friction, and molybdenum diselenide can function at higher temperatures. [ 70 ]
Related dichalcogenides can be fabricated into fairly efficient photoelectric cells. [ 66 ]
Potentially, stacked monolayers of indium nitride and molybdenum ditelluride can result in improved properties for photovoltaics, including lower refractive index, and greater absorbance. [ 71 ]
Cadmium telluride solar cells are often deposited on a backplate of molybdenum. Molybdenum ditelluride can form at the contact, and if this is n-type it will degrade the performance of the solar cell. [ 72 ]
Small pieces of nanolayers of molybdenum ditelluride can be mixed in and dispersed in molten pewter without reacting, and it causes a doubling of the stiffness of the resultant composite. [ 73 ]
Molybdenum ditelluride has been used as a substrate for examining proteins with an atomic force microscope. It is superior because the protein sticks harder than with more traditional materials such as mica. [ 74 ]
β–MoTe 2 is a comparatively good hydrogen evolution electrocatalyst showing even in unsupported form and without any additional nanostructuring a Tafel slope of 78 mV/dec. The semiconducting polymorph of α–MoTe 2 was found inactive for HER. The superior activity was attributed to higher conductivity of β–MoTe 2 phase. [ 75 ]
Recent work has shown that electrodes covered with β–MoTe 2 demonstrated an increase in the amount of hydrogen gas produced during the electrolysis when a specific pattern of high-current pulses was applied. By optimising the pulses of current through the acidic electrolyte, the authors could reduce the overpotential needed for hydrogen evolution by nearly 50% when compared with the original non-activated material. [ 76 ]
Few-layered metallic form 1T'-MoTe 2 (β–MoTe 2 ) enhance SERS signal and therefore, some lipophilic markers (β– sitosterol ) of coronary artery and cardiovascular diseases can be selectively detected at the surface of the few-layered films. [ 77 ] | https://en.wikipedia.org/wiki/MoTe2 |
MoarVM ( M etamodel O n A R untime V irtual M achine ) is a virtual machine built for the 6model object system. It is being built to serve as yet another VM backend for Raku . [ 3 ] MoarVM was created to allow for greater efficiency than Parrot by having a closer internal representation to the model system used by Raku. [ 4 ] Notably it was the virtual machine for the first stable version of Rakudo released in December 2015. [ 5 ] [ 6 ]
Work began on MoarVM on March 31, 2012; the project was first publicly announced the following year on May 31, 2013.
As of March 2014, it is the fastest virtual machine for Rakudo and NQP in terms of startup time and build speed. [ 7 ]
MoarVM is available under the Artistic License 2.0. [ 8 ]
This computing article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/MoarVM |
Mobibase is a France-based company., [ 1 ] publishing and distributing ethnic and thematic TV channels and VOD content [ 2 ] to mobile publishers, operators, cable and satellite TV and IPTV / OTT services in Europe, the Americas, Middle East, and Africa [ 3 ]
The company publishes linear TV channels on sports, news, cooking, lifestyle, cartoons, movies & series, music programming, and distribute live TV channels by satellite or IP capture. [ 4 ]
Mobibase distributes linear and non linear content, providing solutions on content management , captation, encoding and the streaming on several devices: phones , tablets , computers , IPTV and Smart TV [ 5 ]
In 2002, Vincent Roger and Laurent Sarver creates Mobibase company in Paris , France , starting by the aggregation of the content for mobile download services ( wallpaper , screensaver , animations and casual mobile games ). [ 6 ] In 2006, the company develops a streaming platform designed to program, transcode and stream to mobile and web TV . [ 7 ] Mobibase launches its first package One TV Plus [ 8 ] in France edited for mobile television . One TV Plus package includes 24 channels on several thematics (fun, movie, news music, glamour, etc.) and takes part of Orange , SFR , Bouygues channels offering. [ 9 ] In 2007, the company publishes its first thematic TV channels on mobile . In 2013, Mobibase provides worldwide thematic TV and VOD services on multiple devices. [ 10 ] [ 11 ] In 2017, Mobibase distributes 200 TV channels [ 12 ] and 7000+ video on demand through its catalog offer. [ 13 ] Mobibase provides a variety of packages such as Hispanic, Arabic, Turkish, Indian, Italian, Russian, Sports and News. [ 14 ]
Mobibase's TV channels are declared to the French TV Regulation Authority, Conseil Supérieur de l'Audiovisuel (CSA) [ 15 ] and in the database on TV and on-demand audiovisual services and companies in Europe. [ 16 ] The channels' brand are registered at Institut National de la Propriété Industrielle (INPI). [ 17 ]
The first element in the broadcasting ecosystem is the creation of audiovisual content. Broadcast content is offered to users in terms of a broadcast service, bundled and offered as a package. The major part of broadcast services are radio shows , movies , documentaries , news for radio, TV programmes , etc. However, it may also contain new types of content emerged with the advent of Internet such as websites, blogs, social media appearance. The broadcast services includes linear and nonlinear content. Linear content refers to the traditional way of offering radio or TV services with scheduled sequence of content over a certain period of time. This type of content are set up by broadcasters and cannot be changed by a listener or a viewer - the last ones can only change from one service to another or to switch off if the programme is not attractive. A live stream on the Internet is to be considered as a linear, as well. Nonlinear content are time-shifted and catch-up services available for a certain period of time. The viewer can select individual pieces of content and control the timing and the sequence of consumption. Other forms of nonlinear broadcast services encompass on demand access to audio and video content for immediate consumption and the viewer decides what to consume, where to consume it, when and on which device. [ 18 ] Mobibase does not produce its own content but licence content rights acquired from a combination of international and local rights deals. [ 19 ] Many major broadcasters which report under IFRS , including ITV , Channel 4 , Sky, France24 , TV Globo , teleSUR , RTL , Deutsche Well and Bell Media , explicitly highlight acquiring programming rights as a key driver of revenue growth. Acquired programming rights can be for single or multiple broadcasts and can have licence periods spanning away years. The agreements may also specify format ( HD , 3D ) and geographical rights. Programming rights agreements also cover other platforms such as desktop computer, tablet and smartphone. [ 20 ]
Another important element in broadcasting ecosystem is the content distribution. Broadcasters distribute their content over several networks ( terrestrial , cable , satellite , broadband networks , etc.) moving toward complete digital broadcasting . [ 21 ] The content market is characterised by the multi-platform environment through which content is available to end users. There is a distinction between offline content (e.g. content delivered via traditional broadcasting platforms) and online content (e.g. video on demand ). | https://en.wikipedia.org/wiki/Mobibase |
Mobil Composition of Matter (MCM) is the initial name given for a series of mesoporous materials that were first synthesized by Mobil's researchers in 1992. MCM-41 (Mobil Composition of Matter No. 41) and MCM-48 (Mobil Composition of Matter No. 48) are two of the most popular mesoporous molecular sieves that are keenly studied by researchers.
The most striking fact about the MCM-41 and MCM-48 is that, although composed of amorphous silica wall, they possess long range ordered framework with uniform mesopores. These materials also possess large surface area, which can be up to more than 1000 m 2 g −1 . Moreover, the pore diameter of these materials can be nicely controlled within mesoporous range between 1.5 and 20 nm by adjusting the synthesis conditions and/or by employing surfactants with different chain lengths in their preparation.
MCM-41 and MCM-48 have been applied as catalysts for various chemical reactions, as a support for drug delivery system and as adsorbent in waste water treatment .
MCM-41 is a material similar to FSM-16.
This material -related article is a stub . You can help Wikipedia by expanding it .
This catalysis article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Mobil_Composition_of_Matter |
Mobile-assisted language learning ( MALL ) is language learning that is assisted or enhanced through the use of a handheld mobile device. [ 1 ] [ 2 ]
MALL is a subset of both Mobile Learning ( m-learning ) and computer-assisted language learning (CALL). MALL has evolved to support students’ language learning with the increased use of mobile technologies such as mobile phones (cellphones), MP3 and MP4 players, PDAs and devices such as the iPhone or iPad . With MALL, students are able to access language learning materials and to communicate with their teachers and peers at any time, anywhere.
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Enhancing language learning through MALL provides dynamics which are not available through the traditional classroom. MALL offers ubiquitous access to learning anytime, anywhere the user has reception. This enables users to brush up on language skills just before or just after a conversation in the language they are learning. Handheld delivery also affords new dynamics for collaborative learning as users can share the language learning process in small synchronous groups. [ 8 ]
Kloper et al. (2002) claimed 5 properties of mobile devices which can produce unique educational affordances:
The most notable constraints for earlier MALL include poor sound and display quality coupled with very limited devices and download speeds. Newer integrated PDA devices have narrowed the gap with higher access speeds, larger screens, having functions and capacities similar to laptop computers (Nah, et al. 2008). Since the PDA devices are now mostly displaced by smartphones, in particular those based on iOS and Android , it is safe to say the constraints mentioned earlier are now non-existent.
Resources that focusing on Mobile Assisted Language Learning are not common (check Augmented Reality Language Learning ). We more often find resources that are primarily language learning websites with some space dedicated to technology in language learning and vice versa. | https://en.wikipedia.org/wiki/Mobile-assisted_language_learning |
The term mobile to mobile calling is used in many mobile phone plans to refer to making calls to other mobile phones using the same provider's network--which is often cheaper than other calls.
Mobile to mobile convergence (MMC) is a term to describe a technology used in modern computing and telephony . The term is an offshoot of fixed mobile convergence (FMC) and uses dual mode ( cellular network and WiFi ) phones with a special software client and an application server to connect voice calls and business applications via a VoWLAN or through cellular service .
Mobile-to-mobile convergence differs from conventional FMC in that the technology uses the WLAN to route calls via the internet as a primary function, and uses the wireless carrier network if the WLAN is not present as a secondary function. It is significant since it is viewed as a means to compete with carrier companies since the calls are routed around the cellular network. This is viewed as a more efficient use of networking technology than standard FMC solutions that are available as well, since most of the latter use the carrier network as the primary means of communication and do not leverage the lower cost and controls of IP networks that are generally installed at most modern businesses. In theory, it also provides the capability of providing a greater voice coverage area than either carrier or WLAN technology alone since some areas do not have cellular service coverage and others do not have WiFi.
The first offering known in the market successfully deploying MMC is beCherry, which is delivered by Belgian company Mondial Telecom. They offer an MMC solution on Symbian , iOS and Android . Other smartphone OSs are also considered. | https://en.wikipedia.org/wiki/Mobile-to-mobile_convergence |
MobileBits Corporation is an American marketing technology/advertising company that operated a pure brand mobile marketing and engagement network called Samy and which markets a software platform for developing mobile shopping applications. [ citation needed ]
MobileBits Corporation is a United States mobile technology company. Walter Kostiuk, a former BlackBerry executive, founded the company in 2010 [ 1 ] Between 2011 and 2013, MobileBits acquired 3 companies to help accelerate grow of its IP holdings, product platform and software development resources starting with the merger of Pringo Inc. on July 1, 2011 bringing a social media integrated development platform called Pringo Connect. [ 2 ] MobileBits then acquired Aixum Tec on August 20, 2012 bringing it an enterprise back-end software system developed for retailers to market exclusive offers, deals and coupons as well as deliver digital loyalty and rewards cards on mobile devices called Samy4me. [ 3 ] The Company also acquired the assets of Proximus Mobility , an Atlanta-based hyperlocal proximity based marketing software company on June 4, 2013 bringing the Samy product enhanced proximity and geofencing capabilities. [ 4 ]
On August 30, 2012, MobileBits introduced SAMY, a shopping application for iPhone and Android . [ 5 ] A store, merchant, or retailer can upload vouchers, offers, create loyalty cards and create messages in the application. Those vouchers, offers and loyalty cards can be viewed by users of the application. Users can select specific companies that are listed in the application to add to their, 'My Samy' section of the mobile application. SAMY supports over 35,000 merchants in Switzerland, Canada, and the United States. [ 6 ] Due to the success of the Samy mobile application and business model, MobileBits Inc, in 2016 subsequently introduced a white label version of their technology for third party partners to deploy in local markets. It is defined as a mobile commerce Network platform. [ citation needed ]
In 2012, Quantum Group partnered with MobileBits to provide access to SAMY for all of Quantum Groups merchants through their existing Point of Sale systems. [ 7 ]
In May 2013, MobileBits signed a strategic agreement with DDR Corp. (now SITE Centers ), a real estate investment trust . The agreement provided for the acquisition of DDR's proprietary location-based mobile marketing solution called ValuText and the opportunity for MobileBits to distribute Samy through 450 shopping centers. [ 8 ]
MobileBits-owned marketing and engagement network Samy, finalized an exclusive multi-year agreement with Ignivia Technologies on July 8, 2013 to provide Samy services in Turkey, the United Arab Emirates (UAE), Kuwait, Bahrain, Qatar, Oman, Saudi Arabia, Jordan and Lebanon. [ 9 ]
In 2013, MobileBits received a job creation grant from Sarasota County FL with support of the Economic Development Council of Sarasota (EDC). [ 10 ]
MobileBits has received numerous awards for its Mobile Commerce Network and Samy products including a being recognized by the Local Search Association and Local Media Associations as having the "Best New Revenue Solution in Mobile" for the local media industry. There was a 3rd-place finish at the 2013 CTIA E-Tec for best Mobile Apps, Money, Payments, Banking, Mobile Commerce, Shopping & Rewards. [ 11 ]
Finalist at the 2013 Tampa Bay Business Journals 2013 BizTech Awards. [ 12 ]
Winner of the 2012 Effective Mobile Marketing Awards for Most Effective Mobile Couponing or Barcode Campaign - McDonald's Euro 2012 Campaign. [ 13 ]
Three Super Star first-place finishes at MobileVillage Mobile Star Awards in 2012 for Best SUCCESS STORIES: Mobile Marketing – McDonald's & SAMY; Best ENTERPRISE SOLUTIONS: Marketing; Best CONSUMER APPS: Shopping or Sales. [ 14 ] | https://en.wikipedia.org/wiki/MobileBits |
The mobileGT name refers to both a computing platform and an alliance of vendors in the navigation, infotainment and telematics industries. It focuses on automotive , industrial and consumer electronics based on PowerPC and Power ISA processors. The mobileGT Alliance was initiated by Motorola in 2000 and consists today of an array of members from different disciplines like RTOS , middleware , software, graphics, audio, wireless, navigation and development tools. [ 1 ] mobileGT solutions can be found in in-car entertainment and informatics systems from many car manufacturers such as BMW , Ford , General Motors , Hyundai and Mercedes-Benz , but can also be found in computing platforms like the EFIKA . | https://en.wikipedia.org/wiki/MobileGT |
The Mobile 3D Graphics API , commonly referred to as M3G , is an open source graphics API and file format specification for developing Java ME applications that produce 3D computer graphics on embedded devices such as mobile phones and PDAs .
Originally developed at Nokia Research Center Tampere in 2003-2005, M3G was standarized under the Java Community Process as JSR 184 in 22 Dec, 2003. As of 2007 [update] , the latest version of M3G was 1.1, but version 2.0 was drafted as JSR 297 in April 2009. In 2010, M3G 1.1 JNI source code and related Symbian OS Java Runtime Environment were subsequently released into open source through the Symbian Foundation .
M3G is an object-oriented interface consists of 30 classes that can be used to draw complex animated three-dimensional scenes, it provides two ways for developers to draw 3D graphics: immediate mode and retained mode .
In immediate mode, graphics commands are issued directly into the graphics pipeline and the rendering engine executes them immediately. When using this method, the developer must write code that specifically tells the rendering engine what to draw for each animation frame . A camera, and set of lights are also associated with the scene, but is not necessarily part of it. In immediate mode it is possible to display single objects, as well as entire scenes (or worlds, with a camera, lights, and background as parts of the scene).
Retained mode always uses a scene graph that links all geometric objects in the 3D world in a tree structure , and also specifies the camera, lights, and background. Higher-level information about each object—such as its geometric structure, position, and appearance—is retained from frame to frame. In retained mode, data are not serialized by Java's own serialization mechanism. They are optimized by the M3G serialization mechanism, which produces and loads data streams conforming to the .m3g file format specification for 3D model data, including animation data format. This allows developers to create content on desktop computers that can be loaded by M3G on mobile devices. [ 2 ] | https://en.wikipedia.org/wiki/Mobile_3D_Graphics_API |
The Mobile Alliance Against Child Sexual Abuse Content was founded in 2008 by an international group of mobile operators within the GSM Association [ 1 ] to work collectively on obstructing the use of the mobile environment by individuals or organisations wishing to consume or profit from child sexual abuse content.
While the vast majority of child sexual abuse content ( child pornography ) is today accessed through conventional connections to the Internet, there is a danger that broadband networks now being rolled out by mobile operators could be misused in the same way.
The Alliance's ultimate aim is to help stem, and ultimately reverse, the growth of non approved content around the world. Through a combination of technical measures, co-operation and information sharing, the Alliance seeks to create significant barriers to the misuse of mobile networks and services for hosting, accessing, or profiting from not approved content.
Members of the Alliance agree to, among other measures:
· support and promote ‘hotlines’ or other mechanisms for customers to report child sexual abuse content discovered on the Internet or on mobile content services.
· implement notice and take down processes to enable the removal of any child sexual abuse content posted on their own services
· implement technical mechanisms to prevent access to websites identified by an appropriate agency as hosting child sexual abuse content
The Alliance encourages all mobile operators worldwide, regardless of access technology, to participate in the Alliance.
The founding members of the Mobile Alliance were: | https://en.wikipedia.org/wiki/Mobile_Alliance_Against_Child_Sexual_Abuse_Content |
Mobile Broadband Plus ( MBB+ ) is a term for wireless Internet access through mobile devices. Mobile Broadband Plus is distinct from traditional mobile broadband by featuring global Internet access, providing international mobile services without roaming charges.
Standards of Mobile Broadband Plus have been developed by telecommunication, mobile phone, and laptop computer manufacturers which includes virtual SIM and cloud SIM technology . Established in 2012, a group of specialists from uCloudlink has adopted cloud SIM as one of the MBB+ standards which provides a global network solution without roaming charges.
In 2011, 90% of the world's population lived in areas with 2G coverage, while 45% lived in areas with 2G and 3G coverage. [ 1 ] Mobile broadband uses the spectrum of 225 MHz to 3700 MHz. [ 2 ] MBB+ is designed to address issues with connectivity, network capacity, application quality, and mobile network operators' overall inexperience with data traffic. [ 3 ] The service of MBB+ covers the globe, normally in 100+ countries, providing high speed internet on the move with 3G and 4G connectivity.
Through patented Cloud SIM technology, MBB+ taps into a world's worth of SIM cards that are located throughout the globe. It will find the most optimal local mobile network and the corresponding SIM card in the cloud SIM server via the internet, then starts to convert the local mobile connection into Wi-Fi signals. In this case, all the data resource are within "domestic" boundaries and saving the user from international charges.
WBB+ supports Wi-Fi encryption including WPA and WPA2 . | https://en.wikipedia.org/wiki/Mobile_Broadband_Plus |
A mobile content delivery network or mobile content distribution network (Mobile CDN) is a network of servers – systems, computers or devices – that cooperate transparently to optimize the delivery of content to end users on any type of wireless or mobile network. Like traditional CDNs , the primary purpose of a Mobile CDN is to serve content to end users with high availability and high performance. In addition, Mobile CDNs can be used to optimize content delivery for the unique characteristics of wireless networks and mobile devices, such as limited network capacity, or lower device resolution. [ 1 ] Added intelligence around device detection, content adaptation can help address challenges inherent to mobile networks which have high latency, higher packet loss and huge variation in download capacity.
Mobile CDNs should integrate mobile delivery services that optimize the delivery of any kind of content including live video streaming, on demand video and the delivery of other content assets. In the case of video content, these services include device detection, image rendering, video transcoding and bit-rate adaptation. For the optimization of the delivery of other content, mobile CDNs use technologies such as caching.
With currently available mobile CDN solutions, nodes are deployed at the edge of the network and in multiple locations, often over multiple backbones directly connected or peered with Mobile Network Operators (MNOs). These nodes cooperate with each other to satisfy requests for content by end users, transparently moving content to optimize the delivery process. The benefits of optimization can take the form of reduced bandwidth usage, improved end-user performance, or increased global availability of content over a mobile network.
Industry experts speculate whether mobile CDNs will take off due to technical and market issues. CDNs are important for mobile operators as they can lead to significant savings and avoid network congestion. However, a number of network-centric alternatives have been proposed including Fast Dormancy , increasing bandwidth capacity with upgrades to 4G/LTE, and offloading traffic to other networks such as Wi-Fi. [ 2 ]
There is an increasing need to support mobile App performance beyond just mobile content delivery to the browser. For this reason, certain mobile CDNs, such as Neumob or Twin Prime, have moved beyond the browser and specialize in accelerating mobile apps. [ 3 ] That is an important progression for a mobile CDN, as users are increasingly moving away from digesting content on desktops and are migrating to mobile device usage which is a combination of Mobile WEB and Mobile Apps. The challenge of consistent user experience across desktop, mobile device both mobile App and mobile WEB are critical. [ 4 ] [ 5 ] [ 6 ] | https://en.wikipedia.org/wiki/Mobile_CDN |
The Mobile DTV Alliance is a marketing organization based in San Ramon, California that was founded in 2006 by a consortium of companies to promote open standards for mobile TV . Its goal is the rapid adoption of mobile TV technology via DVB-H and to further the mobile TV experience in North America. [ 1 ]
The President of the Mobile DTV Alliance, Yoram Solomon, is also on the boards of the WiMedia Alliance and Wi-Fi Alliance .
The Alliance was founded by Intel , Microsoft , Modeo , Motorola , Nokia and Texas Instruments . | https://en.wikipedia.org/wiki/Mobile_DTV_Alliance |
Mobile DevOps is a set of practices that applies the principles of DevOps specifically to the development of mobile applications. Traditional DevOps focuses on streamlining the software development process in general, but mobile development has its own unique challenges that require a tailored approach. [ 1 ] Mobile DevOps is not simply as a branch of DevOps specific to mobile app development, instead an extension and reinterpretation of the DevOps philosophy due to very specific requirements of the mobile world. [ 2 ]
Traditional DevOps approach has been formed around 2007-2008, [ 3 ] close to the dates when iOS and Android mobile operating systems were released to the public. The traditional DevOps approach primarily evolved to meet the changing needs of the software development world with the paradigm shift towards continuous and rapid development and deployment (such as in web development , where interpreted languages are more prevalent than compiled languages ). [ 4 ] While traditional DevOps embraced agility and flexibility, mobile operating system providers steered towards a walled-garden approach with compiled apps with tight controls over how they can be distributed and installed on a mobile device. [ 5 ] This difference in the mobile development mindset compared to what the traditional DevOps approach is advocating, is augmented further with the mobile applications to be deployed on a high number of varying devices and operating systems. [ 6 ]
Eventually, the concept of Mobile DevOps took off as a trend around 2014-2015, [ 7 ] in line with the fast growth of the number of applications in mobile app stores . [ 8 ] As individuals and corporations alike are developing and publishing more and more mobile applications, the need for efficiency and shorter release cycles increased, which is addressed by the continuous feedback and continuous development approach within the concept of DevOps , [ 1 ] while requiring a significant level of adaptation and extension of the traditional DevOps practices. [ 9 ]
Mobile DevOps has a unique set of challenges and constraints, which solidifies the fact that it needs to be approached as a separate discipline. [ 1 ] [ 9 ]
These challenges can be outlined as follows:
Mobile DevOps is not an abstract concept and offers a range of benefits that can help improve the efficiency and effectiveness of the mobile app development process. These benefits can even be quantified by collecting the data within the mobile application development lifecycle . [ 9 ]
The benefits can be categorized into the following areas:
Even though it is possible to run a mobile DevOps cycle with most of the CI/CD platforms, they may require significant effort compared to non-mobile CI/CD (e.g. you need to bring your own infrastructure [ 12 ] or it may require "reinventing the wheel" for commonly-used platforms like Jenkins [ 13 ] ).
To overcome the mobile-specific challenges specified , there are certain platforms that are dedicated to the lifecycle of mobile applications. These platforms exclusively focus on DevOps processes for mobile app development and are also referred as mobile CI/CD platforms. | https://en.wikipedia.org/wiki/Mobile_DevOps |
Mobile Display Digital Interface (MDDI) is a high-speed digital interface developed by Qualcomm to interconnect the upper and lower clamshell in a flip phone. The MDDI solution supports variable data rates of up to 3.2 Gbit/s, and decreases the number of signals that connect the digital baseband controller with the LCD and camera.
The integration of MDDI is said to enable the adoption of advanced features, such as high-definition (QVGA) LCDs and high-resolution megapixel cameras for wireless devices, and supports capabilities such as driving an external display or a video projector from a handset.
A Video Electronics Standards Association (VESA) approved standard, the MDDI solution is currently available and integrated into select Qualcomm chipsets.
Qualcomm MDDI page | https://en.wikipedia.org/wiki/Mobile_Display_Digital_Interface |
Mobile IPTV is a technology that enables users to transmit and receive multimedia traffic including video, audio, text and graphic services through IP-based wired and wireless networks , with support for quality of service , quality of experience , security, mobility, and interactive functions. Through Mobile IPTV, users can view IPTV services using a mobile device .
This approach uses the traditional digital broadcast networks to deliver IP-based audio, video, graphics and other broadband data services to mobile users. Wide area wireless networks such as cellular networks are integrated to support interactivity. Activities in this approach include Digital Video Broadcast (DVB)-CBMS (Convergence of Broadcasting and Mobile Services) and the WorldDMB . In addition, DVB-IPI (IPI: IP Infrastructure) is an open DVB standard that enables audio/video services to be delivered to and through the mobile device via IP networking. DVB-CBMS is developing bi-directional mobile IP based broadcasting protocol specifications over DVB-H. DVB-CBMS already finished Phase I and currently is working in Phase II. WorldDAB Forum is enhancing and extending Eureka 147 to support IP based services.
Eureka 147 was originally developed for digital radio applications and extended to support video services. Even though this approach is classified as Mobile IPTV technically, the usage of broadcasting networks may incur the loss of individuality of IP.
IPTV services were originally targeted to fixed terminals such as set-top boxes, however, issues on the requirements for mobility support were raised as an out-growth under the auspices of the Fixed-Mobile Convergence (FMC) trend. The outstanding activities are ATIS in the US, Open IPTV Forum , and ITU-T FG IPTV internationally. The development of Mobile IPTV specification is at an early stage. Currently, ITU-T FG IPTV is collecting requirements regarding mobility and wireless characteristics. ATIS has not shown any interest in mobility support yet. In Open IPTV Forum, mobility service entirely based on IMS (IP Multimedia Subsystem) which is a set of specification from 3GPP for delivering IP multimedia to mobile users will be forthcoming.
Open Mobile Alliance (OMA) BCAST is working for IP based mobile broadcasting networks. Its goals are to define an end-to-end framework for mobile broadcast and compile the set of necessary enablers. Its features are bearer agnostic, which means any Broadcast Distribution Network can be adopted as its transport means. OMA BCAST, however, is only applicable to mobile terminals up to now and showing interest in expanding its specification to cover fixed terminals in Phase II.
Internet video services are usually termed as Internet TV or Web TV. This approach is open for anybody to be a content provider , a service provider , or a consumer. Quality of service is not guaranteed since it is based on a best-effort service model.
Mobile IPTV has at least one wireless interface per device. A minimum of 2–3 Mbit/s of bandwidth needs to be provided, due to the characteristics of the IPTV service, [ citation needed ] and until 4G wireless network services are widely deployed, wireless link bandwidth is usually not yet broad enough to accommodate high-definition and ultra-high-definition television quality video services.
Since Mobile IPTV assumes at least one wireless link between the source (e.g. a streaming media server) and the destination (e.g. a mobile terminal), there are technical obstacles related to the usage of the wireless link.
Most mobile terminals have small displays, low power processors, and limited storage, compared to desktop PCs.
Even if mobile terminals are stationary, obstacles around the mobile terminals can affect the received signal and cause packet loss . Packets delivered through the wireless link are exposed to a variety of signal degradation such as shadowing , fast/slow fading , etc.
Because it is currently not possible to deploy wireless networks to cover all geographical areas with no "dead spots", services are restricted in some areas. However, by adopting vertical handovers (hand-overs between different networks), the coverage issue can be mitigated.
The characteristics of the wireless link can vary due to a variety of causes, and the rate of change can be very abrupt. For example, vertical handover can quickly change the path between the source and sink , bandwidth, physical MAC address , IP address . Therefore, some solutions devised for the relatively static wired computer network environment may not work properly.
By deploying middleware , a service provider can control the usage of IPTV services remotely. Also, middleware acts as a transparent way to adapt IPTV services to different platforms. So far, there are several well-known middleware applications for set-top boxes , but which are too large to be implemented on a mobile device. | https://en.wikipedia.org/wiki/Mobile_IPTV |
The Mobile Phone Museum is a virtual museum curating mobile phones and a nonprofit organisation aimed at archiving and preserving mobile technology and increasing educational outreach about developments and innovations in the mobile industry. It has been described as the "world’s most extensive mobile phone museum". [ 3 ]
The museum was founded by Ben Wood and Matt Chatterley, [ 4 ] and officially launched at an event in London in November 2021. [ 5 ] It is supported through a five-year sponsorship agreement with Vodafone . [ 6 ] [ 3 ] At launch the museum consisted of more than 2000 unique devices from 200 different manufacturers, spanning from early developments in mobile phones to the latest models. [ 7 ] [ 8 ]
The museum has plans to develop travelling exhibitions to showcase the collection to science, technology and design museums, and to schools. [ 7 ]
This article related to a non-profit organization is a stub . You can help Wikipedia by expanding it .
This museum-related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Mobile_Phone_Museum |
Quality of service (QoS) mechanism controls the performance, reliability and usability of a telecommunications service. Mobile cellular service providers may offer mobile QoS to customers just as the fixed line PSTN services providers and Internet service providers may offer QoS. QoS mechanisms are always provided for circuit switched services, and are essential for non-elastic services, for example streaming multimedia . It is also essential in networks dominated by such services, which is the case in today's mobile communication networks.
Mobility adds complication to the QoS mechanisms, for several reasons: [ 1 ]
Many factors affect the quality of service of a mobile network. [ 1 ] It is correct to look at QoS mainly from the customer's point of view, that is, QoS as judged by the user. There are standard metrics of QoS to the user that can be measured to rate the QoS. These metrics are: the coverage , accessibility (includes GoS), and the audio quality . [ 2 ] In coverage the strength of the signal is measured using test equipment and this can be used to estimate the size of the cell. Accessibility is about determining the ability of the network to handle successful calls from mobile-to-fixed networks and from mobile-to-mobile networks. The audio quality considers monitoring a successful call for a period of time for the clarity of the communication channel. All these indicators are used by the telecommunications industry to rate the quality of service of a network. [ 2 ]
The QoS in industry is also measured from the perspective of an expert (e.g. teletraffic engineer). This involves assessing the network to see if it delivers the quality that the network planner has been required to target. Certain tools and methods (protocol analysers, drive tests and Operation and Maintenance measurements), are used for this QoS measurement:
In general, grade of service (GoS) is measured by looking at traffic carried, traffic offered and calculating the traffic blocked and lost. [ 1 ] The proportion of lost calls is the measure of GoS. For cellular circuit groups an acceptable GoS is 0.02. This means that two users of the circuit group out of a hundred will encounter a call refusal during the busy hour at the end of the planning period. The grade of service standard is thus the acceptable level of traffic that the network can lose. GoS is calculated from the Erlang-B formula , as a function of the number of channels required for the offered traffic intensity.
The audio quality of a cellular network depends on, among other factors, the modulation scheme (e.g., FSK , QPSK ) in use, matching to the channel characteristics and the processing of the received signal at the receiver using DSPs . [ 3 ] | https://en.wikipedia.org/wiki/Mobile_QoS |
Mobile TV Format is a colloquial and collective name for technology standards set out for broadcasting TV services to mobile devices, mostly mobile handsets for now. Currently, there are four prevalent formats known as DMB , DVB-H , OneSeg and MediaFLO . As of December 2007, ITU approved T-DMB , DVB-H , OneSeg and MediaFLO as the global standard for real-time mobile video and audio broadcasting. Thus far, none of the four formats has secured a dominant position in the global market, except in their respective home markets. [ 1 ]
Samsung and LG were the first to tout new generation mobile phones that would allow users to watch live multi-channel TV on the move during International Broadcasting Convention (IBC) in Amsterdam in September 2005. South Korea's top mobile operator SK Telecom launched a satellite pay-TV service to mobile phones in South Korea in May 2005. The Korean handset makers' push into the European Mobile TV market was soon to be met by strong competition, particularly from Nokia, while the Korean handset makers were looking forward to the 2006 World Cup soccer game in Germany as a crucial launch pad. [ 2 ]
South Korea's DMB made a head start in May 2005, but European Union advocates for a single standard and has officially endorsed Nokia's DVB-H. In the US, however, Qualcomm's MediaFLO has got the upper hand for now. Japan is developing its own standard. Journalists and market analyzers are currently taking widely split views about the future course of mobile TV format wars.
"We see DVB-H winning out over all, but there will also be limited space for some of the other technologies," said Adrian Drozd, a London-based senior analyst with Datamonitor. "DMB has a head start, but from 2007 onward DVB-H should get momentum and become the dominant technology." [ 3 ]
Which format is going to be an ultimate winner in the end is less important than when mobile TV will grow out of its infancy to be a prime pastime for mobile handset users globally. For instance, five-channel Virgin Mobile TV (VMTV) was launched in UK in October 2006, based on DMB technology with a £2.5m advertising campaign. But it failed to take off with customers, and in July 2007 VMTV has reached a decision to dump its mobile TV service. [ 4 ]
Speaking about Virgin's decision to dump its mobile TV service, Bruce Renny, marketing director at mobile TV group ROK Entertainment Group, said expectations of the commercial take-up of broadcast mobile TV had been "over-optimistic, and the demise of Virgin's mobile TV service reflects that". [ 4 ]
"After all, why pay a subscription fee to receive the same TV content on your mobile that you already get at home? Particularly when people don't watch TV on mobiles for more than a few minutes at a time.
"Most mobile TV viewing is for just a few minutes. To be commercially successful, you have to provide a combination of live news, sports updates and video-on-demand made-for-mobile content which is instantly engaging. Simply broadcasting linear TV to mobiles is not the answer," he said.
Contrary to the above-mentioned failure, however, South Korea seems to be on the right track. As of February 2006, Satellite DMB(S-DMB) subscribers came to 440,000 since the service launch in May 2005, while the number of Terrestrial DMB (T-DMB) subscribers reached 110,000 since the service launch in December 2005. [ 5 ] As of December 2007, South Korea is the only country where T-DMB is widely deployed. More than 7 million handsets, laptops, car navigators and other gadgets that are equipped with T-DMB receivers are in use. USB-type receivers are being sold at around 50,000 won ($50). It is being tested in 11 other nations including Germany, Italy, France, Britain and China. Nevertheless, both T-DMB and S-DMB have not garnered decent profits so far. [ 6 ] | https://en.wikipedia.org/wiki/Mobile_TV_format |
Mobile Telecommunication Company of Esfahan (شرکت مخابرات سیار اصفهان, Shirkat-e Mixabrat-e Siyar-e Esfehan , MTCE ) also known as Espadan was a mobile network operator in Iran. [ 1 ] [ 2 ]
Following the agreements reached during the Iranian President Hashemi Rafsanjani's visit to Malaysia in 1994, and according to the laws of attracting and supporting foreign investment, in 29 May 2001 the license for launching the first prepaid mobile telephone network in Iran with an initial capacity of 20 thousand subscribers was granted to Celcom for 15 years, and the Malaysian Technology Resources Industry Company received permission to use GSM 24.18 Mbit/s bandwidth within the Isfahan province. [ 3 ]
In 2005 Celcom sold its stakes to TM International(Telekom Malaysia). [ 4 ] [ 5 ] [ 6 ] [ 7 ]
In 2008 MTCE bought the WiMAX license from Iranian Communications Regulatory Authority (CRA). [ 8 ]
In 2011 MTCE went broke and deactivated all sim cards following merger with Mobile Telecommunications Company of Iran . [ 9 ] [ 10 ] [ 11 ] [ 12 ]
Sim cards numbers had 0931 as prefix. [ 13 ]
Axiata Group Berhad (49%) | Telecommunications Company of Esfahan (49%) | Iran Telecom Industries (2%) [ 14 ] | https://en.wikipedia.org/wiki/Mobile_Telecommunications_Company_of_Esfahan |
The Mobile Telephone Switching Office (MTSO) is the mobile equivalent of a PSTN Central Office. The MTSO contains the switching equipment or Mobile Switching Center (MSC) for routing mobile phone calls. It also contains the equipment for controlling the cell sites that are connected to the MSC.
The systems in the MTSO are the heart of a cellular system. It is responsible for interconnecting calls with the local and long distance landline telephone companies, compiling billing information (with the help of its CBM/SDM), etc. It also provides resources needed to efficiently serve a mobile subscriber such as registration, authentication, location updating and call routing. Its subordinate BSC/RNC are responsible for assigning frequencies to each call, reassigning frequencies for handoffs , controlling handoffs so a mobile phone leaving one cell (formally known as BTS 's) coverage area, can be switched automatically to a channel in the next cell.
All cellular systems have at least one MTSO which will contain at least one MSC. The MSC is responsible for switching calls to mobile units as well as to the local telephone system, recording billing data and processing data from the cell site controllers.
The MSC is connected to a close telephone exchange by a trunk group. This provides an interface to the ( Public Switched Telephone Network ) (PSTN). It also provides connectivity to the PSTN. The region to be served by a Cellular Geographic Serving Area(CGSA) is split into geographic cells. These cells are ideally hexagonal in shape and they are initially laid out with their centers about 4 to 8 miles apart from each other. Other MTSO equipment, the cell site controllers provide control functions for a group of cell sites and actions of mobile phones through command and control data channels. To achieve this, there has to be a method of connectivity between the MTSO and the cell site. This may be by DS1, DS3, OCn or Ethernet circuits.
The MSC also plays a major role in call routing . When a mobile phone is turned on, it listens for the network operator's SID (System Identification Code) on the control channel. If it cannot find any control channels to listen to then it assumes it is outside the range and displays a message indicating no service. If it finds a control channel to listen to, receives the SID and then compares it to the SID programmed into the phone. If both SIDs match then it knows that it is communicating with a cell in its home system.
The phone also transmits a registration request along with the SID. If the subscriber has previously registered to a particular MSC then the MSC will have a record in its VLR and will therefore know the subscriber last registered location. If the subscriber is unknown to the MSC's VLR, it will query the HLR to obtain the subscriber's profile and save it for a set length of time in its VLR. Anytime a MSC successfully registers a subscriber the HLR record is also updated. This will help when a call is received outside of the MSC's coverage area or for an incoming PSTN call.
A subscriber's VLR profile has a LAC(Location Area Code - Area server by cluster of BTS/cell sites) CID (Cell ID) as well as a list of allowed and disallowed services/features and other information.
With the subscriber's VLR Profile the MSC can determine the last known LAC/CID for this subscriber and knows which BTS to use when it needs to ring/page that phone for an incoming call. When the MSC gets the call, it checks its database for the location of the phone. Then it picks a frequency pair the phone will use in that cell to take the call. The MSC communicates with the phone over the control channel to tell it which frequencies to use, and once the phone and the tower switch on those frequencies, the call is connected.
As a mobile unit engaged in a call moves away from a cell site or formally known as Base transceiver station and its signal weakens, the BSC ( GSM ) or RNC (3G UMTS ) will automatically instruct it to tune to a different frequency, one assigned to the newly entered BTS. This process is called handoff. The BSC/RNC determines when handoff should take place by analyzing measurements of radio signal strength made by the present controlling cell site and by its neighbors. The returning instructions for handoff sent during a call must use the voice channel. The data regarding the new channel are sent rapidly (in about 50 milliseconds), and the entire returning process takes only about 300 milliseconds. After handoff, if the SID on the control channel does not match the SID programmed into the phone, then the phone assumes that it is roaming.
The MSC also performs handovers/handoffs, which occur when a call needs to be transferred to either a different BSC/RNC it serves, or to a completely new MSC. A MSC can serve many BSCs/RNCs, which in turn serves many BTSs. As a result, a MSC can serve a large area, typically hundreds of miles. Highly populated areas require more BTSs and BSCs/RNCs, which will in turn reduce the geographic coverage of a DMSC. The above in a MSC is what's considered as its mobility management. The BTS and BSC/RNC are the RAN/UTRAN (Radio Access Network & UMTS Radio Access Network) subset in the mobile network. The remaining functions of a MSC are identical to a PSTN switch. | https://en.wikipedia.org/wiki/Mobile_Telephone_Switching_Office |
A wireless ad hoc network [ 1 ] ( WANET ) or mobile ad hoc network ( MANET ) is a decentralized type of wireless network . The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers or wireless access points . Instead, each node participates in routing by forwarding data for other nodes. The determination of which nodes forward data is made dynamically on the basis of network connectivity and the routing algorithm in use. [ 2 ]
Such wireless networks lack the complexities of infrastructure setup and administration, enabling devices to create and join networks "on the fly". [ 3 ]
Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a router . The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. This becomes harder as the scale of the MANET increases due to 1) the desire to route packets to/through every other node, 2) the percentage of overhead traffic needed to maintain real-time routing status, 3) each node has its own goodput to route independent and unaware of others needs, and 4) all must share limited communication bandwidth , such as a slice of radio spectrum.
Such networks may operate by themselves or may be connected to the larger Internet . They may contain one or multiple and different transceivers between nodes. This results in a highly dynamic, autonomous topology. MANETs usually have a routable networking environment on top of a link layer ad hoc network.
The earliest wireless data network was called PRNET , the packet radio network, and was sponsored by Defense Advanced Research Projects Agency (DARPA) in the early 1970s. Bolt, Beranek and Newman Inc. (BBN) and SRI International designed, built, and experimented with these earliest systems. Experimenters included Robert Kahn , [ 4 ] Jerry Burchfiel, and Ray Tomlinson . [ 5 ] Similar experiments took place in the amateur radio community with the x25 protocol. These early packet radio systems predated the Internet, and indeed were part of the motivation of the original Internet Protocol suite. Later DARPA experiments included the Survivable Radio Network ( SURAN ) project, [ 6 ] which took place in the 1980s. A successor to these systems was fielded in the mid-1990s for the US Army, and later other nations, as the Near-term digital radio .
Another third wave of academic and research activity started in the mid-1990s with the advent of inexpensive 802.11 radio cards for personal computers . Current wireless ad hoc networks are designed primarily for military utility. [ 7 ] Problems with packet radios are: (1) bulky elements, (2) slow data rate, (3) unable to maintain links if mobility is high. The project did not proceed much further until the early 1990s when wireless ad hoc networks were born.
The growth of laptops and 802.11/Wi-Fi wireless networking have made MANETs a popular research topic since the mid-1990s. Many academic papers evaluate protocols and their abilities, assuming varying degrees of mobility within a bounded space, usually with all nodes within a few hops of each other. Different protocols are then evaluated based on measures such as the packet drop rate, the overhead introduced by the routing protocol, end-to-end packet delays, network throughput, ability to scale, etc.
In the early 1990s, Charles Perkins from SUN Microsystems USA, and Chai Keong Toh from Cambridge University separately started to work on a different Internet, that of a wireless ad hoc network. Perkins was working on the dynamic addressing issues. Toh worked on a new routing protocol, which was known as ABR – associativity-based routing . [ 8 ] Perkins eventually proposed DSDV – Destination Sequence Distance Vector routing, which was based on distributed distance vector routing. Toh's proposal was an on-demand based routing, i.e. routes are discovered on-the-fly in real-time as and when needed. ABR [ 9 ] was submitted to IETF as RFCs. ABR was implemented successfully into Linux OS on Lucent WaveLAN 802.11a enabled laptops and a practical ad hoc mobile network was therefore proven [ 3 ] [ 10 ] [ 11 ] to be possible in 1999. Another routing protocol known as AODV was subsequently introduced and later proven and implemented in 2005. [ 12 ] In 2007, David Johnson and Dave Maltz proposed DSR – Dynamic Source Routing . [ 13 ]
The decentralized nature of wireless ad hoc networks makes them suitable for a variety of applications where central nodes can't be relied on and may improve the scalability of networks compared to wireless managed networks, though theoretical and practical limits to the overall capacity of such networks have been identified. [ citation needed ] Minimal configuration and quick deployment make ad hoc networks suitable for emergency situations like natural disasters or military conflicts. The presence of dynamic and adaptive routing protocols enables ad hoc networks to be formed quickly.
A mobile ad hoc network (MANET) is a continuously self-configuring, self-organizing, infrastructure-less [ 14 ] network of mobile devices connected without wires. It is sometimes known as "on-the-fly" networks or "spontaneous networks". [ 15 ]
VANETs are used for communication between vehicles and roadside equipment. [ 16 ] Intelligent vehicular ad hoc networks (InVANETs) are a kind of artificial intelligence that helps vehicles to behave in intelligent manners during vehicle-to-vehicle collisions, accidents. Vehicles are using radio waves to communicate with each other, creating communication networks instantly on-the-fly while vehicles move along roads. VANET needs to be secured with lightweight protocols. [ 17 ]
A SPAN leverages existing hardware (primarily Wi-Fi and Bluetooth ) and software (protocols) in commercially available smartphones to create peer-to-peer networks without relying on cellular carrier networks, wireless access points, or traditional network infrastructure. SPANs differ from traditional hub and spoke networks, such as Wi-Fi Direct , in that they support multi-hop relays and there is no notion of a group leader so peers can join and leave at will without destroying the network. Apple's iPhone with iOS version 7.0 and higher is capable of multi-peer ad hoc mesh networking. [ 18 ]
Mesh networks take their name from the topology of the resultant network. In a fully connected mesh, each node is connected to every other node, forming a "mesh". A partial mesh, by contrast, has a topology in which some nodes are not connected to others, although this term is seldom in use. Wireless ad hoc networks can take the form of a mesh networks or others. A wireless ad hoc network does not have fixed topology, and its connectivity among nodes is totally dependent on the behavior of the devices, their mobility patterns, distance with each other, etc. Hence, wireless mesh networks are a particular type of wireless ad hoc networks, with special emphasis on the resultant network topology. While some wireless mesh networks (particularly those within a home) have relatively infrequent mobility and thus infrequent link breaks, other more mobile mesh networks require frequent routing adjustments to account for lost links. [ 19 ]
Military or tactical MANETs are used by military units with emphasis on data rate, real-time requirement, fast re-routing during mobility, data security, radio range, and integration with existing systems. [ 20 ] Common radio waveforms include the US Army's JTRS SRW , Silvus Technologies MN-MIMO Waveform (Mobile Networked MIMO), [ 21 ] [ 22 ] [ 23 ] [ 24 ] and Codan DTC MeshUltra Waveform. [ 25 ] [ 26 ] [ 27 ] Ad hoc mobile communications come in well to fulfill this need, especially its infrastructureless nature, fast deployment and operation. Military MANETs are used by military units with an emphasis on rapid deployment, infrastructureless, all-wireless networks (no fixed radio towers), robustness (link breaks are no problem), security, range, and instant operation.
Flying ad hoc networks (FANETs) are composed of unmanned aerial vehicles , allowing great mobility and providing connectivity to remote areas. [ 28 ]
Unmanned aerial vehicle , is an aircraft with no pilot on board. UAVs can be remotely controlled (i.e., flown by a pilot at a ground control station) or can fly autonomously based on pre-programmed flight plans. Civilian usage of UAV include modeling 3D terrains, package delivery ( Logistics ), etc. [ 29 ]
UAVs have also been used by US Air Force [ 30 ] for data collection and
situation sensing, without risking the pilot in a foreign unfriendly environment.
With wireless ad hoc network technology embedded into the UAVs, multiple UAVs can communicate with each other and work as a team, collaboratively to complete a task and mission. If a UAV is destroyed by an enemy, its data can be quickly offloaded wirelessly to other neighboring UAVs.
The UAV ad hoc communication network is also sometimes referred to UAV instant sky network. More generally, aerial MANET in UAVs are now (as of 2021) successfully implemented and operational as mini tactical reconnaissance ISR UAVs like the BRAMOR C4EYE from Slovenia.
Navy ships traditionally use satellite communications and other maritime radios to communicate with each other or with ground station back on land. However, such communications are restricted by delays and limited bandwidth. Wireless ad hoc networks enable ship-area-networks to be formed while at sea, enabling high-speed wireless communications among ships, enhancing their sharing of imaging and multimedia data, and better co-ordination in battlefield operations. [ 31 ] Some defense companies (such as Rockwell Collins, Silvus Technologies and Rohde & Schwartz) have produced products that enhance ship-to-ship and ship-to-shore communications. [ 32 ]
Sensors are useful devices that collect information related to a specific parameter, such as noise, temperature, humidity, pressure, etc. Sensors are increasingly connected via wireless to allow large-scale collection of sensor data. With a large sample of sensor data, analytics processing can be used to make sense out of these data. The connectivity of wireless sensor networks rely on the principles behind wireless ad hoc networks, since sensors can now be deploy without any fixed radio towers, and they can now form networks on-the-fly. "Smart Dust" was one of the early projects done at U C Berkeley, where tiny radios were used to interconnect smart dust. [ 33 ] More recently, mobile wireless sensor networks (MWSNs) have also become an area of academic interest.
Efforts have been made to co-ordinate and control a group of robots to undertake collaborative work to complete a task. Centralized control is often based on a "star" approach, where robots take turns to talk to the controller station. However, with wireless ad hoc networks, robots can form a communication network on-the-fly, i.e., robots can now "talk" to each other and collaborate in a distributed fashion. [ 34 ] With a network of robots, the robots can communicate among themselves, share local information, and distributively decide how to resolve a task in the most effective and efficient way. [ 35 ]
Another civilian use of wireless ad hoc network is for public safety. At times of disasters (floods, storms, earthquakes, fires, etc.), a quick and instant wireless communication network is necessary. Especially at times of earthquakes when radio towers had collapsed or were destroyed, wireless ad hoc networks can be formed independently. Firefighters and rescue workers can use ad hoc networks to communicate and rescue those injured. Commercial radios with such capability are available on the market. [ 31 ] [ 36 ]
Wireless ad hoc networks allow sensors, videos, instruments, and other devices to be deployed and interconnected wirelessly for clinic and hospital patient monitoring, doctor and nurses alert notification, and also making senses of such data quickly at fusion points, so that lives can be saved. [ 37 ] [ 38 ]
MANETS can be used for facilitating the collection of sensor data for data mining for a variety of applications such as air pollution monitoring and different types of architectures can be used for such applications. [ 39 ] A key characteristic of such applications is that nearby sensor nodes monitoring an environmental feature typically register similar values. This kind of data redundancy due to the spatial correlation between sensor observations inspires the techniques for in-network data aggregation and mining. By measuring the spatial correlation between data sampled by different sensors, a wide class of specialized algorithms can be developed to develop more efficient spatial data mining algorithms as well as more efficient routing strategies. [ 40 ] Also, researchers have developed performance models for MANET to apply queueing theory . [ 41 ] [ 42 ]
Several books [ 43 ] [ 1 ] and works have revealed the technical and research challenges [ 44 ] [ 45 ] facing wireless ad hoc networks or MANETs. The advantages for users, the technical difficulties in implementation, and the side effect on radio spectrum pollution can be briefly summarized below:
The obvious appeal of MANETs is that the network is decentralised and nodes/devices are mobile, that is to say there is no fixed infrastructure which provides the possibility for numerous applications in different areas such as environmental monitoring , disaster relief and military communications. Since the early 2000s, interest in MANETs has greatly increased which, in part, is due to the fact mobility can improve network capacity, shown by Grossglauser and Tse along with the introduction of new technologies. [ 46 ]
One main advantage to a decentralised network is that they are typically more robust than centralised networks due to the multi-hop fashion in which information is relayed. For example, in the cellular network setting, a drop in coverage occurs if a base station stops working, however the chance of a single point of failure in a MANET is reduced significantly since the data can take multiple paths. Since the MANET architecture evolves with time it has the potential to resolve issues such as isolation/disconnection from the network. Further advantages of MANETS over networks with a fixed topology include flexibility (an ad hoc network can be created anywhere with mobile devices), scalability (adding nodes to the network is easy) and lower administration costs (no need to build an infrastructure first). [ 47 ] [ 48 ]
With a time evolving network it is clear we should expect variations in network performance due to no fixed architecture (no fixed connections). Furthermore, since network topology determines interference and thus connectivity, the mobility pattern of devices within the network will impact on network performance, possibly resulting in data having to be resent a lot of times (increased delay) and finally allocation of network resources such as power remains unclear. [ 46 ] Finally, finding a model that accurately represents human mobility whilst remaining mathematically tractable remains an open problem due to the large range of factors that influence it. [ 49 ] Some typical models used include the random walk, random waypoint and levy flight models. [ 50 ] [ 51 ] [ 52 ] [ 53 ]
Wireless ad hoc networks can operate over different types of radios. All radios use modulation to move information over a certain bandwidth of radio frequencies. Given the need to move large amounts of information quickly over long distances, a MANET radio channel ideally has large bandwidth (e.g. amount of radio spectrum), lower frequencies, and higher power. Given the desire to communicate with many other nodes ideally simultaneously, many channels are needed. Given radio spectrum is shared and regulated , there is less bandwidth available at lower frequencies. Processing many radio channels requires many resources. Given the need for mobility, small size and lower power consumption are very important. Picking a MANET radio and modulation has many trade-offs; many start with the specific frequency and bandwidth they are allowed to use.
Radios can be UHF (300 – 3000 MHz), SHF (3 – 30 GHz), and EHF (30 – 300 GHz). Wi-Fi ad hoc uses the unlicensed ISM 2.4 GHz radios. They can also be used on 5.8 GHz radios.
The higher the frequency, such as those of 300 GHz, absorption of the signal will be more predominant. Army tactical radios usually employ a variety of UHF and SHF radios, including those of VHF to provide a variety of communication modes. At the 800, 900, 1200, 1800 MHz range, cellular radios are predominant. Some cellular radios use ad hoc communications to extend cellular range to areas and devices not reachable by the cellular base station.
Next generation Wi-Fi known as 802.11ax provides low delay, high capacity (up to 10 Gbit/s) and low packet loss rate, offering 12 streams – 8 streams at 5 GHz and 4 streams at 2.4 GHz. IEEE 802.11ax uses 8x8 MU-MIMO, OFDMA, and 80 MHz channels. Hence, 802.11ax has the ability to form high capacity Wi-Fi ad hoc networks.
At 60 GHz, there is another form of Wi-Fi known as WiGi – wireless gigabit. This has the ability to offer up to 7 Gbit/s throughput. Currently, WiGi is targeted to work with 5G cellular networks. [ 54 ]
Circa 2020, the general consensus finds the 'best' modulation for moving information over higher frequency waves to be orthogonal frequency-division multiplexing , as used in 4G LTE , 5G , and Wi-Fi .
The challenges [ 43 ] [ 1 ] affecting MANETs span from various layers of the OSI protocol stack. The media access layer (MAC) has to be improved to resolve collisions and hidden terminal problems. The network layer routing protocol has to be improved to resolve dynamically changing network topologies and broken routes. The transport layer protocol has to be improved to handle lost or broken connections. The session layer protocol has to deal with discovery of servers and services.
A major limitation with mobile nodes is that they have high mobility, causing links to be frequently broken and reestablished. Moreover, the bandwidth of a wireless channel is also limited, and nodes operate on limited battery power, which will eventually be exhausted. These factors make the design of a mobile ad hoc network challenging.
The cross-layer design deviates from the traditional network design approach in which each layer of the stack would be made to operate independently. The modified transmission power will help that node to dynamically vary its propagation range at the physical layer. This is because the propagation distance is always directly proportional to transmission power. This information is passed from the physical layer to the network layer so that it can take optimal decisions in routing protocols. A major advantage of this protocol is that it allows access of information between physical layer and top layers (MAC and network layer).
Some elements of the software stack were developed to allow code updates in situ , i.e., with the nodes embedded in their physical environment and without needing to bring the nodes back into the lab facility. [ 55 ] Such software updating relied on epidemic mode of dissemination of information and had to be done both efficiently (few network transmissions) and fast.
Routing [ 56 ] in wireless ad hoc networks or MANETs generally falls into three categories, namely: proactive routing, reactive routing, and hybrid routing.
This type of protocols maintains fresh lists of destinations and their routes by periodically distributing routing tables throughout the network. The main disadvantages of such algorithms are:
Example: Optimized Link State Routing Protocol (OLSR)
As in a fix net nodes maintain routing tables. Distance-vector protocols are based on calculating the direction and distance to any link in a network. "Direction" usually means the next hop address and the exit interface. "Distance" is a measure of the cost to reach a certain node. The least cost route between any two nodes is the route with minimum distance. Each node maintains a vector (table) of minimum distance to every node. The cost of reaching a destination is calculated using various route metrics. RIP uses the hop count of the destination whereas IGRP takes into account other information such as node delay and available bandwidth.
This type of protocol finds a route based on user and traffic demand by flooding the network with Route Request or Discovery packets. The main disadvantages of such algorithms are:
However, clustering can be used to limit flooding. The latency incurred during route discovery is not significant compared to periodic route update exchanges by all nodes in the network.
Example: Ad hoc On-Demand Distance Vector Routing (AODV)
Is a simple routing algorithm in which every incoming packet is sent through every outgoing link except the one it arrived on. Flooding is used in bridging and in systems such as Usenet and peer-to-peer file sharing and as part of some routing protocols, including OSPF , DVMRP , and those used in wireless ad hoc networks.
This type of protocol combines the advantages of proactive and reactive routing . The routing is initially established with some proactively prospected routes and then serves the demand from additionally activated nodes through reactive flooding. The choice of one or the other method requires predetermination for typical cases. The main disadvantages of such algorithms are:
Example: Zone Routing Protocol (ZRP)
Position-based routing methods use information on the exact locations of the nodes. This information is obtained for example via a GPS receiver. Based on the exact location the best path between source and destination nodes can be determined.
Example: "Location-Aided Routing in mobile ad hoc networks" ( LAR )
An ad hoc network is made up of multiple "nodes" connected by "links."
Links are influenced by the node's resources (e.g., transmitter power, computing power and memory) and behavioral properties (e.g., reliability), as well as link properties (e.g. length-of-link and signal loss, interference and noise). Since links can be connected or disconnected at any time, a functioning network must be able to cope with this dynamic restructuring, preferably in a way that is timely, efficient, reliable, robust, and scalable.
The network must allow any two nodes to communicate by relaying the information via other nodes. A "path" is a series of links that connects two nodes. Various routing methods use one or two paths between any two nodes; flooding methods use all or most of the available paths. [ 59 ]
In most wireless ad hoc networks, the nodes compete for access to shared wireless medium, often resulting in collisions (interference). [ 60 ] Collisions can be handled using centralized scheduling or distributed contention access protocols. [ 60 ] Using cooperative wireless communications improves immunity to interference by having the destination node combine self-interference and other-node interference to improve decoding of the desired signals.
One key problem in wireless ad hoc networks is foreseeing the variety of possible situations that can occur. As a result, modeling and simulation (M&S) using extensive parameter sweeping and what-if analysis becomes an extremely important paradigm for use in ad hoc networks. One solution is the use of simulation tools like OPNET , NetSim or ns2 . A comparative study of various simulators for VANETs reveal that factors such as constrained road topology, multi-path fading and roadside obstacles, traffic flow models, trip models, varying vehicular speed and mobility, traffic lights, traffic congestion, drivers' behavior, etc., have to be taken into consideration in the simulation process to reflect realistic conditions. [ 61 ]
In 2009, the U.S. Army Research Laboratory (ARL) and Naval Research Laboratory (NRL) developed a Mobile Ad-Hoc Network emulation testbed, where algorithms and applications were subjected to representative wireless network conditions. The testbed was based on a version of the "MANE" (Mobile Ad hoc Network Emulator) software originally developed by NRL. [ 62 ]
The traditional model is the random geometric graph . Early work included simulating ad hoc mobile networks on sparse and densely connected topologies. Nodes are firstly scattered in a constrained physical space randomly. Each node then has a predefined fixed cell size (radio range). A node is said to be connected to another node if this neighbor is within its radio range. Nodes are then moved (migrated away) based on a random model, using random walk or brownian motion. Different mobility and number of nodes present yield different route length and hence different number of multi-hops.
These are graphs consisting of a set of nodes placed according to a point process in some usually bounded subset of the n-dimensional plane , mutually coupled according to a Boolean probability mass function of their spatial separation (see e.g. unit disk graphs ). The connections between nodes may have different weights to model the difference in channel attenuations. [ 60 ] One can then study network observables (such as connectivity , [ 63 ] centrality [ 64 ] or the degree distribution [ 65 ] ) from a graph-theoretic perspective. One can further study network protocols and algorithms to improve network throughput and fairness. [ 60 ]
Most wireless ad hoc networks do not implement any network access control, leaving these networks vulnerable to resource consumption attacks where a malicious node injects packets into the network with the goal of depleting the resources of the nodes relaying the packets. [ 66 ]
To thwart or prevent such attacks, it was necessary to employ authentication mechanisms that ensure that only authorized nodes can inject traffic into the network. [ 67 ] Even with authentication, these networks are vulnerable to packet dropping or delaying attacks, whereby an intermediate node drops the packet or delays it, rather than promptly sending it to the next hop.
In a multicast and dynamic environment, establishing temporary 1:1 secure 'sessions' using PKI with every other node is not feasible (like is done with HTTPS , most VPNs , etc. at the transport layer). Instead, a common solution is to use pre-shared keys for symmetric, authenticated encryption at the link layer, for example MACsec using AES -256- GCM . With this method, every properly formatted packet received is authenticated then passed along for decryption or dropped. It also means the key(s) in each node must be changed more often and simultaneously (e.g. to avoid reusing an IV ).
Trust establishment and management in MANETs face challenges due to resource constraints and the complex interdependency of networks. Managing trust in a MANET needs to consider the interactions between the composite cognitive, social, information and communication networks, and take into account the resource constraints (e.g., computing power, energy, bandwidth, time), and dynamics (e.g., topology changes, node mobility, node failure, propagation channel conditions). [ 68 ]
Researchers of trust management in MANET suggested that such complex interactions require a composite trust metric that captures aspects of communications and social networks, and corresponding trust measurement, trust distribution, and trust management schemes. [ 68 ]
Continuous monitoring of every node within a MANET is necessary for trust and reliability but difficult because it by definition is dis-continuous, 2) it requires input from the node itself and 3) from its 'nearby' peers. | https://en.wikipedia.org/wiki/Mobile_ad_hoc_network |
In the past computers needed to be disconnected from their internal network if they needed to be taken or moved anywhere. Mobile architecture allows maintaining this connection whilst during transit. [ 1 ] Each day the number of mobile devices is increasing, mobile architecture is the pieces of technology needed to create a rich, connected user experience.
Currently, there is a lack of uniform interoperability plans and implementation. There is a lack of common industry view on the architectural framework. This increases costs and slows down 3rd party mobile development. An open approach is required across all industries to achieve the same end results and services.
The basic and detailed architecture of the Mobile device consists of Hardware and Software architecture. The main hardware components
of the mobile phone are the application processor that controls all other components of the device such as display, keypad, power, audio, video etc. The radio signals are handled by base band
processor which in turn communicates with other processors to use their functionality. Power and audio processor controls the functioning of speaker and microphone with the help of application
processor. Subscriber Identification Module (SIM) contains the details about the subscriber.
A consortium of companies are pushing for products and services to be based on open, global standards, protocols and interfaces and are not locked to proprietary technologies. The applications layer to be bearer agnostic, for example:
The architecture framework and service enablers will be independent of operating systems. There will be support for inseparability of applications and platforms, seamless geographic and inter-generational roaming. [ citation needed ] | https://en.wikipedia.org/wiki/Mobile_architecture |
Mobile barrages squad is an element of a combat or operational order in the form of a temporary military formation, which is created from units of engineering troops and army aviation . [ 1 ] [ 2 ] [ 3 ]
The abbreviation for the temporary formation of troops or forces used in service documents is MBS . The main purpose of MBS is to set up mine blast barrages during combat and to destroy transport infrastructure on behalf of friendly forces. [ 3 ] Until July 1943 they were referred to simply as a barrage squad . [ 3 ] [ 4 ] [ 5 ]
The theoretical foundation for the practical application of MBS was laid in the work "Разрушения и заграждения" (1931) by the Soviet military engineer Dmitry Karbyshev . [ 1 ] [ 2 ]
During the Second World War (1939 - 1945), and especially the Eastern Front (1941 - 1945), wide use in all types of combat found mines and explosive barrages. For their arrangement in the Battle of Moscow , the Soviet troops for the first time in 1941 were used barrage squads , later called mobile barrage squads , which subsequently were successfully used in other operations of the Red Army of the Soviet Union .
After the Battle of Kursk (1943) on the basis of the experience gained, it was concluded that the army command needed a permanent specialized reserve of engineering units, which would have the means of mechanization of mines, large quantities of mines and explosives of various types. As a consequence, the MBS became a mandatory element of operational structure of the Soviet troops, and in 1942 - 1943 the tactics of MBS in the offensive and defensive were practiced. [ 1 ] [ 2 ] During the Eastern Front, the Red Army expended more than 70,000,000 different mines, including about 30,000,000 anti-tank mines .
The composition and equipment of a squad is determined by its objectives in combat or an operation, the availability of available forces and equipment, the composition of the enemy's troops, and the conditions on the ground. [ 1 ] When setting a mission, the MBS receives data on the area of location, movement routes, mine lines, and possible courses of action (bands). [ 2 ]
On defense, the MBS holds behind the first echelon of its troops in the most likely direction of the enemy's main strike in full readiness to move out to the breakout areas. The primary purpose of the MBS in defensive operations is considered to be: [ 1 ]
On the offensive, the MBS follows the first echelon of troops in readiness to set up barriers at the mines indicated to it.
On the offensive, the tasks of the MBS are usually: [ 1 ]
An MBS formation can be established not only in the ground forces , but also to solve certain tasks within other branches of the armed forces and branches of the military. For example, in the Navy , the tasks of barrages on the high seas are performed by barrage ship units. [ 1 ] In the Strategic Rocket Forces of Russia , units are formed to cover approaches to the facilities of the position area, block enemy reconnaissance groups and landing zones of marines . [ 1 ] While conventional units and formations usually organize one MBS, troops defending a stretch of coastline create an additional MBS with watercraft or aircraft for placing anti-landing mines in the water. In military formations, two or three MBSs are created, one of which is equipped with helicopter vehicles . [ 1 ]
The organizational structure of the armies of NATO member states does not provide for the deployment and use of MBS. [ 1 ] | https://en.wikipedia.org/wiki/Mobile_barrage_squad |
Mobile blogging (also known as moblogging [ 1 ] ) is a method of publishing to a website or blog from a mobile phone or other handheld device. A moblog helps habitual bloggers to post write-ups directly from their phones even when on the move. [ 2 ] Mobile blogging has been made possible by technological convergence , as bloggers have been able to write, record and upload different media all from a single, mobile device. At the height of its growth in 2006, mobile blogging experienced 70,000 blog creations a day and 29,100 blog posts an hour. [ 3 ] Between 2006 and 2010, blogging among teens declined from 28% to 14%, while blogging among adults over 30 increased from 7% to 11%. [ 4 ] However, the growing number of multi-platform blogging apps has increased mobile blogging popularity in recent years creating a brand new market that many celebrities, regular bloggers and specialists are utilizing to widen their social reach. [ 5 ]
Mobile blogging is popular among people with camera phones which allow them to e-mail / MMS or SMS photos and video that then appear as entries on a web site, or to use mobile browsers to publish content directly to any blogging platform with Mobile Posting compatibility. [ 6 ] [ 7 ] As the ability of camera phone users to publish their own blogs has increased, so too has the ability for collective submissions. Users are now able to access the posts of other bloggers in the immediate area through a process called Georeferential Blogging; which utilizes geographical location to collectively group blogging activity. [ 8 ] This advancement unites the posts of local bloggers in an effort to increase the relevancy of information to those in the area.
One of the precursors to a "moblog" was the development of a wearable photographic device by Steve Mann of the University of Toronto. Termed "domewear," the intention was for human rights workers to wear the devices to take photographic and video evidence of dangerous situations while avoiding being targeted for using traditional cameras. [ 9 ] The first recorded example of moblogging was on 1995 February 22, when Steve Mann posted text from his wearable mobile computer to his weblog server, together with video (image sequence). [ 10 ] The term moblogging, however, wasn't coined until 2002, by Adam Greenfield. [ 1 ] Mobile devices have expanded beyond basic communication and now these devices can support multimedia creation tools. [ 11 ]
The mobile blogging system has its origins in a technology-inspired design approach. This approach incorporates the rich feature set of a smartphone, including the ability to create multimedia, capturing decent images, and connectivity options. The intersection between the inherent design functions of the phone with the ongoing, personal nature of both a phone and a blog is how the concept of mobile blogging began. In the case study of SmartBlog, a system created to support mobile blogging, key principles were developed after assessing bloggers' needs. [ 11 ] These include:
The client, in this instance, refers to a Thin client . [ 11 ]
A moblog platform offers the capability to use a phone for administration, editing and writing from a phone or smartphone browser.
There are services and platforms which present different versions of a blog administration interface based on user agent.
Mobile blogging also promotes the dissemination of ideas and perspectives of younger people, who previously have not had as many easily accessible platforms to present their views. [ 12 ]
The continued integration of Mobile Blogging into areas of education has revealed many of its advantages. Its benefits affect both students and teachers, and have improved the overall educational experience. For students, it allows them to stay up-to-date with class schedules, access materials, and it inspires a more creative dimension with the inclusion of visual and audible materials in their work environment. [ 13 ]
For teachers, mobile blogging has allowed further monitoring of students’ progress and participation. [ 13 ]
Mobile blogging can be used alongside computer-supported collaborative learning in the classroom. This provides a positive and encouraging learning environment for students, especially students in a virtual classroom. Working collaboratively with mobile blogging can provide more authentic context learning and can help solve the coordination issue that often arises from working in a collaborative learning environment. [ 14 ]
Mobile blogging is particularly helpful to tourists and travelers when access to a computer with Internet connection may be difficult. The traveller can snap photos and with a GPRS or a WAP -enabled phone can easily upload such pictures with text descriptions directly to his or her blog . If the camera phone is equipped for Autogeotagging , the blog may be able to show a map of the locations.
One of the most significant challenges to mobile blogging is lack of access to both mobile devices and internet connections. While mobile blogging encourages production and spread of information to seemingly limitless people, it must be understood in regards to the advantages and disadvantages of socioeconomic status and geographical location. [ 12 ]
One of the most substantial and relevant challenges to having a mobile blogging network is the costs involved. Western countries face relatively cheap costs in terms of data plans and expenditures related to mobile devices, yet in most places around the world, these costs are very substantial and restrictive. When the costs are too high, mobile blogging and its benefits become irrelevant. [ 13 ] | https://en.wikipedia.org/wiki/Mobile_blogging |
Mobile collaboration is a technology-based process of communicating using electronic assets and accompanying software designed for use in remote locations. Newest generation hand-held electronic devices feature video, audio, and telestration (on-screen drawing) capabilities broadcast over secure networks, enabling multi-party conferencing in real time (although real time communication is not a strict requirement of mobile collaboration and may not be applicable or practical in many collaboration scenarios).
Differing from traditional video conferencing , mobile collaboration utilizes wireless , cellular and broadband technologies enabling effective collaboration independent of location. Where traditional video conferencing has been limited to boardrooms, offices, and lecture theatres, recent technological advancements have extended the capabilities of video conferencing for use with discreet, hand-held mobile devices , permitting true mobile collaborative possibilities. [ 1 ]
The scope of mobile collaboration takes into account a number of elements that continue to evolve in their sophistication and complexity: video, audio and telestration capabilities, conferencing and telepresence systems, collaboration tools, transmission technologies, and mobility.
Cisco Systems predicts "two-thirds of the world's mobile data traffic will be video by 2015." [ 2 ] The Unified Communications Interoperability Forum (UCIF), a non-profit alliance of technology vendors states that "one important driver for the growth of UC ( unified communications ) is mobility and the remote worker. No segment is growing faster than mobile communications, and virtually every smart phone will be equipped with video chat , IM , directory, and other UC features within a few years." [ 3 ]
To date, the use of mobile collaboration technology extends to industries as diverse as manufacturing, [ 4 ] energy, [ 5 ] healthcare, [ 6 ] insurance, [ 7 ] government and public safety. [ 8 ] Mobile collaboration allows multiple users in multiple locations the ability to synergistically combine their input while working towards the resolution of problems or issues in today’s complex work environments. This can be done in real time with advanced video, audio and telestrator capabilities, comparable to working together in the same room but without the associated expense and downtime typically involved in getting the experts to remote locations. [ 9 ]
Manufacturers of all kinds use mobile collaboration technology in a number of ways. Recent trends in globalization and outsourcing in particular, have meant that companies need to communicate with employees, suppliers, and customers the world over. [ 10 ] The flexibility of hand-held mobile collaboration devices allow real-time communication to take place at any location where products are being designed, built, and inspected, such as an automotive assembly plant a continent away. Improved communication through mobile collaboration affects many aspects of complex manufacturing such as production line maintenance, supply chain management and equipment field service . [ 11 ]
Companies in the energy sector face unique challenges due to, for example, the vast distances between a head office and the remote, harsh environment of an offshore oil rig, as well as the often inadequacies or absence of necessary transmission networks. Recent advancements in mobile collaboration technology and transmission networks are making it possible for employees in these situations to collaborate in secure and reliable ways with colleagues thousands of miles away. The use of mobile collaboration in the energy sector is enabling companies to conduct remote inspections, safety audits, maintenance, repair and overhaul work, as well as IT/communication infrastructure troubleshooting. [ 12 ]
Although telemedicine technology has been in use for a number of years in the healthcare sector, mobile collaboration technology extends these capabilities to locations now reachable through the use of hand-held devices such as a remote community, long-term care facility, or a patient’s home. Healthcare professionals in multiple locations can together view, discuss, and assess patient issues. The use of mobile collaboration technology within the healthcare sector has the potential to improve the quality and access to care, while making its delivery more cost-effective. [ 13 ]
Mobile collaboration technology might also be used for remote education. From one on one tutoring to large classes it has many uses. Homeschooling could really benefit from this technology as you participate in a lecture from anywhere in the world. Most useful you can record your classes or lectures and review them. Internet schools, including higher education, will most certainly also benefit from this development in mobile education. Though these methods are not widely used they are quite useful and most likely will become widely popular. [ 14 ]
Mobile collaboration between franchiser and franchisee allows modern technology to be used to allow a better flow of communications similar to face-to-face, albeit remotely via video/voice media such as smartphones, tablets, iPhones, iPads, etc. to be collectively used without requiring one party to travel to another location. This in turn reduces travel time and expenses not to mention better and quicker modes of communication.
Franchisers who have several hundred franchisees find it an absolute must. [ 15 ] | https://en.wikipedia.org/wiki/Mobile_collaboration |
The term mobile commerce was originally coined in 1997 by Kevin Duffey at the launch of the Global Mobile Commerce Forum, to mean "the delivery of electronic commerce capabilities directly into the consumer’s hand, anywhere, via wireless technology." [ 1 ] Some choose to think of Mobile Commerce as meaning "a retail outlet in your customer’s pocket."
Mobile commerce is worth US$800 billion, with Asia representing almost half of the market.
The Global Mobile Commerce Forum, which came to include over 100 organisations, had its fully minuted launch in London on 10 November 1997. Kevin Duffey was elected as the Executive Chairman at the first meeting in November 1997. The meeting was opened by Dr Mike Short, former chairman of the GSM Association, with the very first forecasts for mobile commerce from Kevin Duffey (Group Telecoms Director of Logica ) and Tom Alexander (later CEO of Virgin Mobile and then of Orange). Over 100 companies joined the Forum within a year, a number of them forming mobile commerce teams of their own, e.g. MasterCard and Motorola. Of these one hundred companies, the first two were Logica and Cellnet (which later became O2). Member organisations such as Nokia , Apple, Alcatel , and Vodafone began a series of trials and collaborations.
Mobile commerce services were first delivered in 1997, when the first two mobile-phone-enabled Coca-Cola vending machines were installed in the Helsinki area in Finland . The machines accepted payment via SMS text messages. This work evolved into several new mobile applications such as the first mobile phone-based banking service launched in 1997 by Merita Bank of Finland , also using SMS. Finnair mobile check-in was also a major milestone, first introduced in 2001.
The m-Commerce(tm) server developed in late 1997 by Kevin Duffey and Andrew Tobin at Logica won the 1998 Financial Times award for "most innovative mobile product," in a solution implemented with De La Rue, Motorola and Logica. [ 2 ] The Financial Times commended the solution for "turning mobile commerce into a reality." [ citation needed ] The trademark for m-Commerce was filed on 7 April 2008. [ 3 ]
In 1998, the first sales of digital content as downloads to mobile phones were made possible when the first commercial downloadable ringtones were launched in Finland by Radiolinja (now part of Elisa Oyj ).
Two major national commercial platforms for mobile commerce were launched in 1999: Smart Money in the Philippines , and NTT DoCoMo 's i-Mode Internet service in Japan . i-Mode offered a revenue-sharing plan where NTT DoCoMo kept 9 per cent of the fee users paid for content, and returned 91 percent to the content owner.
Mobile-commerce-related services spread rapidly in early 2000. Norway launched mobile parking payments. Austria offered train ticketing via mobile devices. Japan offered mobile purchases of airline tickets.
In April 2002, building on the work of the Global Mobile Commerce Forum (GMCF), the European Telecommunications Standards Institute (ETSI) appointed Joachim Hoffmann of Motorola to develop official standards for mobile commerce. [ 4 ] In appointing Mr Hoffman, ETSI quoted industry analysts as predicting "that m-commerce is poised for such an exponential growth over the next few years that could reach US$200 billion by 2004". [ 5 ]
As of 2008, UCL Computer Science and Peter J. Bentley demonstrated the potential for medical applications on mobile devices. [ 6 ]
PDAs and cellular phones have become so popular that multiple businesses [ specify ] are beginning to use mobile commerce as a more efficient way to communicate with their customers.
In order to exploit the potential mobile commerce market, mobile phone manufacturers such as Nokia, Ericsson, Motorola, and Qualcomm are working with carriers such as AT&T Wireless and Sprint to develop WAP -enabled smartphones. Smartphones offer fax, e-mail, and phone capabilities.
" Profitability for device vendors and carriers hinges on high-end mobile devices and the accompanying killer applications," said Burchett. [ who? ] Perennial early adopters, such as the youth market, which are the least price sensitive, as well as more open to premium mobile content and applications, must also be a key target for device vendors.
Since the launch of the iPhone in 2007, mobile commerce has moved away from SMS systems and into actual applications. SMS has significant security vulnerabilities and congestion problems, even though it is widely available and accessible. In addition, improvements in the capabilities of modern mobile devices make it prudent to place more of the resource burden on the mobile device.
Unlike online banking using bank websites, mobile banking allows a smaller number of operations based on short messages or applications installed on mobile devices. At present, it is estimated that by 2022, the number of customers adopting mobile banking will increase to 2 billion, and banks are investing more and more in improving mobile applications to improve security and customer satisfaction. [ 7 ]
More recently, brick and mortar business owners, and big-box retailers in particular, have made an effort to take advantage of mobile commerce by utilizing a number of mobile capabilities such as location-based services , barcode scanning , and push notifications to improve the customer experience of shopping in physical stores. By creating what is referred to as a 'bricks & clicks' environment, physical retailers can allow customers to access the common benefits of shopping online (such as product reviews, information, and coupons) while still shopping in the physical store. This is seen as a bridge between the gap created by e-commerce and in-store shopping, and is being utilized by physical retailers as a way to compete with the lower prices typically seen through online retailers. By mid summer 2013, "omnichannel" retailers (those with significant e-commerce and in-store sales) were seeing between 25% and 30% of traffic to their online properties originating from mobile devices. Some other pure play/online-only retail sites (especially those in the travel category) as well as flash sales sites and deal sites were seeing between 40% and 50% of traffic (and sometimes significantly more) originate from mobile devices.
The Google Wallet Mobile App [ 8 ] launched in September 2011 and the m-Commerce joint venture formed in June 2011 between Vodafone, O2, Orange and T-Mobile are recent developments of note. [ 9 ] Reflecting the importance of m-Commerce, in April 2012 the Competition Commissioner of the European Commission ordered an in-depth investigation of the m-Commerce joint venture between Vodafone, O2, Orange and T-Mobile. [ 10 ] A recent survey states that 2012, 41% of smartphone customers have purchased retail products with their mobile devices. [ 11 ]
In Kenya money transfer is mainly done through the use of mobile phones. This was an initiative of a multimillion-shillings company in Kenya named Safaricom. Currently, the companies involved are Safaricom and Airtel. Mobile money transfer services in Kenya are now provided by the two companies under the names M-PESA and Airtel Money respectively.
A similar system called MobilePay has been operated by Danske Bank in Denmark since 2013. It gained considerable popularity with about 1.6 million users by mid-2015. Another similar system called Vipps was introduced in Norway in 2015.
Mobile automated teller machine (ATM) is a special type of ATM. Most ATMs are meant to be stationary, and they're often found attached to the side of financial institutions, in stores, and in malls. A mobile ATM, on the other hand, is meant to be moved from location to location. This type of ATM is often found at special events for which ATM service is only needed temporarily. For example, they may be found at carnivals, fairs, and parades. They may also be used at seminars and workshops where no regular ATM is nearby.
Mobile ATMs are usually self-contained units that don't need a building or enclosure. Usually, a mobile ATM can be placed in just about any location and can transmit transaction information wirelessly, so there's no need to have a phone line handy. Mobile ATMs may, however, require access to an electrical source, though there are some capable of running on alternative sources of power. Often, these units are constructed of weather-resistant materials, so they can be used in practically any type of weather conditions. Additionally, these machines typically have internal heating and air conditioning units that help keep them functional despite the temperature of the environment.ion of mobile money services for the unbanked, operators are now looking for efficient ways to roll out and manage distribution networks that can support cash-in and cash-out. Unlike traditional ATMs, sicap Mobile ATMs have been specially engineered to connect to mobile money platforms and provide bank-grade ATM quality.
In Hungary, Vodafone allows cash or bank card payments for monthly phone bills. [ 12 ] The Hungarian market is one where direct debits are not standard practice, so the facility eases the burden of queuing for the postpaid half of Vodafone's subscriber base in Hungary.
Tickets can be sent to mobile phones using a variety of technologies. Users are then able to use their tickets immediately, by presenting their mobile phone at the ticket check as a digital boarding pass. Most numbers of users are now moving towards this technology. The best example would be IRCTC where the ticket comes as an SMS to users. New technology such as RFID can now be used to directly provide a single association digital ticket via the mobile device hardware associated with relevant software.
Mobile ticketing technology can also be used for the distribution of vouchers, coupons, and loyalty cards. These items are represented by a virtual token that is sent to the mobile phone. A customer presenting a mobile phone with one of these tokens at the point of sale receives the same benefits as if they had the traditional token. Stores may send coupons to customers using location-based services to determine when the customer is nearby. Using a connected device and the networking effect can also allow for gamification within the shopping experience.
Currently, mobile content purchase and delivery mainly consist of the sale of ring-tones, wallpapers, apps, and games for mobile phones. The convergence of mobile phones, portable audio players, and video players into a single device is increasing the purchase and delivery of full-length music tracks and videos. The download speeds available with 4G networks make it possible to buy a movie on a mobile device in a couple of seconds. [ citation needed ]
The location of the mobile phone user is an important piece of information used during mobile commerce or m-commerce transactions. Knowing the location of the user allows for location-based services such as:
A wide variety of information services can be delivered to mobile phone users in much the same way as it is delivered to PCs. These services include:
Customized traffic information, based on a user's actual travel patterns, can be sent to a mobile device. This customized data is more useful than a generic traffic-report broadcast but was impractical before the invention of modern mobile devices due to the bandwidth requirements.
Banks and other financial institutions use mobile commerce to allow their customers to access account information and make transactions, such as purchasing stocks, and remitting money. This service is often referred to as mobile banking , or m-banking.
Stock market services offered via mobile devices have also become more popular and are known as Mobile Brokerage. They allow the subscriber to react to market developments in a timely fashion and irrespective of their physical location.
Over the past three years [ when? ] mobile reverse auction solutions have grown in popularity. [ by whom? ] Unlike traditional auctions, the reverse auction (or low-bid auction) bills the consumer's phone each time they place a bid. Multiple mobiles SMS commerce solutions rely on a one-time purchase or one-time subscription; however, reverse auctions offer a high return for the mobile vendor as they require the consumer to make multiple transactions over a long period of time.
Using a mobile browser—a World Wide Web browser on a mobile device—customers can shop online without having to be at their personal computer. Multiple mobile marketing apps with geo-location capability are now delivering user-specific marketing messages to the right person at the right time.
Catalog merchants can accept orders from customers electronically, via the customer's mobile device. In some cases, the merchant may even deliver the catalog electronically, rather than mailing a paper catalog to the customer. Consumers making mobile purchases can also receive value-add upselling services and offers. Some merchants provide mobile web sites that are customized for the smaller screen and limited user interface of a mobile device.
Payments can be made directly inside an application running on a popular smartphone operating system, such as Google Android. Analyst firm Gartner expects in-application purchases to drive 41 percent of app store (also referred to as mobile software distribution platforms) revenue in 2016. [ 13 ] In-app purchases can be used to buy virtual goods , new and other mobile content and is ultimately billed by mobile carriers rather than the app stores themselves. [ 14 ] Ericsson's IPX mobile commerce system is used by 120 mobile carriers to offer payment options such as try-before-you-buy, rentals and subscriptions. [ 15 ]
In the context of mobile commerce, mobile marketing refers to marketing sent to mobile devices. Companies have reported that they see better responses from mobile marketing campaigns than from traditional campaigns. The primary reason for this is the instant nature of customer decision-making that mobile apps and websites enable. The consumer can receive a marketing message or discount coupon and, within a few seconds, make a decision to buy and go on to complete the sale - without disrupting their current real-world activity.
For example, a busy mom tending to her household chores with a baby in her arm could receive a marketing message on her mobile about baby products from a local store. She can and within a few clicks, place an order for her supplies without having to plan ahead for it. No more need to reach for her purse and hunt for credit cards, no need to log into her laptop and try to recall the web address of the store she visited last week, and surely no need to find a babysitter to cover for her while she runs to the local store.
Research demonstrates that consumers of mobile and wireline markets represent two distinct groups who are driven by different values and behaviors, and who exhibit dissimilar psychographic and demographic profiles. [ 16 ] What aspects truly distinguish between a traditional online shopper from home and a mobile on-the-go shopper? Research shows that how individuals relate to four situational dimensions- place, time, social context and control determine to what extent they are ubiquitous or situated as consumers. [ 17 ] These factors are important in triggering m-commerce from e-commerce. As a result, successful mobile commerce requires the development of marketing campaigns targeted to these particular dimensions and according to user segments.
Mobile media is a rapidly changing field. New technologies, such as WiMax , act to accelerate innovation in mobile commerce. Early pioneers in mobile advertising include Vodafone , Orange , and SK Telecom . An empirical study shows that over 70% of mobile commerce users are under the age of 25, as of 2019. [ 18 ]
Mobile devices are heavily used in South Korea to conduct mobile commerce. Mobile companies in South Korea believed that mobile technology would become synonymous with the youth lifestyle, based on their experience with previous generations of South Koreans. "Profitability for device vendors and carriers hinges on high-end mobile devices and the accompanying killer applications," said Daniel Longfield. [ 19 ]
Consumers can use multiple forms of payment in mobile commerce, including:
Interaction design and UX design has been at the core of the m-commerce experience from its conception, producing apps and mobile web pages that create highly usable interactions for users. [ 20 ] However, much debate has occurred as to the focus that should be given to the apps. In recent research, Parker and Wang [ 21 ] demonstrated that within fashion m-Commerce apps, the degree that the app helps the user shop (increasing convenience) was the most prominent function. Such use examples might be through design cues that help the user find their products with minimal search. [ 22 ] Additionally, shopping for others was a motivator for engaging in m-commerce apps with a great preference for close integration with social media . Research shows that culture makes a significant difference in people's motivation to engage in shopping, where Western consumers - for example - have significantly different motivations to Chinese consumers. [ 23 ]
The popularity of apps has given rise to the latest iteration of mobile commerce: app commerce. This refers to retail transactions that take place on a native mobile app. App commerce is said to perform better than both desktop and mobile web when it comes to browsing duration and interactions. [ 24 ] Average order value is reportedly greater with retail apps than traditional ecommerce, and conversion rates on apps are twice that of mobile websites. [ 24 ]
Mobile applications serve as a means to ensure positive user experience, seamless interaction, and increased revenues for e-commerce. According to DesignRush report, [ 25 ] mobile applications are expected to generate $189 billion by 2020. Moreover, a study by Forrester shows that mobile devices will be leveraged to facilitate over $1 trillion in sales in 2018. | https://en.wikipedia.org/wiki/Mobile_commerce |
MoIP , or mobile communications over Internet Protocol , [ 1 ] is the mobilization of peer-to-peer communications including chat and talk using Internet Protocol via standard mobile communications applications including 3G , GPRS , Wi-Fi as well as WiMax . Unlike mobile VoIP , MoIP is not a VoIP program made accessible from mobile phones or a switchboard application using VoIP in the background. It is rather a native mobile application on users’ handsets and used to conduct talk and chat over the internet connection as its primary channel.
MoIP applications typically work without any proprietary hardware , are enhanced with real-time contact availability (presence) and save the users money by utilizing free Wi-Fi internet access or fixed internet data plans instead of GSM (talk) minutes. They are completely mobile-centric, designed and optimized specifically for mobile-handsets environment rather than the PC . [ 2 ]
This article related to telecommunications is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Mobile_communications_over_IP |
Mobile content is any type of web hypertext and information content and electronic media which is viewed or used on mobile phones , like text, sound, ringtones , graphics, flash, discount offers, mobile games, movies, and GPS navigation. As mobile phone use has grown since the mid-1990s, the usage and significance of the mobile devices in everyday technological life has grown accordingly. Owners of mobile phones can now use their devices to make photo snapshots for upload, twits, mobile calendar appointments, and mostly send and receive text messages ( SMSes or instant messages ), listen to music, watch videos, take mobile pictures and make videos, use websites to redeem coupons for purchases, view and edit office documents, get driving instructions on mobile maps and so on. The use of mobile content in various areas has grown accordingly.
Camera phones may not only present but also produce media, for example photographs and videos with a few million pixels, and can act as pocket video cameras . [ 1 ]
Mobile content can also refer to text and multimedia that is online on websites and hosted on mobile facilitated servers, which may either be standard desktop Internet pages, mobile webpages or specific mobile pages .
Mobile text and image content via SMS is one of the main technologies in mobile phones for communication, and is used to send mobile users and consumers messages, especially simple content such as ringtones and wallpapers . Because SMS is the main messaging (non Internet) technology used by young people, it is still the most effective way to communicate and for providers of reaching this target market. SMS is also easy to use, ubiquitous, sometimes reaching a wider audience than any other technology available in the mobile space (MMS, bluetooth, mobile e-mail or WAP). What is important is that SMS is extremely easy to use, which makes its application for various uses increasingly eady day by day.
Although SMS is a technology that has long history since first cellular phones it maybe replaced in use by the likes of Multimedia Messaging Service (MMS) or WAP, but SMS frequently gains new powers. One example is the introduction of applications whereby mobile tickets are sent to consumers via SMS, which contains a WAP-push that contains a link where a barcode is placed. This clearly substitutes MMS, which has a limited users reach and still has some applicability and interoperability problems.
It is important to keep enhancing the phone user and consumer confidence in using SMS for mobile content applications. This means, if user and consumer has in order some new wallpaper or ringtone, this as the user expects has to work somehow almost properly, and in a speedy and very reliable way. Therefore, it is of importance to choose the right SMS gateway available or as provider as to ensure the quality-of-service along the whole path of the content SMS until it reaches the consumer's mobile.
Modern phones come with Bluetooth and Near field communication . This allows video to be sent from phone to phone over Bluetooth, which has the advantages that there is no data charge. [ 2 ]
Mobile application development , also known as mobile apps, has become a significant mobile content market since the release of the first iPhone from Apple in 2007. Prior to the release of Apple's phone product, the market for mobile applications (outside of games) had been quite limited. The bundling of the iPhone with an app store, as well as the iPhone's unique design and user interface, helped bring a large surge in mobile application use. It also enabled additional competition from other players. For example, Google's Android platform for mobile content has further increased the amount of app content available to mobile phone subscribers.
Some examples of mobile apps would be applications to manage travel schedules, buy movie tickets, preview video content, manage RSS news feeds, read digital version of popular newspapers, identify music, look at star constellations, view Wikipedia , and much more. Many television networks have their own app to promote and present their content. iTyphoon is an example of a mobile application used to provide information about typhoons in the Philippines. [ 3 ]
Mobile games are applications that allow people to play a game on a mobile handset. The main categories of mobile games include Puzzle/Strategy, Retro/Arcade, Action/Adventure, Card/Casino, Trivia/Word, Sports/Racing, given in approximate order of their popularity. [ 4 ]
Several studies have shown that the majority of mobile games are bought and played by women. Sixty-five percent of mobile game revenue is driven by female wireless subscribers. They are the biggest driver of revenue for the Puzzle/Strategy category; comprising 72 percent of the total share of revenue, while men made up 28 percent (see Table 2). Women dominate revenue generation for all mobile game categories, with the exception of Action/Adventure mobile games, in which men drive 60 percent of the revenue for that category. [ 5 ] It is also said that teens are three times as likely as those over twenty to play cell phone games. [ 6 ]
Mobile images are used as the wallpaper to a mobile phone, and are also available as screensavers. On some handsets, images can also be set to display when a particular person calls the users. Sites like adg.ms allow users to download free content, however service operators such as Telus Mobility blocks non Telus website downloads.
Mobile music is any audio file that is played on a mobile phone. Mobile music is normally formatted as an AAC ( Advanced Audio Coding ) file or an MP3 , and comes in several different formats. Monophonic ringtones were the earliest form of ringtone, and played one tone at a time. This was improved upon with polyphonic ringtones, which played several tones at the same time so a more convincing melody could be created. The next step was to play clips of actual songs, which were dubbed Realtones. These are preferred by record labels as this evolution of the ringtone has allowed them to gain a cut of lucrative ringtone market. In short Realtones generate royalties for record labels (the master recording owners) as well as publishers (the writers), however, when Monophonic or Polyphonic ringtones are sold only publishing or "mechanical" royalties are incurred as no master recording has been exploited. [ 7 ] Some companies promote covertones, which are ringtones that are recorded by cover bands to sound like a famous song. Recently Ringback tones have become available, which are played to the person calling the owner of the ringback tone. Voicetones are ringtones that play someone talking or shouting rather than music, and there are various of ringtones of natural and everyday sounds. Realtones are the most popular form of ringtones. As an example, they captures 76.4% of the US ringtone market in the second quarter of 2006, followed by monophonic and polyphonic ringtones at 12% and ringback tones and 11.5% – but monophonic and polyphonic ringtones are falling in popularity while ringback tones are growing. [ 8 ] This trend is common around the globe. A recent innovation is the singtone , whereby "the user’s voice is recorded singing to a popular music track and then “tuned-up” automatically to sound good. This can then be downloaded as a ringtone or sent to another user's mobile phone" said the director of Synchro Arts, the developers.
As well as mobile music there are full track downloads, which are an entire song encoded to play on a mobile phone. These can be purchased and bought over the mobile network, but data charges can make this prohibitive. [ 9 ] The other way to get a song onto a mobile phone is by "side loading" it, which normally involves downloading the song onto a computer and then transferring it to the mobile phone via Bluetooth, infra-red or cable connections. It is possible to use a full track as a ringtone. In recent years, websites have sprung that allow users to upload audio files and customize them into ringtones using specialized applications, including Myxer , MobilesRingtones , Bongotones , Ringtoneslab and Zedge .
Mobile music is becoming an integral part of the music industry as a whole. In 2005, the International Federation of Phonographic Industries (IFPI) said it expects mobile music to generate more revenues that online music before the end of that year. [ 10 ] In the first half of 2005, the digital music market grew enough to offset the fall in the traditional music market – without including the sale of ringtones, which still makes up the majority of mobile music sales around the globe. [ 11 ]
Mobile video comes in several forms including 3GPP , MPEG-4 , RTSP , and Flash Lite . [ citation needed ]
A Mobishow or a cellsode are terms to describe a broadcast quality programme / series which has been produced, directed, edited and encoded for the mobile phone. Mobishows and Cellsodes can range from short video clips such as betting advice or the latest celebrity gossip, through to half-hour drama serials. Examples include The Ashes and Mr Paparazzi Show which both were created for mobile viewing.
Mobile streaming radio is an application that streams on-demand audio channels or live radio stations to the mobile phone. In the U.S., mSpot was the first company to develop and commercialize streaming radio which went live in March 2005 on Sprint. [ citation needed ] Today, all major carriers offer some sort streaming radio service featuring programmed stations based on popular genres and live stations which included both music and talk. [ 12 ]
Mobile video also comes in the form of streaming TV over the mobile network, which must be a 2.5G or 3G network. This mimics a television station in that the user cannot elect to see what they wish but must watch whatever is on the channel at the time.
There is also mobile broadcast TV, which operates like a traditional television station and broadcasts the content over a different spectrum. This frees up the mobile network to handle calls and other data usage, and because of the " one-to-many " nature of mobile broadcast TV the video quality is a lot better than that streamed over the mobile networks, which is a "one-to-one" system.
The problem is that broadcast technologies do not have a natural up link, so for users to interact with the TV stream the service has to be closely integrated to the carriers mobile network. The main technologies for broadcast TV are DVB-H , Digital Multimedia Broadcasting (DMB), and MediaFLO .
Live video can also be streamed and shared from a cell phone through applications like Qik and InstaLively. The uploaded video can be shared to friends through emails or social networking sites . Most Live video streaming application works over the cell network or through Wi-Fi . They also require most users to have a dataplan from their cell phone carriers.
Since the late 1990s, mobile content has become an increasingly important market worldwide. The South Koreans are the world leaders [ citation needed ] in Mobile Content and 3-G mobile networks, then the Japanese , followed closely by the Europeans , are heavy users of their mobile phones and have been attaining custom mobile content for their devices for years. In fact, mobile phone use has begun to exceed the use of PCs in some countries. In the United States and Canada , mobile phone use and the accompanying use of mobile content has been slower to gain traction because of political issues and because open networks do not exist in America.
On current trends, mobile phone content will play an increasing role in the lives of millions across the globe in the years ahead, as users will depend on their mobile phones to keep in touch not only with their friends but with world news, sports scores, the latest movies and music, and more.
Mobile content is usually downloaded through WAP sites, but new methods are on the rise. In Italy, 800,000 people are registered users to Passa Parola, an application that allows users to browse a big database for mobile content and directly download it to their handsets. This tool can also be used to recommend content to others, or send content as a gift. [ 13 ]
An increasing number of people are also beginning to use applications like Qik to upload and share their videos from their cell phone to the internet. [ citation needed ] Mobile phone software like Qik allows user to share their videos to their friends through emails , SMS , and even social networking sites like Twitter and Facebook .
A 2016 Pew Research report "The Modem News Consumer" said 70 percent of those ages 18–29 preferred getting news from mobile devices rather than desktops, while the number was 53 percent for persons 30 to 49. [ 14 ] | https://en.wikipedia.org/wiki/Mobile_content |
Mobile computing devices (e.g., smartphones and PDAs ) store and share data over a mobile network , or access a database which is actually stored by the mobile device. This could be a list of contacts, price information, distance travelled, or any other information. [ 1 ]
Many applications require the ability to download information from an information repository and operate on this information even when out of range or disconnected. An example of this is accessing your contacts and calendar on a mobile phone. In this scenario, a user would require access to update information from files in the home directories on a server or customer records from a database. This type of access and work load generated by such users is different from the traditional workloads seen in client–server systems of today. [ citation needed ]
Mobile databases are not used solely for the revision of company contacts and calendars, but are also utilized in a number of industries.
This is in database theory known as "replication", and good mobile database system should provide tools for automatic replication that takes into account that others may have modified the same data as you while you were away, and not just the last update is kept, but also supports "merge" of variants.
Commercially available mobile databases include those shown on this comparison chart. | https://en.wikipedia.org/wiki/Mobile_database |
Mobile entertainment comprises a range of activities associated with mobile electronics . [ 1 ] The definition is both somewhat subjective and in continual development, but can include purely leisure activities (music, playing games), communications ( social media , instant messaging , Twitter ), and activities which could also be defined as commerce (shopping).
According to Moore and Rutter: "A primary difficulty when researching mobile entertainment is that of definition". It is not always clear to consumers precisely what ‘mobile entertainment’ is. The problem of producing common understandings of mobile entertainment has been previously highlighted by the Mobile Entertainment Forum (MEF) when stating that 'two different industries make up the mobile entertainment industry: entertainment and telecommunications . Mobile entertainment is created as the convergence of both industries. Each of these worlds speaks a different language, and holds different assumptions about the nature of its work' (‘Terminology of Mobile Entertainment: An Introduction’, MEF, August 2003)." [ 2 ]
MGAIN [ 3 ] assumes "mobile entertainment includes any leisure activity undertaken via a personal technology which is, or has the potential to be, networked and facilitates transfer of data ... over geographic distance either on the move or at a variety of discrete locations." [ 2 ] While workable, the definition does not cover whether mobile entertainment services must interact with service providers or telcos . It does not cover whether such service would incur a cost of usage. If mobile entertainment were said to be a subset of mobile commerce , hence, it must involve transactions of economic value. "The social aspects of mobile entertainment are hidden within the phrase ‘any leisure activity’." [ 2 ]
This article "presents a framework to examine mobile entertainment from multiple points of views. This allows future research to be conducted with the clarity of distinguishing mobile entertainment services of different domains." [ 4 ]
Wong and Hiew [ 5 ] examine multiple perspectives from various players of the value web as well as researchers to bridge the gaps found in various definitions in order to reach a common understanding. The authors consider the following as key considerations in determining whether a mobile service falls under mobile entertainment category: a form of leisure activity, interaction with service providers, utilization of wireless telecommunication networks , and transaction which incur a cost upon usage. To understand mobile entertainment, three different segments are suggested in the following figure. Each segment suggests a specific set of theories. It is implicit throughout the study that mobile entertainment is any type of leisure activity on the move.
Segment 1 consists of intersection between mobile commerce and mobile entertainment, sitting on top of wireless telecommunication networks. In other words, mobile entertainment services in segment 1 must be a subset of mobile commerce, which involves exchanges of monetary value and interaction with service providers.
Segment 2 covers mobile entertainment services which utilize wireless telecommunication networks, but do not incur a cost upon usage and do not interact with service providers. For example, one may play multiplayer mobile games with friends via Bluetooth .
Segment 3 involves mobile entertainment which does not require wireless connection and transaction of an economic value. For example, one may play preinstalled single player games on a handheld device such as a mobile phone.
Mobile entertainment via SMS has expanded rapidly in Europe and Asia and it is still the main technology-bearer to send mobile entertainment messages to consumers. Because SMS is the main messaging technology used by young people, it is still the most effective way of reaching this target market. SMS is also ubiquitous, reaching a wider audience than any other technology available in the mobile space ( MMS , bluetooth , mobile e-mail or WAP ). More important than anything else, SMS is extremely easy to use, what makes adoption increase day by day.
What enhances the consumer confidence in using SMS for mobile entertainment applications is the reliability of the service. This means, if a consumer has ordered a new wallpaper or ringtone , this has to work properly, in a speedy and reliable way. Therefore, it is important to choose the right SMS gateway provider in order to ensure quality-of-service along the whole path of the entertainment SMS until reaching the consumer's mobile.
A mobile user connects to the Internet via his WAP-enabled mobile phone, searches for a particular ringtone and downloads it onto his mobile phone. This falls under Segment 1 where this activity utilizes wireless telecommunication networks, incurs a cost upon file download, interacts with the service provider and is a form of leisure activity. If he transfers the ringtone to his friend via Bluetooth or infrared, this falls under Segment 2 where such activity still utilizes the wireless network yet does not incur a cost upon file transfer or involves any interaction with service providers. However, if he composes a ring tone (provided if the mobile device supports composing ring tone) and sets it as default ringtone, such activity is still considered as mobile entertainment but it does not utilize the wireless network or incur a cost upon usage.
Therefore, this activity falls under Segment 3. Hence, in this scenario, the players in the value web differ in all three scenarios. The definitions for all three cases vary as well. Hence, the model in the above-mentioned framework aids the industries to determine the appropriate business model to adopt in order to target the right audience. | https://en.wikipedia.org/wiki/Mobile_entertainment |
A mobile form is an electronic or digital form application that functions on a smartphone or tablet device . Mobile forms enable users to collect data using mobile devices , and then to send the results back to the source. Mobile forms exist to replace paper forms as a more productive means of data collection , eliminating the need to transcribe or scan paper data results into a back office system.
Depending on the mobile form application provider, some mobile form solutions allow offices to dispatch data to mobile form applications. In addition, other mobile form applications can be connected with various cloud services , servers , and social media platforms .
Depending on the business, the motivating factors to deploying mobile forms may vary. Some businesses implement mobile forms to speed up processes, while others institute mobile forms with field users to reduce costs associated with transporting paper forms back and forth. Furthermore, green-minded businesses implement mobile forms in order to be more environmentally friendly, thus reducing their reliance on paper, ink printing, and subsequent waste.
Advanced mobile form features include signature capture, bar code capture, photo capture, GPS location form info, time form info, and skip logic. [ citation needed ]
Location-based mobile forms are applications that associate a specific GPS location to the form data. Theses types of application fall into the category of data collection systems and are used by field personnel to collect data at precise locations in the field. Data collected with these applications is georeferenced and is can be transferred to geographic information systems for further data analysis . Location-based mobile forms act as a bridge between field personnel and geomatics specialists.
Uses for mobile forms include: | https://en.wikipedia.org/wiki/Mobile_forms |
Mobile gambling refers to playing games of chance or skill for money by using a remote device such as a tablet computer , smartphone or a mobile phone with a wireless internet connection. Over a hundred mobile casinos were operating as of December 2013, with most of the big casino operators in gambling now providing a mobile platform for their player base.
In 2003, The Mobile Lottery launched in the United Kingdom as the first mobile gambling venture in the country. [ 1 ] After wireless gambling on casino grounds was legalized in June 2005, in March 2006, the Nevada Gaming Control Board "cleared the way for businesses to propose ways in which establishments can offer wireless gambling." [ 2 ]
In 2006, Europe was the largest market for mobile gambling, but "telecommunications analysts predict that Asia will catch up soon." At the time, a limitation of suitable phones in Asia and unclear legal situations in certain locales was limiting growth, with legal mobile gambling in Asia restricted to Hong Kong and China for sports and lotteries. Only in the Philippines and Macau was casino-style mobile gambling allowed. There were analyst projections in 2006 that the mobile gambling market in the Asia-Pacific region would generate revenue of $3 billion in 2010. [ 3 ] In 2005, Jupiter Research forecast that global mobile gambling services would generate revenues of more than $19.3 billion US dollars by 2009. [ 4 ] In 2010, Gartner analysts showed the 2009 global mobile gambling revenues at $4.7 billion and forecast $5.6 billion for 2010. [ 5 ] Such a large discrepancy between the 2005 forecast and the 2009 reality was attributed to the unexpected 2006 US prohibition of all internet based gambling.
The mobile gambling market, as of 2011 is still in flux. The European Union still does not have a unified mobile gambling legislative framework in place. Each European country has their own set of widely different laws which regulate mobile gambling ranging from Finland where a government monopoly operates internet casinos to Norway which is in favor of complete prohibition of online gambling .
According to a Juniper Research report [ 6 ] released in September 2010 the total sum wagered on mobile casino games is expected to surpass US$48 billion by 2015. The report bases this prediction on (1) the high growth rates of mobile casinos, lotteries and sports betting providers in major emerging markets and China; (2) liberalization of mobile gambling legislation in Europe; (3) United States repealing the Unlawful Internet Gambling Enforcement Act of 2006 , permitting people in the US to legally gamble online again. [ 6 ]
A 2010 Gartner forecast 2014 global mobile gambling revenues reaching $11.4 billion. [ 5 ] Final revenues proved in excess of projects within the year. In early 2011, Apple had allowed real-money gambling apps for the first time into the App Store , with mobile gambling revenue in the UK rising from £19 million in 2009 to £41 million in 2010. In June 2011, The Guardian wrote a story about spiking mobile gambling figures released by gambling companies Paddy Power , Corcoran, and Betfair , with Paddy Power saying its mobile gambling revenues had increased by 300% during 2010. Likewise, Betfair's and Corcoran's mobile user increases were also attributed to the increased adoption of apps. [ 7 ]
Growth of mobile betting in the United States was slowed in 2011, when the DOJ ruled against it, although successful services had been launched in Nevada and New Jersey. [ 8 ] In 2012, there was a push for south Jersey to allow gamblers to use mobile devices to gamble in casinos, pushed by Senator Jim Whelan , to compete with Las Vegas. [ 9 ] At the time, mobile gaming devices were already adopted in Las Vegas in casinos, allowing casinos to extend gaming floor to their outer premises. In 2012, the New Jersey Legislature approved "the use of hand-held gambling devices at Atlantic City casinos," and was waiting on the Governor's signature to pass. [ 10 ]
In March 2019, the governor of Rhode Island signed a bill to allow mobile sports betting in the state, to begin on 1 July. Gina Raimondo 's proposed budget estimated $3 million from mobile gaming profits that year. [ 11 ] With Rhode Island the only state to allow sports betting at that time, [ 12 ] the bill was approved on 12 March 2019, and allowed for the creation of an app to allow remote placing of sports bets at Twin River Casino . The state had legalized sports betting the year before, when the U.S. Supreme Court struck down a federal law forbidding most sports gambling in the country. [ 13 ]
On 19 February 2020, it was reported that New Jersey had collected $837 million from general sports gamblers who were coming from New York state , both mobile and in-person, and that as a result, New York politicians were pushing for a bill that would legalize mobile gambling in New York with a 12.5% tax for each bet placed. [ 14 ]
In September 2019, the Wall Street Journal reported that online gamblers accounted for "80% of all legal wagers on games in New Jersey, which surpassed Nevada for the first time in May in monthly sports bets." At the time, online or mobile gambling was in five states for sports gambling: New Jersey, Pennsylvania , West Virginia , Iowa and Nevada . It was reported that in its first year of legalization, "New Jersey sports bettors wagered a total of $3.2 billion in the first year," with $2.4 billion of that from online or mobile bets. In some states, like Mississippi , gamblers could place bets on a phone while physically inside the associated casino. [ 15 ]
Reuters noted that as mobile gambling increased in popularity, there were increased corruption concerns about using phone hacking to game the system. [ 16 ] Sports betting is the activity of predicting sports results and placing a wager on the outcome. The frequency of sports bet upon varies by culture, with the vast majority of bets being placed on association football, American football, basketball, baseball, hockey, track cycling, auto racing, mixed martial arts, and boxing at both the amateur and professional levels.
But Reuters also talks about the difficulties and government scrutiny that accompany this expansion. Increased chances of addiction and money laundering are causes for concern. Tighter rules have been put in place in some countries, like Australia, to address these problems. The changes are intended to improve industry transparency and enforce stronger anti-money laundering protocols.It's
States in the US are also tightening regulation as mobile betting expands, making sure providers uphold strict guidelines for responsible gaming and player safety.
Full legalized gambling on mobile phone is referred to as iGaming or iGambling. According to The Jerusalem Post , examples of common mobile gambling games include slot games, table games, new games, and classics like roulette , blackjack , poker , and baccarat . There are also live casino versions that are streamed from real casinos or studios. [ citation needed ] According to a February 2010 comScore MobiLens study [ 17 ] of the U.S. mobile gaming market, smartphone subscribers are much more likely to play mobile casino games than subscribers of generic phones. The study revealed that 7.6% of smartphone subscribers and 1.2% of generic mobile subscribers played mobile casino games within a three-month time frame. [ 17 ]
Aside from availability online, United States of America-based mobile casino apps have appeared in several land-based locations that can be utilized to gamble only while physically present on the casino's property. This extends to outside areas that are still within the boundaries of the property, making them the first type of slot machine, sports-betting, and random number generated gambling to take place legally off the licensed gaming floor while still inside a U.S. casino.
According to VentureBeat , Google does not allow any real-money gambling apps on its Google Play Store . [ 18 ] | https://en.wikipedia.org/wiki/Mobile_gambling |
Mobile industrial robots are pieces of machinery that are able to be programmed to perform tasks in an industrial setting. Typically these have been used in stationary and workbench applications; however, mobile industrial robots introduce a new method for lean manufacturing . With advances in controls and robotics , current technology has been improved allowing for mobile tasks such as product delivery. This additional flexibility in manufacturing can save a company time and money during the manufacturing process, and therefore results in a cheaper end product.
Mobile robot technology has potential to revolutionize many sectors of industry; however, it carries with it some disadvantages. The logistics of manufacturing will be streamlined by allowing robots to autonomously navigate to different areas for their work. The labour demands for employees will be lessened as robots will be able to work alongside humans, and robots will assist with medicine and surgery more and more. However, there are drawbacks to this technology. Coordinating the movement of robots around facilities and calibrating their position at their destination is tedious and far from perfect. [ 1 ] A robot malfunctioning in a manufacturing setting will hold up production - and this robot could malfunction anywhere in a facility. Human safety must also be considered. Robots must prioritize the safety of human operators over their programmed task - which may complicate the coordination of multiple autonomous robots . Especially in a surgical setting, there is no room for error on the robot's part. Even though some challenges are present, mobile robot technology promises to streamline aspects across much of the industry. [ 2 ]
Automation began in the automobile industry in the years surrounding WWII (1946) and the origin of the term itself belongs with D.S. Harder, the engineering manager at the Ford Motor Company . At first, the term was used to describe the increased presence of automatic devices in production lines and solely manufacturing contexts. Now, automation is widely used in many industries where computerized action and feedback loops can replace human intervention in the workplace. Over time, development in this area has become increasingly dependent upon advanced computer technologies and the advancement of processing capabilities. [ 3 ]
In its current form, most industrial robots are powered mechanical arms with the ability to perform anthropomorphic actions. Advancements in miniaturization of computers, mathematical control theory as well as improved sensory technologies have had great impact on the feedback control systems that drive robotics. [ 3 ] The first industrial robot performed spot welding and die castings in a General Motors factory in New Jersey , USA in 1962. Soon, robotic arms were exploding within the large-scale manufacturing industry and several new companies came into existence including Kuka in 1973, Nachi in 1969, Fanuc in 1974, Yaskawa in 1977, ASEA in 1977, and several others. By 1980, it is estimated a new major robotics company entered the market every month. [ 4 ]
Mobile robotics are now set to experience similar expansion as they become significantly more reliable in an industrial setting. Even if a mobile robot makes mistakes, it will eventually be less frequently than mistakes caused by human factors.
The simplicity of mobile industrial robots provide their main advantage in industrial settings due to the ease of use and ability to be operated via technologies well understood by most people. In addition, robots are able to operate almost continuously and will never complain about long work hours; greatly increasing efficiency in a lean manufacturing environment. The main current disadvantage lies in high costs of repair as well as the production delays that would be caused by a failure or malfunction. These factors are very preventative to putting major amounts of responsibility on mobile robotics, however they are being continually lessened. [ 1 ] [ 5 ]
The mobile industrial robots have many applications that they have been used in already including in the healthcare industry, home and industrial security, ocean and space exploration, the food service industry, and in distribution applications.
Mobile industrial robots have several uses within the healthcare industry in both hospitals and homes. Drug delivery, patient services, and other nursing functions could be easily adapted to robots. Due to the fact that items being carried around typically weigh less than 100 kg, robots much smaller than the MiR (see above) may be used. Specialized equipment may be mounted on robots, allowing them to assist with surgical procedures. Overall, their place in the medical industry is to provide a more reliable source of customer care while reducing human error. [ 5 ]
The first instances of automation in labs possessed limited capabilities and relied on simple mechanical principles – often resembling the assembly line factory robots they had been based on. These early mobile robots primarily focused on liquid handling. And despite their rudimentary nature, they marked a significant departure from traditional methodologies, laying the groundwork for future efficiency and standardization. [ 6 ]
In the scientific world, there is a large number of applications for mobile robots. Their ability to perform experiments and exploration without putting human lives in danger makes them an important asset. Unlike humans, robots do not require life support systems to function. In space travel, robots are performing science on planets and asteroids because sending humans is far more taxing on resources and money. The same is true in the oceanography domain. In fact, several of the same robotic systems are designed to perform their science under both conditions - space and underwater. In nuclear power plants, robots can service electronics and mechanical systems which prevents human exposure to large amounts of radiation. [ 5 ]
For applications like painting and de-painting aircraft, two fixed robots are inadequate because not all parts of the aircraft can be reached. Adding more fixed robots would complete the task, but the cost is prohibitive. If mobile robots are used, one or two may be enough to service the entire aircraft because they can move to whatever area needs work. Mobile robots need to be truly autonomous to be useful in manufacturing. Erik Nieves said, “Mobility moves robots from being machines to production partners” Rather than bringing work to the robot, the robot should be smart enough to go to where the work is. [ 5 ]
Automated aircraft inspection systems have the potential to make aircraft maintenance safer and more reliable. [ 7 ] Various solutions are currently developed: a collaborative mobile robot named Air-Cobot , [ 8 ] [ 9 ] [ 10 ] and autonomous drones from Donecle or EasyJet . [ 11 ] [ 12 ]
For maintenance of pipelines which are buried underground, mobile robots can travel through the pipeline performing inspection and maintenance operations, replacing other techniques, some of which could only otherwise be done by unearthing the pipeline. CISBOT (cast-iron sealing robot) a cast iron pipe repair robot that seals the joints in natural gas pipelines from the inside. [ 13 ]
Mobile Industrial Robots (MiR)
The Autonomous Mobile Robots (AMRs) from MiR are designed to optimize productivity in logistics and manufacturing operations.
Meant for material transport in industrial centers: [ 14 ] | https://en.wikipedia.org/wiki/Mobile_industrial_robots |
A mobile laboratory is a laboratory that is either fully housed within or transported by a vehicle such as a converted bus, RV , or tractor-trailer . [ 1 ] [ 2 ] Such vehicles can serve a variety of functions, including:
A novel use of the mobile laboratory is in science education. In some cases, the mobile laboratory travels to schools, museums, and other community organizations, providing the schools with educational resources which they otherwise lack. The mobile laboratory coalition is a loose partnership of groups that provide such services. [ 3 ] In other cases, students must also travel to the mobile lab, such as when the lab takes the form of a boat or a train. [ 4 ] Mobile laboratories have recently been gaining favor from the National Institutes of Health , in the form of the particular mobile laboratories such as the Biobus located in New York and Georgia State University's Bio-Bus Program located in Atlanta, GA [ 5 ] and the Boston University MobileLab, as a way to develop knowledge and understanding regarding biotechnology and medicine amongst the United States population. [ 6 ]
The practice of mobile teaching labs exists outside the USA as well with examples, in the UK and in African countries. [ 7 ] The UK Institute of Physics is touring secondary schools with their Lab in a Lorry. This is a large articulated truck with three small laboratories. In these, pupils can learn about the use of Physics in Medicine, and do hands-on experiments with light and sound using good physics lab equipment. These are guided by local volunteers and an IoP scientist. Volunteers usually have an interest in general science, or come from a science background. The project has the backing of the British Science Association , the STEMNET Ambassadors Scheme, and sponsors such as EDF Energy . | https://en.wikipedia.org/wiki/Mobile_laboratory |
Mobile local search is a technology that lets people search for local things using mobile equipment such as mobile phones , PDAs , and other mobile devices. Mobile local search satisfies the need to offer a mobile subscriber spontaneous access to near-position services and information such as businesses, products, events, restaurant, movie theatre or other local information. [ 1 ] Mobile local search is the search and discovery of persons, places, and things within an identifiable space defined by distinct parameters. These parameters are evolving. Today they include social networks, individuals, cities, neighborhoods, landmarks, and actions that are relevant to the searcher's past, current, and future location. These parameters provide structure to vertically deep and horizontally broad data categories that can stand-alone or are combined to comprise searchable directories. [ 1 ]
Mobile local search is usually based on organized directories accessed through specialized search tools, rather than the web, although mobile local search often provides links to mobile ( WAP ) web sites. It is also an application of a location-based service .
Mobile local search involves in some cases GPS tracking , which, without prior consent, may cause privacy concerns. Furthermore, recent surveys expect merely 10% of mobile devices worldwide to be equipped with GPS chips in 2011.
Alternatively, mobile local search can also be done without mobile operators and GPS systems involved. This is possible through access to the SS7 protocol, which mobile operators have. However, having access via the mobile operator is very hard since the mobile operators sell it at a premium rate, if at all.
Although GPS-enabled devices are not prevalent yet, industry experts show that consumers are demanding mobile local search now, with an expected growth of 91% from 2007 to 2011. As a consequence, there is a gap in this opportunity that can be cleverly addressed by mobile operators and service providers with access to the SS7 layer.
Mobile local search may be screen-based using the keypad and display on the mobile device, or voice-based using spoken commands that are interpreted by a speech recognition application.
Screen-based search using the keypad to enter search terms into a form on the mobile screen is the most common access method today. It has the advantages of working in a noisy environment and avoiding speech interpretation problems. But the user has to enter search terms using a small keypad typical of most mobile devices, with results displayed on a small screen. Screen-based search may be awkward for people with coordination or vision handicaps.
Screen-based search may be supported by a specialized application such as where.com running on the handset, by an SMS short code, or by a WAP or XHTML-MP website page on a remote server displayed by the handset browser. Although most search tools today are based on handset software, the trend seems to be towards web-based services.
Also, when the consumer receives a reply to his search request, the most common way of delivery is via SMS .
Voice-based search is becoming viable due to advances in speech recognition technology. It is useful for people who have difficulty using the small keypad, or who need to get information while driving. Spoken prompts guide the users through the local directory to find an entry. The service may include fallback to a live operator if the speech technology has difficulty understanding what they are looking for, or a 'silent agent' may assist the speech recognition software.
Results may be spoken and/or delivered to the handset in SMS or MMS format, where they may be stored for future reference.
Most often, voice-based search uses the voice channel to deliver the caller's utterance to a server-based search application. In some cases, a small application on the mobile device undertakes the first part of speech recognition, breaking down the utterance into a series of elementary components or ' phones ', and then sending the phones over the data channel to a server application.
Multimedia-based search will be prevalent as a hybrid form of both "voice-based" and "screen-based" search that will establish a time-memory tradeoff in the implementation process of fast-evolving mobile equipment.
Mobile search content may include more location-based and more street-smart information on businesses, products, services, events, human relations and other local specifics, which require immediacy and spontaneity. Besides, the location-based content may be formulated by accumulative data mining on consumer behaviors and whereabouts, which may trigger privacy concerns, commercial come-ons and, if necessary, some legislative justifications.
A search for businesses is the mobile equivalent of the printed Yellow Pages, but the search may focus on a small geographical area. For example, the caller may be looking for a nearby pharmacy or restaurant, or may want a local pizza delivery . The more advanced local search tools will vary the search radius depending on the type of business and the density of this type of business in the local area. For example, a caller looking for a coffee shop will probably want one within walking distance. If they are looking for a home furniture store they will expect to travel further. If they want a taxi, distance is not important: the taxi will come to them.
A search for products is more specific than a search for businesses. The user is looking for a particular product and wants to find a local business that stocks this product.
A full-function mobile local search service will go much further, particularly as smartphone penetration increases. For example, mobile users may want to find where a particular movie is playing, what restaurants are near the cinema, read reviews about those restaurants, and book reservations or buy movie tickets. They may want to hear about traffic conditions, the score from the local football game, the winning lottery number or where to go to vote.
As opposed to Web search, mobile local search requires more immediacy and street-smart knowledge and information, local events and driving directions. The technical difference from web-based search is that, whether using the keypad or voice commands, the caller has limited 'bandwidth'. They do not want to hear or scroll through long lists of results. They want to "quickly and unobtrusively" zero in on the type of local information they are looking for, due to privacy, safety and time pressure.
Some of the advancements by the major portals in Internet search, such as Google's famous page-ranking scheme, do not apply in the wireless world since people are not searching for Web sites as much as answers to specific questions. 2006 showed a significant movement to the question-answer model. In this model answers are sent in reply to directory service queries similar to the nature of conventional 411 operators. AskMeNow , Ask.com and Bing.com all made efforts in this regard.
Mobile local search services are usually provided today by mobile carriers, directory enquiry providers, mobile messaging operators or Yellow Pages publishers. Behind these outlets, there is a growing network of agencies, distributors and software providers, some of whom are now starting to offer service direct to the public. Search giants, like Yahoo and Google, and big web publishers, such as Amazon.con and eBay have already embarked on this potentially lucrative market segment.
The services are provided through a caller-pays, advertiser-pays or hybrid business model.
In a caller-pays model, as with voice-based directory enquiry services, the caller pays each time they access the service. Caller-pays voice-based local mobile search services are common outside North America, but have been slow to emerge in the USA due to regulatory restrictions.
In an advertiser-pays model, standard for screen-based search and starting to emerge with voice-based 'Free DA' services in North America, businesses pay to be placed early in the list of results, or pay each time a caller chooses to connect through.
In hybrid models, advertising revenue lets the service provider offer reduced rates.
As with TV, magazines and other media, mobile local search services will most likely continue to be offered under all three models, but the hybrid model may predominate. That is, callers will probably accept a limited amount of advertising (which they may actually find useful) in exchange for reduced prices, but may be less willing to use a free service where they are bombarded with advertising.
The value to an advertiser will vary depending on their type of business, and may range from a dollar or less for a taxi or sandwich shop to well over ten dollars for a real-estate broker, attorney or debt consolidation service. Consultants forecast that the global industry will grow to over US$1 billion by 2010.
The most direct way to find more about what is happening in the MoLo space is to check out the websites of the MoLo service providers and see what they are offering. There are many of them. Almost all mobile carriers have mobile local search offerings, including Verizon Wireless , AT&T , Vodafone , T-Mobile , Sprint Nextel , Orange SA and so on.
Many Directory Assistance providers also offer mobile local search, including free DA providers Jingle Networks and 1-800-San-Diego in the US, 118 118 , Yell Group , Pages Jaunes, Seat Pagine Gialle , Eniro etc. in Europe, and many others. One of the more fully functional services is provided by Contact Center Americas in Colombia .
The Yellow Pages Group in Canada provides one of the first voice-enabled local search services. | https://en.wikipedia.org/wiki/Mobile_local_search |
Mobile marketing research is a method of data collection using the functions of mobile devices, like mobile phones, smartphones, and PDAs . With increasing members of the public having access to personal mobile devices in the 21st century, mobile marketing research developed as a way to utilize mobile communication for research purposes. [ 1 ]
Due to trends towards digitization at the turn of the 21st century, the marketing research industry found increasing difficulty reaching respondents via traditional media , making it harder for marketing researchers to make assumptions about their behavior . Researchers adapted their approaches alongside these changes. [ 2 ]
In the 21st century, mobile device use is common in most countries. [ 3 ] Researchers noticed this trend in the early 2000s and began adapting their marketing research approach, responding to predictions that mobile devices will become the most often used instrument to connect to the internet by the year 2020. [ 4 ]
A Pew Research’s Internet & American Life study in January 2014, 58% of adults in the US had a smartphone, [ 5 ] up from 56% in May 2013. In other parts of the world, like Central and Latin America, many people never had a PC, but they now have a smartphone. For instance, in Chile, more than 85% of the participants of an online panel had a smartphone in 2014, whereas only around 60% had a desktop. [ 6 ]
Some marketing methods include conducting surveys via mobile phones, in part to reach a younger audience. [ 7 ] [ 8 ] Although, generally, researchers found that the proportion which prefers to answer through smartphones is significant across many countries. [ 9 ]
According to Maxl, four different kinds of methods are distinguished which can be used as required. These are listed in the following figure.
Push studies without contexts (A) are conducted independently from time and location. This can be CATI - or CACI studies as well as surveys by SMS or MMS. In cases of these research methods, the feedback impulse actively comes from the researcher.
With pertinent. push studies (B) the researcher prompts the respondent to give appropriate feedback once it is recognized that he/she is located in a particular environment or is in a certain situation. [ 11 ] Pull studies are characterized that participants call in the questionnaire themselves. In many cases, short notes draw attention to a survey or an evaluation. Such communications may be placed in certain contexts (C) (e.g. on receipts, advertisements, or product packaging) to encourage participation. Non-context-sensitive pull studies (D) are not relevant for marketing research since they provide only general feedback, which has no relation to a fixed object of research. Therefore, they are hardly controlled and evaluated. [ 12 ]
On the technical level, there are three different possibilities of data collection. The Short Message Service (SMS) outlines one possibility, which can be used as a basis to conduct interviews. This is very suitable for ad hoc surveys if particular key questions have to be answered. For Java applications, the participants receive a link to a WAP page where an application is to be downloaded. The survey software is immediately installed on the mobile phone and the survey can be filled out straight away.
Furthermore, surveys can be accessed via the mobile internet . The webpage is also called in via WAP push . Questionnaires are created and designed in different formats. This allows disruption to complete the questionnaire to further process on a different technical device with internet access. [ 13 ]
A concern about mobile marketing research is the representation sampling. Members of the population who don’t own a mobile phone are not part of sampling. Mobile phone users have to be able to be reached as well as to be willing to take part in the survey. Equally important is to also know the number of people who use the SMS service and how many of these people own a web-enabled phone. Only if all these aspects are noticed, a conclusion regarding the sampling can be drawn. [ 14 ] For these reasons, mobile surveys alone does not meet standards of statistical representability.
Data acquisition through mobile phones holds more difficulties. On the one hand, there are high costs for incentives and intensive recruitment by the institutes. On the other hand, the participants of the survey have to pay the costs for internet usage via mobile phone. However, more and more respondents do not pay the internet access based on the time spent on the Internet and more and more places propose free Wi-Fi, making this issue less and less relevant for respondents. Additionally, there are also technical difficulties that may occur. The high number of different and not-compatible software or the low transmission rate of data are just a few to name. To improve the respondents' experience in answering web surveys on mobile devices, optimizing the layout of the survey for smaller screens is crucial: non-optimized layouts lead to lower data quality. [ 15 ] Restrictions concerning the reveal and passing on of mobile phone numbers (because of data protection and the lack of Anonymity ) are setting limits to the research in this field of study, too. [ 16 ]
Statistical methods in mobile market research profit from the fact that they do not depend on place or time. [ 17 ] This means that surveys via mobile phone can be done anywhere and at any time and are therefore much more advantageous compared to surveys via landline phones. Considering that a high number of participants of the main target groups cannot be reached at home at most hours of the day, [ 18 ] the chance to get hold of them by mobile phone is much higher.
Especially concerning to people under the age of 25 as well as business people, who are often on the way and cannot get hold of easily, the chances of the mobile market research are promising. As most people always carry their mobile phones with them, an immediate transmission of personal impressions of current events is possible at any time. [ 16 ] Thus, the so-called ‘magic moment’ can be captured, which is often very helpful. Surveys concerning product placement and efficiency of sales promotion measures at the point of sale turned out to be perfectly realizable this way. Looking at the topic “Access possibilities to WAP-Surveys” by mobile phone, as well as at the topic “Getting hold of potential participants”, there are some developments that should be named. The trend towards the increasing distribution of web-enabled mobile phones, and the improved representativity that comes along with it, does continue from 2007 to 2008, Nielsen Mobile noticed an increase in mobile internet usage. [ 19 ] With decreasing costs and improving technology, a further upward tendency can be expected. In addition, mobile internet usage increases with the rapidly developing distribution of smartphones. According to IM (Mediawork Initiative), already in 2013 more people will log in with their smartphones, than with a PC. Mobile statistics show a high and very fast response rate. As a result of the independence from time and place, answers can be submitted immediately. This also means that results can almost be transmitted in real-time. A study from Globalpark shows that approximately 35% of the participants answered a mobile survey within 2 hours. [ 20 ] Through the novelty of the form of the survey and its playful design, mobile research has a motivating effect on the participants. This applies especially to young, technologically interested male persons. iPhone users are also considered to be very communicative. As the devices are easy to handle, the users are more likely and more motivated to take part in surveys. [ 21 ] A study examining how to best reach mobile respondents published in the Journal of Social Science Computer Review underlines the importance of social factors. Especially their subjective belief of how they are seen by significant others, or their intention of how they would like to be seen by significant others seem to play a major role in their mobile phone behavior. [ 8 ] | https://en.wikipedia.org/wiki/Mobile_marketing_research |
Mobile media has been defined as: "a personal, interactive, internet-enabled and user-controlled portable platform that provides for the exchange of and sharing of personal and non-personal information among users who are inter-connected." [ 1 ] The notion of making media mobile can be traced back to the “first time someone thought to write on a tablet that could be lifted and hauled – rather than on a cave wall, a cliff face, a monument that usually was stuck in place, more or less forever”. [ 2 ] In his book Cellphone , Paul Levinson refers to mobile media as “the media-in-motion business.” [ 2 ] Since their incarnation, mobile phones as a means of communication have been a focus of great fascination as well as debate. [ 3 ] In the book, Studying Mobile Media: Cultural Technologies, Mobile Communication, and the iPhone , Gerard Goggin notes how the ability of portable voice communication to provide ceaseless contact complicates the relationship between the public and private spheres of society. [ 3 ] Lee Humphreys' explains in her book that now, "more people in the world today have a mobile phone than have an Internet connection". [ 4 ]
The development of the portable telephone can be traced back to its use by the military in the late nineteenth-century. [ 5 ] By the 1930s, police cars in several major U.S. cities were equipped with one-way mobile radios. [ 5 ] In 1931, the Galvin Manufacturing Corporation designed a mass market two-way radio. This radio was named Motorola , which also became the new name for the company in 1947. [ 5 ] In 1943, Motorola developed the first portable radiotelephone, the Walkie-Talkie , for use by the American forces during World War II. [ 5 ] After the war, two-way radio technology was developed for civilian use. In 1946, AT&T and Southwestern Bell made available the first commercial mobile radiotelephone. This service allowed calls to be made from a fixed phone to a mobile one. [ 5 ]
"Many scholars have noted and praised the mobility of reading brought about the emergence of the book and the advent of early modern print culture". [ 6 ] Along with the book , the transistor radio , the Walkman , and the Kodak camera are also bearers of portable information and early examples of mobile media consumption. [ 3 ] [ 2 ] With the rise of the internet, many forms of media can be considered mobile. Forms of mobile media, such as podcasts and even social networking services , are some of the few that can be downloaded, used or even streamed over the internet. According to Jordan Frith and Didem Ozkul in their book, Mobile Media Beyond Mobile Phones, they believe that mobile media has moved beyond our past knowledge of mobile media. "With this issue, we realized that not only has our understanding of mobile media expanded beyond the mobile phone, but our thinking of the 'mobile in front of media has evolved". [ 7 ] From The Mobile Reader, Jason Farman and other authors describe this expansion of mobile media. "The cultural shift that happened in conjunction with the printing press can be mapped onto our uses of mobile media (especially location-aware technologies): the cultural imaginaries of space became simultaneously about experiencing the expansion of space, an increase in speed of transmission, and a transformed view of the local". [ 6 ]
For a time, mobile phones and PDAs ( Personal Digital Assistants ) were the primary source of portable media from which we could obtain information and communicate with one another. More recently, the smartphone has rendered the PDA obsolete by combining many features of the cell phone with those of the PDA. [ 8 ] In 2011, the growth of new mobile media as a true force in society was marked by smartphone sales outpacing personal computer sales. [ 9 ] With this non-stop consumption of new and improved smartphones, theorists such as Marsha Berry and Max Schleser explain that these change the way we can do things in life. "With the rise of smartphones in 2007 and proliferation of application through Apple's App Store and Android Market in the following year, how citizen users and creative professionals represent, experience and share the everyday is changing". [ 10 ]
While mobile phone independent technologies and functions may be new and innovative (in relation to changes and improvements in media capabilities in respect to their function what they can do when and where and what they look like, in regard to their size and shape) the need and desire to access and use media devices regardless of where we are in the world has been around for centuries. Indeed, Paul Levinson remarks, in regard to telephonic communication, that it was “intelligence and inventiveness" applied to our need to communicate regardless of where we may be, led logically and eventually to telephones that we carry in our pockets”. [ 2 ] Levinson credits the printing press for disseminating information to a mass audience, the reduction in size and portability of the camera for allowing people to capture what they saw regardless of their location, and the Internet for providing on-demand information. [ 2 ]
Smartphones have altered the very structure of society. [ 3 ] "With this issue, we realized that not only has our understanding of mobile media expanded beyond the mobile phone, but our thinking of the 'mobile' in front of media has evolved". [ 7 ] The ability of smartphones to transcend certain boundaries of times and space has revolutionized the nature of communication, allowing it to be both synchronous and asynchronous. [ 11 ] These devices and their corresponding media technologies, such as cloud-based technologies, play an increasingly important role in the everyday lives of millions of people worldwide. [ 5 ] | https://en.wikipedia.org/wiki/Mobile_media |
Membrane systems have been inspired from the structure and the functioning of the living cells. They were introduced and studied by Gh.Paun under the name of P systems [24] ; some applications of the membrane systems are presented in [15] . Membrane systems are essentially models of distributed, parallel and nondeterministic systems. Here we motivate and present the mobile membranes . Mobile membranes represent a variant of membrane systems inspired by the biological movements given by endocytosis and exocytosis. They have the expressive power of both P systems and process calculi with mobility such as mobile ambients [11] and brane calculi [10] . Computations with mobile membranes can be defined over specific configurations (like process calculi), while they represent also a rule-based formalism (like P systems).
The model is characterized by two essential features:
The computations are performed in the following way: starting from an initial structure, the system evolves by applying the rules in a nondeterministic and maximally parallel manner. A rule is applicable when all the involved objects and membranes appearing in its left hand side are available. The maximally parallel way of using the rules means that in each step a maximal multiset of rules is applied, namely a multiset of rules such that no further rule can be added to the set. A halting configuration is reached when no rule is applicable. The result is represented by the number of objects associated to a specified membrane.
Mobile membranes represents a formalism which describes the movement of membranes inside a spatial structure by applying rules from a given set of rules R {\displaystyle R} . The mobility is provided by consumption and rewriting of objects. In terms of computation, the work is performed using membrane configurations. A the set M {\displaystyle {\mathcal {M}}} of membrane configurations (ranged by M , N , … {\displaystyle M,N,\dots } ) os defined by using the free monoid V ∗ {\displaystyle V^{*}} (ranged over by u , v , … {\displaystyle u,v,\dots } ) generated by a finite alphabet V {\displaystyle V} (ranged over by a , b , … {\displaystyle a,b,\dots } ):
M ::= u ∣ [ M ] u ∣ M ‖ M {\displaystyle \qquad \qquad M::=u\;\mid \;[\;M\;]_{u}\;\mid \;M\|M}
If M {\displaystyle M} and N {\displaystyle N} are two membrane configurations, M {\displaystyle M} reduces to N {\displaystyle N} (denoted by M → N {\displaystyle M\rightarrow N} ) if there exists a rule in the set of rules R {\displaystyle R} applicable to the configuration M {\displaystyle M} such that the new configuration N {\displaystyle N} is obtained. When applying the rules of R {\displaystyle R} , also the following inference rules are used:
( C o m p 1 ) M → M ′ M ‖ N → M ′ ‖ N ; ( C o m p 2 ) M → M ′ N → N ′ M ‖ N → M ′ ‖ N ′ {\displaystyle \qquad {\it {(Comp1)}}\quad {\frac {\displaystyle M\ \rightarrow \ M'}{\displaystyle M\|N\ \rightarrow \ M'\|N}};\qquad \qquad {\it {(Comp2)}}\quad {\frac {\displaystyle M\ \rightarrow \ M'\qquad \displaystyle N\ \rightarrow \ N'}{\displaystyle M\|N\ \rightarrow \ M'\|N'}}} ;
( M e m ) M → M ′ [ M ] u → [ M ′ ] u ; ( S t r u c ) M ≡ m e m M ′ M ′ → N ′ N ′ ≡ m e m N M → N {\displaystyle \qquad {\it {(Mem)}}\ {\frac {\displaystyle M\ \rightarrow \ M'}{\displaystyle [\;M\;]_{u}\rightarrow [\;M'\;]_{u}}};\qquad \qquad {\it {(Struc)}}\ {\frac {\displaystyle M\equiv _{mem}M'\quad M'\rightarrow N'\quad \ N'\equiv _{mem}N}{\displaystyle M\rightarrow N}}}
When describing a computation of a systems of mobile membranes, an initial configuration M 0 {\displaystyle M_{0}} and a set of rules R {\displaystyle R} are given. The rules used in this paper describe an o b j e c t e v o l u t i o n {\displaystyle {\it {object~evolution}}} (object rewriting), e n d o c y t o s i s {\displaystyle {\it {endocytosis}}} movement (moving an elementary membrane inside a neighbouring membrane), e x o c y t o s i s {\displaystyle {\it {exocytosis}}} movement (moving an elementary membrane outside the membrane where it is placed), p i n o c y t o s i s {\displaystyle {\it {pinocytosis}}} (engulfing zero external membranes), and p h a g o c y t o s i s {\displaystyle {\it {phagocytosis}}} (engulfing just one external elementary membrane).
A specific feature of the mobile membranes is that this new rule-based model is appropriate to prove computability results in terms of Turing machines rather by reduction to the lambda calculus as in the case of process calculi with mobility. In this section are defined four classes of membranes inspired from biological facts, and it is shown that their computational power depends on the initial configuration and on the set of rules used.
The systems of simple mobile membranes (SM) are defined over the set of configurations M {\displaystyle {\mathcal {M}}} , and evolve using endocytosis and exocytosis rules, namely moving a membrane inside a neighbouring membrane, or outside the membrane where it is placed, respectively. The evolution from a configuration to another is made using rules from the set of rules R {\displaystyle R} defined as follows:
[ [ a ‖ M ] m ‖ N ] k → [ [ v ‖ M ] m ‖ N ] k {\displaystyle [[a\;\|\;M]_{m}\;\|\;N]_{k}\rightarrow [[v\;\|\;M]_{m}\;\|\;N]_{k}} , for k , m ∈ N {\displaystyle k,m\in {\mathcal {N}}} , a ∈ V {\displaystyle a\in V} , v ∈ V ∗ {\displaystyle v\in V^{*}} ; (local object evolution)
[ a ‖ M ] m → [ v ‖ M ] m {\displaystyle [a\;\|\;M]_{m}\rightarrow [v\;\|\;M]_{m}} , for m ∈ N {\displaystyle m\in {\mathcal {N}}} , a ∈ V {\displaystyle a\in V} , v ∈ V ∗ {\displaystyle v\in V^{*}} ; (global object evolution)
[ a ‖ M 1 ] h ‖ [ M ] m → [ [ b ‖ M 1 ] h ‖ M ] m {\displaystyle [a\;\|\;M_{1}]_{h}\;\|\;[M]_{m}\rightarrow [[b\;\|\;M_{1}]_{h}\;\|\;M]_{m}} , for h , m ∈ N {\displaystyle h,m\in {\mathcal {N}}} , a , b ∈ V {\displaystyle a,b\in V} ; (endocytosis)
[ [ a ‖ M 1 ] h ‖ M ] m → [ b ‖ M 1 ] h ‖ [ M ] m {\displaystyle [[a\;\|\;M_{1}]_{h}\;\|\;M]_{m}\rightarrow [b\;\|\;M_{1}]_{h}\;\|\;[M]_{m}} , for h , m ∈ N {\displaystyle h,m\in {\mathcal {N}}} , a , b ∈ V {\displaystyle a,b\in V} ; (exocytosis)
where M 1 {\displaystyle M_{1}} is a multiset, and M {\displaystyle M} , N {\displaystyle N} are arbitrary membrane configurations.
Turing completeness can be obtained by using nine membranes together with the operations of endocytosis and exocytosis [21] . In [17] it is proven that four mobile membranes are enough to get the power of a Turing machine, while in [4] the number of membranes is decreased to three.
S M ( l e v o l , e n d o , e x o ) {\displaystyle SM(levol,endo,exo)} denotes the family of all sets generated inside a given membrane by simple mobile membranes using local evolution rules ( l e v o l {\displaystyle levol} ), endocytosis and exocytosis rules. Whenever global evolution rules ( g e v o l {\displaystyle gevol} ) are used, the parameter l e v o l {\displaystyle levol} is replaced by g e v o l {\displaystyle gevol} . If a type of rules is not used, then its name is omitted from the list. The number of membranes does not increase during the computation, but it can decrease by sending membranes out of the system. In this case, the S M n ( g e v o l , e n d o , e x o ) {\displaystyle SM_{n}(gevol,endo,exo)} denotes the family of sets of vectors of natural numbers computed by using at most $n$ membranes. R E {\displaystyle RE} denoted the family of Turing computable sets of vectors generated by arbitrary grammars.
It is proved in [17] that S M 4 ( g e v o l , e n d o , e x o ) = R E {\displaystyle SM_{4}(gevol,endo,exo)=RE} . The research line initiated in membrane computing is to find membrane systems with a minimal set of ingredients which are powerful enough to achieve the full power of Turing machines. In this way previous result presented in [17] are improved by decreasing the number of membranes to three.
Moreover, this is achieved by using local evolution rules instead of global evolution rules.
Theorem. S M 3 ( l e v o l , e n d o , e x o ) = R E {\displaystyle SM_{3}(levol,endo,exo)=RE} .
The proof of this result uses a similar technique to that used in [4] .
The systems of enhanced mobile membranes are a variant of simple membrane systems proposed in [1] for
describing some biological mechanisms of the immune system. The operations governing the mobility of the systems of enhanced mobile
membranes are endocytosis (endo), exocytosis (exo), forced endocytosis (fendo), forced exocytosis (fexo).The evolution from a
configuration to another is made using rules from the set of rules R {\displaystyle R} defined as follows:
[ u ‖ v ‖ M ] h ‖ [ v ′ ‖ N ] m → [ w ′ ‖ [ w ] h ] m {\displaystyle [u\;\|\;v\;\|\;M]_{h}\;\|\;[v'\;\|\;N]_{m}\!\rightarrow \![w'\;\|\;[w]_{h}]_{m}} for h , m ∈ N ; u ∈ V + , v , v ′ , w , w ′ ∈ V ∗ {\displaystyle h,m\!\in \!{\mathcal {N}};u\!\in \!V^{+},v,v',w,w'\!\in \!V^{*}} ; (endocytosis)
[ v ′ ‖ N ‖ [ u ‖ v ‖ M ] h ] m → [ w ‖ M ] h ‖ [ w ′ ‖ N ] m {\displaystyle [v'\;\|\;N\;\|\;[u\;\|\;v\;\|\;M]_{h}]_{m}\!\rightarrow \![w\;\|\;M]_{h}\;\|\;[w'\;\|\;N]_{m}} , for h , m ∈ N ; u ∈ V + , v , v ′ , w , w ′ ∈ V ∗ {\displaystyle h,m\!\in \!\!{\mathcal {N}};u\in V^{+},v,v',w,w'\in V^{*}} ; (exocytosis)
[ v ‖ M ] h ‖ [ u ‖ v ′ ‖ N ] m → [ [ w ‖ M ] h ‖ w ′ ‖ N ] m {\displaystyle [v\;\|\;M]_{h}\;\|\;[u\;\|\;v'\;\|\;N]_{m}\!\!\rightarrow \!\![[w\;\|\;M]_{h}\;\|\;w'\;\|\;N]_{m}} for h , m ∈ N {\displaystyle h,m\!\!\in \!\!{\mathcal {N}}} , u ∈ V + , v , v ′ , w , w ′ ∈ V ∗ {\displaystyle u\!\in \!V^{+},v,v'\!,w,w'\!\in \!V^{*}} ; (enhanced endocytosis)
[ u ‖ v ′ ‖ [ v ‖ M ] h ‖ N ] m → [ w ‖ M ] h ‖ [ w ′ ‖ N ] m {\displaystyle [u\;\|\;v'\;\|\;[v\;\|\;M]_{h}\;\|\;N]_{m}\!\!\rightarrow \!\![w\;\|\;M]_{h}\;\|\;[w'\;\|\;N]_{m}} for h , m ∈ N , u ∈ V + , v , v ′ , w , w ′ ∈ V ∗ {\displaystyle h,m\!\in \!{\mathcal {N}},u\in V^{+},v,v',w,w'\in V^{*}} ; (enhanced exocytosis)
\noindent where M {\displaystyle M} is a multiset and N {\displaystyle N} is an arbitrary membrane configuration.
The computational power of the systems of enhanced mobile membranes using these four operations was studied in [20] where it is proved that twelve membranes can provide the computational universality, while in [4] the result is improved by reducing the number of membranes to nine. It is worth to note that unlike the previous results, the rewriting of object by means of context-free rules is not used in any of the results (and their proofs).
The interplay between these four operations is quite powerful, and the computational power of a Turing machine is obtained using twelve membranes without using the context-free evolution of objects [20] .
The family of all sets generated inside a given membrane by enhanced mobile membranes of degree at most n {\displaystyle n} using rules α ⊆ { e x o , e n d o , f e n d o , f e x o } {\displaystyle \alpha \subseteq \{exo,endo,fendo,fexo\}} , is denoted by E M n ( α ) {\displaystyle EM_{n}(\alpha )} .
Theorem. E M 3 ( e n d o , e x o ) = E M 3 ( f e n d o , f e x o ) {\displaystyle EM_{3}(endo,exo)=EM_{3}(fendo,fexo)} .
Theorem. E M 12 ( e n d o , e x o , f e n d o , f e x o ) = R E {\displaystyle EM_{12}(endo,exo,fendo,fexo)=RE} .
When proving the result of the previous theorem the authors have not used an optimal construction of a membrane system. In what follows it is proven that using the same types of rules ( endo , exo , fendo , fexo ) a membrane system can be constructed using only nine membranes instead of twelve membranes. If this is an optimal construction remains an open problem.
Theorem. E M 9 ( e n d o , e x o , f e n d o , f e x o ) = R E {\displaystyle EM_{9}(endo,exo,fendo,fexo)=RE} .
The proof is similar to that presented in [4] .
Following the approach presented in [3] , "systems of mutual mobile membranes" representing a variant of systems of simple mobile membranes in which the endocytosis and the exocytosis work whenever the involved membranes "agree" on the movement are defined; this agreement is described by using dual objects a {\displaystyle a} and a ¯ {\displaystyle {\overline {a}}} in the involved membranes. The operations governing the mobility of the systems of mutual mobile membranes are mutual endocytosis (mutual endo), and mutual exocytosis (mutual exo). The evolution from a configuration to another is made using rules from the set of rules R {\displaystyle R} defined as follows:
[ u ‖ v ‖ M ] h ‖ [ u ¯ ‖ v ′ ‖ N ] m → [ [ w ‖ M ] h ‖ w ′ ‖ N ] m {\displaystyle [u\;\|\;v\;\|\;M]_{h}\;\|\;[{\overline {u}}\;\|\;v'\;\|\;N]_{m}\rightarrow [\;[w\;\|\;M]_{h}\;\|\;w'\;\|\;N]_{m}} for h , m ∈ N , u , u ¯ ∈ V + , v , v ′ , w , w ′ ∈ V ∗ {\displaystyle h,m\in {\mathcal {N}},u,{\overline {u}}\in V^{+},v,v',w,w'\!\!\in V^{*}} ; (mutual endocytosis)
[ u ¯ ‖ v ′ ‖ N ‖ [ u ‖ v ‖ M ] h ] m → [ w ‖ M ] h ‖ [ w ′ ‖ N ] m {\displaystyle [{\overline {u}}\;\|\;v'\;\|\;N\;\|\;[u\;\|\;v\;\|\;M]_{h}]_{m}\rightarrow [w\;\|\;M]_{h}\;\|\;[w'\;\|\;N]_{m}} for h , m ∈ N , u , u ¯ ∈ V + , v , v ′ , w , w ′ ∈ V ∗ {\displaystyle h,m\in {\mathcal {N}},u,{\overline {u}}\in V^{+},v,v',w,w'\!\!\in V^{*}} ; (mutual exocytosis)
where M {\displaystyle M} is a multiset and N {\displaystyle N} is an arbitrary membrane configuration.
It is enough to consider the biologically inspired operations of mutual endocytosis and mutual exocytosis and three membranes to get the full computational power of a Turing machine [6] . Three also represents the minimum number of membranes in order to discuss properly about the movement provided by endocytosis and exocytosis: working with configurations corresponding to a system of two membranes moving inside a skin membrane.
The family of all sets generated inside a given membrane by mutual mobile membranes of degree n {\displaystyle n} using mutual endocytosis rules ( mendo ) and mutual exocytosis rules ( mexo ) is denoted by M M n ( m e n d o , m e x o ) {\displaystyle MM_{n}(mendo,mexo)} . Therefore, the result can be formulated as following.
Theorem. M M 3 ( m e n d o , m e x o ) = R E {\displaystyle MM_{3}(mendo,mexo)=RE} .
In systems of simple mobile membranes with local evolution rules and mobility rules it is known that systems of degree three have the same power as a Turing machine, while in systems of enhanced mobile membranes using only mobility rules the degree of systems having the same power as a Turing machine increases to nine. In each mobility rule from systems of simple and enhanced mobile membranes, in the left hand side of the rules only one object appears in the proofs. By using multisets instead of objects and synchronization by objects and co-objects, it is proved that it is enough to consider only systems of three mutual mobile membranes together with the operations of mutual endocytosis and mutual exocytosis to get the full computational power of a Turing machine.
The proof is done in a similar manner with the proof for the computational universality of the systems of enhanced mobile
membranes [20] .
Membrane systems [24] and brane calculus [10] start from the same observations; however, they are built having in mind different goals: membrane systems investigate formally the computational nature and power of various features of membranes, while the brane calculus is capable to give a faithful and intuitive representation of the biological reality. In [12] the initiators of these two formalisms describe the goals they had in mind: "While membrane computing is a branch of natural computing which tries to abstract computing models, in the Turing sense, from the structure and the functioning of the cell, making use especially of automata, language, and complexity theoretic tools, brane calculi pay more attention to the fidelity to the biological reality, have as a primary target systems biology, and use especially the framework of process~algebra."
In [2] are defined systems of mutual membranes with objects on surface, following the idea of adding objects on membrane and using the biologically inspired rules pino/exo/phago coming from [12,14,18,19] . Objects and co-objects are used in phago and exo rules in order to illustrate the fact that both involved membranes agree on the movement.
The evolution from a configuration to another is made using rules from the set of rules R {\displaystyle R} defined as follows:
[ M ] v ‖ a ‖ u → [ [ ] u ‖ x ‖ M ] v ‖ y {\displaystyle [M]_{v\;\|\;a\;\|\;u}\rightarrow [[~]_{u\;\|\;x}\;\|\;M]_{v\;\|\;y}} , for a ∈ V , u , v , x , y ∈ V ∗ , u x , v y ∈ V + {\displaystyle a\in V,u,v,x,y\in V^{*},ux,vy\in V^{+}} (pino)
[ [ M ] a ‖ u ‖ N ] a ¯ ‖ v → M ‖ [ N ] u ‖ v ‖ x {\displaystyle [[M]_{a\;\|\;u}\;\|\;N]_{{\overline {a}}\;\|\;v}\rightarrow M\;\|\;[N]_{u\;\|\;v\;\|\;x}} , for a , a ¯ ∈ V , u , v , x ∈ V ∗ , u v x ∈ V + {\displaystyle ,{\overline {a}}\in V,u,v,x\in V^{*},uvx\in V^{+}} (exo)
[ M 1 ] a ‖ u ‖ [ N ] a ¯ ‖ b ‖ v → [ [ [ M 1 ] u ‖ x ] b ‖ N ] v ‖ y {\displaystyle [M_{1}]_{a\;\|\;u}\;\|\;[N]_{{\overline {a}}\;\|\;b\;\|\;v}\rightarrow [[[M_{1}]_{u\;\|\;x}]_{b}\;\|\;N]_{v\;\|\;y}} , for a , a ¯ , b ∈ V , u , v , x , y ∈ V ∗ , u x , v y ∈ V + {\displaystyle a,{\overline {a}},b\!\in \!V,u,v,x,y\in V^{*},ux,vy\in V^{+}} (phago)
\noindent where M 1 {\displaystyle M_{1}} is a multiset and M {\displaystyle M} , N {\displaystyle N} are arbitrary membrane configurations.
The computational power of systems of mutual membranes with objects on surface controlled by pairs of rules is investigated:
pino/exo or phago/exo, proving that they are universal even using a small number of membranes. These cases were already investigated in [19] ; however better results are provided by improving the number of membranes. A summary of the results (existing and new ones) is given in what follows:
The multiplicity vector of the multiset from all membranes is considered as a result of the computation. Thus, the result of a halting computation consists of all the vectors describing the multiplicity of objects from all the membranes; a non-halting computation provides no output. The number of objects from the right-hand side of a rule is called its weight . The family of all sets generated by systems of mutual membranes with objects on surface using at any moment during a halting computation
at most n {\displaystyle n} membranes, and any of the rules r 1 , r 2 ∈ { p i n o , e x o , p h a g o } {\displaystyle r_{1},r_{2}\in \{pino,exo,phago\}} of weight at most r , s {\displaystyle r,s} respectively, is denoted by M M O S n ( r 1 ( r ) , r 2 ( s ) {\displaystyle MMOS_{n}(r_{1}(r),r_{2}(s)} ). When one of the parameters is not bounded, it is replaced it with a ∗ {\displaystyle *} .
It is proven in [19] that systems of eight membranes with objects on surface and using pino and exo operations of weight four and three are universal. The number of membranes can be reduced from eight to three. However, in order to do this is increased the weight of the pino and exo operations with one, namely from four and three to five and four. This means that in order to construct a universal system of mobile membranes with objects on surface by using pino and exo operations, one needs to decide either he wants to minimize the number of membranes, or the weights of the operations.
Theorem. M M O S m ( p i n o ( r ) , e x o ( s ) ) = R E {\displaystyle MMOS_{m}(pino(r),exo(s))=RE} , for all m ≥ 3 , r ≥ 5 , s ≥ 4 {\displaystyle m\geq 3,r\geq 5,s\geq 4} .
It is proven in [19] that systems of nine membranes with objects on surface and using phago and exo operations of weight four and three (or five and two) are universal. The number of membranes can be reduced from nine to four, but in order to do this the weight of the phago and exo operations are increased from four and three (or five and two) to six and three. When constructing a Turing complete system of mobile membranes with objects on surface by using phago and exo operations, the same problem appears as when using pino and exo operations: namely, to choose either minimizing the number of membranes, or the weights of the operations.
Theorem. M M O S m ( p h a g o ( r ) , e x o ( s ) ) = R E {\displaystyle MMOS_{m}(phago(r),exo(s))=RE} , for all m ≥ 4 , r ≥ 6 , s ≥ 3 {\displaystyle m\geq 4,r\geq 6,s\geq 3} .
In what follows it is shown that mobile membranes have at least the expressive power of mobile ambients and brane calculi by encoding mobile ambients and brane calculi in certain systems of mobile membranes.
The mobile membranes and the mobile ambients [11] have similar structures and common concepts. Both have a hierarchical structure representing locations, intend to describe mobility, and are used in describing various biological phenomena [10,15] . The mobile ambients are suitable to represent the movement of ambients through ambients and the communication which takes place inside the boundaries of ambients. Membrane systems are suitable to represent the evolution of objects and movement of objects and membranes through membranes. A comparing between these new models ( mobile ambients and mobile membranes) is provided, and an encoding the ambients into membranes. This embedding is essentially presented in [5] .
Safe ambients represent a variant of mobile ambients in which any movement of an ambient takes place only if both participants agree. The mobility is provided by the consumption of certain pairs of capabilities. The safe ambients differ from mobile ambients by the addition of co-actions: if in mobile ambients a movement is initiated only by the moving ambient and the target ambient has no control over it, in safe ambients both participants must agree by using a matching between action and co-action. A short description of pure safe ambients (SA) is given below; more information can be found in [22,23] . Given an infinite set of names N {\displaystyle {\mathcal {N}}} (ranged over by m , n , … {\displaystyle m,n,\dots } ), the set A {\displaystyle {\mathcal {A}}} of SA-processes (denoted by A , A ′ , B , B ′ , … {\displaystyle A,A',B,B',\dots } ) together with their capabilities (denoted by C , C ′ , … {\displaystyle C,C',\dots } ) are defined as follows:
C ::= i n n ∣ i n ¯ n ∣ o u t n ∣ o u t ¯ n ∣ o p e n n ∣ o p e n ¯ n {\displaystyle \qquad C::=in\ n\;\mid \;{\overline {in}}\ n\;\mid \;out\ n\;\mid \;{\overline {out}}\ n\;\mid \;open\ n\;\mid \;{\overline {open}}\ n}
A ::= 0 ∣ A ∣ B ∣ C . A ∣ n [ A ] {\displaystyle \qquad A::=0\quad \mid \quad A\;\mid \;B\quad \mid \quad C.A\quad \mid \quad n[\;A\;]}
Process 0 {\displaystyle 0} is an inactive mobile ambient. A movement C . A {\displaystyle C.\,A} is provided by the capability C {\displaystyle C} , followed by the execution of A {\displaystyle A} . An ambient n [ A ] {\displaystyle n[\;A\;]} represents a bounded place labelled by n {\displaystyle n} in which a SA-process A {\displaystyle A} is executed. A ∣ B {\displaystyle A\,\mid \,B} is a parallel composition of mobile ambients A {\displaystyle A} and B {\displaystyle B} . ( ν n ) A {\displaystyle (\nu n)A} creates a new unique name n {\displaystyle n} within the scope of A {\displaystyle A} . The structural congruence ≡ a m b {\displaystyle \equiv _{amb}} over ambients is the least congruence such that ( A , ∣ , 0 ) {\displaystyle ({\mathcal {A}},\mid ,0)} is a commutative monoid.
The operational semantics of pure ambient safe calculus are defined in terms of a reduction relation ⇒ a m b {\displaystyle \Rightarrow _{amb}} by the following axioms and rules.
Axioms:
( I n ) n [ i n m . A ∣ A ′ ] ∣ m [ i n ¯ m . B ∣ B ′ ] ⇒ a m b m [ n [ A ∣ A ′ ] ∣ B ∣ B ′ ] {\displaystyle (In)\quad n[\;in\ m.A\mid A'\;]\mid m[\;{\overline {in}}\ m.B\mid B'\;]\Rightarrow _{amb}m[\;n[\;A\mid A'\;]\mid B\mid B'\;]} ;
( O u t ) m [ n [ o u t m . A ∣ A ′ ] ∣ o u t ¯ m . B ∣ B ′ ] ⇒ a m b n [ A ∣ A ′ ] ∣ m [ B ∣ B ′ ] {\displaystyle (Out)\quad m[\;n[\;out\ m.A\mid A'\;]\mid {\overline {out}}\ m.B\mid B'\;]\Rightarrow _{amb}n[\;A\mid A'\;]\mid m[\;B\mid B'\;]} ;
( O p e n ) o p e n n . A ∣ n [ o p e n ¯ n . B ∣ B ′ ] ⇒ a m b A ∣ B ∣ B ′ {\displaystyle (Open)\quad open\ n.A\;\mid \;n[\;{\overline {open}}\ n.B\mid B'\;]\Rightarrow _{amb}A\;\mid \;B\;\mid \;B'} .
Rules:
( C o m p 1 ) A ⇒ a m b A ′ A ∣ B ⇒ a m b A ′ ∣ B ; ( C o m p 2 ) A ⇒ a m b A ′ B ⇒ a m b B ′ A ∣ B ⇒ a m b A ′ ∣ B ′ {\displaystyle (Comp1)\quad {\frac {\displaystyle A\Rightarrow _{amb}A'}{\displaystyle A\;\mid \;B\Rightarrow _{amb}A'\;\mid \;B}};\qquad \qquad \qquad \qquad (Comp2)\quad {\frac {\displaystyle A\Rightarrow _{amb}A'\quad \displaystyle B\Rightarrow _{amb}B'}{\displaystyle A\;\mid \;B\Rightarrow _{amb}A'\;\mid \;B'}}} ;
( A m b ) A ⇒ a m b A ′ n [ A ] ⇒ a m b n [ A ′ ] ; ( S t r u c ) A ≡ A ′ , A ′ ⇒ a m b B ′ , B ′ ≡ B A ⇒ a m b B {\displaystyle (Amb)\quad {\frac {\displaystyle A\Rightarrow _{amb}A'}{\displaystyle n[\;A\;]\Rightarrow _{amb}n[\;A'\;]}};\qquad \qquad \qquad \qquad (Struc)\quad {\frac {\displaystyle A\equiv A',\ A'\Rightarrow _{amb}B',\ B'\equiv B}{\displaystyle A\Rightarrow _{amb}B}}} .
⇒ a m b ∗ {\displaystyle \Rightarrow _{amb}^{*}} denotes a reflexive and transitive closure of the binary relation ⇒ a m b {\displaystyle \Rightarrow _{amb}} .
A translation from the set A {\displaystyle {\mathcal {A}}} of safe ambients to the set M {\displaystyle {\mathcal {M}}} of membrane configurations is given formally as follows:
Definition. A translation T : A → M {\displaystyle {\mathcal {T}}:{\mathcal {A}}\rightarrow {\mathcal {M}}} is given by T ( A ) = d l o c k T 1 ( A ) {\displaystyle {\mathcal {T}}(A)=dlock~{\mathcal {T}}_{1}(A)} , where T 1 : A → M {\displaystyle {\mathcal {T}}_{1}:{\mathcal {A}}\rightarrow {\mathcal {M}}} is
T 1 ( A ) = {\displaystyle \qquad {\mathcal {T}}_{1}(A)=} { c a p n ‖ [ ] c a p n if A = c a p n c a p n ‖ [ T 1 ( A 1 ) ] c a p n if A = c a p n . A 1 [ T 1 ( A 1 ) ] n if A = n [ A 1 ] [ ] n if A = n [ ] T 1 ( A 1 ) ‖ T 1 ( A 2 ) if A = A 1 ∣ A 2 λ if A = 0 {\displaystyle {\begin{cases}cap~n\;\|\;[~]_{cap~n}&{\mbox{if }}A=cap~n\\cap~n\;\|\;[\;{\mathcal {T}}_{1}(A_{1})\;]_{cap~n}&{\mbox{if }}A=cap~n.\,A_{1}\\\;[\;{\mathcal {T}}_{1}(A_{1})\;]_{n}&{\mbox{if }}A=n[\;A_{1}\;]\\\;[~]_{n}&{\mbox{if }}A=n[~]\\{\mathcal {T}}_{1}(A_{1})\;\|\;{\mathcal {T}}_{1}(A_{2})&{\mbox{if }}A=A_{1}\,\mid \,A_{2}\\\lambda &{\mbox{if }}A=0\end{cases}}}
An object d l o c k {\displaystyle dlock} is placed near the membrane structure to prevent the consumption of capability objects in a membrane system which
corresponds to a mobile ambient which cannot evolve further.
Proposition. Structurally congruent ambients are translated into structurally congruent membrane systems; moreover, structurally congruent translated membrane systems correspond to structurally congruent ambients: A ≡ a m b B {\displaystyle \qquad \qquad A\equiv _{amb}B} iff T ( A ) ≡ m e m T ( B ) {\displaystyle {\mathcal {T}}(A)\equiv _{mem}{\mathcal {T}}(B)} .
Considering two membrane systems M {\displaystyle M} and N {\displaystyle N} with only one object d l o c k {\displaystyle dlock} , M ⇒ m e m N {\displaystyle M\Rightarrow _{mem}N} if there is a sequence of rules r 1 , … , r i {\displaystyle r_{1},\ldots ,r_{i}} , from the particular set of rules used in [7] , such that applying the rules from this set to the membrane configuration M {\displaystyle M} it is obtained the membrane configuration N {\displaystyle N} .
Proposition. If A {\displaystyle A} and B {\displaystyle B} are two ambients and M {\displaystyle M} is a membrane system such that A ⇒ a m b B {\displaystyle A\Rightarrow _{amb}B} and M = T ( A ) {\displaystyle M={\mathcal {T}}(A)} , then there exists a set of rules applicable to M {\displaystyle M} such that M ⇒ m e m N {\displaystyle M\Rightarrow _{mem}N} , and N = T ( B ) {\displaystyle N={\mathcal {T}}(B)} .
Proposition. Let M {\displaystyle M} and N {\displaystyle N} be two membrane systems with only one d l o c k {\displaystyle dlock} object, and an ambient A {\displaystyle A} such that M = T ( A ) {\displaystyle M={\mathcal {T}}(A)} . If there is a set of rules applicable to M {\displaystyle M} such that M ⇒ m e m N {\displaystyle M\Rightarrow _{mem}N} , then there exists an ambient B {\displaystyle B} with A ⇒ a m b ∗ B {\displaystyle A\Rightarrow _{amb}^{*}B} and N = T ( B ) {\displaystyle N={\mathcal {T}}(B)} . The number of pairs of non-star objects consumed in membrane systems is equal with the number of pairs of capabilities consumed in ambients.
Theorem. (Operational correspondence)
A fragment of brane calculus called PEP, and mutual mobile membranes with objects on surface as a variant of systems with mobile membranes are considered. The mobile membranes with objects on surface is inspired by a model of membrane system introduced in [12] having objects attached to membranes. A simulation of the PEP fragment of brane calculus by using mutual
membranes with objects on surface is presented. This approach is related to some other papers trying to show the relationship between membrane systems and brane calculus [8,9,14,18,19] .
As it is expressed in [24] , "at the first sight the role of objects placed on membranes is different in membrane and brane systems: in membrane computing the focus is on the evolution of objects themselves, while in brane calculi the objects ("proteins") mainly control the evolution of membranes". By defining an encoding of the PEP fragment of brane calculus into mutual membranes with objects on surface, it is shown that the difference between the two models is not significant. Another difference regarding the semantics of the two formalisms is expressed in [8] : "whereas brane calculi are usually equipped with an interleaving, sequential semantics (each computational step consists of the execution of a single instruction), the usual semantics in membrane computing is based on maximal parallelism (a computational step is composed of a maximal set of independent interactions)".
Brane calculus [10] deals with membranes representing the sites of activity; thus a computation happens on the membrane surface. The operations of the two basic brane calculi, pino, exo, phago (PEP) and mate, drip, bud (MBD) are directly inspired by biologic processes such as endocytosis, exocytosis and mitosis. The latter operations can be simulated using the formers one [10] .
Membranes are formed of patches, where a patch s {\displaystyle s} can be composed from other patches s = s 1 ∣ s 2 {\displaystyle s=s_{1}\;\mid \;s_{2}} . An elementary patch s {\displaystyle s} consists of an action a {\displaystyle a} followed, after the consumption of it, by another patch s 1 s = a . s 1 {\displaystyle s_{1}s=a.s_{1}} . Actions often come in complementary pairs which cause the interaction between membranes. The names n {\displaystyle n} are used to pair-up actions and co-actions. Cardelli motivates that the replication operator is used to model the notion of a "multitude" of components of the same kind, which is in fact a standard situation in biology [10] . The replicator operator is not used because a membrane system cannot be defined without knowing exactly the initial membrane structure. P {\displaystyle {\mathcal {P}}} denotes the set of brane systems defined above. Some abbreviations can be made: a .0 {\displaystyle a.0} as a {\displaystyle a} , 0 ( P ) {\displaystyle 0(P)} as ( P ) {\displaystyle (P)} , and 0 ( ) {\displaystyle 0(~)} as ( ) {\displaystyle (~)} .
The structural congruence relation is a way of rearranging the system such that the interacting parts come together, as illustrated
in what follows:
In what follows the reduction rules of the calculus are presented:
The action p i n o ( ρ ) {\displaystyle pino(\rho )} creates an empty bubble within the membrane where the p i n o {\displaystyle pino} action resides; imagine that the original membrane buckles towards inside and pinches off. The patch σ {\displaystyle \sigma } on the empty bubble is a parameter of p i n o {\displaystyle pino} . The exo action n ↖ {\displaystyle n^{\nwarrow }} , which comes with a complementary co-action n ¯ ↖ {\displaystyle {\overline {n}}^{\nwarrow }} , models the merging of two nested membranes, which starts with the membranes touching at a point. In the process (which is a smooth, continuous process), the subsystem P {\displaystyle P} gets expelled to the outside, and all the residual patches of the two membranes become contiguous. The phago action n ↘ {\displaystyle n^{\searrow }} , which also comes with a complementary co-action n ¯ ↘ ( ρ ) {\displaystyle {\overline {n}}^{\searrow }(\rho )} , models a membrane (the one with Q {\displaystyle Q} ) "eating" another membrane (the one with P {\displaystyle P} ). Again, the process has to be smooth and continuous, so it is biologically
implementable. It proceeds by the Q {\displaystyle Q} membrane wrapping around the P {\displaystyle P} membrane and joining itself on the other side. Hence, an additional layer of membrane is created around the eaten membrane: the patch on that membrane is specified by the parameter ρ {\displaystyle \rho } of the co-phago action (similar to the parameter of the pino action).
A translation from the set P {\displaystyle {\mathcal {P}}} of brane processes to the set M {\displaystyle {\mathcal {M}}} of membrane configurations is given formally as follows:
Definition A translation T : P → M {\displaystyle {\mathcal {T}}:{\mathcal {P}}\rightarrow {\mathcal {M}}} is given by
T ( P ) = {\displaystyle {\mathcal {T}}(P)=} { [ ] S ( σ ) if P = σ ( ) [ T ( R ) ] S ( σ ) if P = σ ( R ) T ( Q ) ‖ T ( R ) if P = Q ∣ R {\displaystyle {\begin{cases}\;[~]_{{\mathcal {S}}(\sigma )}&{\mbox{if }}P=\sigma (~)\\\;[{\mathcal {T}}(R)]_{{\mathcal {S}}(\sigma )}&{\mbox{if }}P=\sigma (R)\\{\mathcal {T}}(Q)\;\|\;{\mathcal {T}}(R)&{\mbox{if }}P=Q\,\mid \,R\\\end{cases}}}
where S : P → V ∗ {\displaystyle {\mathcal {S}}:{\mathcal {P}}\rightarrow V^{*}} is defined as:
S ( σ ) = {\displaystyle {\mathcal {S}}(\sigma )=} { σ if σ = n ↘ o r σ = n ↖ o r σ = n ¯ ↖ n ¯ ↘ ‖ S ( ρ ) if σ = n ¯ ↘ ( ρ ) p i n o ‖ S ( ρ ) if σ = p i n o ( ρ ) S ( a ) ‖ S ( ρ ) if σ = a . ρ S ( τ ) ‖ S ( ρ ) if σ = τ ∣ ρ λ if σ = 0 {\displaystyle {\begin{cases}\sigma &{\mbox{if }}\sigma =n^{\searrow }or\sigma =n^{\nwarrow }or\sigma ={\overline {n}}^{\nwarrow }\\{\overline {n}}^{\searrow }\;\|\;S(\rho )&{\mbox{if }}\sigma ={\overline {n}}^{\searrow }(\rho )\\pino\;\|\;S(\rho )&{\mbox{if }}\sigma =pino(\rho )\\{\mathcal {S}}(a)\;\|\;{\mathcal {S}}(\rho )&{\mbox{if }}\sigma =a.\rho \\{\mathcal {S}}(\tau )\;\|\;{\mathcal {S}}(\rho )&{\mbox{if }}\sigma =\tau \,\mid \,\rho \\\lambda &{\mbox{if }}\sigma =0\end{cases}}}
The rules of the systems of mutual membranes with objects on surface (MMOS) are presented in what follows.
where M 1 {\displaystyle M_{1}} is a multiset and M {\displaystyle M} , N {\displaystyle N} are arbitrary membrane configurations.
The next result claims that two PEP systems which are structurally equivalent are translated into systems of mutual membranes with objects on surface which are structurally equivalent.
Proposition. If P {\displaystyle P} is a PEP system and M = T ( P ) {\displaystyle M={\mathcal {T}}(P)} is a system of mutual membranes with objects on surface, then there exists N {\displaystyle N} such that M ≡ m N {\displaystyle M\equiv _{m}N} and N = T ( Q ) {\displaystyle N={\mathcal {T}}(Q)} , whenever P ≡ b Q {\displaystyle P\equiv _{b}Q} .
Proposition. If P {\displaystyle P} is a PEP system and M = T ( P ) {\displaystyle M={\mathcal {T}}(P)} is a system of mutual membranes with objects on surface, then there exists Q {\displaystyle Q} such that N = T ( Q ) {\displaystyle N={\mathcal {T}}(Q)} whenever M ≡ m N {\displaystyle M\equiv _{m}N} .
Remark. In the last proposition it is possible that P ≢ b Q {\displaystyle P\not \equiv _{b}Q} . Suppose P = n ↘ . n ↖ ( ) {\displaystyle P=n^{\searrow }.n^{\nwarrow }(~)} . By translation it is obtained that M = T = [ ] n ↘ ‖ n ↖ ≡ m [ ] n ↖ ‖ n ↘ = N {\displaystyle M={\mathcal {T}}=[~]_{n^{\searrow }\;\|\;n^{\nwarrow }}\equiv _{m}[~]_{n^{\nwarrow }\;\|\;n^{\searrow }}=N} . It is possible to have Q = n ↖ . n ↘ ( ) {\displaystyle Q=n^{\nwarrow }.n^{\searrow }(~)} or Q = n ↖ ∣ n ↘ ( ) {\displaystyle Q=n^{\nwarrow }\mid n^{\searrow }(~)} such that N = T ( Q ) {\displaystyle N={\mathcal {T}}(Q)} , but P ≢ b Q {\displaystyle P\not \equiv _{b}Q} .
Proposition. If P {\displaystyle P} is a PEP system and M = T ( P ) {\displaystyle M={\mathcal {T}}(P)} is a system of mutual membranes with objects on surface, then there exists N {\displaystyle N} such that M → N {\displaystyle M\rightarrow N} and N = T ( Q ) {\displaystyle N={\mathcal {T}}(Q)} , whenever P → b Q {\displaystyle P\rightarrow _{b}Q} .
Proposition. If P {\displaystyle P} is a PEP system and M = T ( P ) {\displaystyle M={\mathcal {T}}(P)} is a system of mutual membranes with objects on surface, then there exists Q {\displaystyle Q} such that N = T ( Q ) {\displaystyle N={\mathcal {T}}(Q)} whenever M → N {\displaystyle M\rightarrow N} .
The following remark is a consequence of the fact that a formalism using an interleaving semantic is translated into a formalism working in parallel.
Remark. The last proposition allows P ↛ b Q {\displaystyle P\not \rightarrow _{b}Q} . Let us assume P = n ¯ ↖ . n ¯ ↖ ( n ↖ . n ↘ ( ) ) {\displaystyle P={\overline {n}}^{\nwarrow }.{\overline {n}}^{\nwarrow }(n^{\nwarrow }.n^{\searrow }(~))} . By translation, it is obtained that M = ( ( ) n ↖ ‖ n ↘ ) n ¯ ↖ ‖ n ¯ ↖ {\displaystyle M=((~)_{n^{\nwarrow }\;\|\;n^{\searrow }})_{{\overline {n}}^{\nwarrow }\;\|\;{\overline {n}}^{\nwarrow }}} , such that M → [ ] n ↘ ‖ n ¯ ↖ {\displaystyle M\rightarrow [~]_{n^{\searrow }\;\|\;{\overline {n}}^{\nwarrow }}} . It can be observed that there exist Q = n ↘ . n ¯ ↖ ( ) {\displaystyle Q=n^{\searrow }.{\overline {n}}^{\nwarrow }(~)} such that N = T ( Q ) {\displaystyle N={\mathcal {T}}(Q)} , but P ↛ b Q {\displaystyle P\not \rightarrow _{b}Q} .
These results are presented together with their proofs in [2] . | https://en.wikipedia.org/wiki/Mobile_membranes |
A mobile messaging operator is a specialized form of mobile network operator that provides mobile messaging services such as SMS or Multimedia Messaging Service to businesses or other mobile operators.
There are two types of mobile messaging operators, aggregators and SS7 ( Signaling System 7 ) providers.
The aggregator model involves the mobile messaging operator signing multiple individual agreements with mobile operators to facilitate two-way SMS traffic through that operator's SMSC ( Short Message Service Center ). SMS messages are delivered to the operator's SMSC, but not the subscriber's handset; the SMSC takes care of further handling of the message through the SS7 network.
The SS7 model enables mobile messaging operators to route data directly through the SS7 system, giving the provider greater control and visibility of the transmission path during SMS routing. In this way, SMS messages can be sent directly to and from recipients without having to go through the SMSCs of other mobile operators.
Some mobile messaging operators also operate a mixed model, combining SS7 and aggregated connectivity.
Mobile messaging operators can provide businesses or other mobile operators with a range of messaging services, including: | https://en.wikipedia.org/wiki/Mobile_messaging_operator |
Mobile metering (recording of data using a mobile meter ) is a technology which enables mobile recording of metering data. While railway companies such as the German Deutsche Bahn have been using this technology for years in their trains, it is now also being used for recording the charging transactions of electric vehicles (EVs). [ 1 ]
In the latter case, a mobile electricity meter is integrated either into the vehicle itself or into the respective charging cable. This, together with the necessary communication technology (SIM card), makes it possible to transmit charging data (down to the kWh) to a matching backend. Lean, switchable system sockets suffice for charging – they serve as outlets for the power grid. These system sockets can be reduced to a technical minimum, as the vehicle or the cable, respectively, already carry the necessary billing and communication technology. [ 2 ] This makes these sockets especially affordable and avoids running costs compared to conventional charging infrastructure, such as costs for maintenance or meter point operation.
As a result, precise metering, secure data transmission and efficient billing fulfill all preconditions for a comprehensive and future-proof charging and billing solution for electric mobility.
The mobile meter was developed in the projects „On Board Metering I & II“, that kicked off in March 2003, sponsored by the German ministry for economic affairs and technology. [ 3 ] Participants of the project were: [ 4 ]
The project's approach to electric mobility was not tackling it as a singular challenge. The aim was rather to make a significant contribution to the energy transition by taking electric mobility one step further.
For this to happen, the EV was to become a system-relevant factor as an energy storage device. The goal was to create as much power grid connection points as possible while at the same time safeguarding exact metering and billing of electricity. This way, the vehicle could gain access to the grid anytime it is parked (ratio of EVs to grid connection points greater than 1). Up to that date, charging infrastructure for electric cars was thought of as stationary, similar to conventional gas stations for combustion cars.
For this, a shift of technology from the infrastructure to the vehicle side (or the cable, respectively) was needed. Such a network of ubiquitous charging spots was only to be realized with charging infrastructure that would cause comparably low costs over longer periods of time.
The disruptive approach of mobile metering has by now opened up new possibilities and business models for electric mobility.
Weil/Neumann (January 2016). "Vergleichende Betrachtung der Sicherheitskonzepte von Mobile Metering und Smart Meter Gateways". Physikalisch-technische Bundesanstalt (National Metrology Institute of Germany) . 125 : 53– 58.
PTB-Anforderungen 50.7 (PTB-A 50.7) Elektronische und softwaregesteuerte Messgeräte und Zusatzeinrichtungen für Elektrizität, Gas, Wasser und Wärme . PTB (National Metrology Institute of Germany). 2002. | https://en.wikipedia.org/wiki/Mobile_metering |
Mobile music is music which can be transported, or in other words, mobile. The term itself is a quite ambiguous. [ 1 ]
An outdated definition is as follows; 'mobile music is music which is downloaded or streamed to mobile phones and played by mobile phones. Although many phones play music as ringtones, true "music phones" generally allow users to stream music or download music files over the internet via a WiFi connection or 3G cell phone connection. Music phones are also able to import audio files from their PCs. The case of mobile music being stored within the memory of the mobile phone is the case similar to traditional business models in the music industry. It supports two variants: the user can either purchase the music for outright ownership or access entire libraries of music via a subscription model. In this case the music files are available as long as the subscription is active.' [ 2 ]
While ringtones do not include artists voices, truetones , chaku-uta and chaku-uta full are recordings of artists' interpretation of music. Distributing them usually requires the agreement of record labels and other owners of artists' rights. [ 2 ]
Mobile music is technically any form of music which can be moved. This includes musical instruments . This article, however, does not go over the history of musical instruments, as there are already articles on such.
Radios is one of the earliest forms of technology based mobile music. [ 3 ]
The most prominent and iconic piece of mobile music is Sony's Walkman . [ 4 ] Another term for it is a mobile cassette tape player, a product which multiple companies created. [ 3 ]
The mobile CD player, such as Sony's Discman , is another innovation in the realm of mobile music. [ 3 ] [ 4 ]
The MP3 is step towards a truly digital age of music. [ 4 ] [ 3 ]
The integration of music in a cellphone was not easy. On one hand, technology for portable music had been developed since the 1980s with Sony driving the area with its portable walkman. On the other, cellphone technology had focused on the area of imaging, leveraging the user interest in taking pictures and the operator's need to drive data revenues through the use of its network. The success of ringtones in driving data revenues had placed operators on guard for interactive applications that could drive revenues. Nevertheless, slow data speeds in the GSM and CDMA areas which had 1 and 2G technology, prevented the economic download of music data through networks in comparison with media sites to a computer. So operators, which tended to subsidize phones with data capabilities focused more on ringtone, SMS, and picture phones than on music ready phones, and this prevented many manufacturers to develop those phones because their primary customer is the operator and not the user. Work on compression algorithms for music was extensive with AMR trying to push the envelope, but the revolution of Napster proliferated the world with the MP3 format and manufacturers began to take notice. Another issue was the development of DRM capabilities which helped prevent music piracy and gave mobile music more of a legal status. At that time, Apple was revolutionizing the world with the introduction of the new iPods and its iTunes Store.
The first report on a business plan and need for the successful integration of Music Phones was written in 2004 by Strategy Analytics - "Music phones are key for 3G", a cellular consulting firm in Massachusetts. The report boosted the need for phone manufacturers like Nokia and Motorola to join the bandwagon and explore several music options including the development of a music store strategy by Nokia and the integration of iTunes into a phone by Motorola with its Rocker. Sony, Samsung, and LG were too busy focusing on increasing pixelation and stability within CDDMA camera modules. Sony tried to leverage the Cybershot technology in a multimedia strategy, but it was too slow of a change. While Samsung was driving the high tier segment improving display capability. Nokia worked hard to drive DRM technology to be included into its OVI music store and introduced a new music phone line called Xpress music banking on end user needs rather than on operator's wants because the line was expected to receive lower subsidies from operators than others. In this way, Nokia was banking on the Idea of the report that music could be used to drive customer acquisition at that time rather than data revenues for the time, as mentioned in the report from Strategy Analytics. The Rocker was a success driving new adherents into a highly competitive US market even though it still remained tied to a computer for music downloads. It could be said that it was the adoption of the Rocker by ATT as an acquisition strategy for the US market that prompted operators to purchase music capable phones and manufacturers to develop them. This success of ATT to drive acquisitions was copied by other operators such as Verizon, Sprint, and T-Mobile, which also drove the introduction of music into the cellphones. Two years after the Rocker, Apple introduced its iPhone and things went on its way. Today, most cell phones incorporate music capabilities which have also been transferred to the smartphones. The built-in app that you use to play music on the iPhone or iPod touch is called Music (on iOS 5 or higher) or iPod (on iOS 4 or lower). While many apps offer music, this is the most common and the one that, for many people, will be the only music app they need. [ 2 ]
The iPod and Zune are two similar pieces of technology. [ 4 ] [ 3 ]
Smartphone is the most revolutionary piece of technology to date in regards for mobile music, allowing access to nearly every artist at the click of a button. [ 5 ]
Napster laid the groundwork for the coming wave of streaming audio services. [ 6 ]
Music streaming became prominent in the 2000s. Few Prominent Music Streaming Platforms [ 6 ]
Pirating is another issue artists face. Napster was the first large scale system for such, laying grounds for streaming. [ 6 ]
The introduction of streaming has caused artists to be unable to support themselves through their music and its sales alone. The pandemic made people quickly aware of this issue. [ 7 ]
Mobile music has become prominent in daily life to the point where studies have been done over such. [ 8 ]
The Best Smartphones for Music | https://en.wikipedia.org/wiki/Mobile_music |
A mobile network operator ( MNO ), also known as a mobile network provider , mobile network carrier , mobile , wireless service provider , wireless carrier , wireless operator , wireless telco , or cellular company , [ a ] is a telecommunications provider of services that sells, delivers and maintains mobile telephony services to an end user.
A key defining characteristic of a mobile network operator is that it must own or control access to a radio spectrum license from a regulatory or government entity, and also that it must own or control the elements of the cellular network infrastructure necessary to provide services to subscribers over the licensed radio spectrum . [ 1 ] [ 2 ] In addition the operator would also contain other elements like the back haul infrastructure and provisioning computer systems. [ 3 ]
A mobile network operator typically also has the necessary provisioning, billing, and customer care computer systems, and the marketing, customer care, and engineering organizations needed to sell, deliver, and bill for services. However, a mobile network operator can outsource any of these systems or functions and still be considered a mobile network operator. [ 3 ] [ 4 ]
In addition to obtaining revenue by offering retail services under its own brand, a mobile network operator may also sell access to network services at wholesale rates to mobile virtual network operators (MVNO). [ 2 ] | https://en.wikipedia.org/wiki/Mobile_network_operator |
Mobile news refers to both the delivery and creation of news using mobile devices.
Today, mobile news delivery can be done via SMS , by specialized applications, or using mobile versions of media websites. According to a recent market study across six countries (France, Germany, Italy, Spain, UK, and US), 16.9% of consumers access news and information via mobile devices, either via browser, downloaded application, or SMS alerts. [ 1 ]
The demand for mobile news delivery is growing quickly, with 107 percent growth in daily access to mobile news in the last year alone. [ 2 ] For example, the New York Times mobile site registered 19 million views in May 2008, compared to 500,000 in January 2007. [ 3 ]
July 18, 2011, Time Warner announced that news coverage from CNN and Headline News will be streamed live over the Internet and available for people to view on their laptops, smartphones, or tablets if they subscribe to certain paid TV services. [ 4 ]
From 2014 many media companies launched their native mobile application including Newsdash to engage global users by delivering quick and short news of their choice.
Mobile news also has the potential to place the power of breaking news reporting in the hands of small communities and facilitate a much better exchange of information among users due to the ease of usage of mobile phones compared with conventional media such as radio, TV or newspapers, though issues of quality, journalistic standards and professionalism are of concern to some critics. [ 5 ] [ citation needed ] .
Mobile telephony and full featured mobile devices also facilitate activism and citizen journalism . In addition to individual efforts, major media outlets like CNN , Reuters , and Yahoo are attempting to harness the power of citizen journalists.
The creation of mobile news was fuelled first by the popularity of receiving text alerts, [ 6 ] and then hugely accelerated when mobile companies embraced social media, [ 7 ] making content creation easy and accessible. | https://en.wikipedia.org/wiki/Mobile_news |
A mobile office is an office built within a truck, motorhome , trailer or shipping container . The term is also used for people who don't work at a physical office location but instead carry their office materials with them. The mobile office can allow businesses to cut costs and avoid building physical locations where it would be too costly or simply unnecessary. [ 1 ] | https://en.wikipedia.org/wiki/Mobile_office |
MPDS or M obile P acket D ata S ervice provides remote users with IP capability over satellite for portable and extremely reliable communications for Internet applications such as World Wide Web access, file transfer and e-mail . It was launched by COMSAT mobile communications (CMC).
This article related to telecommunications is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Mobile_packet_data_service |
Mobile phone content advertising is the promotion of ring tones , games and other mobile phone services. Such services are usually subscription-based and use the short message service (SMS) system to join up to them. Another method is broadcasting messages to the mobile phone's idle-screen, enabling the mobile operators or advertisers to reach millions in real-time. The advertising and sale of ring tones in particular has seen a massive growth in recent years [ when? ] , with some commercial breaks, particularly on music television channels and in motor racing (especially NASCAR , with Sprint Nextel as the series sponsor), being dominated by such adverts. Advertising in newspapers and magazines has also become popular.
The first easily customisable aspect of the mobile phone were the operator logos – small, monochrome images that show the logo of the mobile network operator (such as Vodafone ) by default. These were often replaced by a person's name or a small symbol.
As handset manufacturers introduced better ring tones and audio capabilities. The ring tones became the most common method of customising the phone. Web sites containing ring tones of popular songs and tunes started appearing, with many of them providing the service free of charge and with little or no advertising at all – their popularity grew mainly through word of mouth . However, these sites soon started charging a small fee for the privilege. The next step was to advertise these services. However, since the introduction of interchangeable faceplates on mobile phones in 1998, the mobile market has shifted its advertising strategies. [ 1 ]
Some companies started large mass media campaigns to advertise the fact that they had the latest tunes and largest collections of ring tones. One of the biggest advertiser is the German company Jamba! (known as Jamster! in some countries), known for the Sweety the Chick and Crazy Frog ringtone characters. After months of public complaints, the British Advertising Standards Authority (ASA) ruled on 21 September 2005 that many of the advertisements must be shown only after 9 p.m. The primary intention of this was to prevent the company from targeting young people in its campaigns. [1] [2]
A new [ when? ] trend in mobile phone content advertising is the "ad-supported" mobile phone service model. MVNO's such as Virgin Mobile USA, Xero Mobile , and Blyk offer, or plan to offer, free or subsidized mobile phone service in exchange for subscribers viewing a number of targeted advertisements that are supposed to be relevant to the subscriber. These MVNO's use a "one person per presentation" model. The relevancy of any given advertisement is based on user demographics , questionnaires, and the like. Leap Wireless International Inc. holds a patent (Owensby 6,647,257) that allows a subscriber to subsidize his/her calls by viewing advertising, and uses a number of subscriber centric factors.
While advertising via a mobile phone is still relatively new, inventors have developed ways to use a mobile phone to present advertising to persons standing near a mobile phone user while the user speaks in a non-handsfree mode. Bayne's invention (Bayne, U.S. Pat. Application Nos. 20050239448 & 20050239495)teaches providing a mobile phone user with incentives (e.g. discounted talk time, free content, etc.) for allowing the phone to be used as a mini-billboard by manipulating the main screen to face outward to present advertising (in an alternate embodiment the invention uses the rear-facing screen). This invention differs from the conventional approach of "one person per presentation", and is based on the observation that " birds of a feather flock together " to give the advertiser multiple views per presentation and a demographic that is the same, or similar to, the subscriber. Inventor Okawa (U.S. Pat. Application 20040259599) teaches a similar invention for presenting advertising to unspecified persons near a mobile phone user, using the rear screen, while the user speaks on a mobile phone. Presentation to persons other than the user will likely be used to increase market share in low-income /high-population areas, as well as provide a line extension for ad-supported MVNO's.
Anothter approach to mobile content advertising is the use of viral marketing . Through specially designed programmes users can send recommendations for mobile content they like to their contact lists. Passa Parola , the Italian version of Meyou , has reached a total of 800,000 registered users, by the use of viral marketing alone. [ 2 ]
On 19 June 2003 NASCAR prohibited advertising by any new mobile phone companies who were not in the sport at the time; mobile phone companies who were involved could stay with their current teams, but once they break from their current teams, they could not advertise in NASCAR's premier series. This prohibition was a byproduct of the new ten-year contract with Nextel Communications.
Motorsport advertising has been prevalent, especially to replace tobacco; in 2000, Alltel sponsored a car in the NASCAR Busch Series for Herzog Motorsports, and rookie driver Jimmie Johnson . That partnership lasted only one year, as a result of Greg Penske joining the board of directors for Alltel. The firm then moved its sponsorship to Penske Racing with driver Ryan Newman. BellSouth in 1997 began advertising with Team Sabco (later Chip Ganassi Racing) before merging its mobile phone business with Southwestern Bell to form Cingular Wireless in 2001; Cingular then joined Richard Childress Racing in 2002. Both firms are grandfathered under NASCAR's deal with Nextel.
In Formula One, McLaren has signed a deal with Vodafone to sponsor their F1 team effective 2007. Ferrari is reportedly signed with Telecom Italia 's Alice brand of services in 2007 where the Alice brand will appear as the "primary" sponsor of the red cars where Marlboro is prohibited. | https://en.wikipedia.org/wiki/Mobile_phone_content_advertising |
A mobile phone feature is a capability, service, or application that a mobile phone offers to its users. Mobile phones are often referred to as feature phones , and offer basic telephony. [ clarification needed ] Handsets with more advanced computing ability through the use of native code try to differentiate their own products by implementing additional functions to make them more attractive to consumers. This has led to great innovation in mobile phone development over the past 20 years.
The common components found on all phones are:
All mobile phones are designed to work on cellular networks and contain a standard set of services that allow phones of different types and in different countries to communicate with each other. However, they can also support other features added by various manufacturers over the years:
A typical smartphone contains a number of metal–oxide–semiconductor (MOS) integrated circuit (IC) chips, [ 1 ] which in turn contain billions of tiny MOS field-effect transistors (MOSFETs). [ 2 ] A typical smartphone contains the following MOS IC chips. [ 1 ]
Besides the number keypad and buttons for accepting and declining calls (typically from left to right and coloured green and red respectively), button mobile phones commonly feature two option keys, one to the left and one to the right, and a four-directional D-pad which may feature a center button which acts in resemblance to an "Enter" and "OK" button .
A pushable scroll wheel has been implemented in the 1990s on the Nokia 7110 .
In early stages, every mobile phone company had its own user interface, which can be considered as "closed" operating system, since there was a minimal configurability. A limited variety of basic applications (usually games, accessories like calculator or conversion tool and so on) was usually included with the phone and those were not available otherwise. Early mobile phones included basic web browser, for reading basic WAP pages. Handhelds ( Personal digital assistants like Palm , running Palm OS ) were more sophisticated and also included more advanced browser and a touch screen (for use with stylus), but these were not broadly used, comparing to standard phones. Other capabilities like Pulling and Pushing Emails or working with calendar were also made more accessible but it usually required physical (and not wireless) Syncing . BlackBerry 850, an email pager, released January 19, 1999, was the first device to integrate Email.
A major step towards a more "open" mobile OS was the symbian S60 OS, that could be expanded by downloading software (written in C++, java or python), and its appearance was more configurable. In July 2008, Apple introduced its App store , which made downloading mobile applications more accessible. In October 2008, the HTC Dream was the first commercially released device to use the Linux-based Android OS, which was purchased and further developed by Google and the Open Handset Alliance to create an open competitor to other major smartphone platforms of the time (Mainly Symbian operating system, BlackBerry OS, and iOS)-The operating system offered a customizable graphical user interface and a notification system showing a list of recent messages pushed from apps.
The most commonly used data application on mobile phones is SMS text messaging. The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.
The first mobile news service, delivered via SMS, was launched in Finland in 2000. Mobile news services are expanding with many organizations providing "on-demand" news services by SMS. Some also provide "instant" news pushed out by SMS.
Mobile payments were first trialled in Finland in 1998 when two Coca-Cola vending machines in Espoo were enabled to work with SMS payments. Eventually, the idea spread and in 1999 the Philippines launched the first commercial mobile payments systems, on the mobile operators Globe and Smart. Today, mobile payments ranging from mobile banking to mobile credit cards to mobile commerce are very widely used in Asia and Africa, and in selected European markets. Usually, the SMS services utilize short code .
Some network operators have utilized USSD for information, entertainment or finance services (e.g. M-Pesa ).
Other non-SMS data services used on mobile phones include mobile music, downloadable logos and pictures, gaming, gambling, adult entertainment and advertising. The first downloadable mobile content was sold to a mobile phone in Finland in 1998, when Radiolinja (now Elisa) introduced the downloadable ringtone service. In 1999, Japanese mobile operator NTT DoCoMo introduced its mobile Internet service, i-Mode , which today is the world's largest mobile Internet service.
Even after the appearance of smartphones, network operators have continued to offer information services, although in some places, those services have become less common.
Power supply
Mobile phones generally obtain power from rechargeable batteries. There are a variety of ways used to charge cell phones, including USB , portable batteries, mains power (using an AC adapter ), cigarette lighters (using an adapter), or a dynamo . In 2009, the first wireless charger was released for consumer use. [ 9 ] Some manufacturers have been experimenting with alternative power sources, including solar cells . [ 10 ]
Various initiatives, such as the EU Common External Power Supply have been announced to standardize the interface to the charger, and to promote energy efficiency of mains-operated chargers. A star rating system is promoted by some manufacturers, where the most efficient chargers consume less than 0.03 watts and obtain a five-star rating.
Most modern mobile phones use a lithium-ion battery . [ 11 ] [ 12 ] [ 13 ] A popular early mobile phone battery was the nickel metal-hydride (NiMH) type, due to its relatively small size and low weight. Lithium-ion batteries later became commonly used, as they are lighter and do not have the voltage depression due to long-term over-charging that nickel metal-hydride batteries do. Many mobile phone manufacturers use lithium–polymer batteries as opposed to the older lithium-ion, the main advantages being even lower weight and the possibility to make the battery a shape other than strict cuboid. [ 14 ]
GSM mobile phones require a small microchip called a Subscriber Identity Module or SIM card , to function. The SIM card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. The SIM securely stores the service-subscriber key (IMSI) used to identify a subscriber on mobile telephony devices (such as mobile phones and computers). The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device.
A SIM card contains its unique serial number, internationally unique number of the mobile user ( IMSI ), security authentication and ciphering information, temporary information related to the local network, a list of the services the user has access to and two passwords (PIN for usual use and PUK for unlocking).
SIM cards are available in three standard sizes. The first is the size of a credit card (85.60 mm × 53.98 mm x 0.76 mm, defined by ISO/IEC 7810 as ID-1). The newer, most popular miniature version has the same thickness but a length of 25 mm and a width of 15 mm (ISO/IEC 7810 ID-000), and has one of its corners truncated (chamfered) to prevent misinsertion. The newest incarnation known as the 3FF or micro-SIM has dimensions of 15 mm × 12 mm. Most cards of the two smaller sizes are supplied as a full-sized card with the smaller card held in place by a few plastic links; it can easily be broken off to be used in a device that uses the smaller SIM.
The first SIM card was made in 1991 by Munich smart card maker Giesecke & Devrient for the Finnish wireless network operator Radiolinja . Giesecke & Devrient sold the first 300 SIM cards to Elisa (ex. Radiolinja).
Those cell phones that do not use a SIM card have the data programmed into their memory. This data is accessed by using a special digit sequence to access the "NAM" as in "Name" or number programming menu. From there, information can be added, including a new number for the phone, new Service Provider numbers, new emergency numbers, new Authentication Key or A-Key code, and a Preferred Roaming List or PRL. However, to prevent the phone being accidentally disabled or removed from the network, the Service Provider typically locks this data with a Master Subsidiary Lock (MSL). The MSL also locks the device to a particular carrier when it is sold as a loss leader .
The MSL applies only to the SIM, so once the contract has expired, the MSL still applies to the SIM. The phone, however, is also initially locked by the manufacturer into the Service Provider's MSL. This lock may be disabled so that the phone can use other Service Providers' SIM cards. Most phones purchased outside the U.S. are unlocked phones because there are numerous Service Providers that are close to one another or have overlapping coverage. The cost to unlock a phone varies but is usually very cheap and is sometimes provided by independent phone vendors.
A similar module called a Removable User Identity Module or RUIM card is present in some CDMA networks, notably in China and Indonesia.
A hybrid mobile phone can take more than one SIM card, even of different types. The SIM and RUIM cards can be mixed together, and some phones also support three or four SIMs. [ 15 ] [ 16 ]
From 2010 onwards they became popular in India and Indonesia and other emerging markets, [ 17 ] attributed to the desire to obtain the lowest on-net calling rate. In Q3 2011, Nokia shipped 18 million of its low cost dual SIM phone range in an attempt to make up lost ground in the higher end smartphone market. [ 18 ]
Mobile phones have a display device, some of which are also touch screens . The screen size varies greatly by model and is usually specified either as width and height in pixels or the diagonal measured in inches .
Some phones have more than one display, for example the Kyocera Echo , an Android smartphone with a dual 3.5 inch screen. The screens can also be combined into a single 4.7 inch tablet style computer . [ 19 ]
Artificial intelligence is the hot center of the technology industry, especially with the introduction of Large Language Models (LLMs) like ChatGPT and Gemini. The AI revolution, which is underway, has affected the semiconductor market and we have seen chipmaker stocks skyrocket with it. However, semiconductor stocks are not the only beneficiaries, data centers also benefit greatly from the surge in AI.
According to Future Market Intelligence, the data center market is estimated at around $30.4 billion during 2024, it is expected to grow at a compound annual growth rate of 14.4% to reach $117.24 billion by 2034. Data centers were in demand before the AI boom as well, with data from Jefferies showing their demand rising 10% to 20% for the last 15 years before AI. However, AI accelerated the market to around 30% in just two years. Read more here :
Mobile phones have central processing units (CPUs), similar to those in computers, but optimised to operate in low power environments. In smartphones, the CPU is typically integrated in a system-on-a-chip (SoC) application processor .
Mobile CPU performance depends not only on the clock rate (generally given in multiples of hertz ) [ 20 ] but also the memory hierarchy also greatly affects overall performance. Because of these problems, the performance of mobile phone CPUs is often more appropriately given by scores derived from various standardized tests to measure the real effective performance in commonly used applications.
Other features that may be found on mobile phones include GPS navigation , music (MP3) and video ( MP4 ) playback, RDS radio receiver, built-in projector, vibration and other "silent" ring options, alarms, memo recording, personal digital assistant functions, ability to watch streaming video , video download, video calling , built-in cameras (1.0+ Mpx ) and camcorders (video recording), with autofocus [ dubious – discuss ] and flash, ringtones , games, PTT , memory card reader (SD), USB (2.0), dual line support, infrared, Bluetooth (2.0) and WiFi connectivity, NFC , instant messaging , Internet e-mail and browsing and serving as a wireless modem .
The first smartphone was the Nokia 9000 Communicator [ dubious – discuss ] in 1996 which added PDA functionality to the basic mobile phone at the time. As miniaturization and increased processing power of microchips has enabled ever more features to be added to phones, the concept of the smartphone has evolved, and what was a high-end smartphone five years ago, is a standard phone today.
Several phone series have been introduced to address a given market segment, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs; the SonyEricsson Walkman series of musicphones and Cybershot series of cameraphones; the Nokia Nseries of multimedia phones, the Palm Pre the HTC Dream and the Apple iPhone .
Nokia and the University of Cambridge demonstrated a bendable cell phone called the Morph. [ 21 ] Some phones have an electromechanical transducer on the back which changes the electrical voice signal into mechanical vibrations. The vibrations flow through the cheek bones or forehead allowing the user to hear the conversation. This is useful in the noisy situations or if the user is hard of hearing. [ 22 ]
As of 2018, there are smartphones that offer reverse wireless charging. [ 23 ]
Most mobile phone networks are digital and use the GSM , CDMA or iDEN standard which operate at various radio frequencies . These phones can only be used with a service plan from the same company. For example, a Verizon phone cannot be used with a T-Mobile service, and vica versa.
A multi-mode phone operates across different standards whereas a multi-band phone (also known more specifically as dual , tri or quad band ) mobile phone is a phone which is designed to work on more than one radio frequency . Some multi-mode phones can operate on analog networks as well (for example, dual band, tri-mode: AMPS 800 / CDMA 800 / CDMA 1900).
For a GSM phone, dual-band usually means 850 / 1900 MHz in the United States and Canada , 900 / 1800 MHz in Europe and most other countries. Tri-band means 850 / 1800 / 1900 MHz or 900 / 1800 / 1900 MHz. Quad-band means 850 / 900 / 1800 / 1900 MHz, also called a world phone, since it can work on any GSM network.
Multi-band phones have been valuable to enable roaming whereas multi-mode phones helped to introduce WCDMA features without customers having to give up the wide coverage of GSM . Almost every single true 3G phone sold is actually a WCDMA/GSM dual-mode mobile. This is also true of 2.75G phones such as those based on CDMA-2000 or EDGE.
The special challenge involved in producing a multi-mode mobile is in finding ways to share the components between the different standards. The phone keypad and display should be shared, otherwise it would be hard to treat as one phone. Beyond that, though, there are challenges at each level of integration. How difficult these challenges are depends on the differences between systems. When talking about IS-95/GSM multi-mode phones, for example, or AMPS/IS-95 phones, the base band processing is very different from system to system. This leads to real difficulties in component integration and so to larger phones.
An interesting special case of multi-mode phones is the WCDMA/GSM phone. The radio interfaces are very different from each other, but mobile to core network messaging has strong similarities, meaning that software sharing is quite easy. Probably more importantly, the WCDMA air interface has been designed with GSM compatibility in mind. It has a special mode of operation, known as punctured mode, in which, instead of transmitting continuously, the mobile is able to stop sending for a short period and try searching for GSM carriers in the area. This mode allows for safe inter-frequency handovers with channel measurements which can only be approximated using "pilot signals" in other CDMA based systems.
A final interesting case is that of mobiles covering the DS-WCDMA and MC-CDMA 3G variants of the CDMA-2000 protocol. Initially, the chip rate of these phones was incompatible. As part of the negotiations related to patents , it was agreed to use compatible chip rates. This should mean that, despite the fact that the air and system interfaces are quite different, even on a philosophical level, much of the hardware for each system inside a phone should be common with differences being mostly confined to software.
Mobile phones are now heavily used for data communications. such as SMS messages, browsing mobile web sites , and even streaming audio and video files. The main limiting factors are the size of the screen, lack of a keyboard, processing power and connection speed. Most cellphones, which supports data communications, can be used as wireless modems (via cable or bluetooth), to connect computer to internet. Such access method is slow and expensive, but it can be available in very remote areas.
With newer smartphones , screen resolution and processing power has become bigger and better. Some new phone CPUs run at over 1 GHz. Many complex programs are now available for the various smartphones, such as Symbian and Windows Phone .
Connection speed is based on network support. Originally data transfers over GSM networks were possible only over CSD (circuit switched data), it has bandwidth of 9600 bit/s and usually is billed by connection time (from network point of view, it does not differ much from voice call). Later, there were introduced improved version of CSD – HSCSD (high speed CSD), it could use multiple time slots for downlink, improving speed. Maximum speed for HSCSD is ~42 kbit/s, it also is billed by time. Later was introduced GPRS (general packet radio service), which operates on completely different principle. It also can use multiple time slots for transfer, but it does not tie up radio resources, when not transferring data (as opposed to CSD and like). GPRS usually is prioritized under voice and CSD, so latencies are large and variable. Later, GPRS was upgraded to EDGE , which differs mainly by radio modulation, squeezing more data capacity in same radio bandwidth. GPRS and EDGE usually are billed by data traffic volume. Some phones also feature full Qwerty keyboards , such as the LG enV .
As of April 2006, several models, such as the Nokia 6680 , support 3G communications. Such phones have access to the Web via a free download of the Opera web browser. Verizon Wireless models come with Internet Explorer pre-loaded onto the phone.
As more complex features are added to phones, they become more vulnerable to viruses which exploit weaknesses in these features. Even text messages can be used in attacks by worms and viruses . [ 24 ] Advanced phones capable of e-mail can be susceptible to viruses that can multiply by sending messages through a phone's address book. [ citation needed ] In some phone models, the USSD was exploited for inducing a factory reset , [ 25 ] resulting in clearing the data and resetting the user settings.
A virus may allow unauthorized users to access a phone to find passwords or corporate data stored on the device. Moreover, they can be used to commandeer the phone to make calls or send messages at the owner's expense. [ citation needed ]
Mobile phones used to have proprietary operating system unique only to the manufacturer which had the beneficial effect of making it harder to design a mass attack. However, the rise of software platforms and operating systems shared by many manufacturers such as Java , Microsoft operating systems, Linux , or Symbian OS , may increase the spread of viruses in the future.
Bluetooth is a feature now found in many higher-end phones, and the virus Caribe hijacked this function, making Bluetooth phones infect other Bluetooth phones running the Symbian OS. In early November 2004, several web sites began offering a specific piece of software promising ringtones and screensavers for certain phones. Those who downloaded the software found that it turned each icon on the phone's screen into a skull-and-crossbones and disabled their phones, so they could no longer send or receive text messages or access contact lists or calendars . The virus has since been dubbed " Skulls " by security experts. The Commwarrior-A virus was identified in March 2005, and it attempts to replicate itself through MMS to others on the phone's contact list. Like Cabir, Commwarrior-A also tries to communicate via Bluetooth wireless connections with other devices, which can eventually lead to draining the battery. The virus requires user intervention for propagation however.
Bluetooth phones are also subject to bluejacking , which although not a virus, does allow for the transmission of unwanted messages from anonymous Bluetooth users.
Most current phones also have a built-in digital camera (see camera phone ), that can have resolutions as high as 108M pixels. [ 26 ] This gives rise to some concern about privacy , in view of possible voyeurism , for example in swimming pools . South Korea has ordered manufacturers to ensure that all new handsets emit a beep whenever a picture is taken.
Sound recording and video recording is often also possible. Most people do not walk around with a video camera, but do carry a phone. The arrival of video camera phones is transforming the availability of video to consumers, and helps fuel citizen journalism . | https://en.wikipedia.org/wiki/Mobile_phone_feature |
A mobile phone jammer or blocker is a device which deliberately transmits signals on the same radio frequencies as mobile phones , disrupting the communication between the phone and the cell-phone base station , effectively disabling mobile phones within the range of the jammer, preventing them from receiving signals and from transmitting them. Jammers can be used in practically any location, but are found primarily in places where a phone call would be particularly disruptive because silence is expected, such as entertainment venues.
Because they disrupt the operations of legitimate mobile phone services, the use of such blocking devices is illegal in many jurisdictions, especially without a licence. When operational, such devices also block access to emergency services.
Since these jammers actively broadcast radio signals, they are illegal in many jurisdictions. | https://en.wikipedia.org/wiki/Mobile_phone_jammer |
A mobile phone operator , wireless provider , or carrier is a mobile telecommunications company that provides wireless Internet GSM services for mobile device users. The operator gives a SIM card to the customer who inserts it into the mobile device to gain access to the service.
There are two types of mobile operators:
As of May 2016 [update] (and for years before), the world's largest individual mobile operator by subscribers is China Mobile with over 835 million mobile subscribers. [ 1 ] [ 2 ] Over 50 mobile operators have over 10 million subscribers each, and over 150 mobile operators had at least one million subscribers by the end of 2009. [ 3 ] In February 2010, there were 4.6 billion mobile subscribers, a number that is estimated to grow. Total mobile‐cellular subscriptions reached almost 6 billion by end 2011, corresponding to a global penetration of 86%
.
Prior to 1973, cellular mobile device technology was limited to devices installed in cars and other vehicles. [ 4 ] The first fully automated telephone calling system for vehicles was launched in Sweden in 1960, called MTA (mobile telephone system A). Calls from the car were direct dial, whereas incoming calls required an operator to determine which base station the device was currently at. In 1962, an upgraded version called Mobile System B (MTB) was introduced. In 1971, the MTD version was launched, opening for several different brands of equipment and gaining commercial success. [ 5 ] [ 6 ] The network remained open until 1983 and still had 600 customers when it closed.
In 1958, development began on a similar service in the USSR, the Altay system for motorists. [ 7 ] In 1963, the service started in Moscow, and by 1970, was deployed in 30 cities across the USSR. Versions of the Altay system are still in use today as a trunking system in some parts of Russia.
In 1959 a private telephone company located in Brewster, Kansas, US, the S&T Telephone Company, (still in business today) with the use of Motorola radio telephone equipment and a private tower facility, offered to the public cellular telephone services in that local area of NW Kansas.
In 1966, Bulgaria presented the pocket mobile automatic telephone RAT-0,5 combined with a base station RATZ-10 (RATC-10) on Interorgtechnika-66 international exhibition. One base station, connected to one telephone wire line, could serve up to six customers. [ citation needed ]
One of the first successful public commercial mobile phone networks was the ARP network in Finland , launched in 1971.
On April 3, 1973, Martin Cooper , a Motorola researcher and executive, made the first analog mobile phone call using a heavy prototype model. He called Dr. Joel S. Engel of Bell Labs . [ 8 ]
The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT in 1979. The initial launch network covered the full metropolitan area of Tokyo's over 20 million inhabitants with a cellular network of 23 base stations. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network. Several other countries also launched 1G networks in the early 1980s including the UK, Mexico and Canada.
In the 1990s, the 'second generation' ( 2G ) mobile phone systems emerged, primarily using the GSM standard. In 1991, the first GSM network ( Radiolinja ) launched in Finland .
American and Canadian wireless providers tend to subsidize phones for consumers but tend to require 2 or 3-year contracts, while Asian and European providers sell the phone at full cost while the monthly fees charged are lower. [ 9 ] | https://en.wikipedia.org/wiki/Mobile_phone_operator |
A mobile phone signal (also known as reception and service ) is the signal strength (measured in dBm ) received by a mobile phone from a cellular network (on the downlink ). Depending on various factors, such as proximity to a tower , any obstructions such as buildings or trees, etc. this signal strength will vary. Most mobile devices use a set of bars of increasing height to display the approximate strength of this received signal to the mobile phone user. Traditionally five bars are used. (see five by five ) [ 1 ]
Generally, a strong mobile phone signal is more likely in an urban area, though these areas can also have some "dead zones", where no reception can be obtained. Cellular signals are designed to be resistant to multipath reception, which is most likely to be caused by the blocking of a direct signal path by large buildings, such as high-rise towers. By contrast, many rural or sparsely inhabited areas lack any signal or have very weak fringe reception ; many mobile phone providers are attempting to set up towers in those areas most likely to be occupied by users, such as along major highways . Even some national parks and other popular tourist destinations away from urban areas now have cell phone reception, though location of radio towers within these areas is normally prohibited or strictly regulated, and is often difficult to arrange.
In areas where signal reception would normally be strong, other factors can have an effect on reception or may cause complete failure (see RF interference). From inside a building with thick walls or of mostly metal construction (or with dense rebar in concrete ), signal attenuation may prevent a mobile phone from being used. Underground areas, such as tunnels and subway stations , will lack reception unless they are wired for cell signals. There may also be gaps where the service contours of the individual base stations (Cell towers) of the mobile provider (and/or its roaming partners) do not completely overlap.
In addition, the weather may affect the strength of a signal, due to the changes in radio propagation caused by clouds (particularly tall and dense thunderclouds which cause signal reflection ), precipitation , and temperature inversions . This phenomenon, which is also common in other VHF radio bands including FM broadcasting , may also cause other anomalies, such as a person in San Diego "roaming" on a Mexican tower from just over the border in Tijuana , or someone in Detroit "roaming" on a Canadian tower located within sight across the Detroit River in Windsor, Ontario . These events may cause the user to be billed for "international" usage despite being in their own country, though mobile phone companies can program their billing systems to re-rate these as domestic usage when it occurs on a foreign cell site that is known to frequently cause such issues for their customers.
The volume of network traffic can also cause calls to be blocked or dropped due to a disaster or other mass call event which overloads the number of available radio channels in an area, or the number of telephone circuits connecting to and from the general public switched telephone network
Areas where mobile phones cannot transmit to a nearby mobile site , base station , or repeater are known as dead zones . In these areas, the mobile phone is said to be in a state of outage. Dead zones are usually areas where mobile phone service is not available because the signal between the handset and mobile site antennas is blocked or severely reduced , usually by hilly terrain , dense foliage , or physical distance.
A number of factors can create dead zones, which may exist even in locations in which a wireless carrier offers coverage, due to limitations in cellular network architecture (the locations of antennas), limited network density, interference with other mobile sites, and topography. Since cell phones rely on radio waves , which travel through the air and are easily attenuated (particularly at higher frequencies), mobile phones may be unreliable at times. Like other radio transmissions, mobile phone calls can be interrupted by large buildings , terrain, trees, or other objects between the phone and the nearest base. Cellular network providers work continually to improve and upgrade their networks in order to minimize dropped calls , access failures, and dead zones (which they call "coverage holes" or "no-service areas"). For mobile virtual network operators , the network quality depends entirely on the host network for the particular handset in question. Some MVNOs use more than one host, which may even have different technologies (for example, different Starlink , Spectrum (brand) and TracFone handsets use either CDMA and 1xRTT on Verizon Wireless , or GSM and UMTS on AT&T Mobility or GSM and UMTS on T-Mobile US ).
Dead zones can be filled-in with microcells , while picocells can handle even smaller areas without causing interference to the larger network. Personal microcells, such as those for a home , are called femtocells , and generally have the range of a cordless phone , but may not be usable for an MVNO phone. A similar system can be set up to perform inmate call capture, [ 2 ] which prevents cellphones smuggled into a prison from being used. These still complete calls to or from pre-authorized users such as prison staff, while not violating laws against jamming . These systems must be carefully designed so as to avoid capturing calls from outside the prison, which would in effect create a dead zone for any passersby outside.
In the event of a disaster causing temporary dead zones, a cell on wheels may be brought in until the local telecom infrastructure can be restored. These portable units are also used where large gatherings are expected, in order to handle the extra load.
A dropped call is a common term used and expressed by wireless mobile phone call subscribers when a call is abruptly cut-off (disconnected) during midconversation. This happens less often today than it would have in the early 1990s. The termination occurs unexpectedly and is influenced by a number of different reasons such as "Dead Zones." In technical circles, it is called an abnormal release .
One reason for a call to be "dropped" is if the mobile phone subscriber travels outside the coverage area—the cellular network radio tower(s). After a telephone connection between two subscribers has been completed, both the tower and the mobile phone must remain within range of that subscribers network provider or that connection will be lost (dropped). Not all cellular telephone radio towers are owned by the same telephone company (though this is not true to all locations) be maintained across a different company's network (as calls cannot be re-routed over the traditional phone network while in progress), also resulting in the termination of the call once a signal cannot be maintained between the phone and the original network. [ clarification needed ]
Another common reason is when a phone is taken into an area where wireless communication is unavailable, interrupted, interfered with, or jammed . From the network's perspective, this is the same as the mobile moving out of the coverage area.
Occasionally, calls are dropped upon handoff between cells within the same provider's network. This may be due to an imbalance of traffic between the two cell sites ' areas of coverage. If the new cell site is at capacity, it cannot accept the additional traffic of the call trying to "hand in." It may also be due to the network configuration not being set up properly, such that one cell site is not "aware" of the cell to which the phone is trying to handoff. If the phone cannot find an alternative cell to which to move that can take over the call, the call is lost.
Co-channel and adjacent-channel interference can also be responsible for dropped calls in a wireless network. Neighbouring cells with the same frequencies interfere with each other, deteriorating the quality of service and producing dropped calls. Transmission problems are also a common cause of dropped calls. Another problem may be a faulty transceiver inside the base station.
Calls can also be dropped if a mobile phone at the other end of the call loses battery power and stops transmitting abruptly.
Sunspots and solar flares are rarely blamed for causing interference leading to dropped calls, as it would take a major geomagnetic storm to cause such a disruption (except for satellite phones ).
Experiencing too many dropped calls is one of the most common customer complaints received by wireless service providers . They have attempted to address the complaint in various ways, including expansion of their home network coverage, increased cell capacity, and offering refunds for individual dropped calls.
Various signal booster systems are manufactured to reduce problems due to dropped calls and dead zones. Many options, such as wireless units and antennas, are intended to aid in strengthening weak signals.
Arbitrary Strength Unit (ASU) is an integer value indicating the received signal strength measured by the mobile phone.
It is possible to calculate the real signal strength measured in dBm (and thereby power in Watts) by a formula. However, there are different formulas for 2G, 3G and 4G networks.
In GSM networks, ASU maps to RSSI (received signal strength indicator, see TS 27.007 [ 3 ] sub clause 8.5).
In UMTS networks, ASU maps to RSCP level (received signal code power, see TS 27.007 [ 3 ] sub clause 8.69 and TS 25.133 sub clause 9.1.1.3).
In LTE networks, ASU maps to RSRP (reference signal received power, see TS 36.133, sub-clause 9.1.4). The valid range of ASU is from 0 to 97. For the range 1 to 96, ASU maps to
The value of 0 maps to RSRP below -140 dBm and the value of 97 maps to RSRP above -44 dBm.
On Android devices however, the original GSM formula may prevail for UMTS. [ 4 ] Tools like Network Signal Info [ 5 ] can directly show the signal strength (in dBm), as well as the underlying ASU.
ASU shouldn't be confused with "Active Set Update". The Active Set Update is a signalling message used in handover procedures of UMTS and CDMA mobile telephony standards. On Android phones, the acronym ASU has nothing to do with Active Set Update. It has not been declared precisely by Google developers. [ 6 ] | https://en.wikipedia.org/wiki/Mobile_phone_signal |
Mobile phone tracking is a process for identifying the location of a mobile phone, whether stationary or moving. Localization may be affected by a number of technologies, such as the multilateration of radio signals between (several) cell towers of the network and the phone or by simply using GNSS . To locate a mobile phone using multilateration of mobile radio signals, the phone must emit at least the idle signal to contact nearby antenna towers and does not require an active call. The Global System for Mobile Communications (GSM) is based on the phone's signal strength to nearby antenna masts. [ 1 ]
Mobile positioning may be used for location-based services that disclose the actual coordinates of a mobile phone. Telecommunication companies use this to approximate the location of a mobile phone, and thereby also its user. [ 2 ]
The location of a mobile phone can be determined in a number of ways.
The location of a mobile phone can be determined using the service provider's network infrastructure. The advantage of network-based techniques, from a service provider's point of view, is that they can be implemented non-intrusively without affecting handsets. Network-based techniques were developed many years prior to the widespread availability of GPS on handsets. (See US 5519760 , issued 21 May 1996 for one of the first works relating to this. [ 3 ] )
The technology of locating is based on measuring power levels and antenna patterns and uses the concept that a powered mobile phone always communicates wirelessly with one of the closest base stations , so knowledge of the location of the base station implies the cell phone is nearby.
Advanced systems determine the sector in which the mobile phone is located and roughly estimate also the distance to the base station. Further approximation can be done by interpolating signals between adjacent antenna towers. Qualified services may achieve a precision of down to 50 meters in urban areas where mobile traffic and density of antenna towers (base stations) is sufficiently high. [ 4 ] Rural and desolate areas may see miles between base stations and therefore determine locations less precisely.
GSM localization uses multilateration to determine the location of GSM mobile phones, or dedicated trackers, usually with the intent to locate the user. [ 2 ]
The accuracy of network-based techniques varies, with cell identification being the least accurate (due to differential signals transposing between towers, otherwise known as "bouncing signals") and triangulation as moderately accurate, and newer "advanced forward link trilateration " [ 5 ] timing methods as the most accurate. The accuracy of network-based techniques is both dependent on the concentration of cell base stations, with urban environments achieving the highest possible accuracy because of the higher number of cell towers , and the implementation of the most current timing methods.
One of the key challenges of network-based techniques is the requirement to work closely with the service provider, as it entails the installation of hardware and software within the operator's infrastructure. Frequently the compulsion associated with a legislative framework, such as Enhanced 9-1-1 , is required before a service provider will deploy a solution.
In December 2020, it emerged that the Israeli surveillance company Rayzone Group may have gained access, in 2018, to the SS7 signaling system via cellular network provider Sure Guernsey , thereby being able to track the location of any cellphone globally. [ 6 ]
The location of a mobile phone can be determined using client software installed on the handset. [ 7 ] This technique determines the location of the handset by putting its location by cell identification, signal strengths of the home and neighboring cells, which is continuously sent to the carrier. [ 8 ] In addition, if the handset is also equipped with GPS then significantly more precise location information can be then sent from the handset to the carrier.
Another approach is to use a fingerprinting-based technique, [ 9 ] [ 10 ] [ 11 ] where the "signature" of the home and neighboring cells signal strengths at different points in the area of interest is recorded by war-driving and matched in real-time to determine the handset location. This is usually performed independent from the carrier.
The key disadvantage of handset-based techniques, from service provider's point of view, is the necessity of installing software on the handset. It requires the active cooperation of the mobile subscriber as well as software that must be able to handle the different operating systems of the handsets. Typically, smartphones , such as one based on Symbian , Windows Mobile , Windows Phone , BlackBerry OS , iOS , or Android , would be able to run such software, e.g. Google Maps.
One proposed work-around is the installation of embedded hardware or software on the handset by the manufacturers, e.g., Enhanced Observed Time Difference (E-OTD). This avenue has not made significant headway, due to the difficulty of convincing different manufacturers to cooperate on a common mechanism and to address the cost issue. Another difficulty would be to address the issue of foreign handsets that are roaming in the network.
Crowdsourced Wi-Fi data can also be used to identify a handset's location. [ 14 ] The poor performance of the GPS-based methods in indoor environment and the increasing popularity of Wi-Fi have encouraged companies to design new and feasible methods to carry out Wi-Fi-based indoor positioning. [ 15 ] Most smartphones combine Global Navigation Satellite Systems (GNSS), such as GPS and GLONASS , with Wi-Fi positioning systems .
Hybrid positioning systems use a combination of network-based and handset-based technologies for location determination. One example would be some modes of Assisted GPS , which can both use GPS and network information to compute the location. Both types of data are thus used by the telephone to make the location more accurate (i.e., A-GPS). Alternatively tracking with both systems can also occur by having the phone attain its GPS-location directly from the satellites , and then having the information sent via the network to the person that is trying to locate the telephone. Such systems include Google Maps , as well as, LTE 's OTDOA and E-CellID .
There are also hybrid positioning systems which combine several different location approaches to position mobile devices by Wi-Fi , WiMAX , GSM, LTE, IP addresses , and network environment data.
In order to route calls to a phone, cell towers listen for a signal sent from the phone and negotiate which tower is best able to communicate with the phone. As the phone changes location, the antenna towers monitor the signal, and the phone is "roamed" to an adjacent tower as appropriate. By comparing the relative signal strength from multiple antenna towers, a general location of a phone can be roughly determined. Other means make use of the antenna pattern, which supports angular determination and phase discrimination .
Newer phones may also allow the tracking of the phone even when turned on but not active in a telephone call. This results from the roaming procedures that perform hand-over of the phone from one base station to another. [ 16 ]
A phone's location can be shared with friends and family, posted to a public website, recorded locally, or shared with other users of a smartphone app. The inclusion of GPS receivers on smartphones has made geographical apps nearly ubiquitous on these devices. Specific applications include:
In January 2019, the location of her iPhone as determined by her sister helped Boston police find kidnapping victim Olivia Ambrose. [ 17 ]
Locating or positioning touches upon delicate privacy issues, since it enables someone to check where a person is without the person's consent. [ 18 ] Strict ethics and security measures are strongly recommended for services that employ positioning. In 2012 Malte Spitz held a TED talk [ 19 ] on the issue of mobile phone privacy in which he showcased his own stored data that he received from Deutsche Telekom after suing the company. He described the data, which consists of 35,830 lines of data collected during the span of Germany 's data retention at the time, saying, "This is six months of my life [...] You can see where I am, when I sleep at night, what I'm doing." He partnered up with ZEIT Online and made his information publicly available in an interactive map which allows users to watch his entire movements during that time in fast-forward. Spitz concluded that technology consumers are the key to challenging privacy norms in today's society who "have to fight for self determination in the digital age." [ 20 ] [ 21 ]
The Chinese government has proposed using this technology to track commuting patterns of Beijing city residents. [ 22 ] Aggregate presence of mobile phone users could be tracked in a privacy-preserving fashion. [ 23 ] This location data was used to locate protesters during protests in Beijing in 2022 . [ 24 ]
In Europe most countries have a constitutional guarantee on the secrecy of correspondence , and location data obtained from mobile phone networks is usually given the same protection as the communication itself. [ 25 ] [ 26 ] [ 27 ] [ 28 ]
In the United States , there is a limited constitutional guarantee on the privacy of telecommunications through the Fourth Amendment . [ 29 ] [ 30 ] [ 31 ] [ 32 ] [ 33 ] The use of location data is further limited by statutory , [ 34 ] administrative , [ 35 ] and case law . [ 29 ] [ 36 ] Police access of seven days of a citizen's location data is unquestionably enough to be a fourth amendment search requiring both probable cause and a warrant . [ 29 ] [ 37 ]
In November 2017, the United States Supreme Court ruled in Carpenter v. United States that the government violates the Fourth Amendment by accessing historical records containing the physical locations of cellphones without a search warrant. [ 38 ] | https://en.wikipedia.org/wiki/Mobile_phone_tracking |
Mobile phone use while driving is common but it is dangerous due to its potential for causing distracted driving and subsequent crashes. Due to the number of crashes that are related to conducting calls on a phone and texting while driving, some jurisdictions have made the use of calling on a phone while driving illegal in an attempt to curb the practice, with varying levels of efficacy. Many jurisdictions have enacted laws making handheld mobile phone use illegal. Many jurisdictions allow use of a hands-free device. Driving while using a hands-free device has been found by some studies to provide little to no benefit versus holding the device itself and carrying on a conversation. [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] In some cases restrictions are directed only at minors, those who are newly qualified license holders (particularly those of a younger age), or to drivers in school zones . In addition to voice calling , activities such as texting while driving , web browsing, playing video games , or phone use in general may also increase the risk of a crash.
In the United States, automobile crashes due to distracted driving are increasing even after the passage of laws intended to lessen such use while driving. Using a cell phone while driving increases the driver's risk of causing a crash. Drivers can become distracted, decreasing the driver's awareness on the road, leading to more car crashes. When drivers talk on cell phones the risk of an automobile crash resulting in hospitalization is four times higher than when not talking on a cell phone. [ 8 ] Drivers who text when behind the wheel are twenty-three times more likely to have an automobile crash. [ 9 ] One out of every four automobile crashes in the United States are caused by texting while driving. [ 10 ]
The Société de l'assurance automobile du Québec (SAAQ), the provincial automobile insurance association in Quebec, conducted a study on driving and cellphones in 2003. Questionnaires were sent to 175,000 drivers and analysis was done on the 36,078 who responded. The questionnaire asked about driving habits, risk exposure, collisions over the past 24 months, socio-demographic information, and cell phone use. Questionnaires were supported with data from cell phone companies and crash records held by police. The study found that the overall relative risk (RR) of having a crash for cell phone users when compared to non-cell phone users averaged 1.38 across all groups. When adjusted for distance driven per year and other crash risk exposures, RR was 1.11 for men and 1.21 for women. They also found that increased cell phone use correlated with an increase in RR. When the same data were reanalyzed using a Bayesian approach, the calculated RR of 0.78 for those making less than 1 call/day and 2.27 for those with more than 7 calls/day was similar to cohort analysis . When the data were reanalyzed using case-crossover analysis, RR was calculated at a much higher 5.13. The authors expressed concern that misclassification of phone call and cell phone usage due to reporting errors of the exact time of the collisions was a major source of bias with all case-crossover analysis of this issue. [ 3 ] [ 4 ] [ 13 ]
In March 2011, the US insurance company State Farm Insurance announced the results of a study which showed 19% of drivers surveyed accessed the Internet on a smart phone while driving. [ 14 ] In September 2010, the US National Highway Traffic Safety Administration (NHTSA) released a report on distracted driving fatalities for 2009. The NHTSA considers distracted driving to include some of the following as distractions: other occupants in the car, eating, drinking, smoking, adjusting radio, adjusting environmental control, reaching for object in car, and cell phone use. In 2009 in the US, there was a reported 5,474 people killed by distracted drivers. Of those, 995 were considered to be killed by drivers distracted by cell phones . The report does not state whether this under- or overrepresents the level of cell phone use amongst drivers, and whether there is a causal relationship. [ 15 ]
A 2003 study of US crash data states that driver inattention is estimated to be a factor in 25% to 50% of all police-reported crashes. Driver distraction, a sub-category of inattention, has been estimated to be a contributing factor in 8% to 13% of all crashes. Of distraction-related crashes, cell phone use may range from 1.5 to 5% of contributing factors. [ 16 ] However, large unknowns in each category may increase the inaccuracy of these estimates. A 2001 study sponsored by the American Automobile Association recorded "Unknown Driver Attention Status" for 41.5% of crashes, and "Unknown Distraction" in 8.6% of all distraction related crashes. [ 17 ] According to NHTSA, "There is clearly inadequate reporting of crashes". [ 18 ]
Currently, being distracted by an "outside person, object, event" (commonly known as " rubbernecking ") is the most reported cause of distraction-related crashes, followed by "adjusting radio/cassette/CD". "Using/dialing cell phone" is eighth. A 2003 study by the University of Utah psychology department measured response time, following distance, and driving speed of a control group, subjects at the legal blood alcohol content (BAC) limit of 0.08%, and subjects involved in cell phone conversations. As the study notes; "... this is the third in a series of studies that we have conducted evaluating the effects of cell phone use on driving using the car following procedure (see also Strayer & Drews, 2004; and Strayer et al., 2003). Across these three studies, 120 participants performed in both baseline and cell phone conditions. Two of the participants in our studies were involved in a crash in baseline conditions, whereas 10 participants were involved in a crash when they were conversing on a cell phone." However, no drunk driver had a crash in any test. After controlling for driving difficulty and time on task, the study concluded that cell phone drivers exhibited greater impairment than drunk drivers. [ 5 ]
A 2005 review by the Hawaii House of Representatives entitled "Cell Phone Use and Motor Vehicle Collisions: A Review of the Studies" contains an analysis of studies on cell phone/motor vehicle crash causality . A key finding was that: "No studies were found that directly address and resolve the issue of whether a
causal relation exists between cellular telephone use while operating a motor vehicle and motor vehicle collisions." [ 19 ] Meta-analysis by the Canadian Automobile Association [ 6 ] and the University of Illinois [ 7 ] found that response time while using both hands-free and hand-held phones was approximately 0.5 standard deviations higher than normal driving (i.e. an average driver, while talking on a cell phone, has response times of a driver in roughly the 40th percent
In the US, the number of cell phone subscribers has increased by 1,262.4% between the years 1985-2008. In approximately the same period the number of crashes has fallen by 0.9% (1995–2009) and the number of fatal crashes fallen by 6.2%. [ 21 ] [ 22 ] [ 23 ] It has been argued that these statistics contradict the claims that mobile use impairs driving performance. [ 24 ] Similarly, a 2010 study from the Highway Loss Data Institute published in February 2010 reviewed auto claims from three key states along with Washington, D.C., prior to cell phone bans while driving and then after. The study found no reduction in crashes, despite a 41% to 76% reduction in the use of cell phones while driving after the ban was enacted. [ 25 ]
Driving while using a handsfree cellular device is not safer than using a hand held cell phone, as concluded by case-crossover studies, [ 1 ] [ 2 ] epidemiological, [ 3 ] [ 4 ] simulation, [ 5 ] and meta-analysis. [ 6 ] [ 7 ] The increased cognitive workload involved in holding a conversation, not the use of hands, causes the increased risk. [ 26 ] [ 27 ] [ 28 ] For example, a Carnegie Mellon University study found that merely listening to somebody speak on a phone caused a 37% drop in activity in the parietal lobe , where spatial tasks are managed. [ 29 ]
In the UK using a mobile phone while driving has been illegal since 2003, unless it is in a handsfree kit. [ 30 ] The penalty originally started with a £30 ($40) fine which later became a fine of £60 ($80) plus 3 penalty points in 2006, then £100 ($134) and 3 points in 2013. [ 31 ] The 2013 fine increase proved ineffective at stopping motorists from using their phones while driving. The percentage of drivers admitting to using their phones while on the road increased from 8% in 2014 to 31% in 2016, an increase of 23% in two years. [ 32 ] In the same year statistics revealed that only 30,000 drivers were given a Fixed penalty notice (FPN) for the offence, compared to 123,000 in 2011. [ 33 ] The increased percentage of people using their phones can be attributed in part to the growing affordability of smartphones. Increased smartphone sales and lack of enforcement created a situation where it began to be considered acceptable to use a phone while driving, even though it had been illegal for over 13 years. [ 34 ]
In 2017 the Department of transport (DfT) decided to increase the penalties to a £200 ($268) fine with 6 penalty points as a result of the growing acceptance of phone use while driving. [ 35 ] This would mean that motorists who perhaps already had 6 points on their driving licence, would be disqualified from driving for 6 months if caught. The biggest detriment would be for newly qualified drivers who have passed their driving tests within the last two years. [ 36 ] New drivers have conditions on their licence for two years after passing their test in the UK, with the most significant being that if they gain 6 penalty points on their licence they have to fully retake their driving test. Licence holders after 2 years have 12 points until licence disqualification in most circumstances rather than a ban/retest. [ 37 ] The decision to make the penalty 6 points rather than 4 or 5 was likely made to deter young/new drivers from using their phones while driving, as they were observed to be one of the largest age groups committing the offence. A year after the stricter law came in, a smaller 23% of motorists had admitted to using a phone while driving, an 8% reduction compared to 2 years ago. [ 38 ] Studies will continue to monitor whether or not this habit persist among motorists as it has done throughout the past, while the British government aims to make picking up your phone as socially unacceptable as drink driving. [ 39 ]
The scientific literature is mixed on the dangers of talking on a cell phone versus those of talking with a passenger. The common conception is that passengers are able to better regulate conversation based on the perceived level of danger, therefore the risk is negligible. A study by a University of South Carolina psychology researcher featured in the journal, Experimental Psychology, found that planning to speak and speaking put far more demands on the brain's resources than listening. Measurement of attention levels showed that subjects were four times more distracted while preparing to speak or speaking than when they were listening. [ 40 ] The Accident Research Unit at the University of Nottingham found that the number of utterances was usually higher for mobile calls when compared to blindfolded and non-blindfolded passengers across various driving conditions. The number of questions asked averaged slightly higher for mobile phone conversations, although results were not constant across road types and largely influenced by a large number of questions on the urban roads. [ 41 ]
A 2004 simulation study that compared passenger and cell-phone conversations concluded that the driver performs better when conversing with a passenger because the traffic and driving task become part of the conversation. Drivers holding conversations on cell phones were four times more likely to miss the highway exit than those with passengers, and drivers conversing with passengers showed no statistically significant difference from lone drivers in the simulator. [ 42 ] A study led by Andrew Parkes at the Transport Research Laboratory , also with a driving simulator, concluded that hands-free phone conversations impair driving performance more than other common in-vehicle distractions such as passenger conversations. [ 43 ] However, some have criticized the use of simulation studies to measure the risk of cell-phone use while driving since the studies may be impacted by the Hawthorne effect . [ 44 ]
In contrast, the University of Illinois meta-analysis concluded that passenger conversations were just as costly to driving performance as cell phone ones. [ 7 ] AAA ranks passengers as the third most reported cause of distraction-related crashes at 11%, compared to 1.5% for cellular telephones. [ 17 ] A simulation study funded by the American Transportation Research Board concluded that driving events that require urgent responses may be influenced by in-vehicle conversations, and that there is little practical evidence that passengers adjusted their conversations to changes in the traffic. It concluded that drivers' training should address the hazards of both mobile phone and passenger conversations. [ 45 ]
The scientific literature on the dangers of driving while sending a text message from a mobile phone, or texting while driving , is limited. A simulation study at the Monash University Accident Research Centre has provided strong evidence that both retrieving and, in particular, sending text messages has a detrimental effect on a number of critical driving tasks. Specifically, negative effects were seen in detecting and responding correctly to road signs, detecting hazards, time spent with eyes off the road, and (only for sending text messages) lateral position. Surprisingly, mean speed, speed variability, lateral position when receiving text messages, and following distance showed no difference. [ 46 ]
The low number of scientific studies may be indicative of a general assumption that if talking on a mobile phone increases risk, then texting also increases risk, and probably more so. Market research by Pinger , a company selling a voice-based alternative to texting reported that 89% of US adults think that text messaging while driving is "distracting, dangerous and should be outlawed." [ 47 ] The AAA Foundation for Traffic Safety released polling data in 2009 that showed 87% of people consider texting and e-mailing while driving a "very serious" safety threat, almost equivalent to the 90% of those polled who consider drunk driving a threat. Despite the acknowledgement of the dangers of texting behind the wheel, about half of drivers 16 to 24 say they have texted while driving, compared with 22% of drivers 35 to 44. [ 48 ]
Texting while driving received greater attention in the late 2000s, corresponding to a rise in the number of text messages being sent. Over a year approximately 2,000 teens die from texting while driving. [ 48 ] Texting while driving attracted interest in the media after several highly publicized car crashes were caused by texting drivers, including a May 2009 incident involving a Boston tram driver who crashed while texting his girlfriend. [ 49 ] Texting was blamed in the 2008 Chatsworth train collision which killed 25 passengers. Investigations revealed that the driver of that train had sent 45 text messages while at the controls.
In a 2011 study it was reported that over 90% of college students surveyed text (initiate, reply or read) while driving. [ 50 ] On July 27, 2009, the Virginia Tech Transportation Institute released preliminary findings of their study of driver distraction in commercial vehicles. Two studies, comprising about 200 long-haul trucks driving 3 million combined miles, used video cameras to observe the drivers and road; researchers observed "4,452 safety-critical events, which includes crashes, near-crashes, crash-relevant conflicts, and unintended lane deviations." 81% of the safety-critical events had some type of driver distraction. Text messaging had the greatest relative risk , with drivers being 23 times more likely to experience a safety-critical event when texting. The study also found that drivers typically take their eyes off the forward roadway for an average of four out of six seconds when texting, and an average of 4.6 out of the six seconds surrounding safety-critical events. [ 48 ]
In 2013 it was reported that, according to a national survey in the US, the number of drivers who reported using their cellphones to access the internet while driving had risen to nearly one of four. [ 51 ]
A study conducted by the University of Vienna using the theory of planned behavior identified two key determinants of high-level mobile phone use. Those two factors, subjective norm (i.e., perceived social norms ) and self-identity (i.e., the degree to which individuals see mobile phones as a part of their self), might be promising targets for the development of persuasive strategies and other interventions aimed at reducing inappropriate and problematic use of mobile phones, such as using mobile phones while driving. [ 52 ]
Mobile phone use while driving has economic impacts. Using a mobile phone while driving can definitely have economic costs to the driver using the phone (ex. paying for costs of collision, losing pay if late to work from distracted driving, etc.). More interesting however is how a driver's mobile phone use while driving can have external effects on both other drivers' safety and other drivers' economic property. Specifically, mobile phone use while driving produces negative consumption externalities where the consumer's (driver's) use of the phone while driving can reduce the well-being of others who are not paid by the consumer (i.e. outside the market mechanism). Mobile phone use can cause drivers to take their eyes off the road, minds off the road, and hands off the steering wheel. [ 53 ] These consumer distractions can negatively affect others in many ways such as collision or even fatality due to consumer distraction, congestion on the road due to slower driving speeds because of multitasking, and tardiness of those affected by the externality because of others' distracted driving. The negative consumption externalities produced from mobile phone use while driving not only affects others on the road but also causes economic inefficiencies. Externalities are a form of market failure where, by definition, the market fails to deliver an efficient outcome.
Figure 1 details the effects of this negative externality. In this case, the market quantity is too high where there are too many that use their mobile phone while driving. The socially optimal quantity (Q*) is thus lower than the market quantity (Q). To overcome this inefficiency, governments often must get involved and regulate price or quantity.
While there is no feasible way to ensure that driver's attention remains sufficiently focused on driving, there are ways that the government can intervene legislatively to discourage drivers from engaging in behaviors that potentially distract them from driving. [ 53 ] In cases of a negative consumption externality such as mobile phone use while driving, the government will usually impose a ban by way of price burden, in this case a fine or ticket, [ 53 ] in order to reduce the market quantity to a socially optimal quantity. An illustration of this intervention can be found below (Figure 2) where, in this case, the government has the ability to fine or ticket those who use a phone while driving in order to reduce the number of distracted drivers on the road. As illustrated, the market quantity (Q) of distracted driver's produced by mobile phone use while driving is too high and the socially optimal point for society is lower. Thus a ticket or some sort of price burden is put in place to reduce the market quantity to the socially optimal quantity (Q*).
The negative consumption externalities caused by mobile phone use while driving, as shown, has economic costs. Not only does mobile phone use while driving jeopardize safety for the driver, anyone in the car, or others on the road but it also produces economic costs to all parties involved. As shown, these costs are best managed with government intervention through policy or legislation changes. Ticketing is often the best choice as it affects only those who are caught performing the illegal act. Ticketing is another cost induced from mobile phone use and driving because ticketing laws for this act have only been put into place due to the large number of crashes caused by distracted drivers due to mobile phone use. Further, not only are the tickets costly to individuals who receive them but so is the price that must be paid to enforce the prohibition of mobile phone use while driving. Key to the success of a legislative measure is the ability to maintain and sustain them through enforcement or the perception of enforcement. [ 53 ] Police officer and photo radar cameras are other costs that must be paid in order to reduce this externality.
While paying tickets may be an undesired cost to pay by those who are given the ticket, ticket payments can actually have positive impacts in reducing the externality (discussed above) and increasing the total welfare of society. Ticket revenue often goes to state or local needs. For example, revenue from tickets can be used to improve local/state infrastructure and public schooling.
The effects of ticketing this negative consumption externality of mobile phone use while driving can be seen below. The graph shows the implementation of a ticket as having the same effect of a Pigouvian tax .
While this is the goal of the ticket, that is, to have the same effect of a Pigouvian tax which is intended to correct an inefficient market outcome, and does so by being set equal to the social cost of the negative externalities, that us usually not the case of a ticket. Tickets only affect those who receive the ticket while a tax effects all. The graphs shows ticket implementation as having the same effect as a Pigouvian tax. This is the ideal revenue brought in by ticketing as that is the price burden that will bring the socially optimal quantity. While this is ideal, this is very unlikely to happen through ticketing because, with ticketing, one must factor in the probability of someone receiving the ticket and multiple that probability by the price. The graph does not show this theoretical situation because the data of how often tickets are given for mobile phone use while driving is not conclusive.
While ticketing can be tricky to apply, the revenue brought in by ticket is a benefit to society as it can be used for local and state needs and will help reduce the externality.
Crashes involving a driver being distracted by talking on a mobile phone have begun to be prosecuted as negligence similar to speeding. In the United Kingdom , from 1 March 2017, motorists who are caught using a hand-held mobile phone while driving will have six penalty points added to their license in addition to the fine of £ 200. [ 54 ] This increase was introduced to try to stem the increase in drivers ignoring the law. [ 55 ] Japan prohibits hand-held mobile phone or mobile device use while driving. New Zealand has banned hand held mobile phone use since 1 November 2009. Many states in the United States have banned texting on cell phones while driving. Some states allow for drivers to use a cell phone mount but some states do not. Illinois became the seventeenth U.S. state to enforce this law. [ 56 ] As of July 2010, 30 states had banned texting while driving, with Kentucky becoming the most recent addition on July 15. [ 57 ]
Public Health Law Research maintains a list of distracted driving laws in the United States. This database of laws provides a comprehensive view of the provisions of laws that restrict the use of mobile communication devices while driving for all 50 states and the District of Columbia between 1992, when first law was passed, through December 1, 2010. The dataset contains information on 22 dichotomous, continuous or categorical variables including, for example, activities regulated (e.g., texting versus talking, hands-free versus handheld), targeted populations, and exemptions. [ 58 ]
In 2014, various state police forces in Australia have trialed cameras which have the ability to pick up errant drivers from more than 500 metres (1,600 ft) away. [ 59 ] Police in Western Australia makes use of undercover motorcycles to keep an eye on other motorists and any offence will be recorded on the officer's helmet camera. [ 60 ] Other countries with high levels of car crashes relating to distracted driving are also considering similar measures.
NSW road rules were changed on 1 December 2016 for P2 drivers. Learner, P1 and P2 drivers must not use mobile phones for any function while driving or riding or while stationary (at traffic lights). Drivers must be parked out of traffic to use their phones. [ 61 ]
The Road Transport Legislation Amendment (Mobile Phones—P2 Licences) Regulation 2016 under the Road Transport Act 2013 enforces this new rule and the objects of this Regulation sought:
(a) to amend the Road Rules 2014 to extend the restriction on drivers who are holders of learner or provisional P1 licences from using a mobile phone while driving a vehicle (whether or not the mobile
phone is held by the driver) to include drivers who are holders of provisional P2 licences, and
(b) to make consequential amendme [ 62 ] nts to the Road Transport (Driver Licensing) Regulation 2008.
This Regulation was made under the Road Transport Act 2013.
Prior to the introduction of this new law on 1 December 2016, only learner and P1 provisional licence-holders were barred from using mobile phones in any capacity while driving, as P2 drivers faced the same restrictions as other licence-holders.
Countries where using either a hand-held or hands-free phone while driving is illegal:
Countries where using a hand-held phone while driving is illegal: | https://en.wikipedia.org/wiki/Mobile_phones_and_driving_safety |
In the U.S., the Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight . [ 1 ] Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 permits airlines to determine if devices can be used in flight, allowing use of "any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used." [ 2 ]
In Europe, regulations and technology have allowed the limited introduction of the use of passenger mobile phones on some commercial flights, and elsewhere in the world many airlines are moving towards allowing mobile phone use in flight. [ 3 ] Many airlines still do not allow the use of mobile phones on aircraft. [ 4 ] Those that do often ban the use of mobile phones during take-off and landing.
Many passengers are pressing airlines and their governments to allow and deregulate mobile phone use, while some airlines, under the pressure of competition, are also pushing for deregulation or seeking new technology which could solve the present problems. [ 5 ] Official aviation agencies and safety boards are resisting any relaxation of the present safety rules unless and until it can be conclusively shown that it would be safe to do so. There are both technical and social factors which make the issues more complex than a simple discussion of safety versus hazard. [ 6 ]
A regulation, SR-446, prohibiting the usage of FM radios onboard aircraft at certain times was issued by the Federal Aviation Agency on 25 May 1961 in response to studies that showed they could interfere with VHF omnidirectional range navigation systems operating on the 108 to 118 MHz frequency band. Subsequent testing led to the expansion of the covered devices to all "portable electronic devices" in the first published rulemaking in 14 CFR 91.19 in 1966. [ 7 ] [ 8 ] [ 9 ] [ a ] The Federal Communications Commission ban on use of cell phones in flight was promulgated in 1994. [ 11 ]
In the United States , the Federal Communications Commission (FCC) restricts cell phone usage on aircraft in order to prevent disruption to cellular towers on the ground. [ 12 ] As mentioned above, the FAA allows the in-flight use of wireless devices but only after the airline has determined that the device will not interfere with aircraft communication or navigation.
One study [ 13 ] concluded that some "portable electronic devices", including laptops, electronic toys and laser pointers, used in the cabin can exceed the aircraft manufacturer's permissible emission levels for safety with regard to some avionics, while they were unsuccessful in duplicating any of the errors suspected to be caused by these devices' use in controlled lab conditions.
Since these regulations were originally imposed by various international aviation agencies, ultra-low-power devices, such as picocells , have been developed. Reasons for this include improved security, reduction of interference, and allowing safe in-flight use of mobile phones. Many airline companies have now added such equipment to their aircraft. More are expected to do so in the coming years. [ 3 ]
Electromagnetic interference to aircraft systems is a common argument offered for banning mobile phones (and other passenger electronic devices) on planes. Theoretically, active radio transmitters like mobile phones, walkie-talkies , and wireless computer peripherals (such as mice or game controllers using Bluetooth or other wireless technologies) may interfere with the aircraft. Non-transmitting electronic devices also emit electromagnetic radiation, although typically at a lower power level, and could also theoretically affect the aircraft electronics. Collectively, any of these may be referred to as portable electronic devices (PEDs).
A NASA publication [ 14 ] details the 50 most recent reports to the Aviation Safety Reporting System (ASRS) regarding "avionics problems that may result from the influence of passenger electronic devices." The nature of these reports varies widely. Some merely describe passengers' interactions with flight crews when asked to stop using an electronic device. Other reports amount to crews reporting an anomaly experienced at the same time a passenger was witnessed using a mobile phone. A few reports state that interference to aircraft systems was observed to appear and disappear as that particular suspect device was turned on and off. One entry in the ASRS, designated ACN: 440557, [ 15 ] reports a clear link where a passenger's DVD player induced a 30-degree error in the display of the aircraft's heading, each time the player was switched on. However, this report dates back to 1999 and involves a Boeing 727 , an old type of aircraft that is no longer in use by airlines today.
A 2003 study [ 16 ] involved three months of testing with RF spectrum analyzers and other instruments aboard regular commercial flights, and one passage reads:
...our research has found that these items can interrupt the normal operation of key cockpit instruments, especially Global Positioning System (GPS) receivers, which are increasingly vital to safe landings. Two different studies by NASA further support the idea that passengers' electronic devices dangerously produce interference in a way that reduces the safety margins for critical avionics systems. There is no smoking gun to this story: there is no definitive instance of an air accident known to have been caused by a passenger's use of an electronic device. Nonetheless, although it is impossible to say that such use has contributed to air accidents in the past, the data also make it impossible to rule it out completely. More importantly, the data support a conclusion that continued use of portable RF-emitting devices such as cell phones will, in all likelihood, someday cause an accident by interfering with critical cockpit instruments such as GPS receivers. This much is certain: there exists a greater potential for problems than was previously believed.
A 2000 study by the British Civil Aviation Authority [ 17 ] found that a mobile phone, when used near the cockpit or other avionics equipment location, will exceed safety levels for older equipment (compliant with 1984 standards). Such equipment is still in use, even in new aircraft. Therefore, the report concludes, the current policy, which restricts the use of mobile phones on all aircraft while the engines are running, should remain in force.
Critics of the ban doubt that small battery-powered devices would have any significant influence on a commercial jetliner's shielded electronic systems. Safety researchers Tekla S. Perry and Linda Geppert point out that shielding and other protections degrade with increasing age, cycles of use, and even some maintenance procedures, as is also true of the shielding in PEDs, including mobile phones. [ 16 ]
Several reports argue both sides of the issue in the same article; on the one hand they highlight the lack of definite evidence of mobile phones causing significant interference, while on the other hand they point out that caution in maintaining restrictions on using mobile phones and other PEDs in flight is the safer course to take. [ 4 ] [ 13 ] [ 18 ]
Many people may prefer a ban on mobile phone use in flight as it prevents undue amounts of noise from mobile phone chatter. AT&T has suggested that in-flight mobile phone restrictions should remain in place in the interests of reducing the nuisance to other passengers caused by someone talking on a mobile phone near them. [ 6 ]
Skeptics of the ban have suggested that the airlines support the ban because they do not want passengers to have an alternative to the in-flight phone service such as GTE's Airfone . [ 19 ] Andy Plews, a spokesman for UAL's United Airlines, was quoted as saying "We don't believe it's a good safety issue...We'd like people to use the air phones." [ 20 ]
On 31 October 2013, the FAA issued a press release entitled "FAA to Allow Airlines to Expand Use of Personal Electronics" [ 21 ] in which it announced that "airlines can safely expand passenger use of Portable Electronic Devices (PEDs) during all phases of flight." This new policy does not include cell phone use in flight, because, as the press release states, "The FAA did not consider changing the regulations regarding the use of cell phones for voice communications during flight because the issue is under the jurisdiction of the Federal Communications Commission (FCC)."
This FAA press release was quickly followed up by an FCC press release entitled "Chairman Wheeler Statement on In-Flight Mobile Services Proposal" [ 22 ] in which FCC Chairman Tom Wheeler states, "modern technologies can deliver mobile services in the air safely and reliably, and the time is right to review our outdated and restrictive rules." This has led to media speculation [ 23 ] that the use of cell phones for voice communication on board an aircraft in flight will soon be allowed.
Some airlines have installed technologies to allow phones to be connected within the airplane as it flies. Such systems were tested on scheduled flights from 2006 and in 2008 several airlines started to allow in-flight use of mobile phones. [ 3 ]
As of 2018, Chinese regulations (and major carriers including China Southern Airlines, China Eastern Airlines and Air China) permit phone usage in flight mode (with transmitters off). [ 24 ]
On 20 March 2008, Emirates flights began allowing in-flight voice calls on some commercial airline flights. [ 25 ]
AeroMobile and OnAir allow the use of personal electronics devices aboard flights. The services are most readily available in Europe and are licensed to specific airlines. [ 3 ] [ 26 ]
Since 26 August 2014, Qantas permits mobile phones (and other portable electronic devices weighing less than 1 kg; 2 lb) to be switched on during the entire flight, if the devices are in flight mode while on board the aircraft. [ 27 ] [ 28 ] Jetstar (owned by Qantas) adopted the same arrangements on 30 August 2014. [ 29 ]
On 30 August 2006, the Irish airline Ryanair announced that it would introduce a facility to allow passengers to use their mobile phones in-flight. [ 30 ] This service started on 19 February 2009 with 20 of their Dublin-based aircraft. [ 31 ]
Turkish Airlines ' stated position is that "Mobile phones interfere with the flight instruments and have a negative effect on flight safety." [ 16 ]
Dassault Aviation implemented a new concept designated SafeCell on 2 April 2009 when the Falcon 2000 commenced flying. [ 32 ]
On 18 October 2007, the Office of Communications published proposals [ 33 ] for the technical and authorisational approach that would be adopted to allow this for European GSM users on the 1800 MHz band on UK registered aircraft. [ 34 ] and on 26 March 2008 Ofcom approved the use of mobile phone-supporting picocells aboard aircraft in the United Kingdom. Airline companies will have to first equip the aircraft with picocells and apply for licences. [ 35 ] [ 36 ]
To prevent disruption to the cellular phone network from the effects of fast-moving cell phones at altitude (see Technical discussion , below), the FCC has banned the use of mobile phones on all aircraft in flight. [ 1 ] The FCC did, however, allocate spectra in the 450 MHz and 800 MHz frequency bands for use by equipment designed and tested for air-ground radiotelephone service . These systems use far more widely separated ground stations than standard cellular systems. In the 450 MHz band co-channel assignments are at least 497 miles apart and in the 800 MHz band only specific sites were authorized by the FCC. The 450 MHz service is limited to "general aviation" users, usually corporate jets, while the 800 MHz spectrum can be used by airliners as well as for general aviation. [ 37 ]
The FAA in 14 C.F.R § 91.21 prohibits the use of portable electronic devices, including mobile phones, for all commercial flights and for those private flights being made under instrument flight rules (IFR). It does allow that the airline (or, for privately operated aircraft, the pilot) can make an exception to this rule if the operator deems that device safe. This effectively gives the airline, or the private pilot, the final word as to what devices may safely be used aboard an aircraft as far as the FAA is concerned although the FCC restriction still applies. [ 2 ] (Note that for aircraft operated by an airline the pilot is not considered the "operator" and cannot legally allow exceptions to the airline's restrictions although the pilot may dictate additional restrictions. [ 38 ] )
On February 11, 2014, the House Committee on Transportation and Infrastructure approved the Prohibiting In-Flight Voice Communications on Mobile Wireless Devices Act. The bill would forbid airline passengers from talking on mobile phones during a flight. [ 39 ] In September 2014, a bipartisan group of lawmakers opposed the FCC ending the ban on mobile phones aboard, citing safety as one of the main concerns. [ 40 ]
In September 2014, the European Aviation Safety Agency removed its ban on mobile phone use during flights. [ 41 ] The new guidance allows airlines to permit portable electronic devices to stay switched on, without the need to be in 'Airplane Mode'. This enables the ability to offer 'gate-to-gate' telecommunication or WiFi services. [ 42 ]
On 19 January 2018, the Telecom Regulatory Authority of India (TRAI) permitted the use of mobile phones and internet access through Wi-Fi on-board all flights operating in Indian airspace. However, passengers are only permitted to make mobile phone calls when the aircraft is at an altitude of over 3,000 metres (9,800 ft). TRAI stated that the height restriction was to ensure "compatibility with terrestrial mobile networks". [ 43 ] [ 44 ]
A few U.S. airlines have announced plans [ 45 ] [ 46 ] to install new technology on aircraft which would allow mobile phones to be used on aircraft, pending approval by the FCC and the FAA. This method is similar to that used in most cars on the German ICE train. The aircraft would carry a device known as a picocell . A picocell acts as a miniature base station (like a cellphone tower) communicating with cellphones within the aircraft and relaying the signals to either satellites or a terrestrial-based system. The picocell will be designed and maintained for full compatibility with the aircraft avionics. Communication between the picocell and the rest of the telephone network will be on separate frequencies that do not interfere with either the cellular system or the aircraft's avionics, similarly to the on–board proprietary phone systems already aboard many commercial aircraft. Since the picocell's antennas within the aircraft would be very close to the passengers and inside the aircraft's metal shell both the picocell's and the cell phones' output power could be reduced to very low levels, which would reduce the risk of interference. Such systems have been tested on a few flights within the United States under a waiver from the FCC. [ citation needed ]
ARINC and Telenor have formed a joint venture company to offer such a service aboard commercial aircraft. The cell phone calls are routed via satellite to the ground network and an on-board EMI screening system prevents the cell phones from attempting to contact ground-based networks. [ 47 ]
These systems are comparatively easy to implement for customers in most of the world where GSM phones operating on one of just two bands are the norm. The multitude of incompatible mobile phone systems in the United States and some other countries makes the situation more difficult—it is not clear if the onboard repeaters will be compatible with all of the different cell-phone protocols ( TDMA , GSM , CDMA , iDen ) and their respective providers.
The U.S. Federal Communications Commission (FCC) currently prohibits the use of mobile phones aboard any aircraft in flight. The reason given is that cell phone systems depend on frequency reuse , which allows for a dramatic increase in the number of customers that can be served within a geographic area on a limited amount of radio spectrum, and operating a phone at an altitude may violate the fundamental assumptions that allow channel reuse to work. [ 48 ] [ further explanation needed ] And since the aircraft is moving at a high speed, cell phones will try to reconnect to every base station it passes over, as cellular devices are meant to connect to a base station that has the strongest signal. This can cause interference with cellular services on the ground. | https://en.wikipedia.org/wiki/Mobile_phones_on_aircraft |
Mobile porn , also known as mobile adult content , mobile erotica or cellphone adult content , is pornography transmitted over mobile telecommunications networks for consumption on mobile devices (mainly mobile phones , tablets and smartphones ). [ 1 ]
Just like the internet and pay TV , the adult entertainment industry was one of the first forms of mass media to embrace mobile devices as a new means to distribute content. During 2002, Private Media Group became the first adult media company to employ a dedicated mobile specialist. This initiative led to the industry's first adult SMS services, erotic mobile content distribution and mobile internet (WAP) site, called "Private Mobile", offering a small range of videos directly to their consumers. [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] This service was intended for the increasing range of Private consumers using feature phones in Europe with colour screens.
From the mid-2000s onwards, many mobile network operators eventually deployed age verification systems and industry-regulated explicitness grading levels that gradually allowed mobile erotica to be legally purchased through gated mobile operator portal communities only by consenting adults. [ 7 ]
With the onset of smartphones in 2007 and portable tablet computers thereafter, more and more consumers in developed markets have since left these gated mobile operator communities and now browse the internet on their mobile and apps instead for their mobile erotica.
Widespread adoption of Apple's iPhone was initially expected to encourage growth in the mobile erotica industry. [ 8 ] Following the release of the original iPhone in 2007, the search term "iPhone Porn" spiked considerably in popularity. [ 9 ] with 37% of iPhone users watching video on their iPhone [ 10 ] However, Apple chairman Steve Jobs made it clear that no adult content would ever be sold from Apple's App Store , [ 11 ] and thousands of adult apps have been banned on the App Store. [ 12 ] However, Apple's ban on adult apps has been criticized as being impractical and ineffective. [ 13 ]
Other companies in the mobile and video industries situated themselves to take advantage of this trend. Google built a new phone system called Google Play that supports any application within reasonable decency guidelines. Since then, dedicated adult-only app stores like MiKandi and other mobile internet publishers have benefited from this gap in the market instead.
Following its inception in 2002, the mobile erotica business was expected to grow to a market value of $2.3 billion within its first eight years. [ 14 ]
The North American mobile erotica market differs from Europe in that carriers were slow to allow adult sites to use their subscriber payment mechanisms such as SMS , slowing market growth. [ citation needed ] Alternate business models involve offering free videos in the 'tube' style of websites with advertising funding. For the cost of viewing an ad, users can get free video clips.
Verizon Wireless and Sprint Nextel Corporation announced as late as 2008 that they would allow some adult content to be viewed on their networks, while working to prevent access to this content by children. There have been expectations for some time that these companies will overcome age-verification, political, and religious challenges that have become a barrier to this market, to take advantage of the resulting increase in mobile web-surfing on their networks. [ 15 ]
There has been some criticism of mobile porn, namely the exposure of children to inappropriate and unregulated content. [ 16 ] [ 17 ] However, most mobile network operators have implemented age verification systems, which require that customers who want to buy porn through their phone legally prove that they are a consenting adult first. [ citation needed ]
Sony , the company which created the PlayStation Portable (PSP), say that they are unhappy with the spread of PSP porn, but claim to be unable to stop its spread. [ 18 ] | https://en.wikipedia.org/wiki/Mobile_porn |
Mobile procurement is mobile business software that helps organizations streamline their procurement process from a mobile device. Features of mobile procurement software include mobile purchase order creation, on-demand notifications, and real-time analytics. What makes mobile procurement successful is the ability to leverage software-side servers to move data along. The key benefit for organizations using mobile procurement systems is the ability to track business operations using any ordinary mobile device.
Mobile procurement software is generally represented in the form of custom applications provided as an add-on feature of a larger enterprise resource planning software solution. As such, if the goal of a mobile procurement system should be to complement existing information systems, [ 1 ] mobile procurement software should typically involve the needs of procurement professionals before implementation. Assuring that necessary features are prioritized over having many features is key to successful user adoption.
It also simplifies order management processes by removing the confusion and disorder often seen with paper-based procurement. Mobile procurement provides a clearer view of the steps behind procurement and give companies the insight needed to consistently secure the best possible total cost of ownership.
Mobile enterprise application software is the use of office software applications on a mobile platform in a way that adapts to different devices and networks. Many organizations use these applications to increase employee productivity and streamline business operations.
The first common mobile enterprise application was the implementation of email. Now, 53% of emails [ 2 ] are opened on a mobile device, a 45% increase in three years. The next wave of popular mobile enterprise application software was the advent of the CRM software . This allows salespeople to stay up-to-date with the business and manage customer relationships crucial to success from anywhere.
Another enterprise software application being leveraged on a mobile platform is procurement . This trend is led by the consumer shopping experience. Over 36% of online sales on Black Friday in 2015 came from mobile shopping, according to IBM. [ 3 ] As more shoppers are migrating to mobile applications, procurement departments need to keep up with user preferences. This mobile platform provides capabilities to complete the procurement process from start to finish. This includes searching for items and services, comparing vendors and prices, submitting purchase requests, approving requests, electronic signing, purchase orders and invoicing. Being able to accomplish this all in one place from any device significantly streamlines business procurement and operations.
Users leverage mobile procurement for various reasons, and the tool can benefit businesses in many ways.
User Convenience The clear advantage of using mobile procurement is the ability to use it anywhere from any device. This eliminates interruptions in the process or the need to complete a request from a single device. Users can search, compare and request items from anywhere. Suppliers can receive and sign purchase orders electronically. Checking inventory levels of physical locations provides a strong utility for mobile procurement.
Save Time Mobile procurement saves time by reducing approval cycle time. A manager can make approvals from anywhere, not just his office. Users can request things they need when they need it, instead of after the fact, breaking corporate policy. Procurement now fills idle time rather than being a major item on a to-do list. This keeps employees and business moving forward. A fast procurement turnaround increases outcomes.
Visibility Full visibility of suppliers and information helps businesses make informed decisions for better results and quicker processes. User analytics also help companies shop smarter in the long run.
Mobile interaction now exceeds desktop Web interaction by 9%. [ 4 ] Now that mobile is the dominant form of online activity, mobile procurement is simply a natural step into today's digital landscape. Mobile procurement platforms can be approached in two ways: native apps or Web apps using HTML5.
Native Apps A native app is a mobile application developed specifically for use on mobile devices, launched directly from the home screen. In the United States, use of mobile apps greatly exceeds use of mobile Web browsing, but that trend is not worldwide. [ 5 ]
Using a native app requires development for all operating systems and brands. A fully operational native app needs to be designed for iOS , Android , Microsoft , all their various generations, and at different resolutions and orientations. For total success of an app, users will expect it to work on everything from a high-resolution tablet down to an Apple Watch.
The other factor to consider with native apps is the way they access backend data. This is often more complex than a simple push to read data that takes place on a Web browser. Apps are developed, depending on their purpose and functionality, to access other applications such as the camera or local storage.
Native apps can be the preferred use of mobile procurement in environments with either no IT access or highly secure networks. Financial institutions value privacy and security when considering mobile tools operating in their network. Oil and gas environments are often remote and require apps that can work with limited Internet access.
A downside to mobile apps is the memory they occupy on a device. Because of this, many businesses will steer away from apps that require a great deal of storage.
Web Apps and HTML5 A Web app is run by a browser and is really a responsive Web site. Responsive sites change and adapt to any digital environment, including operating system, screen size and orientation. This has several advantages for mobile procurement platforms.
Responsive design can adjust to any browser on any device. The design is such that images, text, and user experience adjust based on the size and resolution of the platform. Adaptive web design is based on predetermined parameters for each platform. Both are ideal for any business that plans on interacting with customers on any type of mobile device.
HTML , JavaScript and CSS3 seamlessly integrate backend systems with browsers and user interfaces. This creates an easy-to-use experience for all users on any device. Although some designs are scaled down, which can limit functionality, responsive and adaptive web design is easily accessible for any customer. And functionality is all about priority. If a scaled down site still performs the necessary functions, users will still find the advantages of increased turnarounds and time saving.
The widespread availability of Wi-Fi increases the availability of HTML5 sites, reducing concerns about accessibility. With Wi-Fi everywhere, mobile procurement can happen in any place on a responsive site.
Elegantly designed responsive and adaptive sites are the ideal solution for mobile procurement because of the simplicity of creating and implementing one. If a user's experience is smooth and consistent, they will have no problem accessing a mobile procurement platform from any device. With the advancement of tools and technology it is currently possible to provide a native feel and minimal native feature set to your mobile products. Examples would be AngularJS, which allows for rapid web app development while preserving quality. | https://en.wikipedia.org/wiki/Mobile_procurement |
Mobile radio or mobiles refer to wireless communications systems and devices which are based on radio frequencies (using commonly UHF or VHF frequencies), and where the path of communications is movable on either end. There are a variety of views about what constitutes mobile equipment. For US licensing purposes, mobiles may include hand-carried , (sometimes called portable ), equipment. An obsolete term is radiophone . [ a ] [ 1 ] [ 2 ] [ 3 ]
A sales person or radio repair shop would understand the word mobile to mean vehicle-mounted : a transmitter-receiver (transceiver) used for radio communications from a vehicle. Mobile radios are mounted to a motor vehicle usually with the microphone and control panel in reach of the driver. In the US, such a device is typically powered by the host vehicle's 12 Volt electrical system.
Some mobile radios are mounted in aircraft (aeronautical mobile), shipboard (maritime mobile), on motorcycles, or railroad locomotives. Power may vary with each platform. For example, a mobile radio installed in a locomotive would run off of 72 or 30 Volt DC power. A large ship with 117 V AC power might have a base station mounted on the ship's bridge.
According to article 1.67 of the ITU , a mobile radio is "A station in the mobile service intended to be used while in motion or during halts at unspecified points." [ 4 ]
The distinction between radiotelephones and two-way radio is becoming blurred as the two technologies merge. [ citation needed ] The backbone or infrastructure supporting the system defines which category or taxonomy applies. A parallel to this concept is the convergence of computing and telephones.
Radiotelephones are full-duplex (simultaneous talk and listen), circuit switched, and primarily communicate with telephones connected to the public switched telephone network . [ citation needed ] The connection sets up based on the user dialing. [ citation needed ] The connection is taken down when the end button is pressed. They run on telephony-based infrastructure such as AMPS or GSM . [ citation needed ]
Two-way radio is primarily a dispatch [ citation needed ] tool intended to communicate in simplex or half-duplex modes using push-to-talk, and primarily intended to communicate with other radios rather than telephones. These systems run on push-to-talk-based infrastructure such as Nextel's iDEN , Specialized Mobile Radio (SMR), MPT-1327 , Enhanced Specialized Mobile Radio (ESMR) or conventional two-way systems. Certain modern two-way radio systems may have full-duplex telephone capability.
Early users of mobile radio equipment included transportation and government. These systems used one-way broadcasting instead of two-way conversations. Railroads used medium frequency range ( MF ) communications (similar to the AM broadcast band) to improve safety. Instead of hanging out of a locomotive cab and grabbing train orders while rolling past a station, voice communications with rolling trains became possible. Radios linked the caboose with the locomotive cab. Early police radio systems were initially one way using MF frequencies above the AM broadcast band, (1.7 MHz ). Some early systems talked back to dispatch on a 30-50 MHz link, (called crossband ).
Early mobile radios used amplitude modulation (AM) to convey intelligence through the communications channel. In time, problems with sources of electrical noise showed that frequency modulation (FM) was superior for its ability to cope with vehicle ignition and power line noise. The frequency range used by most early radio systems, 25–50 MHz (vhf "low band") is particularly susceptible to the problem of electrical noise. This plus the need for more channels led to the eventual expansion of two-way radio communications into the VHF "high band" (150–174 MHz) and UHF (450–470 MHz). The UHF band has since been expanded again.
One of the major challenges in early mobile radio technology was that of converting the six or twelve volt power supply of the vehicle to the high voltage needed to operate the vacuum tubes in the radio. Early tube-type radios used dynamotors - essentially a six or twelve volt motor that turned a generator to provide the high voltages required by the vacuum tubes. Some early mobile radios were the size of a suitcase or had separate boxes for the transmitter and receiver. As time went on, power supply technology evolved to use first electromechanical vibrators , then solid-state power supplies to provide high voltage for the vacuum tubes. These circuits, called " inverters ", changed the 6 or 12 V direct current (DC) to alternating current (AC) which could be passed through a transformer to make high voltage. The power supply then rectified this high voltage to make the high voltage DC required for the vacuum tubes, (called valves in British English). The power supplies needed to power vacuum tube radios resulted in a common trait of tube-type mobile radios: their heavy weight due to the iron -core transformers in the power supplies. These high voltage power supplies were inefficient, and the filaments of the vacuum tubes added to current demands, taxing vehicle electrical systems. Sometimes, a generator or alternator upgrade was needed to support the current required for a tube-type mobile radio.
Examples of US 1950s-1960s tube-type mobile radios with no transistors :
Equipment from different US manufacturers had similar traits. This was partly dictated by Federal Communications Commission (FCC) regulations. The requirement that unauthorized persons be prohibited from using the radio transmitter meant that many radios were wired so they could not transmit unless the vehicle ignition was on. Persons without a key to the vehicle could not transmit. Equipment had to be "type accepted", or technically approved, by the FCC before it could be offered for sale. In order to be type accepted, the radio set had to be equipped with an indicator light, usually green or yellow, that showed power was applied and the radio was ready to transmit. Radios were also required to have a lamp (usually red) indicating when the transmitter was on. These traits continue in the design of modern radios.
Early tube-type radios operated on 50 kHz channel spacing with ±15 kHz modulation deviation. This meant that the number of radio channels that could be accommodated in the available radio frequency spectrum were limited to a certain number, dictated by the bandwidth of the signal on each channel.
Solid-state electronic equipment arrived in the 1960s, with more efficient circuitry and smaller size. Metal–oxide–semiconductor (MOS) large-scale integration (LSI) provided a practical and economic solution for radio technology, and was used in mobile radio systems by the early 1970s. [ 5 ] Channel spacing narrowed to 20–30 kHz with modulation deviation dropping to ±5 kHz. This was done to allow more radio spectrum availability to accommodate the rapidly growing national group of two-way radio users. By the mid-1970s, tube-type transmitter power amplifiers had been replaced with high-power transistors . From the 1960s to the 1980s, large system users with specialized requirements often had custom built radios designed for their unique systems. Systems with multiple- CTCSS tone encoders and more than two channels were unusual. Manufacturers of mobile radios built customized equipment for large radio fleets such as the California Department of Forestry and the California Highway Patrol .
Examples of US hybrid partially solid state mobile radios:
Custom design for a particular customer is a thing of the past. Modern mobile radio equipment is "feature rich". A mobile radio may have 100 or more channels, be microprocessor controlled and have built-in options such as unit ID . A computer and software is typically required to program the features and channels of the mobile radio. Menus of options may be several levels deep and offer a complicated array of possibilities. Some mobile radios have alphanumeric displays that translate channel numbers (F1, F2) to a phrase more meaningful to the user, such as "Providence Base", "Boston Base", etc. Radios are now designed with a myriad of features to preclude the need for custom design. For example, Hytera 's HM68X mobile radio, which was introduced in September 2022, offers a variety of features, including GPS location, emergency alarm, noise cancellation, and more. [ 6 ]
Examples of US microprocessor-controlled mobile radios:
As use of mobile radio equipment has virtually exploded, channel spacing has had to be narrowed again to 12.5–15 kHz with modulation deviation dropped to ±2.5 kilohertz. In order to fit into smaller, more economical vehicles, today's radios are trending toward radically smaller sizes than their tube-type ancestors. The traditional analogue radio communications have been surpassed by digital radio voice communications capabilities that provide greater clarity of transmission, enable security features such as encryption and, within the network, allow low band data transmissions to accommodate simple text or picture messaging as an example. (Examples: Project 25 (APCO-25), Terrestrial Trunked Radio ( TETRA ), DMR .)
Commercial and professional mobile radios are often purchased from an equipment supplier or dealer whose staff will install the equipment into the user's vehicles. Large fleet users may buy radios directly from an equipment manufacturer and may even employ their own technical staff for installation and maintenance.
A modern mobile radio consists of a radio transceiver, housed in a single box, and a microphone with a push-to-talk button. Each installation would also have a vehicle-mounted antenna connected to the transceiver by a coaxial cable. Some models may have an external, separate speaker which can be positioned and oriented facing the driver to overcome ambient road noise present when driving. The installer would have to locate this equipment in a way that does not interfere with the vehicle's sun roof, electronic engine management system, vehicle stability computer, or air bags.
Mobile radios installed on motorcycles are subject to extreme vibration and weather. Professional equipment designed for use on motorcycles is weather and vibration resistant. Shock mounting systems are used to reduce the radio's exposure to vibration imparted by the motorcycle's modal, or resonant, shaking.
Some mobile radios use noise-canceling microphones or headsets. At speeds over 100 MPH, the ambient road and wind noise can make radio communications difficult to understand. For example, California Highway Patrol mobile radios have noise-canceling microphones which reduce road and siren noise heard by the dispatcher . Most fire engines and radios in heavy equipment use noise-canceling headsets. These protect the occupant's hearing and reduce background noise in the transmitted audio. Noise-canceling microphones require the operator speak directly into the front of the microphone. Hole arrays in the back of the microphone pick up ambient noise. This is applied, out-of-phase, to the back of the microphone, effectively reducing or canceling any sound which is present both in front and back of the microphone. Ideally, only the voice present on the front side of the microphone goes out on the air.
Many radios are equipped with transmitter time-out timers which limit the length of a transmission. A bane of push-to-talk systems is the stuck microphone: A radio locked on transmit, which disrupts communications on a two-way radio system. One example of this problem occurred in a car with a concealed two-way radio installation where the microphone and coiled cord were hidden inside the glove box. An operator tossed the mike into the glove box and shut it, causing the push-to-talk button to be depressed and locking the transmitter on. On taxi systems, a driver may be upset when a dispatcher assigns a call (s)he wanted to another driver and may deliberately hold the transmit button down (for which the owner can be fined by the FCC). Radios with time-out timers transmit for the preset amount of time, usually 30–60 seconds, after which the transmitter automatically turns off and a loud tone comes out of the radio speaker. The volume level of the tone on some radios is loud and cannot be adjusted. As soon as the push-to-talk button is released, the tone stops and the timer resets.
Mobile radio equipment is manufactured to specifications developed by the Electronic Industries Association / Telecommunications Industry Association (EIA/TIA). These specifications have been developed to help assure the user that mobile radio equipment performs as expected and to prevent the sale and distribution of inferior equipment which could degrade communications.
A mobile radio must have an associated antenna. The most common antennas are stainless steel wire or rod whips which protrude vertically from the vehicle. Physics defines the antenna length: length relates to frequency and cannot be arbitrarily lengthened or shortened (more likely) by the end user. The standard "quarter wave" antenna in the 25-50 MHz range can be over nine feet long. A 900 MHz antenna may be three inches long for a quarter wavelength. A transit bus may have a ruggedized antenna, which looks like a white plastic blade or fin, on its roof. Some vehicles with concealed radio installations have antennas designed to look like the original AM/FM antenna, a rearview mirror, or may be installed inside windows, or hidden on the floor pan or underside of a vehicle. Aircraft antennas look like blades or fins, the size and shape being determined by frequencies used. Microwave antennas may look like flat panels on the aircraft's skin. Temporary installations may have antennas which clip on to vehicle parts or are attached to steel body parts by a strong magnet.
Though initially relatively inexpensive mobile radio system components, frequently damaged antennas can be costly to replace since they are usually not included in maintenance contracts for mobile radio fleets. Some types of vehicles in 24-hour use, with stiff suspensions, tall heights, or rough diesel engine idle vibrations may damage antennas quickly. The location and type of antenna can affect system performance drastically. Large fleets usually test a few vehicles before making a commitment to a certain antenna location or type.
U.S. Occupational Safety and Health Administration guidelines for non-ionizing radio energy generally say the radio antenna must be two feet from any vehicle occupants. This rule of thumb is intended to prevent passengers from being exposed to unsafe levels of radio frequency energy when the radio transmits.
Dispatch-reliant services, such as tow cars or ambulances , may have several radios in each vehicle. For example, tow cars may have one radio for towing company communications and a second for emergency road service communications. Ambulances may have a similar arrangement with one radio for government emergency medical services dispatch and one for company dispatch.
US ambulances often have radios with dual controls and dual microphones allowing the radio to be used from the patient care area in the rear or from the vehicle's cab. [ 7 ]
Both tow cars and ambulances may have an additional radio which transmits and receives to support a mobile data terminal . A data terminal radio allows data communications to take place over the separate radio. In the same way that a facsimile machine has a separate phone line, this means data and voice communication can take place simultaneously over a separate radio. Early Federal Express (FedEx) radio systems used a single radio for data and voice. The radio had a request-to-speak button which, when acknowledged, allowed voice communication to the dispatch center.
Each radio works over a single band of frequencies. If a tow car company had a frequency on the same band as its auto club, a single radio with scanning might be employed for both systems. Since a mobile radio typically works on a single frequency band, multiple radios may be required in cases where communications take place over systems on more than one frequency band. [ 8 ] [ 7 ]
Intended as a cost savings, some systems employ vehicular chargers instead of a mobile radio. Each radio user is issued a walkie talkie . Each vehicle is equipped with a charger system console. The walkie talkie inserted into a vehicular charger or converter while the user is in the vehicle. The charger or converter (1) connects the walkie talkie to the vehicle's two-way radio antenna, (2) connects an amplified speaker, (3) connects a mobile microphone, and (4) charges the walkie talkie's battery. [ b ] The weak point of these systems has been connector technology which has been proven unreliable in some installations. Receiver performance is a problem in congested radio signal and urban areas. These installations are sometimes referred to as jerk-and-run systems. | https://en.wikipedia.org/wiki/Mobile_radio |
Mobile reporting is a trend emerging in the field of news and content generation. [ 1 ] [ 2 ] The term describes the use of a mobile phone as a reporting tool. The user creates text, photo and video that combined produces a multimedia based report. The content is edited on the phone before being uploaded to the internet via mobile network or Internet connection. [ 3 ] Usually mobile reporting is used for publishing to the web. [ 4 ] This is particularly the case with video as the technology does not yet allow for the production of high end video. However, the low quality is suitable for Internet.
Mobile reporting is particularly relevant in areas that lack modern Internet infrastructure (Sub Sahara Africa, [ 5 ] [ 6 ] Central Asia , South America, Latin America ). [ 7 ] [ 8 ] The mobile phone is low in cost when compared to more traditional reporting equipment.
Specifically, mobile field reporting may also refer to enabling employees and staff, and first responders (police, fire, EMS ) to access their networks and resources in a secure and timely manner using various public or proprietary mobile devices and applications. [ 9 ] [ 10 ]
Mobile Reporting makes use of a content repurposing platform. This is a platform that supports services that let content owners and users create, share and publish multimedia content whenever and wherever, regardless of format or device. A mobile reporting platform takes care of the compatibility between the originating and target device. | https://en.wikipedia.org/wiki/Mobile_reporting |
The mobile switching station , abbreviated as MSC Server or MSS , is a 2G core network element which controls the network switching subsystem elements. Alternatively or adaptively, MSS can be used in GSM networks as well, if the manufacturer has implemented support for GSM networks in the MSS. Since an immediate upgrade of existing GSM network to 3G is not viable due to various issues like handset incompatibilities and high expenditure, most manufacturers do implement GSM support in MSS. In fact, MSS along with other 3G network elements such as media gateway (MGW), can be configured to support GSM network exclusively and can be considered as an upgraded version of existing GSM mobile switching centres . The MSC Server is standards-based and communicates with other distributed elements using industry open standards such as media gateway control protocol , megaco / H.248 , Session Initiation Protocol , M2UA and M3UA . The MSC server incorporates industry standards as defined by ETSI , ITU , GSM , 3GPP and 3GPP2 and other leading standard bodies. The MSS supports the regulatory environment set by governing bodies via its support for E911, CALEA/legal intercept, wireless and local number portability , TTY/TTD, and Number Pooling requirements.
Alternatively MSS is also called an MTS-U (Motorola telephony soft-switch) in Motorola terminology, and as MSC-S in Ericsson terminology. MSC server functionality enables split between control plane (signalling) and user plane (bearer in network element called a media gateway), which guarantees better placement of network elements within the network.
MSC server and MGW makes it possible to cross-connect circuit switched calls switched by using IP, ATM AAL2 as well as TDM . | https://en.wikipedia.org/wiki/Mobile_switching_centre_server |
Mobile computing is human–computer interaction in which a computer is expected to be transported during normal usage and allow for transmission of data, which can include voice and video transmissions. Mobile computing involves mobile communication , mobile hardware, and mobile software . Communication issues include ad hoc networks and infrastructure networks as well as communication properties, protocols, data formats, and concrete technologies. Hardware includes mobile devices or device components. Mobile software deals with the characteristics and requirements of mobile applications.
Some of the most common forms of mobile computing devices are as given below:
These classes are expected to endure and to complement each other, none replacing another completely.
Other types of mobile computers have been introduced since the 1990s, including the:
Many commercial and government field forces deploy a rugged portable computer with their fleet of vehicles. This requires the units to be anchored to the vehicle for driver safety, device security, and ergonomics . Rugged computers are rated for severe vibration associated with large service vehicles and off-road driving and the harsh environmental conditions of constant professional use such as in emergency medical services , fire, and public safety.
Other elements affecting function in the vehicle:
Mobile security has become increasingly important in mobile computing. It is of particular concern as it relates to the security of personal information now stored on the smartphone . Mobile applications might copy user data from these devices to a remote server without the users’ permission and often without the users’ consent. [ 4 ] The user profiles automatically created in the cloud for smartphone users raise privacy concerns on all major platforms, in terms of, including, but not limited to, location tracking [ 5 ] and personal data collection, [ 6 ] regardless of user settings on the device. [ 7 ]
More and more users and businesses use smartphones as a means of planning and organizing their work and private life. Within companies, these technologies are causing profound changes in the organization of information systems and therefore they have become the source of new risks. Indeed, smartphones collect and compile an increasing amount of sensitive information to which access must be controlled to protect the privacy of the user and the intellectual property of the company.
All smartphones are preferred targets of attacks. These attacks exploit weaknesses related to smartphones that can come from means of wireless telecommunication like WiFi networks and GSM . There are also attacks that exploit software vulnerabilities from both the web browser and operating system. Finally, there are forms of malicious software that rely on the weak knowledge of average users.
Different security counter-measures are being developed and applied to smartphones, from security in different layers of software to the dissemination of information to end-users. There are good practices to be observed at all levels, from design to use, through the development of operating systems , software layers, and downloadable apps.
Several categories of portable computing devices can run on batteries but are not usually classified as laptops: portable computers, PDAs , ultra mobile PCs (UMPCs), tablets, and smartphones.
Boundaries that separate these categories are blurry at times. For example, the OQO UMPC is also a PDA-sized tablet PC; the Apple eMate had the clamshell form factor of a laptop but ran PDA software. The HP Omnibook line of laptops included some devices small enough to be called ultra mobile PCs. The hardware of the Nokia 770 internet tablet is essentially the same as that of a PDA such as the Zaurus 6000; the only reason it's not called a PDA is that it does not have PIM software. On the other hand, both the 770 and the Zaurus can run some desktop Linux software, usually with modifications.
Wireless data connections used in mobile computing take three general forms. [ 11 ] Cellular data service uses technologies GSM , CDMA or GPRS , 3G networks such as W-CDMA , EDGE or CDMA2000 . [ 12 ] [ 13 ] and more recently 4G and 5G networks. These networks are usually available within range of commercial cell towers . Wi-Fi connections offer higher performance, [ 14 ] may be either on a private business network or accessed through public hotspots , and have a typical range of 100 feet indoors and up to 1000 feet outdoors. [ 15 ] Satellite Internet access covers areas where cellular and Wi-Fi are not available [ 16 ] and may be set up anywhere the user has a line of sight to the satellite's location, [ 17 ] which for satellites in geostationary orbit means having an unobstructed view of the southern sky. [ 11 ] Some enterprise deployments combine networks from multiple cellular networks or use a mix of cellular, Wi-Fi and satellite. [ 18 ] When using a mix of networks, a mobile virtual private network ( mobile VPN ) not only handles the security concerns, but also performs the multiple network logins automatically and keeps the application connections alive to prevent crashes or data loss during network transitions or coverage loss. [ 19 ] [ 20 ] | https://en.wikipedia.org/wiki/Mobile_system |
Mobile tagging is the process of providing data read from tags for display on mobile devices , commonly encoded in a two-dimensional barcode , using the camera of a camera phone as the reader device. The contents of the tag code is usually a URL for information addressed and accessible through Internet.
Mobile tagging is currently most prominent in Asia, especially Japan. It was developed in 2003 and ever since it has been used in several fields of mobile marketing. Denso 's QR Code
in Asia and the Data Matrix are currently the most popular 2D barcodes. Both are ISO -standardised. In 2009, prominent electronics company Microsoft introduced the Microsoft Tag format, based on the company's self-developed High Capacity Color Barcode (HCCB) standard, in an effort to establish the format through emerging mobile tagging markets in the west. [ 1 ] Unlike most popular 2D barcodes, which use black-and-white square pixels , HCCBs are based on colors in a triangle-based arrangement.
The reason for the success of mobile tagging, besides the flexible and multiple fields of application, is the quick, precise and customer-driven access to information. According to the principle of physical world connection (see also Object hyperlinking ), the user is able to gather digital information immediately by scanning a two-dimensional barcode, like one on an advertisement.
In Europe mobile tagging is now gaining traction, albeit that the primary usage has been direct linking of URLs to 2D codes. Indeed, several campaigns in relation to physical world connection have been launched, however a standard for multi-dimensional barcodes is still missing.
One of the key organizations driving wider implementation of two-dimensional barcodes is GS1 / GS1's main activity is the development of the GS1 System, a series of standards designed to improve supply chain management . The GS1 System is composed of four key product areas: Barcodes (used to automatically identify things), eCom (electronic business messaging allowing automatic electronic transmission of data), GDSN (Global Data Synchronisation Network which allows partners to have consistent item data in their systems at the same time) and EPCglobal (which uses RFID technology to immediately track an item).
Currently about 70 different types of barcodes and their specific versions exist and are mostly in use in the field of logistics. In terms of mobile tagging, the number of codes is essentially restricted to a dozen types. For reading out 2d-barcodes it is essential to install specific software, a reader, on the mobile device.
The reader uses the camera of a mobile phone for the mobile tagging process. The producers of the reader are very involved in developing solutions to increase the number of compatible mobile phones. Most services on the corresponding websites offer the download directly onto the mobile device or PC. In addition, many providers offer the user a generator for creating their own codes.
Smartphone cameras can be used in Google's mobile Android operating system via both their own Google Goggles application or 3rd party mobile tag readers. Nokia's Symbian operating system features a scanner which can scan mobile tags, [ 2 ] while mbarcode [ 3 ] is a reader for the Maemo operating system. In the Apple iOS, a mobile tagging reader is natively included in the iOS 11 update through the camera app, although there are more than fifty paid and free apps are available with both scanning capabilities and hard-linking to URI. With BlackBerry devices, the App World application can natively scan mobile tags. Windows Phone 7.5 is able to scan tags through the Bing search app.
Due to the absence of a standard code, the readers are faced with the same problem. On the one hand there is a remarkable number of readers which aren't able to identify barcodes apart from their own proprietary codes. On the other hand, there are several readers which were created to read out non-proprietary code, these ' open source codes' are the most used for Optical Reading with Mobile like the QR Code and the Data Matrix. However, a QR code is always 60% larger than a DataMatrix code and this tends to mean that DM is the primary code used in packaging and enterprise solutions for example.
At present, mobile tagging is not only finding its way into the day-to-day-life of campaigns in the fields of commercial, public and private tagging but also may end absolute convergence between information media. Mobile tagging connects static information carriers with the Internet and encourages the interactive behaviour of the user. At least this is not the only reason why leading experts are firmly convinced that performance in the European markets will almost reach Asian levels in the foreseeable future. However, the future success will not be attributed to simply linking to URL's, as with the internet no one will pay to connect to a URL. The real enterprise solutions are where the codes will be monetized and customization for business and commercial use will be at the forefront of intelligent and professional use, examples of which are; e-government , tourism, advertising and targeted marketing , packaging, supply chain management, brand management and brand protection , logistics, track and trace , anti-counterfeit or smuggling, id & passports, transport and ticketing, parking, disability, CRM , cross media campaigns, m-ticketing , m-payments , e-learning, complete integration of localization, personalization, objects and other data.
Commercial tagging includes the use of multi-dimensional barcodes, especially in the fields of mobile marketing and advertising. Showcases in this context are additional information on products
(such as the nutrient content on hamburgers), direct downloads such as free ringtones, clips or mobile games) and the direct link to a specific site of a company. Particularly in the field of commercial tagging it is vital for the code to be able to be branded (it is possible to integrate a logo in the code). It is hard to convince people to use this technology.
The first company used QR Code for IT Asset Inventory Tagging System was initiated last October 11, 2012 made by Castlewood Group Pte Ltd Singapore led by IT Manager, Engr. Men-She-Vik P. San Diego, MIT. This unique concept innovates the use of QR Code as a medium for proper handling and monitoring of IT devices and peripherals for this company. Earlier concept made by other companies with the help of bar code tagging technology for IT asset inventory but now with the latest technology of encrypting and decrypting of information, QR Code may consider as one of the best application to manage IT asset of the company.
In terms of public tagging, barcodes serve as a hyperlink to additional information on public information carriers. This information may include maps, customer reviews or other non-commercial advice.
In view of private tagging, personal motives come to the fore. Besides the opportunity for creating direct hyperlinks on blogs or profiles, it is possible to participate immediately in online auctions (such as barcodes on cars with eBay hyperlinks).
Furthermore, barcodes allow services like saving data automatically in the contact list of mobile phones by scanning a code printed on business cards.
In addition to higher user friendliness, private tagging offers novel opportunities for self-presentation. [ original research? ] | https://en.wikipedia.org/wiki/Mobile_tagging |
Mobile technology in Africa is a fast growing market. [ 1 ] Nowhere is the effect more dramatic than in Africa, where mobile technology often represents the first modern infrastructure of any kind. [ 2 ] Over 10% of Internet users are in Africa. [ 3 ] However, 50% of Africans have mobile phones and their penetration is expanding rapidly. [ 4 ] This means that mobile technology is the largest platform in Africa, and can access a wide range of income groups. AppsAfrica reports Mobile App downloads has surpassed 98 billion [ 5 ] which is a very huge benefit for mobile app developers in Africa. [ 6 ]
As a consequence of the wider availability of mobile telephony with respect to fixed telephony, in many African countries, most Internet traffic goes through the mobile network. An example is Seychelles , that is the African country with a larger percentage of Internet subscribers, where most Internet users access the net through the mobile network. [ 7 ]
Several factors contributed to the "boom" of mobile telephony in Africa in the 2000s.
A major success factor of mobile telephony in Africa is the scarce diffusion of PSTNs (fixed line networks). In 2000, Sub-Saharan Africa as a whole had fewer telephone lines than Manhattan alone. Fixed line networks hardly reach the remote rural areas where a relevant percentage of the African population lives. Of about 400.000 rural settlements that are estimated to exist in Africa, less than 3% have PSTN access. Mobile telephony providers have taken advantage of this situation, implementing a very aggressive diffusion strategy for mobile networks. In 2006, 45% of rural settlements in Africa had GSM coverage. More recently, coverage has reached 90% of the territory in several countries, including Comoros , Kenya , Malawi , Mauritius , Seychelles , South Africa , and Uganda . Other countries that in 2007 reached above 50% of GSM coverage are Botswana , Burkina Faso , Burundi , Cape Verde , Guinea , Namibia , Rwanda , Senegal , Swaziland , and Togo . [ 7 ] As a consequence of the larger diffusion of GSM networks over fixed line networks, "mobile-telephone booths" are common in some areas of Africa.
The fixed line market in Africa is generally based on monopoly (often state monopoly ), with a few number of incumbent operators who did not invest in spreading their networks much farther than the larger urban areas. While this situation is changing (for example, both Telkom Kenya and Botswana Telecommunications Corporation have recently been privatized, and a market liberalization strategy has been initiated in several countries [ 7 ] ), the mobile telephony market is generally more competitive and dynamic. [ 7 ]
The table below outlines the percentage of African countries where telecommunications markets (fixed line telephony, mobile telephony, Internet ) are fully competitive, partially competitive, or monopolistic, either de iure or de facto (data refer to 2007). [ 7 ]
Mobile telephony providers that introduced mobile telephony in Africa in the 2000s adopted business models explicitly designed to reach the poorest (and largest) section of the population, with low-priced mobile phones and small denomination prepaid cards . [ 7 ]
Another key success factor in the providers' strategy in Africa has been the cutting down of roaming costs. This is especially relevant in Africa since strong relationships often hold between neighbouring communities that happen to be separated by national borders. [ 7 ] Celtel was the first operator to provide free roaming with the 2006 One Network campaign, whereby roaming became free between Uganda , Kenya , and Tanzania . In 2007 this has been extended to Gabon , DR Congo , Congo-Brazzaville , Burkina Faso , Chad , Malawi , Niger , Nigeria , and Sudan . [ 8 ] After Celtel, other providers operating in African markets have announced their intent to gradually reduce and eventually abolish roaming costs for certain areas.
Orange Guinée builds off-grid sites that improve the cell network using masts powered by photovoltaic panels , expanding coverage in rural areas and strengthening coverage in urban areas. This is being financed with a $30 million loan from the European Investment Bank . These solar-powered cell telecommunications a ntennae will slash grid fuel usage by more than 80%. [ 9 ] [ 10 ]
Mobile technology can be used, not only to generate profit from high income groups, but to provide information and create social change for low income groups. For example, mobile technology is used to provide information on health, education, finances or to access specific groups such as the youth.
However, people who are very poor have very basic phones. Thus non-profit mobile technology is not aimed at advanced smart phones, but ranges from sending out bulk SMSs to USSD , mobi-sites and mobile communities. AppsAfrica [ 11 ] writes the next 1 Billion phone users will come from Rural areas. [ 12 ]
The ultimate aim of non-profit mobile technology is to make it free, or as near to free, for the end user. This means enlisting donors and getting mobile networks on board. Internationally, companies such as TextToChange, FrontlineSMS , RapidSMS , Ushahidi all work with mobiles in health, disaster relief and aid management.
mHealth is using mobile technology to provide groups with health information. It was pioneered in part by the UN Foundation and Vodafone Foundation through partnerships with the World Health Organization (WHO) and the social enterprise DataDyne, who then joined with other partners in forging the mHealth Alliance. [ 13 ] mHealth activities come in the form of appointment reminders, community mobilization and health promotion, emergency toll-free telephone services, health call centres, health surveys, information initiatives and patient monitoring among others. [ 14 ]
In June 2011, the first African mobile health summit was held in Cape Town . At the summit, the WHO released a report stating that eighty-three per cent of governments surveyed had at least one mHealth project in their country. However, the majority of mHealth activities were limited in size and scope.
mHealth initiatives were health call centres (59%), emergency toll-free telephone services (55%), managing emergencies and disasters (54%), and mobile telemedicine (49%).
In South Africa, companies like Cell-Life and GeoMed and HealthSMS use mobile technology for health. [ 15 ]
The Praekelt Foundation is a South African example of a non profit organisation that is using mobile technology to create social change. Their programmes have currently reached 50 million people across 15 countries in sub-Saharan Africa . [ 16 ]
The founders saw that the technology they were creating for corporate clients could be useful for NGOs to provide information to their target markets. “Full profit want to reach people for different reasons, but people should not be charged for having access to life saving information,” says Marcha Neethling, head of operations at Praekelt Foundation.
One of the mobile technologies developed by Praekelt Foundation is a mobile community called YoungAfricaLive (YAL). Users do not need to have airtime or data bundles on their phones to use it. The aim of the mobile community was to create a space that would be interactive and fun where young people could talk candidly and learn about love, relationships and sex and HIV/AIDS. [ 16 ]
The mobile community is unique to the Vodacom network. At the end of 2010, Vodacom’s mobile platform, Vodafone Live, was receiving 3.2 million unique users monthly. [ 17 ] As (young) people were already using mobile technology to surf the net and download songs etc. it seemed the perfect place to engage with this target group.
The community is aimed at users between 16 and 24 and users receive daily news and celeb stories. All with a social call to action at the end, they participate in polls, watch videos that link to stories and can engage in anonymous chat rooms. Experts come on to the chat rooms to discuss sexual topics and allow users to ask personal questions anonymously. For example, well known South African sexologist Dr Eve hosts live chats once a week.
Users have engaged with the community and many of the updated features of the community have come directly from user suggestions. Users have commented saying YoungAfricaLive creates a platform for them to express their ideas, making them proud of their status and encouraging them to be responsible around sex.
The ongoing challenge with free mobile communities and technology is continuing to engage the service provider to allow the community to be entirely free. “With YoungAfricaLive South Africa, Vodacom is sponsoring the bandwidth, which is a massive investment... (thus) sustainability is always a question.” [ 18 ]
In 2011 Vodacom pioneered a project in South Africa to fight crime using mobile phones. [ 19 ] They partnered with The Khulisa's Youth out of School Ubuntu Club in Tembisa, Johannesburg and donated a computer and seven mobile phones to the Club. These are used by the young patrollers in the community to keep in touch and to report all crime incidents, as well as update the community on current events.
The project is based in the Phomolong area of Tembisa, which is notorious for high levels of criminal activity. Each mobile phone donated has internet capabilities and the members of the Club will be allocated a mobile phone that they will use to capture events, interview members of the community and create video clips. These will be uploaded to their Facebook page and website all in an effort to report on criminal activity in the community.
The South African Police Service also runs a national crime line which they encourage citizens to SMS in and report crimes in their communities. | https://en.wikipedia.org/wiki/Mobile_technology_in_Africa |
In India , mobile numbers (including pagers) on GSM, WCDMA, LTE and NR networks start with either 9 , 8 , 7 or 6 . Each telecom circle is allowed to have multiple private operators; previously it was two private + BSNL/MTNL, subsequently it changed to three private + BSNL/MTNL in GSM; however currently each telecom circle has all four operators including Reliance Jio, Bharti Airtel, Vodafone idea ltd and BSNL/MTNL.
All mobile phone numbers are 10 digits long. The way to split the numbers is
defined in the National Numbering Plan as XXXXX-NNNNN. Here, XXXXX identifies the network operator and the telecom circle while NNNNN identifies the subscriber. [ 1 ]
The Department of Telecommunications has divided India into various telecom circles such that within each circle, the call is treated as a local call, while across zones, it becomes a long-distance call. As of July 2018 there are 22 telecom circles or service areas. They are classified into four categories: Metro, A, B, C. Chennai, Delhi, Mumbai, and Kolkata fall under Metro category. [ 2 ]
A telecom circle is normally the entire state , with a few exceptions like Mumbai and Kolkata (which are different zones than their respective states), Goa (which is a part of the Maharashtra zone), Chhattisgarh (which is part of Madhya Pradesh ), Sikkim (which is part of West Bengal ) Jharkhand (which is a part of the Bihar zone), Northeastern states except Assam and Sikkim (which are part of Northeast zone) or Uttar Pradesh (divided into east and west zones). Delhi is a unique circle because it includes cities from Haryana ( Gurgaon and Faridabad ) and Uttar Pradesh ( Noida and Ghaziabad ) as well. The new state of Telangana remains in the same circle as Andhra Pradesh .
From May 20, 2005, calls between Mumbai Metro and Maharashtra Telecom Circle, between Chennai Metro and Tamil Nadu Telecom Circle, and between Uttar Pradesh (East) and Uttar Pradesh (West) Telecom Circle service areas are merged in Inter service area connected in the above-mentioned four states would be treated as intra-service area call for the purposes of routing as well as Access Deficit Charges (ADC). The dialing procedure for calls within a state for these states would also be simplified, i.e. dialing of mobile-to mobile subscribers and fixed-to-mobile subscribers would be without prefixing '0'. [ 3 ]
In December 2017, Reliance Jio started with the newest of all, "the six-series-mobile numbers", keeping in mind the growing number of users in India. The growth in the number of 4G users in the country has made the 4G base larger than the 2G users in India pushing number of 2G users to second position.
[ 4 ] | https://en.wikipedia.org/wiki/Mobile_telephone_numbering_in_India |
Mobile telephony is the provision of wireless telephone services to mobile phones , distinguishing it from fixed-location telephony provided via landline phones . Traditionally, telephony specifically refers to voice communication , though the distinction has become less clear with the integration of additional features such as text messaging and data services .
Modern mobile phones connect to a terrestrial cellular network of base stations (commonly referred to as cell sites ), using radio waves to facilitate communication. Satellite phones use wireless links to orbiting satellites , providing an alternative in areas lacking local terrestrial communication infrastructure, such as landline and cellular networks. Cellular networks, satellite networks, and landline systems are all linked to the public switched telephone network (PSTN), enabling calls to be made to and from nearly any telephone worldwide.
As of 2010, global estimates indicated approximately five billion mobile cellular subscriptions, highlighting the significant role of mobile telephony in global communication systems.
According to internal memos, American Telephone & Telegraph discussed developing a wireless phone in 1915, but were afraid that deployment of the technology could undermine its monopoly on wired service in the U.S. [ 1 ]
Public mobile phone systems were first introduced in the years after the Second World War and made use of technology developed before and during the conflict. The first system opened in St. Louis, Missouri , United States in 1946 whilst other countries followed in the succeeding decades. The UK introduced its 'System 1' manual radiotelephone service as the South Lancashire Radiophone Service in 1958. [ 2 ] Calls were made via an operator using handsets identical to ordinary phone handsets. [ 3 ] The phone itself was a large box located in the boot (trunk) of the vehicle containing valves and other early electronic components. Although an uprated manual service ('System 3') was extended to cover most of the UK, automation did not arrive until 1981 with 'System 4'. Although this non-cellular service, based on German B-Netz technology, was expanded rapidly throughout the UK between 1982 and 1985 and continued in operation for several years before finally closing in Scotland, it was overtaken by the introduction in January 1985 of two cellular systems - the British Telecom / Securicor ' Cellnet ' service and the Racal/ Millicom / Barclays ' Vodafone ' (from voice + data + phone) service. These cellular systems were based on US Advanced Mobile Phone Service (AMPS) technology, the modified technology being named Total Access Communication System (TACS).
In 1947, Bell Labs was the first to propose a cellular radio telephone network. The primary innovation was the development of a network of small overlapping cell sites supported by a call switching infrastructure that tracks users as they move through a network and passes their calls from one site to another without dropping the connection. In 1956, the MTA system was launched in Sweden. The early efforts to develop mobile telephony faced two significant challenges: allowing a great number of callers to use the comparatively few available frequencies simultaneously and allowing users to seamlessly move from one area to another without having their calls dropped. Both problems were solved by Bell Labs employee Amos Joel who, in 1970 applied for a patent for a mobile communications system. [ 4 ] However, a business consulting firm calculated the entire U.S. market for mobile telephones at 100,000 units and the entire worldwide market at no more than 200,000 units based on the ready availability of pay telephones and the high cost of constructing cell towers. As a consequence, Bell Labs concluded that the invention was "of little or no consequence," leading it not to attempt to commercialize the invention. The invention earned Joel induction into the National Inventors Hall of Fame in 2008. [ 5 ]
The development of metal–oxide–semiconductor (MOS) large-scale integration (LSI) technology, information theory and cellular networking led to the development of affordable mobile communications . [ 6 ] The first call on a handheld mobile phone was made on April 3, 1973, by Martin Cooper, then of Motorola [ 7 ] to his opposite number in Bell Labs who were also racing to be first. Bell Labs went on to install the first trial cellular network in Chicago in 1978. This trial system was licensed by the FCC to ATT for commercial use in 1982 and, as part of the divestiture arrangements for the breakup of ATT, the AMPS technology was distributed to local telcos. The first commercial system opened in Chicago in October 1983. [ 8 ] [ 9 ] A system designed by Motorola also operated in the Washington D.C./Baltimore area from summer 1982 and became a full public service later the following year. [ 10 ] Japan's first commercial radiotelephony service was launched by NTT in 1979.
The first fully automatic first generation cellular system was the Nordic Mobile Telephone (NMT) system, simultaneously launched in 1981 in Denmark, Finland, Norway and Sweden. [ 11 ] NMT was the first mobile phone network featuring international roaming . The Swedish electrical engineer Östen Mäkitalo started to work on this vision in 1966, and is considered as the father of the NMT system and some also consider him the father of the cellular phone. [ 12 ] [ 13 ]
There was a rapid growth of wireless telecommunications towards the end of the 20th century, primarily due to the introduction of digital signal processing in wireless communications , driven by the development of low-cost, very large-scale integration (VLSI) RF CMOS (radio-frequency complementary MOS ) technology. [ 6 ]
In 1990, AT&T Bell Labs engineers Jesse Russell , Farhad Barzegar and Can A. Eryaman filed a patent for a digital mobile phone that supports the transmission of digital data. Their patent was cited several years later by Nokia and Motorola when they were developing 2G digital mobile phones. [ 14 ]
In 1991, WiLAN founders Hatim Zaghloul and Michel Fattouche invented wideband orthogonal frequency-division multiplexing (WOFDM), the basis for wideband wireless communication applications, [ 15 ] including 4G mobile communications. [ 16 ]
The advent of cellular technology encouraged European countries to co-operate in the development of a pan-European cellular technology to rival those of the US and Japan. This resulted in the GSM system, the initials originally from the Groupe Spécial Mobile that was charged with the specification and development tasks but latterly as the 'Global System for Mobile Communications'. The GSM standard eventually spread outside Europe and is now the most widely used cellular technology in the world and the de facto standard. The industry association, the GSMA, now represents 219 countries and nearly 800 mobile network operators. [ 17 ] There are now estimated to be over 5 billion phone subscriptions according to the " List of countries by number of mobile phones in use " (although some users have multiple subscriptions, or inactive subscriptions), which also makes the mobile phone the most widely spread technology and the most common electronic device in the world. [ 18 ]
The first mobile phone to enable internet connectivity and wireless email, the Nokia Communicator , was released in 1996, creating a new category of multi-use devices called smartphones. In 1999 the first mobile internet service was launched by NTT DoCoMo in Japan under the i-Mode service. By 2007 over 798 million people around the world accessed the internet or equivalent mobile internet services such as WAP and i-Mode at least occasionally using a mobile phone rather than a personal computer.
Mobile phones receive and send radio signals with any number of cell site base stations fitted with microwave antennas . These sites are usually mounted on a tower, pole or building, located throughout populated areas, then connected to a cabled communication network and switching system. The phones have a low-power transceiver that transmits voice and data to the nearest cell sites, normally not more than 8 to 13 km (approximately 5 to 8 miles) away. In areas of low coverage , a cellular repeater may be used, which uses a long-distance high-gain dish antenna or yagi antenna to communicate with a cell tower far outside of normal range, and a repeater to rebroadcast on a small short-range local antenna that allows any cellphone within a few meters to function properly.
When the mobile phone or data device is turned on, it registers with the mobile telephone exchange , or switch, with its unique identifiers, and can then be alerted by the mobile switch when there is an incoming telephone call. The handset constantly listens for the strongest signal being received from the surrounding base stations, and is able to switch seamlessly between sites. As the user moves around the network, the " handoffs " are performed to allow the device to switch sites without interrupting the call.
Cell sites have relatively low-power (often only one or two watts) radio transmitters which broadcast their presence and relay communications between the mobile handsets and the switch. The switch in turn connects the call to another subscriber of the same wireless service provider or to the public telephone network , which includes the networks of other wireless carriers. Many of these sites are camouflaged to blend with existing environments, particularly in scenic areas.
The dialogue between the handset and the cell site is a stream of digital data that includes digitised audio (except for the first generation analog networks). The technology that achieves this depends on the system which the mobile phone operator has adopted. The technologies are grouped by generation. The first-generation systems started in 1979 with Japan, are all analog and include AMPS and NMT. Second-generation systems, started in 1991 in Finland, are all digital and include GSM , CDMA and TDMA .
The GSM standard is a European initiative expressed at the CEPT ("Conférence Européenne des Postes et Telecommunications", European Postal and Telecommunications conference). The Franco-German R&D cooperation demonstrated the technical feasibility, and in 1987 a Memorandum of Understanding was signed between 13 European countries who agreed to launch a commercial service by 1991. The first version of the GSM (=2G) standard had 6,000 pages. The IEEE/RSE awarded to Thomas Haug and Philippe Dupuis the 2018 James Clerk Maxwell medal for their contributions to the first digital mobile telephone standard. [ 19 ] In 2018, the GSM was used by over 5 billion people in over 220 countries. The GSM (2G) has evolved into 3G, 4G and 5G. The standardisation body for GSM started at the CEPT Working Group GSM (Group Special Mobile) in 1982 under the umbrella of CEPT. In 1988, ETSI was established and all CEPT standardization activities were transferred to ETSI. Working Group GSM became Technical Committee GSM. In 1991, it became Technical Committee SMG (Special Mobile Group) when ETSI tasked the committee with UMTS (3G).
The nature of cellular technology renders many phones vulnerable to 'cloning': anytime a cell phone moves out of coverage (for example, in a road tunnel), when the signal is re-established, the phone sends out a 're-connect' signal to the nearest cell-tower, identifying itself and signalling that it is again ready to transmit. With the proper equipment, it is possible to intercept the re-connect signal and encode the data it contains into a 'blank' phone—in all respects, the 'blank' is then an exact duplicate of the real phone and any calls made on the 'clone' will be charged to the original account. This problem was widespread with the first generation analogue technology, however the modern digital standards such as GSM greatly improve security and make cloning hard to achieve.
In an effort to limit the potential harm from having a transmitter close to the user's body, the first fixed/mobile cellular phones that had a separate transmitter, vehicle-mounted antenna, and handset (known as car phones and bag phones ) were limited to a maximum 3 watts Effective Radiated Power . Modern handheld cellphones which must have the transmission antenna held inches from the user's skull are limited to a maximum transmission power of 0.6 watts ERP. Regardless of the potential biological effects, the reduced transmission range of modern handheld phones limits their usefulness in rural locations as compared to car/bag phones, and handhelds require that cell towers are spaced much closer together to compensate for their lack of transmission power.
An increasing number of countries, particularly in Europe, now have more mobile phones than people. According to the figures from Eurostat, the European Union's in-house statistical office, Luxembourg had the highest mobile phone penetration rate at 158 mobile subscriptions per 100 people, closely followed by Lithuania and Italy. [ 20 ] In Hong Kong the penetration rate reached 139.8% of the population in July 2007. [ 21 ] Over 50 countries have mobile phone subscription penetration rates higher than that of the population and the Western European average penetration rate was 110% in 2007 (source Informa 2007).
There are over five hundred million active mobile phone accounts in China, as of 2007, but the total penetration rate there still stands below 50%. [ 22 ] The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005. [ 23 ] The subscriber count reached 2.7 billion by end of 2006 according to Information [ citation needed ] , and 3.3 billion by November, 2007, [ 18 ] thus reaching an equivalent of over half the planet's population. Around 80% of the world's population has access to mobile phone coverage, as of 2006. This figure is expected to increase to 90% by 2010. [ 24 ]
In some developing countries with little "landline" telephone infrastructure , mobile phone use has quadrupled in the last decade. [ 25 ] The rise of mobile phone technology in developing countries is often cited as an example of the leapfrog effect . Many remote regions in the third world went from having no telecommunications infrastructure to having satellite based communications systems. At present, Africa has the largest growth rate of cellular subscribers in the world, [ 26 ] its markets expanding nearly twice as fast as Asian markets. [ 27 ] The availability of prepaid or 'pay-as-you-go' services, where the subscriber is not committed to a long-term contract, has helped fuel this growth in Africa as well as in other continents.
On a numerical basis, India is the largest growth market, adding about 6 million mobile phones every month. [ 28 ] It currently has a mobile subscriber base of 937.06 million mobile phones. [ 29 ]
Since the world is operating quickly to 3G and 4G networks, mobile traffic through video is heading high. It is expected that by the end of 2018, the global traffic will reach an annual rate of 190 exabytes/year. This is the result of people shifting to smartphones.
It is predicted by 2018, mobile traffic will reach by 10 billion connections with 94% traffic comes from smartphones, laptops and tablets. Also 69% of mobile traffic will be from videos since we have high definition screens available in smart phones and 176.9 wearable devices to be at use. Apparently, 4G will be dominating the traffic by 51% of total mobile data by 2018. [ 30 ]
Law enforcement have used mobile phone evidence in a number of different ways. Evidence about the physical location of an individual at a given time can be obtained by triangulating the individual's cellphone between several cellphone towers. This triangulation technique can be used to show that an individual's cellphone was at a certain location at a certain time. The concerns over terrorism and terrorist use of technology prompted an inquiry by the British House of Commons Home Affairs Select Committee into the use of evidence from mobile phone devices, prompting leading mobile telephone forensic specialists to identify forensic techniques available in this area. [ 31 ] NIST have published guidelines and procedures for the preservation, acquisition, examination, analysis, and reporting of digital information present on mobile phones can be found under the NIST Publication SP800-101. [ 32 ]
In the UK in 2000 it was claimed that recordings of mobile phone conversations made on the day of the Omagh bombing were crucial to the police investigation. In particular, calls made on two mobile phones which were tracked from south of the Irish border to Omagh and back on the day of the bombing, were considered of vital importance. [ 33 ]
Further example of criminal investigations using mobile phones is the initial location and ultimate identification of the terrorists of the 2004 Madrid train bombings . In the attacks, mobile phones had been used to detonate the bombs. However, one of the bombs failed to detonate, and the SIM card in the corresponding mobile phone gave the first serious lead about the terrorists to investigators. By tracking the whereabouts of the SIM card and correlating other mobile phones that had been registered in those areas, police were able to locate the terrorists. [ 34 ]
The Finnish government decided in 2005 that the fastest way to warn citizens of disasters was the mobile phone network. In Japan, mobile phone companies provide immediate notification of earthquakes and other natural disasters to their customers free of charge. [ 35 ] In the event of an emergency, disaster response crews can locate trapped or injured people using the signals from their mobile phones. An interactive menu accessible through the phone's web browser notifies the company if the user is safe or in distress. [ citation needed ] In Finland rescue services suggest hikers carry mobile phones in case of emergency even when deep in the forests beyond cellular coverage , as the radio signal of a cellphone attempting to connect to a base station can be detected by overflying rescue aircraft with special detection gear. Also, users in the United States can sign up through their provider for free text messages when an AMBER Alert goes out for a missing person in their area.
However, most mobile phone networks operate close to capacity during normal times, and spikes in call volumes caused by widespread emergencies often overload the system just when it is needed the most. Examples reported in the media where this has occurred include the September 11, 2001 attacks , the 2003 Northeast blackouts , the 2005 London Tube bombings , Hurricane Katrina , the 2006 Kiholo Bay earthquake , and the 2007 Minnesota bridge collapse .
Under FCC regulations, all mobile telephones must be capable of dialing emergency telephone numbers , regardless of the presence of a SIM card or the payment status of the account.
Since the introduction of mobile phones, concerns (both scientific and public) have been raised about the potential health impacts from regular use. [ 36 ] But by 2008, American mobile phones transmitted and received more text messages than phone calls. [ 37 ] Numerous studies have reported no significant relationship between mobile phone use and health, but the effect of mobile phone usage on health continues to be an area of public concern. [ citation needed ]
For example, at the request of some of their customers, Verizon created usage controls that meter service and can switch phones off, so that children could get some sleep. [ 37 ] There have also been attempts to limit use by persons operating moving trains or automobiles, coaches when writing to potential players on their teams, and movie theater audiences. [ 37 ] By one measure, nearly 40% of automobile drivers aged 16 to 30 years old text while driving, and by another, 40% of teenagers said they could text blindfolded. [ 37 ]
18 studies have been conducted on the link between cell phones and brain cancer; A review of these studies found that cell phone use of 10 years or more "give a consistent pattern of an increased risk for acoustic neuroma and glioma". [ 38 ] The tumors are found mostly on the side of the head that the mobile phone is in contact with. In July 2008, Dr. Ronald Herberman , director of the University of Pittsburgh Cancer Institute , warned about the radiation from mobile phones. He stated that there was no definitive proof of the link between mobile phones and brain tumors but there was enough studies that mobile phone usage should be reduced as a precaution. [ 39 ] To reduce the amount of radiation being absorbed hands free devices can be used or texting could supplement calls. Calls could also be shortened or limit mobile phone usage in rural areas. Radiation is found to be higher in areas that are located away from mobile phone towers. [ 40 ]
According to Reuters , The British Association of Dermatologists is warning of a rash occurring on people's ears or cheeks caused by an allergic reaction from the nickel surface commonly found on mobile devices’ exteriors. There is also a theory it could even occur on the fingers if someone spends a lot of time text messaging on metal menu buttons. In 2008, Lionel Bercovitch of Brown University in Providence , Rhode Island, and his colleagues tested 22 popular handsets from eight different manufacturers and found nickel on 10 of the devices. [ 41 ]
Between the 1980s and the 2000s, the mobile phone has gone from being an expensive item used by the business elite to a pervasive, personal communications tool for the general population. In most countries, mobile phones outnumber land-line phones, with fixed landlines numbering 1.3 billion but mobile subscriptions 3.3 billion at the end of 2007.
In many markets from Japan and South Korea, to Europe, to Malaysia, Singapore, Taiwan and Hong Kong, most children age 8-9 have mobile phones and the new accounts are now opened for customers aged 6 and 7. Where mostly parents tend to give hand-me-down used phones to their youngest children, in Japan already new cameraphones are on the market whose target age group is under 10 years of age, introduced by KDDI in February 2007. The USA also lags on this measure, as in the US so far, about half of all children have mobile phones. [ 42 ] In many young adults ' households it has supplanted the land-line phone. Mobile phone usage is banned in some countries, such as North Korea and restricted in some other countries such as Burma. [ 43 ]
Given the high levels of societal mobile phone service penetration, it is a key means for people to communicate with each other. The SMS feature spawned the " texting " sub-culture amongst younger users. In December 1993, the first person-to-person SMS text message was transmitted in Finland. Currently, texting is the most widely used data service; 1.8 billion users generated $80 billion of revenue in 2006 (source ITU). Many phones offer Instant Messenger services for simple, easy texting. Mobile phones have Internet service (e.g. NTT DoCoMo 's i-mode ), offering text messaging via e-mail in Japan, South Korea, China, and India. Most mobile internet access is much different from computer access, featuring alerts, weather data, e-mail, search engines, instant messages, and game and music downloading; most mobile internet access is hurried and short.
Because mobile phones are often used publicly, social norms have been shown to play a major role in the usage of mobile phones. [ 44 ] Furthermore, the mobile phone can be a fashion totem custom-decorated to reflect the owner's personality [ 45 ] and may be a part of their self-identity. [ 44 ] This aspect of the mobile telephony business is, in itself, an industry, e.g. ringtone sales amounted to $3.5 billion in 2005. [ 46 ] Mobile phone use on aircraft is starting to be allowed with several airlines already offering the ability to use phones during flights. Mobile phone use during flights used to be prohibited and many airlines still claim in their in-plane announcements that this prohibition is due to possible interference with aircraft radio communications. Shut-off mobile phones do not interfere with aircraft avionics. The recommendation why phones should not be used during take-off and landing, even on planes that allow calls or messaging, is so that passengers pay attention to the crew for any possible accident situations, as most aircraft accidents happen on take-off and landing.
Mobile phone use can be an important matter of social discourtesy: phones ringing during funerals or weddings; in toilets, cinemas and theatres. Some book shops , libraries, bathrooms, cinemas, doctors' offices and places of worship prohibit their use, so that other patrons will not be disturbed by conversations. Some facilities install signal-jamming equipment to prevent their use, although in many countries, including the US, such equipment is illegal.
Many US cities with subway transit systems underground are studying or have implemented mobile phone reception in their tunnels for their riders, and trains, particularly those involving long-distance services, often offer a "quiet carriage" where phone use is prohibited, much like the designated non-smoking carriage of the past. Most schools in the United States and Europe and Canada have prohibited mobile phones in the classroom, or in school in an effort to limit class disruptions.
A working group made up of Finnish telephone companies, public transport operators and communications authorities has launched a campaign to remind mobile phone users of courtesy, especially when using mass transit—what to talk about on the phone, and how to. In particular, the campaign wants to impact loud mobile phone usage as well as calls regarding sensitive matters. [ 47 ]
The use of mobile phones by people who are driving has become increasingly common, for example as part of their job, as in the case of delivery drivers who are calling a client, or socially as for commuters who are chatting with a friend. While many drivers have embraced the convenience of using their cellphone while driving, some jurisdictions have made the practice against the law, such as Australia, the Canadian provinces of British Columbia , Quebec , Ontario, Nova Scotia , and Newfoundland and Labrador as well as the United Kingdom, consisting of a zero-tolerance system operated in Scotland and a warning system operated in England, Wales , and Northern Ireland . Officials from these jurisdictions argue that using a mobile phone while driving is an impediment to vehicle operation that can increase the risk of road traffic accidents.
Studies have found vastly different relative risks (RR). Two separate studies using case-crossover analysis each calculated RR at 4, [ 48 ] [ 49 ] while an epidemiological cohort study found RR, when adjusted for crash-risk exposure, of 1.11 for men and 1.21 for women. [ 50 ]
A simulation study from the University of Utah Professor David Strayer compared drivers with a blood alcohol content of 0.08% to those conversing on a cell phone, and after controlling for driving difficulty and time on task, the study concluded that cell phone drivers exhibited greater impairment than intoxicated drivers. [ 51 ] Meta-analysis by The Canadian Automobile Association [ 52 ] and The University of Illinois [ 53 ] found that response time while using both hands-free and hand-held phones was approximately 0.5 standard deviations higher than normal driving (i.e., an average driver, while talking on a cell phone, has response times of a driver in roughly the 40th percentile).
Driving while using a hands-free device is not safer than driving while using a hand-held phone, as concluded by case-crossover studies. [ 49 ] [ 48 ] epidemiological studies, [ 50 ] simulation studies, [ 51 ] and meta-analysis. [ 52 ] [ 53 ] Even with this information, California initiated new Wireless Communications Device Law (effective January 1, 2009) makes it an infraction to write, send, or read text-based communication on an electronic wireless communications device, such as a cell phone, while driving a motor vehicle. Two additional laws dealing with the use of wireless telephones while driving went into effect July 1, 2008. The first law prohibits all drivers from using a handheld wireless telephone while operating a motor vehicle. The law allows a driver to use a wireless telephone to make emergency calls to a law enforcement agency, a medical provider, the fire department, or other emergency services agency. The base fine for the FIRST offense is $20 and $50 for subsequent convictions. With penalty assessments, the fine can be more than triple the base fine amount. [ 54 ] [ 55 ] According to California Vehicle Code [VC] §23123, Motorists 18 and over may use a “hands-free device". The second law effective July 1, 2008, prohibits drivers under the age of 18 from using a wireless telephone or hands-free device while operating a motor vehicle (VC §23124). The consistency of increased crash risk between hands-free and hand-held phone use is at odds with legislation in over 30 countries that prohibit hand-held phone use but allow hands-free. Scientific literature is mixed on the dangers of talking on a phone versus those of talking with a passenger, with the Accident Research Unit at the University of Nottingham finding that the number of utterances was usually higher for mobile calls when compared to blindfolded and non-blindfolded passengers, [ 56 ] but the University of Illinois meta-analysis concluding that passenger conversations were just as costly to driving performance as cell phone ones. [ 53 ]
As of 2007, several airlines are experimenting with base station and antenna systems installed on the airplane, allowing low power, short-range connection of any phones aboard to remain connected to the aircraft's base station. [ 57 ] Thus, they would not attempt connection to the ground base stations as during takeoff and landing. [ citation needed ] Simultaneously, airlines may offer phone services to their travelling passengers either as full voice and data services, or initially only as SMS text messaging and similar services. The Australian airline Qantas is the first airline to run a test aeroplane in this configuration in the autumn of 2007. [ citation needed ] Emirates has announced plans to allow limited mobile phone usage on some flights. [ citation needed ] However, in the past, commercial airlines have prevented the use of cell phones and laptops, due to the assertion that the frequencies emitted from these devices may disturb the radio waves contact of the airplane.
On March 20, 2008, an Emirates flight was the first time voice calls have been allowed in-flight on commercial airline flights. The breakthrough came after the European Aviation Safety Agency (EASA) and the United Arab Emirates-based General Civil Aviation Authority (GCAA) granted full approval for the AeroMobile system to be used on Emirates. Passengers were able to make and receive voice calls as well as use text messaging. The system automatically came into operation as the Airbus A340-300 reached cruise altitude. Passengers wanting to use the service received a text message welcoming them to the AeroMobile system when they first switched their phones on. The approval by EASA has established that GSM phones are safe to use on airplanes, as the AeroMobile system does not require the modification of aircraft components deemed "sensitive," nor does it require the use of modified phones.
In any case, there are inconsistencies between practices allowed by different airlines and even on the same airline in different countries. For example, Delta Air Lines may allow the use of mobile phones immediately after landing on a domestic flight within the US, whereas they may state "not until the doors are open" on an international flight arriving in the Netherlands. In April 2007 the US Federal Communications Commission officially prohibited passengers' use of cell phones during a flight. [ 58 ]
In a similar vein, signs are put up in many countries, such as Canada, the UK and the U.S., at petrol stations prohibiting the use of mobile phones, due to possible safety issues. [ citation needed ] However, it is unlikely that mobile phone use can cause any problems, [ 59 ] and in fact "petrol station employees have themselves spread the rumour about alleged incidents."
Like all high structures, cellular antenna masts pose a hazard to low flying aircraft. Towers over a certain height or towers that are close to airports or heliports are normally required to have warning lights . There have been reports that warning lights on cellular masts, TV-towers and other high structures can attract and confuse birds. US authorities estimate that millions of birds are killed near communication towers in the country each year. [ 60 ]
Some cellular antenna towers have been camouflaged to make them less obvious on the horizon, and make them look more like a tree.
An example of the way mobile phones and mobile networks have sometimes been perceived as a threat is the widely reported and later discredited claim that mobile phone masts are associated with the Colony Collapse Disorder (CCD) which has reduced bee hive numbers by up to 75% in many areas, especially near cities in the US. The Independent newspaper cited a scientific study claiming it provided evidence for the theory that mobile phone masts are a major cause in the collapse of bee populations, with controlled experiments demonstrating a rapid and catastrophic effect on individual hives near masts. [ 61 ] Mobile phones were in fact not covered in the study, and the original researchers have since emphatically disavowed any connection between their research, mobile phones, and CCD, specifically indicating that the Independent article had misinterpreted their results and created "a horror story". [ 62 ] [ 63 ] While the initial claim of damage to bees was widely reported, the corrections to the story were almost non-existent in the media.
There are more than 500 million used mobile phones in the US sitting on shelves or in landfills, [ 64 ] and it is estimated that over 125 million will be discarded this year alone. [ citation needed ] The problem is growing at a rate of more than two million phones per week, putting tons of toxic waste into landfills daily. Several companies offer to buy back and recycle mobile phones from users. In the United States many unwanted but working mobile phones are donated to women's shelters to allow emergency communication.
There are two principal ways to pay for mobile telephony: the 'pay-as-you-go' model where conversation time is purchased and added to a phone unit via an Internet account or in shops or ATMs, or the contract model where bills are paid by regular intervals after the service has been consumed. It is increasingly common for a consumer to purchase a basic package and then bolt-on services and functionality to create a subscription customised to the users needs.
Pay as you go (also known as "pre-pay" or "prepaid") accounts were invented simultaneously in Portugal and Italy and today form more than half of all mobile phone subscriptions. [ citation needed ] USA, Canada, Costa Rica, Japan, Israel and Finland are among the rare countries left where most phones are still contract-based. [ citation needed ]
In the early days of mobile telephony , the operators (carriers) charged for all air time consumed by the mobile phone user, which included both outbound and inbound telephone calls . As mobile phone adoption rates increased, competition between operators meant that some decided not to charge for incoming calls in some markets (also called "calling party pays").
The European market adopted a calling party pays model throughout the GSM environment and soon various other GSM markets also started to emulate this model.
In Hong Kong, Singapore, Canada, and the United States, it is common for the party receiving the call to be charged per minute, although a few carriers are beginning to offer unlimited received phone calls. This is called the "Receiving Party Pays" model. In China, it was reported that both of its two operators were to adopt the caller-pays approach as early as January 2007. [ 65 ]
One disadvantage of the receiving party pays systems is that phone owners keep their phones turned off to avoid receiving unwanted calls, which results in the total voice usage rates (and profits) in Calling Party Pays countries outperforming those in Receiving Party Pays countries. [ 66 ] To avoid the problem of users keeping their phone turned off, most Receiving Party Pays countries have either switched to Calling Party Pays, or their carriers offer additional incentives such as a large number of monthly minutes at a sufficiently discounted rate to compensate for the inconvenience.
When a user roams in another country, international roaming tariffs apply to all calls received, regardless of the model adopted in the home country. [ 67 ]
The list below is a non-comprehensive attempt at listing the technologies used in mobile telephony :
0G (mobile radio telephone)
1G networks (analog networks)
2G networks (the first digital networks):
3G networks:
4G networks:
5G networks:
Starting with EVDO the following techniques can also be used to improve performance: | https://en.wikipedia.org/wiki/Mobile_telephony |
Mobile television is television watched on a small handheld or mobile device, typically developed for that purpose. It includes service delivered via mobile phone networks , received free-to-air via terrestrial television stations, or via satellite broadcast. Regular broadcast standards or special mobile TV transmission formats can be used. Additional features include downloading TV programs and podcasts from the Internet and storing programming for later viewing.
According to the Harvard Business Review , the growing adoption of smartphones allowed users to watch as much mobile video in three days of the 2010 Winter Olympics as they watched throughout the entire 2008 Summer Olympics , a five-fold increase. [ 1 ] However, except in South Korea, consumer acceptance of broadcast mobile TV has been limited due to lack of compatible devices. [ 2 ]
Early mobile TV receivers were based on old analog television systems. They were the earliest televisions that could be placed in a coat pocket. The first was the Panasonic IC TV MODEL TR-001, introduced in 1970. The second was sold to the public by Clive Sinclair in January 1977. It was called the Microvision or the MTV-1 . It had a two-inch (50 mm) CRT screen and was also the first television that could pick up signals in multiple countries. It measured 4.0 inches (100 mm) x 6.25 inches (159 mm) × 1.6 inches (41 mm) and was sold for less than £ 100 in the UK and for around $ 400 in the United States . The project took over ten years to develop and was funded by around £1.6 million in British government grants. [ 3 ] [ 4 ]
In 2002, South Korea was the first country to introduce commercial mobile TV via 2G CDMA IS95 -C, and 3G ( CDMA2000 1X EVDO ) networks. [ 5 ] In 2005, South Korea became the first country to broadcast satellite mobile TV via DMB ( S-DMB ) on May 1, and terrestrial DMB ( T-DMB ) on December 1. South Korea and Japan are developing the sector. [ 6 ] Mobile TV services were launched in Hong Kong during March 2006 by the operator CSL on the 3G network. [ 7 ] BT launched mobile TV in the United Kingdom in September 2006, although the service was abandoned less than a year later. [ 8 ] Germany had a failed endeavor with MFD Mobiles Fernsehen Deutschland, who launched their DMB -based service June 2006 in Germany, but ended it in April 2008. [ 9 ] Also in June 2006, mobile operator 3 in Italy (part of Hutchison Whampoa ) launched their mobile TV service, but in contrast to Germany's MFD it was based on the European DVB-H standard. [ 10 ] In the US Verizon Wireless and AT&T offered MediaFLO , a subscription service from March 2007 until March 2011.
In the 2010s, specialized mobile TV platforms and protocols were discontinued due to the rapid deployment of LTE cellular networks and the growing popularity of streaming television over the internet on modern smartphones . [ 11 ] [ 12 ] [ 13 ] [ 14 ]
As of January 2012 [update] , there were 120 stations in the United States broadcasting using the ATSC-M/H "Mobile DTV" standard – a mobile and handheld enhancement to the HDTV standard that improves handling of multipath interference while mobile. [ 15 ]
While MediaFLO used the TV spectrum and MobiTV used cell phone networks, [ 16 ] "mobile DTV" (ATSC-M/H) used the digital TV spectrum.
ION Media Networks started a test station on channel 38, which was to be used for digital LPTV , which used a single-frequency network (SFN) . In some areas, more than one TV transmitter would be needed to cover all areas. Mobile DTV could have been used at that time because it would not affect HDTV reception. A single standard, however, had to be developed. [ 17 ]
Gannett Broadcasting president David Lougee pointed out that many of those attending the inauguration of Barack Obama would likely hear him but not see him; had the new technology been in place, this would not have been a problem. [ 18 ]
In April 2009, the Open Mobile Video Coalition , made up of over 800 broadcast stations, selected four test stations: Gannett's WATL , ION's WPXA-TV in Atlanta , Fisher Communications' KOMO-TV , and Belo Corporation 's KONG-TV in Seattle . WPXA began mobile DTV broadcasting on April 1. The others would begin in May. [ 19 ]
ION chairman and CEO Brandon Burgess said mobile DTV lets stations "think beyond the living room and bring live television and real-time information to consumers wherever they may be." [ 20 ] The Advanced Television Systems Committee started work on mobile DTV standards in May 2007, and manufacturers and sellers worked quickly to make the new technology a reality.
The technology was expected to be used for Opinion polls and even voting. [ 21 ] [ 22 ] By the end of the year, the ATSC and the Consumer Electronics Association began identifying products meeting the standard with "MDTV". [ 23 ]
Paul Karpowicz, NAB Television Board chairman and president of Meredith Broadcast Group, said
"This milestone ushers in the new era of digital television broadcasting, giving local TV stations and networks new opportunities to reach viewers on the go. This will introduce the power of local broadcasting to a new generation of viewers and provide all-important emergency alert, local news, and other programming to consumers across the nation." [ 22 ]
ION technology vice president Brett Jenkins said, "We're really at a stage like the initial launch of DTV back in 1998. There are almost going to be more transmitters transmitting mobile than receive devices on the market, and that's probably what you'll see for the next six to nine months." [ 24 ]
Devices would eventually include USB dongles, netbooks , portable DVD players and in-car displays. [ 24 ]
White House officials and members of Congress saw the triple-play concept in an ION demonstration on July 28, 2009, in conjunction with the OMVC. [ 25 ] [ 26 ] Another demonstration took place October 16, 2009 with journalists, industry executives and broadcasters riding around Washington, D.C., in a bus with prototype devices. Included were those who would be testing the devices in the Washington and Baltimore markets in January 2010. [ 27 ]
On August 7, 2009, BlackBerry service began on six TV stations. Eventually, 27 other stations are expected to offer the service. By October, 30 stations were airing mobile DTV signals, and that number is expected to grow to 50. Also in the same month, FCC chair Julius Genachowski announced an effort to increase the spectrum available to wireless services. [ 22 ] Also in August, WTVE and Axcera began testing a single-frequency network (SFN) with multiple transmitters using the new mobile standard. The RNN affiliate in Reading, Pennsylvania had used this concept since 2007. [ 28 ]
An amplified antenna or higher power for the transmitting station would likely be needed, as well as repeater stations where terrain is a problem. [ 29 ] Lougee, whose company planned testing in its 19 markets in 2010, said the chip designs with the new devices made targeted advertising possible. [ 27 ]
In December 2009, Concept Enterprises introduced the first mobile DTV tuner for automobiles. Unlike earlier units, this one provides a clear picture without pixelation in a fast-moving vehicle, using an LG M/H chip and a one-inch roof-mounted antenna. No subscription is required. [ 30 ] Also in December, the Consumer Electronics Association hosted a "plugfest" in Washington, D.C. to allow manufacturers to test various devices. More than 15 companies, and engineers from different countries, tested four transmission systems, 12 receiver systems, and four software types. [ 23 ] [ 31 ] On December 1, News Corp. chairman Rupert Murdoch said mobile DTV would be important to the future of all journalism, and he planned to offer TV and possibly newspaper content in this way. [ 32 ]
Wireless broadband , which some wanted to replace broadcasting, would not be able to handle the demand for video services. [ 33 ] ION's Burgess showed off one of the first iPhones capable of receiving mobile DTV, while ION's Jenkins showed an LG Maze, a Valups , and a Tivit ; the latter sends signals to the iPod Touch and is expected to soon work with the Google Nexus . [ 34 ] Sinclair Broadcast Group director of advanced technology Mark Aitken said the mobile DTV concept of multiple transmitters would help free up spectrum for wireless broadband in rural areas but not large cities. He also explained to the FCC that mobile DTV was the best method for sending out live video to those using cell phones and similar devices. [ 35 ]
The OMVC 's Mobile DTV Consumer Showcase began May 3, 2010, and lasted all summer. Nine stations planned to distribute 20 programs, including local and network shows as well as cable programs, to Samsung Moment phones. Dell Netbooks and Valups Tivits also received programming. [ 36 ]
On September 23, 2010, Media General began its first MDTV service at WCMH-TV in Columbus, Ohio and had plans to do the same a month later at WFLA-TV in the Tampa Bay, Florida area and five to seven more stations in its portfolio. [ 37 ]
On November 19, 2010, a joint venture of 12 major broadcasters known as the Mobile Content Venture (MCV) announced plans to upgrade TV stations in 20 markets representing 40 percent of the United States population to deliver live video to portable devices by the end of 2011. [ 38 ]
Brian Lawlor, a Scripps TV senior vice president said that in September 2011, Scripps stations would offer a mobile app allowing people with an iPhone or iPad to see emergency information (e.g. weather bulletins) in the event of a power outage. [ 39 ] In 2012, a number of stations plan to conduct tests of the Mobile Emergency Alert System (M-EAS), a system to deliver emergency information via mobile DTV. [ 40 ]
In January 2012, the MCV announced that MetroPCS would offer MCV's Dyle mobile DTV service. Samsung planned an Android phone capable of receiving this service late in 2012. [ 41 ] At the end of 2012, Dyle was in 35 markets and capable of reaching 55 percent of viewers. [ 42 ] According to the home page on its website, "As of May 22, 2015, Dyle mobile TV is no longer in service, and Dyle-enabled devices and their apps will no longer be supported." [ 43 ]
At the NAB show in April 2012, MCV announced that 17 additional television stations would launch mobile DTV, bringing the total to 92, covering more than 55% of US homes. Included are stations in three new markets: Austin, Texas , Boston, Massachusetts , and Dayton, Ohio . [ 44 ]
In September 2012, WRAL-TV announced rollout of a Mobile Emergency Alert System based around mobile digital television technology. [ 45 ]
By early 2013, 130 stations were providing content, but the adoption of devices such as dongles was not widespread. [ 46 ]
According to NPD's "Free Streaming TV" report, released in February 2013, 12 percent of United States TV watchers reported streaming TV shows for free during the prior three months, compared to 14 percent who watched a TV show via SVOD.
As of 2023, WNUV CW 54, a Nextgen TV station in Baltimore, is broadcasting in a format called MobileW at 480p resolution for cell phone reception. WNUV owner Sinclair also operates an experimental TV station on Baltimore on RF 24 to test the One Media ATSC 3.0 chip-enabled Nextgen TV cell phone, The Mark One. [ 47 ] | https://en.wikipedia.org/wiki/Mobile_television |
Mobile ticketing is the process whereby customers order, pay for, obtain, and validate tickets using mobile phones . A mobile ticket contains a verification unique to the holder's phone. Mobile tickets reduce the production and distribution costs associated with paper-based ticketing for operators by transferring the burden to the customer, [ 1 ] who is required to contribute the cost of the physical device ( smartphone ) and internet access to the process. [ 2 ] As a result of these prerequisites, and in contrast to paper-based systems, mobile ticketing does not follow the principles of universal design . [ 3 ] [ 4 ] [ 5 ]
Mobile tickets should not be confused with e-tickets , which are simply tickets issued in electronic form , independent of a specific device and in a standard, intelligible format, that can be printed and used in paper form. While a mobile phone is compatible with an e-ticket, mobile ticketing is a distinct system.
There are several methods of implementing a mobile ticketing system, with varying degrees of complexity and transparency depending on the underlying technology. Mobile tickets may lessen the potential for scalping (touting) and fraud. [ 6 ] [ 7 ]
The QR code was created by a subsidiary of the Japanese automotive company Denso in 1994. Philips and Sony developed near-field communication (NFC) in 2002. [ 8 ] It is based on radio-frequency identification (RFID) technology and enables short-range communication between electronic devices. Philips published an early paper on NFC in 2004, [ 9 ] while the NFC Forum was established in the same year. [ 10 ] The GSMA published a whitepaper on M-Ticketing in 2011, having commissioned research to examine the opportunities for network operators in a mobile ticketing market. [ 11 ] The research was focused on a specific NFC system based on the UICC , which is owned and controlled by the network operator that issues it, and other technologies such as SMS and barcode were given passing consideration in the report.
The first mobile ticketing deployment for a public transport operator in the UK was for Chiltern Railways in 2007. [ 12 ] The first transit agency in the US to deploy mobile ticketing was Boston's MBTA in 2012, [ 13 ] while the first system in Australia was Adelaide Metro in 2017. [ 14 ]
The New York Yankees partnered with Ticketmaster in 2015 and adopted a new ticketing policy the following year. [ 15 ] The option of a print-at-home e-ticket ( PDF ), which was popular among fans for its convenience, was replaced by a mobile ticketing system. [ 16 ] [ 17 ] In 2017, the state of Connecticut passed a law that requires venues to make printed, paper tickets available to customers and provide a means to transfer tickets without restrictions. [ 18 ]
In 2019, a mobile-only ticketing system developed by Ticketmaster was installed in stadiums across the NFL , based on the Presence platform developed by the company in 2017. [ 19 ] The platform is an access control system and marketing tool involving personalized digital tickets and tracking software. The mobile-only version of the system, SafeTix, links the tickets to individual smartphones and was adopted by the vast majority of NFL franchises due to Ticketmaster's position as primary ticket partner of the league. [ 20 ] The Buffalo Bills received praise from several organizations, including the NAACP , for not adopting mobile-only ticketing, while fans across the league experienced delays and refusals of entry due to a range of issues with the system. [ 21 ]
The All England Club implemented mobile ticketing with an online-only ballot and a ban on ticket transfers for the 2021 Wimbledon Championships , citing COVID-19 protocols developed by the SGSA . The policy was criticized by Age UK for lacking an offline option. [ 5 ] A number of Premier League clubs adopted a mobile-only policy for the 2021–22 season, resulting in problems accessing their respective grounds and pushback from supporters' groups. [ 22 ] Liverpool F.C. gave its fans the option of a photographic smart card for those without an NFC-enabled phone. [ 23 ] ID cards of any form are controversial among football supporters and have been rejected by English fans in the past. [ 24 ] [ 25 ]
For the 2021 season, the NFL is mandating mobile-only ticketing across the league. [ 26 ] The mandate removes the option to issue paper tickets for the few franchises that had not enforced a mobile-only policy, and codifies the requirement for every fan to own a smartphone and grant access to it in order to attend a game. [ 27 ] A fifth of Americans do not own a smartphone, either by choice or due to constraint. [ 4 ] [ 28 ]
There are several methods of implementing a mobile ticketing system, depending on the technology used. In a system based on text messaging , the user receives their ticket in the form of either an alphanumeric code or a barcode. [ 29 ] In a process based on a mobile application , the user carries out a transaction through the app and receives a verification, such as a QR code, specific to their account. Where NFC technology is used, a ticket is issued in the form of a discreet token generated by emulation software on the user's phone itself. [ 30 ]
The operation of a mobile ticketing system raises issues of privacy and security . [ 31 ] The harvesting of personal data points enables an operator to model, predict, and potentially modify, the behavior of a customer. [ 32 ] [ 33 ] The implementation of OMNY , a contactless fare payment system for public transport in New York City, has provoked a number of concerns related to surveillance , data security , and transparency in the usage of passengers' information . [ 34 ] The system, which uses NFC technology, collects significant amounts of user data, including device identifiers and IP addresses , locations of entry, billing addresses, and payment information. [ 34 ] | https://en.wikipedia.org/wiki/Mobile_ticketing |
Mobile translation is any electronic device or software application that provides audio translation . The concept includes any handheld electronic device that is specifically designed for audio translation. It also includes any machine translation service or software application for hand-held devices, including mobile telephones , Pocket PCs , and PDAs . Mobile translation provides hand-held device users with the advantage of instantaneous and non-mediated translation from one human language to another, usually against a service fee that is, nevertheless, significantly smaller than a human translator charges.
Mobile translation is part of the new range of services offered to
mobile communication users, including location positioning ( GPS service), e-wallet (mobile banking), business card/bar-code/text
scanning etc.
It relies on computer programming in the sphere of computational linguistics and the device's
communication means (Internet connection or SMS ) to work.
A translation system allowing the Japanese to exchange conversations with foreign nationals through mobile phones was first developed in 1999 by the Advanced Telecommunications Research Institute International-Interpreting Telecommunications Research Laboratories, based in Kansai Science City , Japan . Words spoken into the mobile device are translated into the target language and then sent as voice to the other user's mobile phone [ 1 ]
Machine translation software for handheld devices featuring translation capabilities for user-input text, SMS and email, was commercially released in 2004 by Transclick and a patent was issued to Transclick for SMS, email and IM translation in 2006. [ 2 ]
In November 2005, another Japanese company, NEC Corporation , announced the development of a translation system that could be loaded in mobile phones. This mobile translation system could recognize 50,000 Japanese words and 30,000 English words, and could be used for simple translations when travelling. [ 3 ] However, it was not until January 2009 that NEC Corporation officially demonstrated their product. [ 4 ]
Technological advances within the miniaturization of computing and communication devices have made possible the usage of mobile telephones in language learning. Among the early projects were the Spanish study programs which included vocabulary practice, quizzes, and word and phrase translations. Soon after, projects were developed using mobile phones to teach English at a Japanese university. By 2005, they shifted their focus to providing vocabulary instruction by SMS. A similar program was created for learning Italian in Australia. Vocabulary phrases, quizzes, and short sentences were sent via SMS. [ 5 ]
Google Translate is one of the most highly-utilized translation services. [ 6 ] See also Infoscope , which is a handheld device composed of a digital camera and wireless internet access, developed at IBM 's Almaden Research Center .
The Ili is a handheld device that can provide instantaneous audio translation from one language to another; it only provides translation from English into Japanese or Chinese. [ 7 ] [ 8 ] [ 9 ]
One2One is a prototype that does not rely on Internet connectivity in order to function. It can provide audio translation in eight languages [ 10 ]
Pixel Buds is a device produced by Google which can provide real-time audio translation in over 40 languages. [ 11 ]
In order to support the machine translation service, a mobile device needs to be able to communicate with external computers (servers) that receive the user-input text/speech, translate it and send it back to the user. This is usually done via an Internet connection ( WAP , GPRS , EDGE , UMTS , Wi-Fi ) but some earlier applications used SMS to communicate with the translation server.
Mobile translation is not to be confused for the user-editable (talking) dictionaries and phrase books that are already widespread and available for many hand-held devices and do not normally require internet connectivity on the mobile device.
Mobile translation may include a number of useful features, auxiliary to text translation which forms the basis of the service. While the user can input text using the device keyboard, they can also use pre-existing text in the form of email or SMS messages received on the user's device (email/SMS translation). It is also possible to send a translated message, optionally containing the source text as well as the translation.
Some mobile translation applications also offer additional services that further facilitate the translated communication process, such as:
may be transformed into human speech (by a computer that renders the
voice of a native speaker of the target language);
will record the speech and send it to the translation server to convert
into text before translating it;
device camera) of some printed text (a road sign, a restaurant menu, a
page of a book etc.), have the application send it to the translation
server which will apply Optical Character Recognition (OCR)
technology, extract the text, return it to the user for editing (if
necessary) and then translate it into the chosen language.
combination and then get connected automatically to a live interpreter.
Recently, there has been a notable increase of the number of language
pairs offered for automatic translation on mobile devices. While
Japanese service providers traditionally offer cross-translation for
Japanese, Chinese, English and Korean, others may offer translation from and into over 20 languages, or over 200 language pairs, including most Latin languages.
Speech generation is, however, limited to a smaller portion of the above, including English, Spanish, Italian, French, Chinese etc. Image translation depends on the OCR languages available.
Having portable real-time automated translation at one's disposal has a
number of practical uses and advantages.
Advances of mobile technology and of the machine translation services have helped reduce or even eliminate some of the disadvantages of mobile translation such as the reduced screen size of the mobile device and the one-finger keyboarding. Many new hand-held devices come equipped with a QWERTY keyboard and/or a touch-sensitive screen, as well as handwriting recognition which significantly increases typing speed. After 2006, most new mobile phones and devices began featuring large screens with greater resolutions of 640 x 480 px, 854 x 480 px, or even 1024 x 480 px, [ 12 ] which gives the user enough visible space to read/write large texts. [ citation needed ]
However, the most important challenge facing the mobile translation industry is the linguistic and communicative quality of the translations. Although some providers claim to have achieved an accuracy as high as 96%, [ 13 ] boasting proprietary technology that is capable of “understanding” idioms and slang language, machine translation is still distinctly of lower quality than human translation and should be used with care if the matters translated require correctness.
One method that has been utilized to mitigate the lack of accuracy in mobile translation, is ontology learning combined with terminology extraction to identify frequently-used phrases, semantic interpretation to determine the correct context and meaning of a given phrase, and implementation of a data structure to store the nuances found in the prior multi-meaning terms and phrases. This combination of basic translation structures in conjunction with machine learning algorithms is what makes this multi-phase method so accurate, and also gives it the ability to progressively become more accurate. [ 14 ] The caveat is that this method is extremely difficult to automate; implementing this structure in a user-friendly fashion remains a major challenge facing translation app developers.
A disadvantage that needs mentioning is the requirement for a stable Internet connection on the user's mobile device. Since the SMS method of communicating with the translation server has proved less efficient that sending packets of data – because of the message length limit (160 characters) and the higher cost of SMS as compared with Internet traffic charges – Internet connectivity on mobile devices is a must, while coverage in some non-urban areas is still unstable. | https://en.wikipedia.org/wiki/Mobile_translation |
A mobile virtual network enabler ( MVNE) is a company that provides network infrastructure and related services, such as business support system , and operation support system to a mobile virtual network operator (MVNO). [ 1 ] This enables MVNOs to offer services to their own customers with their own brands. The MVNE does not have a relationship with consumers, but rather is a provider of network enablement platforms and services. [ 2 ]
MVNEs specialize in planning, implementation, and management of mobile services. Typically this includes SIM provisioning and configuration, customer billing, customer relationship management, and value-added service platforms. In effect, they enable an MVNO to outsource both the initial integration with the MNO, and the ongoing business and technical operations management. A related type of company is a mobile virtual network aggregator ( MVNA ). MVNE is a telecom solution, whereas MVNA is a business model which includes wholesale of an operator's airtime and routing of traffic over the MVNE's own switches.
The benefits of using an MVNE include a reduction in the upfront capital expenses of an MVNO due to reduced operational expenses via outsourcing management of business and technical operations.
Using an MVNE may not be appropriate for all MVNOs. The considerations for this decision are manifold; however, some of the key reasons for an MVNO to not use an MVNE would be: | https://en.wikipedia.org/wiki/Mobile_virtual_network_enabler |
A mobile virtual network operator ( MVNO ) is a wireless communications services provider that does not own the wireless network infrastructure over which it provides services to its customers. An MVNO enters into a business agreement with a mobile network operator (MNO) to obtain bulk access to network services at wholesale rates, then sets retail prices independently. [ 1 ] An MVNO may use its own customer service, billing support systems, marketing, and sales personnel, or it could employ the services of a mobile virtual network enabler (MVNE). [ 2 ]
MVNO agreements with network operators date back to the 1990s, when the European and Australian telecom markets saw market liberalization, new regulatory frameworks, better 2G network technology, and a subsequent jump in wireless subscriber numbers. [ 3 ] [ 4 ] Though the new 2G networks more efficiently managed the limited frequency bands allocated to wireless service, new mobile entrants were still limited by their ability to access frequency bands in a restricted spectrum . [ 5 ]
With European markets newly open to competition and new technology enabling better service and cheaper handsets, there was a massive surge in demand for cellular phones. [ 4 ] In the midst of this swell, Sense Communications fought for access to MNO spectrum in Scandinavia in 1997. [ 6 ] Sense was able to establish an MVNO agreement with Sonera in Finland, but it failed to persuade MNOs in Sweden, Denmark, and Norway. [ 7 ] Sense then appealed to EU regulators, citing provisions that required certain MNOs to allow new entrants interconnection. While Sense's claim was denied, in November 1999, the company signed a service provider agreement with Telia/Telenor Mobile for GSM network capacity access, allowing Sense to offer services to its own customers in Sweden and Norway. [ 8 ]
Despite Sense's initial failure, the regulator in Denmark saw the promise in the MVNO model as a cost-effective route for telecom companies to enter the market and in May 2000, legislation passed that required network operators with significant market power to open up access to their infrastructure. [ 9 ] By August of that same year, the MNO SONOFON had solidified the first viable MVNO agreement with Tele2 . This agreement provided Tele2 with access to SONOFON's network for both mobile and roaming services, the latter of which had been requested by (and denied to) Sense Communications. With the new regulations in place, MVNOs in Scandinavia eventually grew to a market share of above 10%. [ 10 ]
By 2008, US wireless subscribers had a choice between around 40 MVNOs. According to the FCC, approximately 7% of all U.S. mobile subscribers were served by resellers, including MVNOs, and analysts found that the 15.1 million wireless subscribers served by resellers by the end of 2006 had increased by 1.6 million over the previous year. [ 11 ]
MVNOs are distinguished by their commitment to owning and managing the operational components of the MVNO business model, [ 12 ] consisting of:
Because MVNOs are effectively defined by their lack of spectrum licenses, an MVNO necessarily will need to have agreements in place to access the network of at least one MNO. The type of MVNO is determined by how "thick" or "thin" a technological layer an MVNO adds over its access to its host MNO's network.
Sometimes referred to as a "Skinny MVNO" or Reseller. A Branded Reseller, will either operate under its own brand or co-branded with the mobile network operator (MNO). In most cases, the branded reseller brings a brand, distribution channels and/or a large existing customer base to the table, from which it can leverage its sales. It is often the easiest MVNO type for a host network operator (HNO) to accept, as the HNO stays in control over most of the processes. The Reseller MVNO, possesses no core elements and only holds the means that ensure the contact and relationship with the customers. [ 13 ]
Sometimes referred to as a "Light MVNO" or "Service provider MVNO". The Thin MVNO, provides its own brand and is normally responsible for the customer support, billing processes, tariffs, bundles and promotion packages, costs of marketing, sales and distribution, as well as the OPEX and CAPEX associated with these. [ 14 ]
Sometimes referred to as a "Enhanced Service Provider". The Medium MVNO, operates under its own brand with its own SIM cards, marketing, sales, distribution, and can in some countries obtain its own numbering range/mobile network code. The Medium MVNO has the ability to set tariff bundles and packages independently from the retail prices set by the host network operator (MNO). It can add its own value added services (VAS) platform to upsell or differentiate from the competition, on apps, data, and content services. [ 15 ]
The Full MVNO is responsible for, and has full control over all the services and products it offers in the market, as well as flexibility in designing and deploying new services, either to end-users or for Internet of Things (IoT) / Machine-to-machine (M2M). It operates technically, in a similar way to a mobile network operator, but without spectrum and radio access network (RAN), which it still leases access to from a mobile network operator (MNO).
The Full MVNO has a switching and transmission infrastructure allowing the management of its traffic. It can administer numbering resources, customer service, VAS, Roaming, SIM and device management and other services required for the provision of mobile services. [ 16 ]
As of June 2014, 943 MVNOs and 255 MNO sub-brands were active worldwide. This represents a total of almost 1,200 mobile service providers worldwide hosted by MNOs, up from 1,036 in 2012, [ 17 ]
According to GSMA Intelligence, between June 2010 and June 2015, the number of MVNOs worldwide increased by 70 percent, reaching 1,017 in June 2015. [ 18 ]
As of December 2018, there were 1,300 active MVNOs operating in 80 countries, representing more than 220 million mobile connections—approximately 2.46% of the total 8.9 billion mobile connections in the world. The eight countries with the largest number of active MVNOs in 2018 were: the US with 139 MVNOs (4.7% market share), Germany with 135 (19.5% market share), Japan 83 (10.6%), UK 77 (15.9%), Australia 66 (13.1%), Spain 63 (11.5%), France 53 (11.2%) and Denmark 49 (34.6%). [ 19 ]
In addition to traditional cellular voice and messaging services, in 2014, 120 MVNOs also were offering mobile broadband services. [ 20 ] In Africa, Uganda has registered three MVNOs so far, some having their own network infrastructure within major cities, but acting as an MVNO out of these cities. [ 21 ]
In 2015, one of the "big five" banks in South Africa , FNB , created an MVNO named FNB Connect providing voice, SMS and data services. As of 31 December 2019, FNB Connect had around 670,000 subscribers. The service makes use of Cell C network infrastructure. The move came not necessarily to compete in the telecommunications market, but to offer a greater value to customers of the banking division. [ 22 ] There have been several banks in South Africa making this move, like Standard Bank 's SB Mobile established in 2019.
MVNOs target both the consumer and enterprise markets. The majority of MVNOs are consumer-focused and most have a focus on price as their selling point; on average, customers of major carriers spend about 3.4 times as much on their service as MVNO customers. [ 23 ]
At the end of year 2022, there were 1,986 active MVNOs globally, more than double the amount of traditional telecom network operators. Europe lead in terms of most active MVNOs in operation with 1,012, representing half of the total global MVNO market. It is followed by Americas with 379 MVNOs, Asia with 322, International with 131, Oceania with 84, Africa with 54 and Middle East with 5. [ 24 ]
Some MVNOs have a presence in multiple countries, either as subsidiaries, joint ventures, or through brand licensing agreements with local partners, including Lycamobile in 60 countries, Virgin Mobile in 14 countries, Lebara in 10 countries, CMLink in five countries, Tesco Mobile in four countries, Line Mobile in three countries, Aldi Talk in six countries, Kogan.com Mobile in two countries, and L-Mobi Mobile in two countries.
Japan has about 80 MVNO brands, and the market share of MVNOs is 12.2% in 2019. The total number of contractors is 22.3 million. [ 25 ] [ 26 ] [ 27 ]
The three US national carriers have partial or full ownership of several large MVNO brands, such as Cricket Wireless (AT&T), TracFone Wireless (Verizon) and Metro by T-Mobile (T-Mobile). [ 28 ]
The UK had 77 active MVNOs as of December 2018. The MVNOs combined market share was 15.9% of the total UK mobile market, representing 15.3 million connections. [ 29 ]
Ireland has seven active MVNO brands as of February 2021, and the market share of MVNOs in 2022 is 13.4%. [ 30 ]
As of May 2024, Vietnam had five MVNO providers using the networks of the two mobile network operators VinaPhone and MobiFone. The five MVNOs are: iTel, Wintel, myLocal, VNSKY and FPT SIM.
In 2003, the European Commission issued a recommendation to national telecom regulators to examine the competitiveness of the market for wholesale access and call origination on public mobile telephone networks. [ 31 ] The study resulted in new regulations from regulators in several countries, including Ireland and France forcing operators to open up their networks to MVNOs. [ 32 ] [ 33 ]
Jordan 's top watchdog issued its first MVNO regulations in 2008, facilitating the creation of the first MVNO in the Arab world in 2010. [ 34 ]
The Saudi government is making preparations to permit MVNO services in the country. [ 35 ]
In Brazil , MVNOs are regulated by Anatel , the Brazilian Agency of Telecommunications , in November 2010. As of September 2014 the combined market share of all Brazilian MVNOs was just 0.04%. [ 36 ]
In Thailand , five MVNOs were given a Type II license to operate on the 2100 MHz 3G network of state telecom service TOT Public Company Limited (TOT) in 2009. As of January 2017, two of the original five MVNOs are still in service. [ 37 ] As of December 2018, the National Broadcasting and Telecommunications Commission (NBTC) had issued 58 MVNO licenses in Thailand, a total of nine have launched, four remain active. [ 38 ]
In India , the Telecom Department under the Ministry of Communications and Information Technology, accepted a recommendation from the national telecom regulator, Telecom Regulatory Authority of India , to permit VNOs in the country, and announced the grant of a unified license for Virtual Network Operators on 31 May 2016. [ 39 ] VNOs have formed an association to represent current regulatory issues impacting their MVNO business viability. [ 40 ]
In Nigeria, the licensing of telecommunications operators is overseen by the Nigerian Communications Commission (NCC). [ 41 ] As part of its regulatory framework, the NCC reclassified telecommunications licences into class and individual licences. This regulatory structure ensures that all telecom service providers, including MVNOs, comply with national guidelines and operate within the appropriate legal framework for their respective services. | https://en.wikipedia.org/wiki/Mobile_virtual_network_operator |
A mobile virtual private network (mobile VPN or mVPN) is a VPN which is capable of persisting during sessions across changes in physical connectivity, point of network attachment, and IP address. [ 1 ] The "mobile" in the name refers to the fact that the VPN can change points of network attachment, not necessarily that the mVPN client is a mobile phone or that it is running on a wireless network. [ 2 ]
Mobile VPNs are used in environments where workers need to keep application sessions open at all times, throughout the working day, as they connect via various wireless networks, encounter gaps in coverage, or suspend-and-resume their devices to preserve battery life. A conventional VPN cannot survive such events because the network tunnel is disrupted, causing applications to disconnect, time out, [ 1 ] fail, or even the computing device itself to crash . [ 3 ] Mobile VPNs are commonly used in public safety , home care , hospital settings, field service management , utilities and other industries. [ 4 ] Increasingly, they are being adopted by mobile professionals and white-collar workers . [ 3 ]
A VPN maintains an authenticated, encrypted tunnel for securely passing data traffic over public networks (typically, the Internet .) Other VPN types are IPsec VPNs, which are useful for point-to-point connections when the network endpoints are known and remain fixed; or SSL VPNs, which provide for access through a Web browser and are commonly used by remote workers . [ 5 ]
Makers of mobile VPNs draw a distinction between remote access and mobile environments. A remote-access user typically establishes a connection from a fixed endpoint, launches applications that connect to corporate resources as needed, and then logs off. In a mobile environment, the endpoint changes constantly (for instance, as users roam between different cellular networks or Wi-Fi access points ). A mobile VPN maintains a virtual connection to the application at all times as the endpoint changes, handling the necessary network logins in a manner transparent to the user. [ 6 ]
The following are functions common to mobile VPNs. [ 7 ] [ 8 ] [ 9 ]
Some mobile VPNs offer additional "mobile-aware" management and security functions, giving information technology departments visibility and control over devices that may not be on the corporate premises or that connect through networks outside IT's direct control. [ 10 ]
Mobile VPNs have found uses in a variety of industries, where they give mobile workers access to software applications. [ 11 ]
In telecommunication , a mobile VPN is a solution that provides data user mobility and ensures secure network access with predictable performance. Data user mobility is defined as uninterrupted connectivity or the
ability to stay connected and communicate to a possibly remote data network while changing the network access medium or points of attachment. [ 2 ]
In 2001, Huawei launched a product named "MVPN". In this case "MVPN" had a different meaning from the way that later industry sources would use the term. [ 12 ] The Huawei product was focused on delivering a seamless corporate phone system to users whether they were on desktop phones or mobile devices. Although the web page is no longer available, the company advertised that their MVPN had the following advantages over a standard phone system: | https://en.wikipedia.org/wiki/Mobile_virtual_private_network |
Mobile Workflows within mobile technology are specialized workflows . The purpose is to address deployment of workflows in mobile device infrastructure, thus enabling automation of process interaction for traditional business processes from within the device.
Mobile Process - Workflows for Mobile centric services composition [1]
This business-related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Mobile_workflow |
A mobile workspace is a user's portable working environment that gives them access to the applications, files and services they need to do their job no matter where they are.
Mobile workspace technology describes a set of software and services that deliver corporate apps, files and services to a user on any device and over any network. This technology was designed for business users that require access to all of their content on both corporate and personally-owned devices, including PCs, smartphones and tablets. Mobile workspace technologies are formed by bringing together a set of software and services including desktop virtualization , application virtualization , enterprise mobility management , file sharing , virtual private networks and more (see the full list below).
According to recent research, combined shipments of devices including PCs, tablets, ultramobiles and mobile phones are projected to reach 2.5 billion units in 2014, a 7.6 percent increase from 2013. [ 1 ] This trend, which is expected to continue to grow, is being driven by users who utilize more than one device. In fact, today the average user has 3+ different devices that they use for work purposes on a daily basis. [ 2 ] These mobile devices entering the enterprise has led to over 60% of information workers working outside of a traditional office. [ 3 ] While the shift to mobility seems to be growing, it is causing problems for both the end user and IT department. End users don't feel they are equipped to work outside of the office [ 4 ] and IT is forced to manage the security risks presented by data and applications leaving the corporate network. [ 5 ]
To address these challenges, organizations are looking to mobile workspace technology that can provide users access to their corporate applications, files and services while maintaining security for their IT department. [ 6 ] Mark Bowker, senior analyst, Enterprise Strategy Group said, "Mobile workspaces are playing a key role in addressing the new organizational imperative around secure mobility". [ 7 ]
Applications Microsoft (particularly Microsoft Office ) have been the dominant office software suite for enterprise along with numerous other Windows applications . Newer to the market is the growth of Software-as-a-Service [ 8 ] and web-based applications such as Salesforce.com , LinkedIn and Evernote . Additionally, mobile applications have seen growth of 200% from 2011 to 2012, a trend that is expected to continue into 2013. [ 9 ] A mobile workspace includes access to all types of applications (Windows, mobile, web, SaaS, and HTML5-based) from the user device.
Data Files access is important for business productivity as well as business collaboration. A user's mobile workspace must give a user access to all of their corporate data and allow for this data to be accessible on multiple devices. This requirement for file sync and sharing has led to the growth of many online sharing options [ 10 ] including Citrix Sharefile, Dropbox, Google Drive, Box , and iCloud .
Collaboration Due to factors like globalization, telecommuting [ 11 ] and employees working outside of traditional offices, collaboration tools are becoming increasingly important. Collaboration tools include electronic communication , online web-conferencing , file sharing and social collaboration software .
Network access People now work from all locations – the office, a coffee shop, the airport, their homes – yet still require access to their content. [ 12 ] When outside the office, people still need access to resources behind the firewall generally requiring VPN access. A mobile workspace allows secure access to apps, data and services no matter where the user is or what type of network they are using (LAN, WAN, 3G/4G, etc.).
Cloud As cloud computing becomes more popular, IT organizations are looking to the cloud to host more services than ever before. [ 13 ] IT departments now can choose where to host their apps, data, desktops, etc. in the most appropriate location whether that's on-premises in a datacenter or a private, public or hybrid cloud . Users need access to these resources from their mobile workspace.
Any device Research suggests that mobile devices are set to outnumber the total number people on earth by 2014. [ 14 ] As device types and manufacturers continue to grow, users still need to access their mobile workspace irrespective of device type, operating system or manufacturer. | https://en.wikipedia.org/wiki/Mobile_workspace |
Mobileye Global Inc. is a United States- domiciled , Israel-headquartered autonomous driving company. It is developing self-driving technologies and advanced driver-assistance systems (ADAS) including cameras, computer chips, and software. [ 4 ] [ 5 ] Mobileye was acquired by Intel in 2017 and went public again in 2022. [ 6 ] [ 7 ]
Mobileye was founded in 1999 by Hebrew University professor Amnon Shashua . He evolved his academic research into a vision system that could detect vehicles using a camera and software. [ 8 ] It developed into a supplier of automotive safety technologies based on adding "intelligence" to inexpensive cameras for commercialization. [ 9 ]
Mobileye established its first research center in 2004. It launched the first generation EyeQ1 processor in 2008. The technology offered driver assistance including automatic emergency braking . One of the first vehicles to use this technology was the fifth-generation BMW 7 Series . Versions of the chip were released in 2010, 2014 and 2018. [ 10 ]
In 2013, Mobileye announced the sale of a 25% stake to investors for $400 million, valuing the company at approximately $1.5 billion. [ 11 ] [ 12 ]
Mobileye went public on the New York Stock Exchange in 2014. It raised $890 million, and became the largest Israeli IPO in U.S. history. [ 13 ] [ 14 ] By the end of the year, Mobileye's technology had been implemented in 160 car models made by 18 different OEMs. [ 15 ]
In 2017, Mobileye unveiled a mathematical model for safe self-driving cars based on research by CEO Amnon Shashua and VP of Technology Shai Shalev-Shwartz. Their study outlined a system called Responsibility-Sensitive Safety (RSS) which redefines fault and caution and could potentially be used to inform insurers and driving laws. [ 16 ] Shalev-Shwartz was promoted to CTO in 2019. [ 17 ]
In March 2017, Intel announced that it would acquire Mobileye for $15.3 billion [ 18 ] — the biggest-ever acquisition of an Israeli tech company at the time. [ 19 ] Following the acquisition, Reuters reported that the U.S. Securities and Exchange Commission had charged two Israelis, Ariel Darvasi and Amir Waldman, with insider trading prior to the announcement. [ 20 ] Both had connections to Mobileye through the Hebrew University of Jerusalem , where Mobileye's technology was first developed. [ 21 ] The SEC obtained an emergency court order, freezing certain assets of Virginia residents Lawrence F. Cluff, Jr. and Roger E. Shaoul, who allegedly used insider information to make approximately $1 million on the announcement. [ 22 ] Neither Intel nor Mobileye were accused by the SEC of violating the law.
In October 2018, Mobileye and Volkswagen released plans to commercialize Mobility-as-a-Service (MaaS) in Israel. Mobileye instead began "robotaxi" trials with Nio electric vehicles in Israel in May 2020 due to Volkswagen delays, and unveiled its robotaxi in 2021 at the IAA Mobility show in Munich. [ 23 ] [ 24 ]
Mobileye demonstrated an autonomous car equipped only with cameras in Jerusalem in January 2020. [ 25 ] It later tested the cars in Munich [ 26 ] and New York City. [ 27 ]
In December 2021, Intel announced its plan to take Mobileye public via in 2022, while maintaining its majority ownership, this time on Nasdaq . [ 28 ] In October 2022, Intel offered 5–6% of outstanding shares, raising $861 million on 41 million shares. This valued Mobileye at around $17 billion – more than what Intel had paid in 2017. [ 29 ] [ 30 ] Intel continued to hold all Class B shares, giving itself an overall 99.4% of voting power. [ 30 ]
Mobileye formed partnerships with various automakers. Mobileye launched multiple series productions for LDW on GM Cadillac STS and DTS vehicles, [ 31 ] and on BMW 5 and 6 Series vehicles. [ 32 ] In 2016, Mobileye and Delphi formed a partnership to develop an autonomous driving system. [ 33 ] In early 2017, Mobileye announced a partnership with BMW to integrate Mobileye technology into vehicles going to market in 2018. In 2018, Mobileye announced partnerships with BMW, Nissan and Volkswagen. [ 34 ] In 2019, Mobileye and NIO announced that they would partner on the development of AVs for consumer markets in China and other major territories. [ 35 ] In July 2020, Mobileye and Ford announced a deal in which Mobileye would supply its EyeQ camera-based gear and software across Ford's global product line. [ 36 ] [ 37 ] Also in 2020, Mobileye partnered with WILLER29 [ 38 ] to launch a robotaxi service in Japan , Taiwan and Southeast Asia [ 39 ] and with Geely for ADAS. [ 40 ] [ 41 ] The same year, Intel announced that it had acquired Moovit, a mobility-as-a-service (MaaS) company, to enhance Mobileye's MaaS offering. [ 42 ]
In February 2021, Mobileye, Transdev Autonomous Transport System (ATS) and Lohr Group formed a partnership to develop and deploy autonomous shuttles, [ 43 ] and in April Mobileye announced a partnership with Udelv on the company's Transporter electric self-driving delivery vehicle. [ 44 ] In 2021, Toyota Motor Corp. selected Mobileye and German supplier ZF to develop and supply ADAS [ 45 ] [ 46 ] and Mobileye began a partnership with Mahindra . [ 47 ]
In May 2023, Porsche and Mobileye [ 48 ] launched a collaboration to provide Mobileye’s SuperVision™ in future Porsche production models.
In August 2015, Tesla Motors announced that it would incorporate Mobileye's technology in Model S cars. [ 49 ] Tesla reportedly did not share its plans with Mobileye, and after the first deadly crash of a self-driving Model S with Autopilot became public in June 2016, Mobileye ended their partnership. [ 50 ] [ 51 ] The two companies expressed disagreement over what caused the accident, [ 52 ] with Shashua claiming that Tesla "was pushing the envelope in terms of safety" and that Autopilot is a "driver assistance system" and not a "driverless system". [ 53 ] Mobileye issued a statement that its systems did not recognize a "lateral turn across path". [ 54 ]
The EyeQ system-on-chip (SoC) utilizes a single camera sensor to provide passive/active ADAS features including automatic emergency braking (AEB), adaptive cruise control (ACC), lane keeping assist (LKA), traffic jam assist (TJA) and forward collision warning (FCW). [ 55 ] Mobileye's fifth-generation EyeQ supports fully autonomous vehicles. More than 27 automobile manufacturers utilize EyeQ for their assisted-driving technologies. [ 56 ]
Mobileye's Road Experience Management, or REM, uses real-time data from Mobileye-equipped vehicles to maintain its 3D maps. [ 57 ] The data collected amounts to about 10 kilobytes per kilometer. [ 27 ] It is compiled in a map called Mobileye RoadBook that leverages anonymized, crowdsourced data from vehicle cameras for navigation and localization. [ 58 ] According to Mobileye, REM had mapped more than 7.5 billion kilometers of roads by January 2021. [ 59 ]
RSS, or the Responsibility-Sensitive Safety Model, is a mathematical safety model first proposed by Mobileye in 2017. [ 60 ] [ 61 ] RSS models AV decision-making and digitizes the implicit rules of safe driving for AVs to prevent self-driving vehicles from causing accidents. RSS is defined in software. [ 62 ]
True Redundancy is an integrated autonomous driving system that utilizes data streams from 360-surround view cameras, lidar, and radar. [ 63 ] This approach adds a lidar/radar subsystem to its computer-vision subsystem for redundancy. [ 64 ]
SuperVision uses EyeQ5 SoC data from 11 cameras. [ 65 ] [ 66 ] The system uses cameras only and is designed for hands-off cars. [ 67 ] [ 66 ] Geely's Zeekr electric vehicle is equipped with Mobileye SuperVision ADAS and began road trials in 2021. [ 68 ] [ 69 ]
Mobileye Drive is a Level 4 self-driving system. The sensor suite includes 13 cameras, 3 long-range LiDARs , 6 short-range LiDARs and 6 radars . [ 70 ] Mobileye Drive was first fitted to vehicles used for ride-hailing services in 2021, with plans for public testing in Germany and Israel in 2022. [ 71 ] [ 70 ]
Mobileye Chauffeur is a full-featured hands-off/eyes-off (highway)/hands-off/eyes-on street autonomous driving system. As of August 2023, it was planned for initial release on Polestar 4 . [ 72 ]
Mobileye's aftermarket vision-based ADAS systems are based on the same core technology as for production models. These systems offer lane departure warning, forward collision warning, headway monitoring and warning, intelligent headlamp control and speed limit indication (tsr). [ 73 ] These systems have been integrated with fleet management systems. [ 74 ]
Mobileye created operating system DXP for autonomous vehicles. [ 75 ]
It has sales and marketing offices in Midtown, Manhattan , U.S. ; Shanghai , China ; Tokyo , Japan ; and Düsseldorf , Germany . | https://en.wikipedia.org/wiki/Mobileye |
Mobility models characterize the movements of mobile users with respect to their location, velocity and direction over a period of time. These models play a vital role in the design of Mobile Ad Hoc Networks(MANET) . Most of the times simulators play a significant role in testing the features of mobile ad hoc networks. Simulators like (NS , QualNet , etc.) allow the users to choose the mobility models as these models represent the movements of nodes or users. As the mobile nodes move in different directions, it becomes imperative to characterize their movements vis-à-vis to standard models. The mobility models proposed in literature have varying degrees of realism i.e. from random patterns to realistic patterns. Thus these models contribute significantly while testing the protocols for mobile ad hoc networks.
The study of large and complex networks is possible by experimenting on a simulator rather than on analytical studies. The relatively new form of networks like Mobile Ad Hoc Networks(MANET) , Vehicular Ad Hoc Networks (VANET) , etc. are characterized by nodes which are autonomous and dynamic in nature. Thus it becomes very essential to capture their movements so that the corresponding simulations results are nearer to reality. Mobility models are basically classified as stochastic, detailed, Hybrid and Trace based Realistic models. [ 1 ]
For mobility modelling, the behavior or activity of a user's movement can be described using both analytical and simulation models. The input to analytical mobility models are simplifying assumptions regarding the movement behaviors of users. Such models can provide performance parameters for simple cases through mathematical calculations. In contrast, simulation models consider more detailed and realistic mobility scenarios. Such models can derive valuable solutions for more complex cases. Typical mobility
models include
Mobility model metrics are useful to study the impact of mobility models on the performances of mobile ad hoc networks. Metrics are usually classified as mobility metrics, connectivity graph metrics and protocol performance metrics. [ 2 ] | https://en.wikipedia.org/wiki/Mobility_model |
The mobilome is the entire set of mobile genetic elements in a genome . Mobilomes are found in eukaryotes , [ 1 ] prokaryotes , [ 2 ] and viruses . [ 3 ] The compositions of mobilomes differ among lineages of life, with transposable elements being the major mobile elements in eukaryotes, and plasmids and prophages being the major types in prokaryotes. [ 4 ] Virophages contribute to the viral mobilome. [ 5 ]
Transposable elements are elements that can move about or propagate within the genome, and are the major constituents of the eukaryotic mobilome. [ 4 ] Transposable elements can be regarded as genetic parasites because they exploit the host cell's transcription and translation mechanisms to extract and insert themselves in different parts of the genome, regardless of the phenotypic effect on the host. [ 6 ]
Eukaryotic transposable elements were first discovered in maize ( Zea mays ) in which kernels showed a dotted color pattern. [ 7 ] Barbara McClintock described the maize Ac/Ds system in which the Ac locus promotes the excision of the Ds locus from the genome, and excised Ds elements can mutate genes responsible for pigment production by inserting into their coding regions . [ 8 ]
Other examples of transposable elements include: yeast ( Saccharomyces cerevisiae ) Ty elements , a retrotransposon which encodes a reverse transcriptase to convert its mRNA transcript into DNA which can then insert into other parts of the genome; [ 9 ] [ 10 ] and fruit fly ( Drosophila melanogaster ) P-elements , which randomly inserts into the genome to cause mutations in germ line cells , but not in somatic cells . [ 11 ]
Plasmids were discovered in the 1940s as genetic materials outside of bacterial chromosomes . [ 12 ] Prophages are genomes of bacteriophages (a type of virus) that are inserted into bacterial chromosomes; prophages can then be spread to other bacteria through the lytic cycle and lysogenic cycle of viral replication . [ 13 ]
While transposable elements are also found in prokaryotic genomes, [ 14 ] the most common mobile genetic elements in the prokaryotic genome are plasmids and prophages . [ 4 ]
Plasmids and prophages can move between genomes through bacterial conjugation , allowing horizontal gene transfer . [ 15 ] Plasmids often carry genes that are responsible for bacterial antibiotic resistance ; as these plasmids replicate and pass from one genome to another, the whole bacterial population can quickly adapt to the antibiotic . [ 16 ] [ 17 ] Prophages can loop out of bacterial chromosomes to produce bacteriophages that go on to infect other bacteria with the prophages; this allows prophages to propagate quickly among the bacterial population, to the harm of the bacterial host. [ 13 ]
Discovered in 2008 in a strain of Acanthamoeba castellanii mimivirus , [ 18 ] virophages are an element of the virus mobilome. [ 5 ] Virophages are viruses that replicate only when host cells are co-infected with helper viruses . [ 19 ] Following co-infection, helper viruses exploit the host cell's transcription/translation machinery to produce their own machinery; virophages replicate through the machinery of either the host cell or the viruses. [ 19 ] The replication of virophages can negatively impact the replication of helper viruses. [ 18 ] [ 20 ]
Sputnik [ 18 ] [ 21 ] and mavirus [ 22 ] are examples of virophages. | https://en.wikipedia.org/wiki/Mobilome |
Mobinex is a provider of mobile applications to mobile operators, content providers and media companies since 2002. Mobinex provides mobile applications to:
Company provides a drag-and-drop cross-platform mobile application development called Smartface Platform and management tool which enables publishing of mobile applications across different operating systems.
The company was founded on May 15, 2002. It was initially focused on developing Smartface Platform, cross mobile application development and management tool.
2002 – Mobinex is founded
2002 – Mobinex launches “ Push to Talk ”
2003 – The service “Push to Talk Plus” is acquired by Telsim (Vodafone Turkey) [ 1 ]
2004 – Mobinex launches Smartface Platform
2006 – Smartface Platform is selected by operators for their value added services operations
2009 – Smarface Platform started facilitating in Banking Sector by integration with OTP Providers [ 2 ]
2010 – Smartface Platform is chosen by Banks for their operations in mobile channels [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ]
2010 – Mobinex unveils Smartface Designer Community Edition [ 8 ]
2011 – Mobinex launches Smartface Financial Services Platform [ 9 ]
2014 – Smartface Platform was spun-off to Smartface Inc. for the development of next generation Smartface App Studio
Main customers of Mobinex: [ 10 ]
Push to Talk Plus , also known as PoC+, is an application that uses a method of conversing on half-duplex communication lines, including two-way radio, using a momentary button to switch from voice reception mode to transmit mode. It uses a service option for a cellular phone network which permits subscribers to use their phone as a walkie-talkie with unlimited range. One significant advantage of PoC+ is that it allows a single person to reach an active talk group with a single button press; users need not make several calls to coordinate with a group. [ 11 ]
Smartface Platform is drag-and-drop cross-platform mobile application development and management tool and first released in 2006. Smartface Designer, the component of Smartface Platform enables visual development of mobile applications with drag-and-drop actions and interactive wizards. Smartface Server the other component of the platform provides an application life-cycle management system, with capabilities of distributing, tracking, promoting and advertising of applications. After its spin-off from Mobinex in 2014, the next generation of the platform, Smartface App Studio is being developed by Smartface Inc , a Palo Alto company. | https://en.wikipedia.org/wiki/Mobinex |
Mobolize is a mobile device software company with headquarters in Los Altos, CA .
In 2013, Sprint announced a technology partnership with Mobolize. [ 1 ] In October 2020, Akamai and Mobolize announced a partnership to offer security to mobile devices for enterprises. Mobolize's Data Management Engine will support Akamai Enterprise Threat Protector, a cloud secure web gateway (SWG). [ 2 ] In June 2021, Akamai expanded its partnership with Mobolize to include zero trust capabilities on mobile devices. [ 3 ]
Mobolize was recognized in 2014 by CTIA as winner of the Telecom Council Showcase. [ 4 ] In 2015, Mobolize was recognized by LightReading as a Leading Lights finalist for Best New Mobile Product, and also by FierceWireless as a Fierce Innovation Awards finalist for Network Service Delivery. [ 5 ] [ 6 ]
The company is led by co-founders David Cohen and William Chow as Co–CEOs. David Cohen was previously a founder of Frontbridge Technologies , which was acquired by Microsoft and became Microsoft Exchange Hosted Services. [ 7 ] William Chow was previously the chief architect of QLogic Storage Solutions Group (formerly Troika Networks) and security team lead at Stamps.com . | https://en.wikipedia.org/wiki/Mobolize |
Mocha is a Java decompiler , which allows programmers to translate a program's bytecode into source code .
A beta version of Mocha was released in 1996, by Dutch developer Hanpeter van Vliet, alongside an obfuscator named Crema . A controversy erupted and he temporarily withdrew Mocha from public distribution. [ 2 ] As of 2009 the program is still available for distribution, and may be used freely as long as it is not modified. Borland 's JBuilder includes a decompiler based on Mocha. Van Vliet's websites went offline as he died of cancer on December 31, 1996, at the age of 34. [ 1 ] | https://en.wikipedia.org/wiki/Mocha_(decompiler) |
In manufacturing and design , a mockup , or mock-up , is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes. A mockup may be a prototype if it provides at least part of the functionality of a system and enables testing of a design. [ 1 ]
Mock-ups are used by designers mainly to acquire feedback from users. Mock-ups address the idea captured in a popular engineering one-liner: "You can fix it now on the drafting board with an eraser or you can fix it later on the construction site with a sledge hammer". [ 2 ]
Mockups are used as design tools virtually everywhere a new product is designed.
Mockups are used in the automotive device industry as part of the product development process, where dimensions, overall impression, and shapes are tested in a wind tunnel experiment. They can also be used to test consumer reaction.
Mockups are part of the military acquisition process. Mockups are often used to test human factors and aerodynamics , for example. [ 3 ] In this context, mockups include wire-frame models . They can also be used for public display and demonstration purposes prior to the development of a prototype, as with the case of the Lockheed Martin F-35 Lightning II mock-up aircraft.
Mockups are used in the consumer goods industry as part of the product development process, where dimensions, human factors, overall impression, and commercial art are tested in marketing research .
Mockups help to visualise how all design decisions play together, they are convincing and closely resemble the final product, it can be easily revised rather than much later in the production stage, It also helps in visualisation of package design projects in 3D & speed up approvals.
Mockups are commonly required by designers, architects, and end users for custom furniture and cabinetry. [ 4 ] [ 5 ] The intention is often to produce a full-sized replica, using inexpensive materials in order to verify a design. Mockups are often used to determine the proportions of the piece, relating to various dimensions of the piece itself, or to fit the piece into a specific space or room. The ability to see how the design of the piece relates to the rest of the space is also an important factor in determining size and design.
When designing a functional piece of furniture, such as a desk or table, mockups can be used to test whether they suit typical human shapes and sizes. Designs that fail to consider these issues may not be practical to use. Mockups can also be used to test color, finish, and design details which cannot be visualized from the initial drawings and sketches. Mockups used for this purpose can be on a reduced scale.
The cost of making mockups is often more than repaid by the savings made by avoiding going into production with a design which needs improvement. [ citation needed ]
The most common use of mockups in software development is to create user interfaces that show the end user what the software will look like without having to build the software or the underlying functionality. Software UI mockups can range from very simple hand drawn screen layouts, through realistic bitmaps, to semi functional user interfaces developed in a software development tool.
Mockups are often used to create unit tests - there they are usually called mock objects . The main reason to create such mockups is to be able to test one part of a software system (a unit) without having to use dependent modules. The function of these dependencies is then "faked" using mock objects.
This is especially important if the functions that are simulated like this are difficult to obtain (for example because it involves complex computation) or if the result is non-deterministic, such as the readout of a sensor.
A common style of software design is Service-oriented architecture (SOA), where many components communicate via protocols such as HTTP . Service virtualization and API mocks and simulators are examples of implementations of mockups or so called over-the-wire test doubles in software systems that are modelling dependent components or microservices in SOA environments.
Mockup software can also be used for micro level evaluation, for example to check a single function, and derive results from the tests to enhance the products power and usability on the whole.
Mockups, wireframes and prototypes are not so cleanly distinguished in software and systems engineering , where mockups are a way of designing user interfaces on paper or in computer images. A software mockup will thus look like the real thing, but will not do useful work beyond what the user sees. A software prototype, on the other hand, will look and work just like the real thing. In many cases it is best to design or prototype the user interface before source code is written or hardware is built, to avoid having to go back and make expensive changes.
Early layouts of a World Wide Web site or pages are often called mockups . A large selection of proprietary or open-source software tools are available for this purpose.
At the beginning of a project's construction, architects will often direct contractors to provide material mockups for review. These allow the design team to review material and color selections, and make modifications before product orders are placed. Architectural mockups can also be used for performance testing (such as water penetration at window installations, for example) and help inform the subcontractors how details are to be installed. | https://en.wikipedia.org/wiki/Mockup |
In cryptography , mod n cryptanalysis is an attack applicable to block and stream ciphers . It is a form of partitioning cryptanalysis that exploits unevenness in how the cipher operates over equivalence classes (congruence classes) modulo n . The method was first suggested in 1999 by John Kelsey , Bruce Schneier , and David Wagner and applied to RC5P (a variant of RC5 ) and M6 (a family of block ciphers used in the FireWire standard). These attacks used the properties of binary addition and bit rotation modulo a Fermat prime .
For RC5P, analysis was conducted modulo 3. It was observed that the operations in the cipher (rotation and addition, both on 32-bit words) were somewhat biased over congruence classes mod 3. To illustrate the approach, consider left rotation by a single bit:
Then, because
it follows that
Thus left rotation by a single bit has a simple description modulo 3. Analysis of other operations (data dependent rotation and modular addition) reveals similar, notable biases. Although there are some theoretical problems analysing the operations in combination, the bias can be detected experimentally for the entire cipher. In (Kelsey et al., 1999), experiments were conducted up to seven rounds, and based on this they conjecture that as many as 19 or 20 rounds of RC5P can be distinguished from random using this attack. There is also a corresponding method for recovering the secret key .
Against M6 there are attacks mod 5 and mod 257 that are even more effective. | https://en.wikipedia.org/wiki/Mod_n_cryptanalysis |
mod_qos is a quality of service (QoS) module for the Apache HTTP server implementing control mechanisms that can provide different priority to different requests.
A web server can only serve a limited number of concurrent requests. QoS is used to ensure that important resources stay available under high server load. mod_qos is used to reject requests to unimportant resources while granting access to more important applications. It is also possible to disable access restrictions, for example, for requests to very important resources or for very important users.
Control mechanisms are available at the following levels:
The module can be useful when used in a reverse proxy in order to divide up resources to different webserver .
The first use case shows how mod_qos can avoid service outage of a web server due to slow responses of a single application. In case an application (here /ccc) is very slow, requests wait until a timeout occurs. Due to many waiting requests, the web server runs out of free TCP connections and is not able to process other requests to application /aaa or /bbb. mod_qos limits the concurrent requests to an application in order to assure the availability of other resources.
The keep-alive extension to HTTP 1.1 allows persistent TCP connections for multiple request/responses. This accelerates access to the web server due to less and optimised network traffic. The disadvantage of these persistent connections is that server resources are blocked even though no data is exchanged between client and server. mod_qos allows a server to support keep-alive as long as sufficient connections are free, stopping the keep-alive support when a defined connection threshold is reached.
A single client may open many simultaneous TCP connections in order to download different content from the web server. While the client gets many connections other users may not be able to access the server since no free connections remain for them. mod_qos can limit the number of concurrent connections for a single IP source address.
If you have to limit the number of requests to a URL, mod_qos can help with that too. mod_qos limits the maximum number of requests per second to this URL. The module may also control bandwidth. Simply specify the maximum allowed bandwidth and moq_qos starts throttling when it becomes necessary.
mod_qos may help to protect an Apache web server against low-bandwidth DoS attacks by enforcing a minimum upload/download throughput a client must generate. [ 1 ]
The initial release of mod_qos was created in May 2007 and published on SourceForge.net [ 2 ] as an open source software project. It was able to limit the number of concurrent HTTP requests for specified resources (path portion of request URLs ) on the web server.
More features were added and some of them were useful to protect Apache servers against DoS attacks. [ 3 ] [ 4 ] In 2012, mod_qos was included to the Ubuntu Linux distribution. [ 5 ]
Major releases: [ 6 ] | https://en.wikipedia.org/wiki/Mod_qos |
Modafinil , sold under the brand name Provigil among others, is a central nervous system (CNS) stimulant and eugeroic ( wakefulness promoter) medication used primarily to treat narcolepsy , [ 3 ] [ 7 ] [ 14 ] a sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks . [ 15 ] Modafinil is also approved for stimulating wakefulness in people with sleep apnea and shift work sleep disorder . [ 3 ] It is taken by mouth . [ 3 ] [ 7 ] Modafinil is not approved by the US Food and Drug Administration (FDA) for use in people under 17 years old. [ 7 ]
Common side effects of Modafinil include anxiety , insomnia , dizziness , and headache . Modafinil has potential for causing severe allergic reactions , psychiatric effects, [ 3 ] hypersensitivity , adverse interactions with prescription drugs , and misuse or abuse . [ 3 ] [ 7 ] [ 14 ] Modafinil may harm the fetus if taken during or two months prior to pregnancy . [ 16 ]
While modafinil is used as a cognitive enhancer , or "smart drug", among healthy individuals seeking improved focus and productivity, [ 17 ] [ 18 ] its use outside medical supervision raises concerns regarding potential misuse or abuse. [ 3 ] [ 7 ] [ 19 ] Research on the cognitive enhancement effects of modafinil in non-sleep deprived individuals has yielded mixed results, with some studies suggesting modest improvements in attention and executive functions, while others show no significant benefits or even a decline in cognitive functions at high doses. [ 20 ] [ 21 ]
Modafinil, a eugeroic or wakefulness-promoting drug , is primarily used for treating narcolepsy, a sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks. [ 15 ] Being a central nervous system (CNS) stimulant itself, [ 22 ] modafinil has lower addictive potential than classical stimulants such as amphetamine , cocaine , or methylphenidate , [ 12 ] [ 23 ] [ 24 ] but still produces psychoactive and subjective effects typical of classical stimulants. [ 3 ] [ 7 ] [ 19 ]
Narcolepsy causes a strong urge to sleep during the day and can include symptoms like cataplexy (sudden muscle weakness), sleep paralysis (inability to move or speak while falling asleep or waking up), and hallucinations . Narcolepsy is linked to a lack of the brain chemical hypocretin ( orexin ), primarily produced in the hypothalamus . [ 25 ] [ 26 ] Modafinil is not a cure for narcolepsy, but it can help manage the symptoms. While modafinil is primarily used to treat excessive sleepiness, it may also help reduce the frequency and severity of cataplexy attacks in some people. Modafinil is approved for management of narcolepsy with or without cataplexy. However, it is not specifically approved for the treatment of cataplexy. [ 27 ] [ 28 ]
Modafinil is also prescribed for shift work sleep disorder . [ 7 ]
Modafinil performs moderately (but better than armodafinil or solriamfetol ) [ 29 ] as a drug to overcome excessive daytime sleepiness caused by obstructive sleep apnea , [ 30 ] though it is recommended that people with apnea use continuous positive airway pressure (CPAP) therapy, that is a sleep breathing apparatus to prevent apnea, before starting modafinil. [ 7 ] [ 21 ] [ 31 ] When obstructive sleep apnea is comorbid with narcolepsy, modafinil is an effective drug to reduce the associated excessive daytime sleepiness. [ 32 ]
Modafinil's use varies by region. In the US, it is approved for adult narcolepsy, shift work sleep disorder, and obstructive sleep apnea, but not for children. [ 19 ] In the UK and the EU, since 2014, it is approved solely for narcolepsy, including in children ( pediatric narcolepsy ), with its use for other conditions restricted by the European Medicines Agency. [ 27 ] [ 33 ]
As of 2024, [update] both the French and the American Academy of Sleep Medicine strongly recommend modafinil as the first-choice treatment for narcolepsy. [ 34 ] In Europe, modafinil is considered one of the primary drugs recommended for treating narcolepsy according to the guidelines. [ 35 ]
The UK's National Institute for Health and Care Excellence (NICE), and the US's National Multiple Sclerosis Society , endorsed the off-label use of modafinil to alleviate fatigue associated with MS in 2022. [ 36 ] [ 37 ]
MS-related fatigue is a common and often debilitating symptom experienced by people with multiple sclerosis. [ 38 ] [ 39 ] It can significantly impact their daily functioning, quality of life , and ability to perform everyday activities. When prescribed for MS-related fatigue management, modafinil works by promoting wakefulness and increasing alertness without causing drowsiness or disrupting nighttime sleep. People with multiple sclerosis often report increased energy levels, reduced feelings of tiredness, improved cognitive function, and an overall improvement in their quality of life when taking modafinil. [ 40 ] While modafinil can provide relief from MS-related fatigue symptoms, [ 40 ] it does not treat the underlying cause or cure MS itself.
Modafinil is occasionally prescribed off-label for individuals with attention deficit hyperactivity disorder (ADHD). [ 41 ] [ 42 ] [ 43 ] It has not consistently shown efficacy in treating adult ADHD, [ 44 ] especially when compared to other treatments such as lisdexamfetamine . [ 45 ] [ 46 ] In children, modafinil is more effective than placebo for treating ADHD symptoms. [ 47 ] [ 48 ]
Given its approved status in the US to treat narcolepsy, physicians can also prescribe modafinil for off-label uses, such as treating ADHD in both children and adults. [ 49 ] [ 50 ] [ 51 ]
The Canadian Network for Mood and Anxiety Treatments (CANMAT) suggests modafinil as a second-line treament for comorbid ADHD and bipolar disorder , after first-line psychostimulants and the antidepressant bupropion . [ 52 ]
Modafinil is used off-label as an adjunctive treatment (i.e., in combination therapy) for the acute depressive phase in bipolar disorder. [ 53 ] [ 54 ] [ 55 ] [ 56 ] The depressive phase of bipolar disorder may feature excessive sleepiness and fatigue. Adjunctive treatment with modafinil can be used as an augmentation for the main treatment to increase its effect and is safe and effective, especially for people who do not respond well to standard antidepressants. [ 57 ] [ 58 ] [ 44 ] Modafinil does not significantly increase the risk of mood switch to mania or suicide attempts in people with bipolar disorder. [ 59 ] [ 57 ] Modafinil may also have cognitive benefits in people with bipolar disorder who are in a remission state. [ 60 ] [ 61 ] [ 44 ]
Whereas modafinil and armodafinil are approved for narcolepsy, they have been repurposed as adjunctive treatments to alleviate symptoms of acute depressive phase in people with bipolar disorder. [ 62 ] Drug repurposing in psychiatry is a strategy for discovering new uses for drugs that have already been approved or tested in clinical trials for other illnesses. As such, drug repurposing is a rapid, cost-effective, and reduced-risk strategy for the development of new treatment options for psychiatric disorders. [ 62 ] 2021 meta-analysis concluded that add-on modafinil and armodafinil were more effective than placebo on response to treatment, clinical remission, and reduction in depressive symptoms, with only minor side effects, but the effect sizes are small and the quality of evidence is therefore low, limiting the clinical relevance of the evidence. [ 62 ] [ 63 ] Very low rates of mood swing (a change in mood from one extreme to another) [ 59 ] [ 64 ] have been observed with modafinil and armodafinil in depressive phase of bipolar disorder. [ 55 ] [ 65 ]
Modafinil was used during the Gulf War by the French Foreign Legion , [ 66 ] the US Air Force , [ 67 ] [ 68 ] and US Marine [ 69 ] infantry to enhance "operational tempo" (a term that denotes the speed and intensity at which military operations or activities are executed), aiming to optimize the overall performance and efficiency of the units. [ 68 ] [ 70 ] [ 71 ]
Armed forces in various countries, including the United States, the United Kingdom, India, and France, have considered modafinil as an alternative to traditional amphetamines for managing sleep deprivation in combat or extended missions. [ 72 ] The US military approved modafinil for specific Air Force missions, replacing amphetamines for fatigue management. [ 73 ] The use of modafinil in military contexts without sleep deprivation is not recommended due to inconclusive evidence on its cognitive enhancement benefits and potential risks of adverse effects. [ 67 ]
Modafinil is also available to astronauts aboard the International Space Station for the management of fatigue caused by circadian dyssynchrony in orbit. [ 74 ]
Modafinil has been used non-medically as a "smart drug" [ 17 ] [ 18 ] by various groups, including students, [ 75 ] [ 76 ] [ 77 ] office workers, transhumanists , [ 78 ] [ 79 ] and professionals in various sectors. Its use is attributed by these individuals to its potential for enhancing attention, cognitive capabilities, and alertness . [ 80 ] [ 81 ]
The effectiveness of modafinil as a cognitive enhancer is still debated. Some studies suggest significant increases in cognitive abilities, while others indicate mild to nonexistent cognitive improvements. [ 82 ] [ 83 ] [ 53 ] [ 84 ] In some cases, it has even been associated with impairments in certain cognitive functions. [ 20 ] [ 21 ] [ 85 ] It has been shown that modafinil's positive impact on cognitive abilities is more noticeable on sleep-deprived individuals. [ 86 ] Therefore, in people who are not sleep-deprived, the potential of modafinil as a cognitive enhancer may be limited. [ 87 ]
Modafinil is generally well-tolerated but can have potential risks and side effects. Common adverse effects of modafinil, experienced by less than 10% of users, include headaches , nausea , and reduced appetite . [ 88 ] [ 89 ] [ 19 ] Anxiety , insomnia , dizziness , diarrhea , and rhinitis are also reported in 5% to 10% of users. [ 19 ] Psychiatric reactions have occurred in individuals with and without a preexisting psychiatric history. [ 90 ] Urinary retention and paresthesia have also been reported. [ 91 ]
No significant changes in body weight have been observed in clinical trials, although decreased appetite and weight loss have been noted in children and adolescents. [ 92 ] Modafinil can cause a slight increase in aminotransferase enzymes , indicative of liver function, but there is no evidence of serious liver damage when levels are within reference ranges. [ 93 ]
Rare but serious adverse effects include severe skin rashes and allergy-related symptoms. Between December 1998 and January 2007, the FDA received reports of six cases of severe cutaneous adverse reactions, including erythema multiforme , Stevens–Johnson syndrome , toxic epidermal necrolysis , and DRESS syndrome . The FDA has issued alerts regarding these risks and also noted reports of angioedema and multi-organ hypersensitivity reactions in postmarketing surveillance . [ 94 ] [ 95 ] In 2007, the FDA required Cephalon to modify the Provigil leaflet to include warnings about these serious conditions. The long-term safety and effectiveness of modafinil have not been conclusively established. [ 96 ]
The FDA does not endorse modafinil for children's medical conditions due to an increased risk of rare but serious dermatological toxicity, manifested as Stevens–Johnson syndrome which is a type of severe skin reaction. [ 97 ] [ 60 ] [ 98 ] However, in Europe, modafinil may be prescribed for treating narcolepsy in children. [ 99 ]
Modafinil is commercially available in 100 mg and 200 mg oral tablet forms. [ 7 ] Additionally, it is offered as the ( R )- enantiomer , known as armodafinil , and as a prodrug named adrafinil . [ 100 ]
Modafinil is contraindicated during pregnancy and 2 months before getting pregnant. [ 101 ] Women who take modafinil should not become pregnant, and, additionally, should be aware that modafinil reduces effectiveness of hormonal contraceptives, increasing chances of getting pregnant. [ 7 ] [ 14 ] [ 102 ] Modafinil therapy during pregnancy increases the risk of birth defects, [ 16 ] [ 103 ] [ 104 ] [ 101 ] such as with congenital torticollis , hypospadias , and congenital heart defects . [ 103 ]
Modafinil is contraindicated for individuals with known hypersensitivity to either modafinil or armodafinil. [ 7 ] [ 12 ]
Modafinil is also contraindicated in certain cardiac conditions, including uncontrolled moderate to severe hypertension , arrhythmia , cor pulmonale , [ 105 ] [ 106 ] and in cases with signs of CNS stimulant-induced mitral valve prolapse or left ventricular hypertrophy . [ 107 ] [ 108 ] The package insert in the United States cautions about using modafinil in people with a documented medical history of left ventricular hypertrophy or those diagnosed with mitral valve prolapse who have previously exhibited symptoms associated with the mitral valve prolapse syndrome while undergoing treatment involving central nervous system stimulants. [ 109 ] The reasons why modafinil is contraindicated in certain cardiac conditions are because modafinil affects the autonomic nervous system and, in particular, exerts significant effects on autonomic cardiovascular regulation, leading in some people to notable increases in heart rate and blood pressure. These substantial changes in the autonomic system warrant careful consideration when prescribing modafinil to people with pre-existing cardiovascular conditions. [ 110 ] The increase in heart rate and blood pressure can worsen the symptoms of such pre-existing conditions as hypertension, arrhythmia, and cor pulmonale. These changes in the autonomic system induced by modafinil can increase the risk of heart attack, stroke, and heart failure. Modafinil can stimulate the release of norepinephrine and epinephrine, hormones that activate the sympathetic nervous system. This can cause vasoconstriction , which is the narrowing of blood vessels, and increase the heart's workload, which is not desired in people with pre-existing heart conditions. In particular, modafinil can worsen the consequences of mitral valve prolapse or left ventricular hypertrophy, which are structural abnormalities of the heart. These can affect the blood flow and oxygen delivery to the heart and other organs. [ 111 ]
Modafinil is also contraindicated in people with congenital problems like galactose intolerance, lactase deficiency , or glucose-galactose malabsorption . [ 112 ] [ 105 ] [ 106 ]
Extensive clinical research has not demonstrated drug tolerance as a common adverse effect, even with therapeutic use extending up to 40 weeks. [ 66 ] [ 113 ] [ 96 ] Drug tolerance in this context is defined as a reduction in response, to wakefulness-promoting and anti-fatigue properties of modafinil. [ 66 ]
While modafinil is generally found to be safe and significant adverse effects are rare, including in pediatric narcolepsy cases (sleep disorders in children), there is evidence that long-term usage can lead to tolerance in some individuals. [ 21 ] This necessitates higher doses to maintain the same level of cognitive enhancement or relief from sleepiness. [ 21 ]
People with current or past substance addictions and those with a family history of addiction are particularly at risk for developing tolerance. [ 21 ] [ 99 ] [ 114 ]
The mechanisms driving tolerance to modafinil, which may involve its impact on dopamine and norepinephrine levels in the brain, are not fully understood. [ 21 ] [ 99 ] [ 114 ]
Repeated administration of modafinil for off-label use, such as increased alertness and cognitive-enhancing effects in sleep deprivation, can lead to drug tolerance, which means that the effectiveness of the drug may decrease over time. Still, modafinil therapy as a eugeroic agent to treat narcolepsy does not typically lead to drug tolerance, i.e., the effectiveness does not usually decrease on prolonged use, although individual responses may vary. [ 21 ] [ 99 ] [ 114 ]
Despite being a CNS stimulant , the addiction and dependence liabilities of modafinil are considered low. [ 7 ] [ 2 ] [ 24 ] [ 115 ] The exact mechanisms of action of modafinil are not known, [ 116 ] and it is believed that pharmacological profile of modafinil is different from that of the classical stimulants such as cocaine or amphetamine . [ 12 ] Although modafinil shares biochemical mechanisms with stimulant drugs, it is less likely to have mood-elevating properties . [ 7 ] The similarities in effects with caffeine are not clearly established. [ 12 ] [ 117 ] Unlike other stimulants, modafinil does not induce a strong subjective feeling of pleasure or reward , which is commonly associated with euphoria , an intense feeling of well-being. [ 21 ] Euphoria may be an indicator of a drug's potential to be abused. Substance abuse is a compulsive and excessive use of the substance despite adverse consequences. [ 118 ] In comparison to classical stimulants, modafinil exhibits a low propensity for abuse, as it lacks significantly expressed pleasurable or euphoric effects. [ 21 ] Albeit to a lower degree than classical stimulants, modafinil still can produce psychoactive, euphoric, and subjective effects typical for abused stimulants. [ 7 ] [ 3 ]
Modafinil was not observed to promote overuse or misuse, even in people who have a history of cocaine addiction. [ 119 ] Despite the initial belief that modafinil carried no abuse potential, emerging evidence suggests that it works at the same neurobiological mechanisms as other addictive stimulants. Consequently, there exists a potential risk of modafinil abuse, necessitating prudent consideration and caution when prescribing or using this medication. [ 87 ] Modafinil exhibits a lower response on the amphetamine scale of the addiction research center inventory, suggesting reduced propensity for abuse compared to amphetamine. [ 120 ]
The US Drug Enforcement Administration has classified modafinil as a Schedule IV controlled substance ; [ 2 ] [ 7 ] the medicine is recognized for having valid medical uses with low addiction potential. [ 115 ] [ 49 ] The International Narcotics Control Board does not classify it as a narcotic or a psychotropic substance. [ 121 ] [ 122 ]
An overdose of modafinil can lead to a range of symptoms and complications. Psychiatric symptoms may include psychosis , mania , hallucinations , and suicidal ideation, which can occur even in individuals without a history of mental illness and may persist after discontinuation of the drug. [ 123 ] Neurological complications, such as seizures, tremors, dystonia , and dyskinesia , may arise from modafinil's interaction with various neurotransmitter systems. [ 123 ]
Allergic reactions such as rash, angioedema , anaphylaxis , and Stevens–Johnson syndrome may rarely be triggered by an immunological response to modafinil or its metabolites. [ 124 ] [ 125 ] Cardiovascular complications like hypertension, tachycardia , chest pain, and arrhythmias may also be observed due to modafinil's sympathomimetic action. [ 123 ]
In animal studies, the median lethal dose (LD 50 ) of modafinil varies among species and depends on the route of administration. In mice and rats, the LD 50 is approximately 1250 mg/kg if administered via an injection, but the oral LD 50 for rats is 3400 mg/kg . [ 126 ] [ 127 ] The LD 50 value for humans have not been established. Human clinical trials have involved total daily doses up to 1200 mg/d for 7–21 days. Acute one-time total overdoses up to 4500 mg have not been life-threatening but resulted in symptoms like agitation , insomnia , tremor , palpitations , and gastrointestinal disturbances . [ 7 ] [ 128 ]
The management of modafinil overdose involves supportive care, monitoring of vital signs, and treatment of specific complications. In cases of recent consumption, activated charcoal , gastric lavage , or hemodialysis may be used. [ 123 ] There is no specific antidote for modafinil overdose. [ 128 ] [ 129 ] [ 130 ] The main way to deal with modafinil overdose is supportive care, which includes sedating the patient and stabilizing their blood pressure, and muscle activity in case of manifestations such as agitation or tremor. [ 128 ]
Some of the drugs that frequently interact with modafinil include aripiprazole (an antipsychotic), amphetamine (including its enantiomers and salts; stimulants), aspirin , diphenhydramine (an antihistamine ), and others. [ 131 ]
Modafinil is a weak to moderate inducer of CYP3A4 [ 102 ] [ 132 ] [ 133 ] and a weak inhibitor of CYP2C19 , [ 10 ] enzymes of the cytochrome P450 group of enzymes. [ 19 ] Modafinil also induces or inhibits other cytochrome P450 enzymes. [ 102 ] One in vitro study predicts that modafinil may induce the cytochrome P450 enzymes CYP1A2 , CYP3A4, and CYP2B6 , as well as may inhibit CYP2C9 and CYP2C19 . [ 13 ] However, other in-vitro studies find no significant inhibition of CYP2C9 . [ 10 ] [ 134 ] Modafinil may induce P-glycoprotein , which may affect drugs transported by P-glycoprotein, such as digoxin . [ 135 ] It was clinically found that modafinil affects pharmacodynamics of drugs which are metabolized by CYP3A4 and other enzymes of the cytochrome P450 family so that interactions of modafinil with these drugs were observed in real people, rather than being predicted in a lab setting. [ 102 ] [ 132 ] For instance, it was observed that induction of CYP3A4 by modafinil affects metabolism of the following medications and endogenous substances: [ 136 ]
Hypertensive crises have been reported when armodafinil (one of modafinil's enantiomers ) has been taken with monoamine oxidase inhibitors (MAOIs) like tranylcypromine . [ 141 ]
The precise mechanism of action of modafinil for narcolepsy and other sleep disorders remains unclear. [ 3 ] [ 116 ] [ 147 ] [ 148 ] Although modafinil may have interactions with neurotransmitter systems, its exact mode of action is not fully understood. [ 116 ] [ 149 ]
From laboratory research, modafinil has little to no affinity for serotonin or norepinephrine transporters and does not directly interact with these systems. [ 19 ] [ 148 ] However, studies have shown that elevated concentrations of norepinephrine and serotonin can occur as an indirect effect following modafinil administration due to increased extracellular dopamine activity. [ 148 ] [ 19 ] Unlike traditional psychostimulant drugs, [ 22 ] such as cocaine or amphetamine , modafinil shows low potential for causing euphoria due to differences in how it interacts with dopamine transporters at a cellular level. [ 116 ] [ 148 ] [ 149 ]
In addition to its influence on dopaminergic pathways , modafinil may impact other neurotransmitter systems, such as orexin ( hypocretin ). [ 148 ] Orexin neurons are involved in promoting wakefulness and regulating arousal states. Modafinil may increase signaling within hypothalamic orexin pathways, potentially contributing to its wake-promoting effects. [ 19 ] [ 148 ]
C max (peak levels) occurs approximately 2 to 3 hours after modafinil administration. [ 10 ] Food slows the absorption of modafinil but does not affect the total area under the curve (AUC). In vitro measurements indicate that 60% of modafinil is bound to plasma proteins at clinical concentrations of the drug. This percentage changes very little when the concentration of modafinil is varied. [ 150 ]
Renal excretion of unchanged modafinil usually accounts for less than 10% of an oral dose. This means that when modafinil is taken by mouth, the only approved route of administration, less than 10% of the drug is eliminated from the body through the urine without being metabolized by the liver or other organs. The rest of the drug is either metabolized or excreted through other routes, such as feces or bile. [ 10 ]
The two major circulating metabolites of modafinil are modafinil acid (CRL-40467) and modafinil sulfone (CRL-41056). Both of these metabolites have been described as inactive, and neither appears to contribute to the wakefulness-promoting effects of modafinil. [ 60 ] [ 151 ] However, modafinil sulfone does appear to possess anticonvulsant effects, a property that it shares with modafinil. [ 60 ] [ 152 ]
Elimination half-life is in the range of 10 to 12 hours, [ 10 ] [ 150 ] subject to differences in sex, [ 102 ] in cytochrome P450 genotypes , liver function and renal function. Modafinil is metabolized mainly in the liver, [ 10 ] and its inactive metabolites are excreted in the urine. Urinary excretion of the unchanged drug is usually less than 10% but can range from 0% to as high as 18.7%, depending on the factors mentioned. [ 150 ]
Modafinil exhibits sex-specific pharmacokinetic differences. [ 102 ] It demonstrates higher bioavailability in women compared to men. The mean C max is higher in women than in men, 5.2 mg/L vs. 4.2 mg/L (p < 0.05), following a single 200 mg oral dose of modafinil. [ 102 ] This difference persists even after adjusting for body weight ( 0.88 ml/min/kg vs. 0.72 ml/min/kg ). [ 102 ] The clearance of modafinil is 30% higher in men than in women, and plasma concentrations after a single dose are significantly higher in women than in men. These sex-specific pharmacokinetic differences may have implications for the efficacy and safety of modafinil. [ 102 ]
Modafinil is a racemic mixture of two enantiomers , armodafinil (( R )-modafinil) and esmodafinil (( S )-modafinil). [ 153 ]
Modafinil and/or its major metabolite, modafinil acid, may be quantified in plasma, serum, or urine to monitor dosage in those receiving the drug therapeutically, to confirm a diagnosis of poisoning in hospitalized patients, or to assist in the forensic investigation of a vehicular traffic violation. [ 154 ] Instrumental techniques involving gas or liquid chromatography are usually employed for these purposes. [ 84 ] [ 155 ] [ 156 ] In 2011, modafinil was not tested for by common drug screens (except for anti-doping screens) and is unlikely to cause false positives for other chemically unrelated drugs such as substituted amphetamines . [ 145 ] [ 153 ] [ 157 ]
Reagent testing can screen for the presence of modafinil in samples. [ 158 ] [ 159 ]
Many derivatives and structural analogs of modafinil have been synthesized. [ 23 ] [ 160 ] [ 161 ] Examples include adrafinil , CE-123 , fladrafinil (CRL-40941; fluorafinil), flmodafinil (CRL-40940; bisfluoromodafinil, lauflumide), RDS03-94 , JJC8-088 , modafiendz and modafinil sulfone (CRL-41056). [ 162 ] [ 23 ]
Modafinil was developed in France by neurophysiology professor Michel Jouvet and Lafon Laboratories. It is part of a series of benzhydryl sulfinyl compounds, including adrafinil , initially used as a treatment for narcolepsy in France in 1986. [ 163 ] Modafinil, the primary metabolite of adrafinil , [ 164 ] has been prescribed in France since 1994 under the name Modiodal, [ 163 ] and in the United States since 1998 as Provigil. [ 7 ] Unlike modafinil, adrafinil does not have FDA approval and was withdrawn from the French market in 2011. [ 165 ]
The FDA approved modafinil in 1998 for narcolepsy treatment, and later for shift work sleep disorder and obstructive sleep apnea in 2003. [ 7 ] [ 166 ] [ 167 ] It was approved in the UK in December 2002. In the United States, modafinil is marketed by Cephalon , [ 168 ] who acquired the rights from Lafon and purchased the company in 2001. [ 168 ]
Cephalon introduced armodafinil, the ( R )-enantiomer of modafinil, in the United States in 2007. Generic versions of modafinil became available in the US in 2012 after extensive patent litigation. [ 169 ] [ 170 ]
Modafinil is not approved for use by children in multiple jurisdictions. [ 1 ] [ 171 ] [ 6 ] [ 7 ] [ 172 ]
In Australia, modafinil is considered to be a Schedule 4 prescription-only medicine . This means that it is a drug with a perceived low potential for abuse and low risk of dependence; still, the use of Schedule 4 drugs in Australia is restricted to those who have a valid prescription from a medical practitioner; import from abroad is illegal. [ 173 ]
In Canada, modafinil is not specifically included in the lists of controlled drugs and substances specified within the Controlled Drugs and Substances Act . [ 174 ] However, it is classified as a Schedule F prescription drug. [ 175 ] [ 176 ] [ 177 ] This means that modafinil can only be obtained legally with a valid prescription from a licensed health care practitioner in Canada, and the import of modafinil to Canada from other countries is subject to restrictions: importing prescription drugs without an import permit may result in the seizure of the drugs at the border, the refusal of entry of the drugs into Canada, or prosecution. [ 178 ]
In mainland China, modafinil is strictly controlled like other stimulants such as amphetamines and methylphenidate . It is classified as Class I psychotropic drug. This classification means that modafinil is considered to have a high potential for abuse and dependence, and is therefore subject to strict regulation and control. As a result, modafinil is only available by prescription and cannot be purchased over the counter. In order to obtain a prescription for modafinil, a patient must have a valid medical reason for using the drug, such as narcolepsy or obstructive sleep apnea . Additionally, the prescription must be written by a licensed physician and filled at a licensed pharmacy . The use of modafinil for non-medical purposes, such as with the aim to improve cognitive performance or to stay awake for long periods of time, is strictly prohibited and can result in legal consequences. [ 179 ] [ 180 ]
In Denmark, modafinil is a prescription drug but not listed as a controlled substance. According to the Danish Medicines Agency , modafinil is approved for use in the treatment of narcolepsy, still, importing modafinil to Denmark is considered illegal without a valid prescription. [ 181 ] [ 182 ] [ 183 ] [ 184 ]
In Finland, modafinil is a prescription drug but not listed as a controlled substance . Finland is a member of the European Union, and it is illegal to import prescription medicine from outside the European Union unless the person has a valid prescription. [ 185 ] [ 186 ] [ 187 ]
In the Republic of Moldova, modafinil is classified as a psychotropic drug (included in table III list 3 which is the list of psychotropic substances as defined by the Government of Moldova ) [ 188 ] and is available by prescription. [ 188 ] Importation of modafinil may be considered illegal and subject to severe penalties, even if you have a prescription. [ 189 ] For example, on June 29, 2017, Moldovan postal officers discovered 60 tablets of Modalert (200 mg modafinil tablets) in a parcel sent from India to a resident in Chișinău , Moldova. The prohibited substance was detected during a routine scan and was seized as illegal. The authorities were notified of the incident and the recipient was charged with criminal penalties. [ 190 ] [ 191 ] In the Transnistria region of Moldova, modafinil is completely prohibited, due to application of the legislation similar to that of Russia where modafinil is completely prohibited and is in the same list as narcotics. Possession or an attempt to bring modafinil to Transnistria potentially leads to imprisonment. [ 192 ]
In Romania, modafinil is classified as a stimulant doping agent and is prohibited in sports competitions. [ 193 ] In 2022, laws were passed making its importation or sale a felony, punishable by three to seven years in jail. [ 194 ] Simple possession for personal use may result in a fine and confiscation. [ 194 ]
In Sweden, modafinil is classified as a schedule IV substance, which means that it is considered to have a low potential for abuse and a low risk of dependence. Still, possession is illegal without a prescription. [ 195 ]
In the United Kingdom, it is not listed in Misuse of Drugs Act , so possession is not illegal, but a prescription is required. [ 196 ]
In Mexico, modafinil is not listed as a controlled substance, in the National Health Law, and can be purchased in pharmacies without prescription. [ 197 ]
In Japan, modafinil is Schedule I psychotropic drug. This means that it is considered to have a high potential for abuse and dependence, and is therefore subject to strict regulations. The use of Schedule I drugs in Japan is generally prohibited, except under certain circumstances, such as for medical purposes. It can only be prescribed by a doctor. It cannot be imported or exported without a permit. It cannot be used while driving or operating machinery. [ 198 ] [ 199 ] Cephalon licensed Alfresa Corporation to produce, and Mitsubishi Tanabe Pharma to sell modafinil products under the trade name Modiodal in Japan. [ 200 ] There have been arrests of people who imported modafinil for personal use. [ 201 ] [ 202 ]
In Russia, starting from May 18, 2012, modafinil is Schedule II controlled substance. Being classified as a Schedule II controlled substance in Russia means that it is seen as a drug with a high potential for abuse and dependence. This classification imposes strict regulations on the production, distribution, and use of modafinil. Possession of a few modafinil pills can lead to three to ten years imprisonment. Modafinil is not approved for medical use in Russia and cannot be bought even in pharmacies. It also cannot be imported from abroad, even if you have a prescription issued outside Russia. [ 192 ] [ 203 ] There are multiple cases of criminal proceedings initiated against Russian residents who tried to import modafinil by mail from abroad. [ 204 ] [ 205 ]
In South Africa, modafinil is Schedule V substance, which means that it is legal to use modafinil in South Africa, but only with a valid prescription from a licensed medical practitioner. [ 206 ]
In the United States, modafinil is classified as a schedule IV controlled substance [ 2 ] under US federal law. [ 7 ] [ 207 ] This means that the drug has a low potential for abuse and dependence compared to other controlled substances. However, it still requires a prescription from a licensed healthcare provider to obtain. [ 207 ]
It is illegal to import modafinil to the United States without a Drug Enforcement Administration ( DEA )–registered importer and a prescription. [ 208 ] Individuals may legally bring modafinil into the US from a foreign country for personal use, limited to 50 dosage units, with a prescription and proper declaration at the border. [ 209 ] Under the Pure Food and Drug Act , marketing drugs for off-label uses is prohibited. [ 210 ] Cephalon, the manufacturer of Provigil, faced legal issues for promoting off-label uses and paid significant fines in 2008. [ 211 ]
Modafinil is sold under a variety of brand names worldwide, including Alertec, Alertex, Altasomil, Aspendos, Bravamax, Forcilin, Intensit, Karim, Mentix, Modafinilo, Modalert, Modanil, Modasomil, Modvigil, Modiodal, Modiwake, Movigil, Provigil, Resotyl, Stavigile, Vigia, Vigicer, Vigil, Vigimax, Waklert, and Zalux. [ 212 ]
Originally developed in the 1970s by French neuroscientist Michel Jouvet and Lafon Laboratories, modafinil has been prescribed in France since 1994, [ 163 ] [ 35 ] and was approved for medical use in the United States in 1998. [ 7 ] [ 35 ]
Concerns have been raised about the growing use of modafinil as a "smart drug" or cognitive enhancer among healthy individuals who use it with the aim to improve concentration and memory. [ 213 ] [ 214 ] In 2003, modafinil sales were skyrocketing, with some experts concerned that it had become a tempting pick-me-up for people looking for an extra edge in a productivity-obsessed society. [ 213 ] The cost of modafinil varied depending on factors such as location and insurance coverage; [ 213 ] [ 214 ] [ 215 ] still, in 2004, the price of modafinil in the US was around $120 or more per monthly supply. [ 213 ] However, the availability of generic versions has increased since then and may have driven down prices. [ 213 ] [ 214 ] [ 215 ]
In 2020, modafinil was the 302nd most commonly prescribed medication in the United States, with just over 1,000,000 prescriptions. [ 216 ]
As of 2024, [update] the global sales figures for modafinil are not known. Still, modafinil sold under the brand name Provigil accounted for over 40% of Cephalon 's global turnover for several years, according to the information published in 2020. [ 217 ]
Modafinil's patent history involves several key developments. The original patent, U.S. patent 4,927,855 , was granted to Laboratoire L. Lafon in 1990, covering the chemical compound of modafinil. This patent expired in 2010. [ 218 ] In 1994, Cephalon filed a patent for modafinil in the form of particles of a defined size, represented by U.S. patent 5,618,845 , which expired in 2015. [ 219 ]
Following the nearing expiration of marketing rights in 2002, generic manufacturers, including Mylan and Teva, applied for FDA approval to market a generic form of modafinil, leading to legal challenges by Cephalon regarding the particle size patent. [ 220 ] The patent RE 37,516 was declared invalid and unenforceable in 2011. [ 221 ]
In addition, Cephalon entered agreements with several generic drug manufacturers to delay the sale of generic modafinil in the US. These agreements were subject to legal scrutiny and antitrust investigations, culminating in a ruling by the Court of Appeals in 2016, which found that the settlements did not violate antitrust laws. [ 222 ]
The regulation of modafinil as a doping agent has been controversial in the sporting world, with high-profile cases attracting press coverage since several prominent American athletes tested positive for the substance. Some athletes who used modafinil protested that the drug was not on the prohibited list at the time of their offenses. [ 223 ] However, the World Anti-Doping Agency (WADA) maintains that modafinil was related to already-banned substances. The Agency added modafinil to its list of prohibited substances on August 3, 2004, ten days before the start of the 2004 Summer Olympics . [ 157 ]
Several athletes, such as sprinter Kelli White in 2003, [ 224 ] cyclist David Clinger [ 225 ] and basketball player Diana Taurasi [ 226 ] in 2010, and rower Timothy Grant in 2015, [ 227 ] were accused of using modafinil as a performance-enhancing doping agent. Taurasi and another player—Monique Coker, tested at the same lab—were later cleared. [ 228 ] Kelli White, who tested positive after her 100m victory at the 2003 World Championships in Paris, was stripped of her gold medals. [ 229 ] She claimed that she used modafinil to treat narcolepsy, but the International Association of Athletics Federations (IAAF) ruled that modafinil was a performance-enhancing drug. [ 229 ]
The BALCO scandal brought to light an unsubstantiated (but widely published) account of Major League Baseball's all-time leading home-run hitter Barry Bonds ' supplemental chemical regimen that included modafinil in addition to anabolic steroids and human growth hormone . [ 230 ]
The use of modafinil as a supposed cognitive enhancer may be considered as cheating, unnatural, or risky. [ 231 ] The University of Sussex explained that it is a prescription drug and the decision should be made by the doctor on whether to prescribe modafinil to a student. [ 232 ] As a matter of bioethics , the US President's Council on Bioethics argued that excellence achieved through the use of drugs like modafinil is "cheap" as it obviates the need for hard work and study, and is not fully authentic because the excellence is partly attributable to the drug, not the individual. [ 233 ] Alternately, people in environments like Wall Street trading may not view the use of modafinil as cheating, believing that if modafinil can give them an edge and they are aware of the risks involved, it should not be considered as cheating. [ 234 ] Due to such varying views, modafinil users for narcolepsy may cope with stigma by hiding, denying, or justifying their use, or by seeking support from others who share their views or experiences. [ 235 ] [ 236 ]
Modafinil has been studied in the treatment of major depressive disorder . [ 237 ] [ 238 ] [ 239 ] In a 2021 systematic review and meta-analysis of randomized controlled trials of psychostimulants for depression, modafinil and other stimulants such as methylphenidate and amphetamines improved depression in traditional meta-analysis. [ 239 ] However, when subjected to network meta-analysis , modafinil and most other stimulants did not significantly improve depression, with only methylphenidate remaining effective. [ 239 ] Modafinil and other stimulants likewise did not improve quality of life in the meta-analysis, although there was evidence for reduced fatigue and sleepiness with modafinil and other stimulants. [ 239 ] While significant effectiveness of modafinil for depression has been reported by particular trials, [ 65 ] [ 238 ] [ 240 ] reviews and meta-analyses note that the effectiveness of modafinil for depression is limited, the quality of available evidence is low, and the results are inconclusive. [ 239 ] [ 241 ] [ 242 ]
Modafinil was considered for the treatment of ADHD because of its lower abuse potential than conventional psychostimulants [ 22 ] like methylphenidate and amphetamines. [ 50 ] [ 243 ] In 2008, an application to market modafinil for pediatric ADHD was submitted to the Food and Drug Administration in the US. [ 88 ] [ 44 ]
However, evidence of modafinil for treatment of adult ADHD is mixed, and a 2016 systematic review of alternative drug therapies for adult ADHD did not recommend its use in this context. [ 46 ] In a later large phase 3 clinical trial of modafinil for adult ADHD, modafinil was not effective in improving symptoms, there was also a high rate of side effects (86%) and discontinuation (47%). [ 244 ] The poor tolerability of modafinil in this study was possibly due to the use of high doses ( 210–510 mg/d ). [ 244 ] Another reason for the denial of the approval was due to concerns about rare but serious dermatological toxicity in Stevens–Johnson syndrome . [ 88 ]
The research on the use of modafinil for treating individuals with Autism Spectrum Disorder (ASD) who also exhibit ADHD symptoms is currently in its early stages with no results delivered. [ 245 ]
Modafinil was studied for the treatment of stimulant dependence , but the results are mixed and inconclusive. [ 23 ] [ 246 ] Modafinil is not a controlled substance in some countries, unlike other medications, such as bupropion , which is also used to treat depression and nicotine dependence . [ 247 ] The clinical trials that have tested modafinil as a treatment for stimulant abuse have failed to demonstrate its efficacy and the optimal dose and duration of modafinil treatment remain unclear, and modafinil is not a recommended treatment for stimulant abuse. [ 247 ] 2024 reviews found that modafinil was ineffective for treating individuals with amphetamine-type stimulant use disorder [ 248 ] or methamphetamine use disorder [ 249 ] from these dependencies. [ 249 ] [ 248 ]
Modafinil and armodafinil were studied as a complement to antipsychotic medications in the treatment of schizophrenia . They showed no effect on positive symptoms or cognitive performance. [ 250 ] [ 251 ] A 2015 meta-analysis found that modafinil and armodafinil may slightly reduce negative symptoms in people with acute schizophrenia, though they do not appear useful for people with the condition who are stable, with high negative symptom scores. [ 251 ] Among medications demonstrated to be effective for reducing negative symptoms in combination with antipsychotics, modafinil, and armodafinil are among the smallest effect sizes . [ 252 ]
Modafinil is researched to determine whether it might improve abstinence in people with cocaine addiction . [ 253 ]
Modafinil has been found to reverse tetrabenazine -induced motivational deficits in animals and hence can produce pro-motivational effects. [ 254 ] [ 255 ] [ 256 ] Novel modafinil analogs with greater potency , including CE-123 , CE-158 , JJC8-088 , MK-26 , and RDS03-94 , have also been developed and have shown pro-motivational effects in animals. [ 254 ] [ 257 ] These agents are of potential interest in the treatment of motivational disorders in humans. [ 254 ] [ 257 ]
A 2019 review conducted on the potential nootropic effects of modafinil in healthy, non-sleep-deprived individuals revealed the following: [ 258 ] a) while studies using basic testing paradigms demonstrated that modafinil enhances executive function , only half of these studies showed improvements in attention, learning, and memory, with a few studies even reporting impairments in divergent creative thinking; b) modafinil displayed small levels of enhancement in attention, executive functions, and learning abilities; c) no substantial side effects or mood changes were observed; d) the available evidence showed limited evidence for modafinil as a cognitive enhancer outside of its use for sleep-deprived populations.
A 2020 review reported that modafinil has a modest effect on memory updating, but the effect is small and may not accurately reflect the perception that it is useful as a cognitive enhancer, as there is insufficient evidence to support such a claim. [ 259 ]
General anesthesia is required for many surgeries , but may cause lingering fatigue, sedation, and/or drowsiness after surgery that lasts for hours to days. [ 260 ] [ 261 ] In outpatient surgery the sedation , fatigue , and occasional dizziness is problematic. [ 262 ] [ 263 ] Modafinil was tested as a potential remedy to alleviate these symptoms. [ 49 ] For example, it was expected that modafinil would help people recover quicker from general anesthesia after a short surgery, [ 88 ] but the results were uncertain and the inconclusive studies could not reliably verify the expectation. [ 49 ] The use of modafinil to relieve post-anesthesia sedation is investigational. [ 88 ]
Caution should be exercised in people who have narcolepsy in comorbidity with postural orthostatic tachycardia syndrome (POTS). [ 264 ]
Modafinil is being researched as a potential remedy for excessive daytime sleepiness in myotonic dystrophy (DM), an inherited condition characterized by progressive muscle loss, weakness, and myotonia. Myotonia is a condition where muscles cannot relax after they contract. [ 265 ] Myotonic dystrophy has two main types: DM1 (Steinert disease) and DM2 (proximal myotonic myopathy). Both types can cause excessive daytime sleepiness. Studies suggest that modafinil may be a promising drug that can reduce both daytime sleepiness and myotonia itself, without significant cardiac conduction effects. These presumed property of modafinil is of particular interest for eventual treatment of people with myotonic dystrophy who often have underlying cardiac issues. [ 265 ] Still, modafinil is not approved by the FDA for use in myotonic dystrophy, and the value and role of modafinil in DM remain the subject of debate. [ 265 ]
Modafinil has been studied for its potential therapeutic effects in patients with disorders of consciousness . [ 266 ] Researchers are investigating whether modafinil can stimulate neurotransmitters such as histamine , norepinephrine , serotonin , dopamine , and orexin , and whether modafinil has potential anti-oxidative effects . [ 266 ]
Disorders of consciousness are states characterized by impaired arousal and awareness. [ 266 ] These states include coma , vegetative state / unresponsive wakefulness syndrome (VS/UWS), minimally conscious state (MCS), cognitive motor dissociation , and covert cortical processing . [ 266 ] Brain injuries can impair consciousness through neuroanatomic lesions involving the bilateral cerebral hemispheres , rostral brainstem , diencephalon , or basal forebrain . [ 266 ]
Neuroimaging studies have shown that modafinil increases cerebral blood flow in several brain regions, such as the thalamus , locus coeruleus , limbic system , and insular cortex ; [ 266 ] still, observational reports on the use of modafinil in patients with disorders of consciousness have produced mixed results, indicating that its effectiveness may vary among individuals. [ 266 ]
A possible link between inflammatory processes and depressive disorders [ 267 ] has stimulated preliminary research on modafinil for its potential anti-inflammatory effects. [ 268 ] | https://en.wikipedia.org/wiki/Modafinil |
In algebra and logic , a modal algebra is a structure ⟨ A , ∧ , ∨ , − , 0 , 1 , ◻ ⟩ {\displaystyle \langle A,\land ,\lor ,-,0,1,\Box \rangle } such that
Modal algebras provide models of propositional modal logics in the same way as Boolean algebras are models of classical logic . In particular, the variety of all modal algebras is the equivalent algebraic semantics of the modal logic K in the sense of abstract algebraic logic , and the lattice of its subvarieties is dually isomorphic to the lattice of normal modal logics .
Stone's representation theorem can be generalized to the Jónsson–Tarski duality , which ensures that each modal algebra can be represented as the algebra of admissible sets in a modal general frame .
A Magari algebra (or diagonalizable algebra ) is a modal algebra satisfying ◻ ( − ◻ x ∨ x ) = ◻ x {\displaystyle \Box (-\Box x\lor x)=\Box x} . Magari algebras correspond to provability logic .
This algebra -related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Modal_algebra |
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