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17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 4 Introduction to DECT services and applications | DECT is a general radio access technology for wireless telecommunications. It is a high capacity, picocellular digital technology, for cell radii ranging from about 10 m to 5 km depending on application and environment. It provides telephony quality voice services, and a broad range of data services, including Integrated Services Digital Network (ISDN) and packet data over the Internet. It can be effectively implemented as a simple residential cordless telephone or as a system providing all telephone services in a city centre. Applications include Radio in the Local Loop, RLL, with ranges of several kilometres. Figure 1 gives a high level graphic overview of DECT services and applications. The basic 2 level modulation of DECT allows up to 552 kbit/s, and with implemented higher level modulation options, bitrates exceeding 4 Mbit/s are possible. Protected asymmetric links with bit rates beyond these bit rates are possible if needed, for example by having multiple radio circuits in a subscriber unit. Together with DECT/GSM/UMTS interworking evolving products will provide 3rd generation mobile radio services. DECT is one of the IMT-2000 radio technologies, denoted "IMT-2000 FDMA/TDMA (DECT)". It is the only IMT-2000 family member optimized for uncoordinated use in unlicensed spectrum. Access to PSTN, ISDN ADSL, IP GSM, UMTS LANs Application Areas Residential Small Office Large Office Public Pedestrian Radio Local Loop Services Multi-media, Speech, Audio, Video, Internet browsing, File transfer, Gaming, Remote control, etc. Figure 1: Graphic high level overview of DECT services and applications The aim of the DECT standardization has been to develop a modern and complete standard within the area of cordless telecommunications. The DECT standardization effort has received substantial legal and financial support by the European Commission (EC). The CEPT European wide allocation of the frequency band 1 880 MHz to 1 900 MHz has been reinforced by the Council Directive 91/287/EEC [24]. The Directive states that "DECT shall have priority and be protected in the designated band (1 880 MHz to 1 900 MHz)" and "recognizing that, subject to system development of DECT, additional frequency spectrum may be required". NOTE: Most of the examples in the present document are based on the initial European allocation of 1 880 MHz to 1 900 MHz. However the results can be applied to a different spectrum allocation as well. The most common protected spectrum allocation is 1 880 MHz to 1 900 MHz, but outside Europe spectrum is also available in 1 900 MHz to 1 920 MHz and in 1 910 MHz to 1 930 MHz (several countries in Latin America). For rapid introduction on European wide basis, harmonized standards [26], [27] according to the R&TTE Directive [23] have been developed for DECT. Conformance to the relevant harmonized standard gives access to a single European market. DECT is classified under the R&TTE Directive as class1 equipment. That means that it can be placed on the European market and be put into service without restrictions [33], [34], [35], [36]. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 14 The Council Recommendation 91/288/EEC [25] recommends that the DECT standard should meet user requirements for residential, business, public and RLL applications. The standard should also provide compatibility and multiple access rights to allow a single handset to access several types of systems and services, e.g. a residential system, a business system and one or more public systems. The public applications should be able to support full intersystem European roaming of DECT handsets. The DECT standard provides these features. Of special importance is the Generic Access Profile (GAP) which define common mobility and interoperability requirements for private and public DECT speech services. For a more comprehensive overview of the DECT standardization, see TR 101 178 [13]. The deregulation of fixed services will speed up fixed-mobile convergence in service offerings from operators. The different DECT interoperability profile standards are designed to facilitate provision of mixtures of fixed and mobile services through a single infrastructure. See clause A.5.2.3.1 and examples in ETR 308 [16]. The DECT instant or Continuous Dynamic Channel Selection (CDCS) provides effective coexistence of uncoordinated installations of private and public systems on the common designated DECT frequency band, and avoids any need for traditional frequency planning. The present document describes configurations for typical DECT applications and relevant mixes of these, including residential, office, public pedestrian and RLL applications, and the traffic capacity is analysed, mainly by advanced simulations. These results are used together with relevant deployment scenarios to estimate spectrum requirements for reliable services, specifically for a public multi-operator licensing regime. Recommendations are given on conflict solving rules that conserves the high spectrum efficiency gain of shared spectrum while maintaining control of the service quality in one's own system. These recommendations cover synchronization, directional gain antennas, traffic limits per DECT RFP, use of WRS, different rules for private and public operators, and procedures needed for timely local adjustments where and when the local traffic increases. Annex B contains results and recommendations on coexistence with other relevant radio technologies operating on the same or adjacent frequency band. Annex F gives information on RF modifications of DECT enabling applications on FDD (paired up-link/down-link) spectrum. 5 Principles for providing required traffic capacity and link quality on a common spectrum allocation The key DECT features and principles that provide a required traffic capacity and link quality are described below. Annex E of the present document gives further information on fundamental aspects of DECT for providing a required traffic capacity and link quality. NOTE: The earlier ETSI technical report, ETR 042 "Digital Enhanced Cordless Telecommunications (DECT); A Guide to DECT features that influence the traffic capacity and the maintenance of high radio link transmission quality, including the results of simulations" [21], is now declared "historical", has a good description of the fundamental aspects of DECT. The simulation results presented below in the present document, are more complete and more accurate than the results of ETR 042 [21], since more complete simulation tools have been available for the more recent simulations. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.1 A new concept: the local load on the spectrum | The present document introduces a new concept, the "local load on the spectrum". This concept has been a very useful tool to estimate the local interference potential of different DECT system deployments. The local load on the spectrum from one system is defined as the number of different full-slot duplex (or equivalent) access channels that this system on average occupies in a specific local area. For simplicity we have expressed the local load on the spectrum in Erlangs (E). A local load of N E means that N different full-slot duplex access channels in average are occupied in a specific local area. The total local load shall be related to the local load that can be carried by the allocated spectrum. 10 carriers, as available within the frequency band 1 880 MHz to 1 900 MHz, provide 120 full-slot duplex access channels. This means that there are 120 local trunks available in the ether. The Erlang B traffic formula shows that 120 trunks can carry 100 E average traffic for about 0,5 % blocking probability. Therefore, for 10 DECT carriers, the total local load always has to be less than 100 E. We call these 100 E the local loadable traffic. A local area may be defined as the area in which a traffic channel typically can not be reused. It must be understood, that for example for above roof top RLL systems, sectorized antennas decrease the size of the above roof top local areas, and that large obstacles like houses create separate local areas below roof top level. This concept of "local load on the spectrum" is useful due to the instant Dynamic Channel Selection feature of DECT, which makes it feasible to use the average load measure, since those few connections that become interfered from traffic in adjacent local areas can find escapes to non-interfered channels. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 15 Since the present document deals with spectrum requirements, the high capacity Carrier to Interference ratio (C/I) limited scenarios are relevant, but not the range limited or device trunk limited scenarios. Trunk limitation can however be a means to limit the local load on the spectrum from a single system. The present document does not contain any detailed range calculations for different propagation models. The ETR 139 [22] contains some scenarios and range calculations these are partly re-used below. Many of the results in ETR 042 [21] (see above note in clause 5) are trunk limited by the maximum 12 access channels per single radio RFP. It is very important to differentiate between device (RFP) trunk limited capacity and capacity limitation due to the local load on the spectrum (C/I limitation). An example is a double-slot for fax transmission that may have a larger blocking probability than a full-slot due to trunk limitation in the RFP or WRS. However, fax services over double slots give lower average local load on the spectrum than fax services over a full-slot, since the double-slot transfers faxes (28,8 kbit/s) more that twice as fast as a full-slot (4,8 kbit/s to 9,6 kbit/s). See clause 7. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2 Dynamic Channel Selection (DCS) | A main characteristic of DECT is the instant DCS. DECT has 10 carriers available on a 20 MHz bandwidth (1 880 MHz to 1 900 MHz). For speech services each carrier is divided in frames of 24 full-slot time slots (12 in one direction and 12 in the other direction for symmetric duplex services). A DECT access channel is defined by a carrier frequency and a time slot. If for example 10 DECT carriers are allocated, as in the frequency band 1 880 MHz to 1 900 MHz, totally 120 full-slot duplex access channels will be provided. A more detailed description of the DECT instant DCS procedures is found in annex E of in ETR 042 [21] and in EN 300 175-3 [3], clause 11.4. The terminals select the DECT traffic channel. Each terminal maintains an ordered list of the 6 to 10 least interfered channels. This list, and information on strongest detected base station (to which the PT has access rights), are regularly updated in order to detect changes in the local environment and to detect movement between basestations. The least interfered channel of its list is used for the first bearer set up attempt to the strongest accessible base station. The big advantage of this kind of channel selection is that the set-up of a new channel takes into account the local interference situation in that instant: in this way the system is self-adapting. There is no need for a pre-planning of the system, but different applications and different operators can share dynamically the same spectrum resource without prior distribution of channels to specific services or base stations. This will give to each user an additional capacity when compared with cellular systems using Fixed Channel Allocation (FCA) mechanisms. See clause 5.2.1 and annex D. DECT systems provide micro-cellular coverage; a very good frequency reuse can be achieved because of the intrinsic high robustness of the DECT channel to interferers. For example, the separation of an obstacle such as a wall or a floor can be sufficient for the same channel to be reused on both sides of the obstacle at the same time. Another very important factor for providing the high traffic capacity and the maintenance of a high quality radio link, is the quick DECT seamless inter-cell and intra-cell handover that does not depend on signalling on the old (interfered) access channel. More details on this can be found in annex E. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2.1 Spectrum efficiency of DECT compared with a system using FCA | The spectrum required for different DECT systems compared with the spectrum required by a comparable system using FCA has been analysed in annex D. A comparable technology is a duplex 32 kbit/s service transfer by Frequency Division Multiple Access (FDMA) or TDMA, Frequency Division Duplex (FDD) or Time Division Duplex (TDD), using radio receivers with limiter/discriminator detector or differential detector. The modulation type has only secondary influence. The spectrum efficiency of DECT compared with FCA is indicated by the factor K and has been calculated in annex D for a typical large office and for a suburban outdoor pedestrian application. The conclusions are as follows: - for indoor multi-storey applications, DECT is typically 7 to 10 times more spectrum efficient than a comparable technology using FCA, K = 7 to 10; - for outdoor pedestrian suburban applications, DECT is typically 3 to 7 times more spectrum efficient than a comparable technology using FCA, K = 3 to 7. DECT is therefore, basically very spectrum efficient compared to the technologies using FCA. This property is amplified the smaller the cells are and the more irregular the propagation patterns are. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 16 Furthermore, with FCA, it is not possible to share spectrum between operators of different systems. Therefore DECT will, for example for office applications, gain another factor N in efficiency over FCA, where N is the number of operators of office systems not sharing spectrum for office applications. See clause 5.2.2. 5.2.2 Spectrum efficiency due to multi-operator multi-application coexistence on a common allocation In clause 5.2.1 the spectrum efficiency for one operator having one system was analysed for DECT and for a comparable system having FCA. In this clause we will analyse the gain of having several systems and operators sharing a common spectrum, compared to allocating a specific spectrum per system and/or operator, but supposing that DECT is used in both cases. So we only deal with the gain of sharing spectrum, isolated from the gain of DCS verses FCA, which has been analysed above. DCS is of course a prerequisite for being able to share spectrum. The spectrum efficiency gain due to multi-system multi-application coexistence on a common spectrum allocation depends on the deployment scenarios, the number of operators, and the level of co-ordination of installations between operators. See clauses 9 and 10. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2.2.1 Residential base station applications | Residential base station applications are either private residential systems operating on a common spectrum or residential base stations supplied by a public operator as an addition to a public mobile or cordless telephone subscription to offer low cost mobility service within the subscriber's residence. Basic characteristics of these systems are that they mainly operate within the user premises, and that these premises may be close to each other, but do not normally overlap. Another basic characteristic is that the geographical location of a system will vary when the owner changes residence. It is obvious that offering substantive penetration of reliable residential services is very difficult without having some type of semi-fixed sharing or instantaneous dynamic sharing of control and traffic channels. With FCA theoretically one unique access channel per residential system in a country would be needed, which of course is totally impractical. To let the user manually select between a limited number of channels is more practical, and obviously works well for low cost analogue cordless telephones due to the relatively low traffic density. A divided spectrum between N public operators offering residential base stations, will require N times more spectrum than a shared spectrum as applied for DECT, since any of the operators may get all residential customers in an area or in a block of domestic flats. However, the office traffic (see below) is much higher than the residential traffic, and residential and office traffic are typically in different buildings. Therefore, only the spectrum requirements for offices need consideration in the context of residential and office systems of this clause. Therefore, we can conclude that: - general application of residential base stations requires some kind of semi-fixed sharing or instantaneous dynamic sharing of control and traffic channels. The traffic density is so low that the spectrum need for residential applications will be covered by the spectrum needs for office applications. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2.2.2 Office base station applications | Office base station applications are private systems operating on a common spectrum or base stations supplied by a public operator to offer telecommunications services for a company. A basic characteristic for office systems, as for residential systems, is that they mainly operate within the user premises, and that these premises may be close to each other, but do not normally overlap. For office systems, at least for the larger ones, we may assume that they are more stationary than residential systems, and that a traditional FCA planning is possible. There is normally a natural isolation between office installations as indicated in figure 4. Therefore in a first approximation, the spectrum requirements are the same for covering one multi-story office, as for covering all offices in a city. Therefore, a divided spectrum between N public operators, providing office telecommunications services, will require N times more spectrum than a shared spectrum as applied for DECT. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 17 Therefore, we can conclude: - unlicensed office systems operating on a common spectrum requires dynamic sharing of control and traffic channels; - a divided spectrum between N public operators offering office telecommunications applications, will require N times more spectrum than a shared spectrum as applied for DECT. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2.2.3 Public outdoor above roof top RLL systems | The public systems generally cover the same area and compete for the same subscribers, whereby the total (shared) local traffic will be limited by the total local number of potential subscribers. A multi-operator scenario with RLL applications with above roof-top base station installations is a typical example. If the spectrum is (equally) divided between N operators, the spectrum efficiency will decrease due to loss of trunking efficiency even with equal traffic share between the operators. In reality the local loss of spectrum utilization will further decrease, due to the uneven local market share of the different operators. Results from simulations in clause A.3.2 show that the spectrum efficiency can be increased by up to 60 % by not dividing the 20 MHz of spectrum between 3 operators. This is for the case where all 3 systems have equal local load on the spectrum. In reality, for RLL, we can expect that there will be many local areas where one of the operators will be dominating. In such areas the spectrum efficiency can be up to 3,1 times (2 operators) and 4,8 times (3 operators) better compared to splitting the frequency band between operators. This assumes frame and slot synchronization between the systems and about equal cell sizes in the different systems. The gain will be considerably reduced for above roof-top cases if synchronization is not provided. In the case of the dominant operator having 90 % of the traffic and a second operator has 10 % and nine times larger cell area than the dominant operator, the spectrum efficiency gain over an equal split of the spectrum is reduced to 1,6 instead of 3,1 with equal cell sizes. In this case it was necessary to reduce the number of carriers of the dominant operator from 10 to 8, to provide escapes for the large cell connections. See clause 10. Therefore, for case with three operators, by providing synchronized systems, sharing spectrum will, compared to equal division of the spectrum, provide up to between 3,1 and 4,8 times more efficient use of the spectrum. The 3,1 times relates to trunking efficiency gain when all operators have equal share of the traffic, and 4,8 times for the case when one of three operators has all the traffic in a local area. In the latter case only a fraction of the spectrum will be utilized if the spectrum has been divided between the operators. Therefore we can conclude: - there is a large preference for DECT outdoor public operators to share a common spectrum instead of dividing the spectrum. This requires synchronization within and between the systems. The simulations made, indicate a spectrum efficiency gain factor of at least 1,6 for above roof top installations. The more operators the larger the gain of sharing compared to dividing the spectrum; - there must be a mechanism to ensure that a dominant operator does not limit the spectrum access of the other operators in case of hot spot local area with large differences of cell sizes. This is covered in clause 10.6. 5.2.2.4 Summary on multi-operator multi-application coexistence on a common allocation Sharing by instant DCS and the use of a common spectrum are necessary requirements for unlicensed (no limit on number of system operators) operation of office and residential systems. The total spectrum requirement for office and residential systems will not be larger than the requirement for a single operator having a dedicated spectrum. Therefore, dividing the spectrum between N operators would require N times more spectrum. For outdoor public systems the gain of not dividing the spectrum is estimated to be at least a factor 1,6 for above roof top installations, provided the systems are synchronized. Since there is no natural isolation between above roof-top public systems, additional rules are required to guarantee proper fair coexistence between the operators in local hot spot areas. See clause 10. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 18 There is a spectrum efficiency gain in also letting the different applications (fully or partly) share a common spectrum. The gain is typically 30 % to 50 %. Table 1 illustrates the combined gain of letting different applications and operators coexist on a common spectrum allocation. The spectrum estimates allow for a predicted increase in the use of data and multimedia services (see clause 6). Table 1: Spectrum efficiency gain by sharing spectrum between applications and operators for speech and emerging data services Scenario (speech and estimated emerging data services) Office and Residential Public pedestrian hot spots RLL Separate allocations for all applications Total spectrum requirement (multi-application shared allocation) N operators having own spectrum N x 15 MHz N x 7 MHz N x 7 MHz N x 29 MHz N x 15 MHz Operators share spectrum (see note) 20 MHz 8 MHz 20 MHz 48 MHz 28 MHz NOTE 1: At least four RLL operators, a number of public street system operators and an unlimited number of private operators for office and residential DECT systems. NOTE 2: Public applications should use all the spectrum, private applications should only use the basic 20 MHz DECT spectrum. The basis for the figures in table 1 is the following: - Office and residential applications: office traffic is much higher than residential traffic, and residential and office traffic is typically in different buildings. Therefore only the spectrum requirements for offices need consideration. From clause A.1.2 it can be seen that 7 carriers (about 15 MHz) will provide 5 to 6 E per base station. This capacity is as regarded feasible for one operator, including a predicted increase in the use of data and multi media applications. See clauses 6, 7 and 9. Clause A.2 also shows that if operators share a common spectrum in the same building, at most 20 % additional capacity is required than for a single operator. Therefore, including provision for some emerging increase of data and multi media applications 10 carriers (20 MHz) will be adequate for a shared spectrum. - Public pedestrian hot spots: the hot spot public areas are railway stations, airports and sport arenas. We see from clause 6.3 that the public pedestrian hot spot application will have an office Private Automatic Branch Exchange (PABX) type infrastructure, but the traffic may be a quarter of high traffic office applications. On the other hand, the public pedestrian applications are in larger open spaces/halls than offices, which will require a somewhat higher reuse. Therefore 3 carriers (7 MHz) will be reasonable for a single operator and 4 carriers (8 MHz) reasonable for a shared spectrum, because possible different cell sizes may require some extra spectrum. More is not needed since they share the same potential number of customers. See clause 8.6. - RLL: the above roof top RLL applications are simulated in clause A.3. Clause 8.7.1 concludes that, including the estimated increase of data traffic, 4 carriers (7 MHz) is needed for a single operator, and that shared spectrum for at least 4 operators will need 10 carriers (20 MHz). - Common allocation for different applications: for a single operator we estimate instead of the total sum (15 + 7 + 7 = 29 MHz) that only 15 MHz are needed, if all applications share the same allocation. The reason is the limited interference between office, public pedestrian and RLL systems. See clause 8.10. Similarly when all operators share the same allocation, only 28 MHz are estimated to be needed instead of the sum 48 MHz. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2.2.4.1 Conclusion for the case with speech and estimated emerging data services | From the table above we see that the combination of sharing spectrum both between DECT applications and operators compared to splitting spectrum between DECT applications and operators, the spectrum efficiency gain is expressed by the factor N x 29 / 28. Therefore, the gain is about a factor N, where N is the number of public operators. This is however not a realistic case, since if the spectrum is split between a few operators (typically 4), they will share applications on their part of the spectrum. Therefore, the gain will be (N x 15) / 28 equal to a factor 2 for four public operators. Remember that an assumption here is that DCS is used both for the shared and split spectrum cases, and that, as shown in clause 5.2.2.3, the gain for sharing spectrum will further increase for cases with very uneven local operator market shares. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 19 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.2.2.4.2 Conclusion for the case with mainly speech services | From the calculations above, we can also make adjustments for excluding the increase of data services and try to fit into the initial 1 880 MHz to 1 900 MHz DECT allocation by limiting the number of RLL operators to 3 (see table 2). Table 2: Spectrum requirements for mainly speech services Scenario (mainly speech services) Office and Residential Public pedestrian hot spots RLL Total spectrum requirement (allocation shared by all applications and operators) Shared spectrum, 3 RLL operators 10 MHz 7 MHz 16 MHz 20 MHz The office system will only need 5 carriers (10 MHz). There will be no significant change for the public pedestrian systems. For RLL systems, in total up to about 120 (see note) E can be shared by similar sized DECT access nodes with 8 carriers (16 MHz). Three operators will have up to 40 E per DECT access node each (per site with 6 sectors). See clause 6.4.1 and the summary in clause 8.10. NOTE: Up-link power control implemented. See clause A.3.4. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 5.3 Increase traffic by denser infrastructure, C/I limited capacity | The capacity of a system can be trunk limited or C/I limited. It is very important to distinguish between the two cases of traffic limitation, especially when analysing the simulation results. The trunk limitation is caused by limited provision of number of simultaneous connections via some interface, for example the line interface or the air interface of a base station. The traffic capacity that depends on the amount of allocated spectrum is related to the C/I limited traffic only. The least interfered channel selection principle of DECT does not impose any additional upper limit that the interfering signal must not exceed on a monitored access channel candidate. Therefore, the capacity of DECT will be C/I limited also at very short cell radii. Therefore, as a first approximation, the capacities per base station shown in the simulations in annex A are constant, independent of the selected distance between the base stations (a practical lower limit may be 10 m to 15 m separation). Therefore, on a given spectrum, the capacity, E/km2, will be proportional to the base station density. This is an essential property to provide required traffic density: - any operator can locally always increase his traffic density by increasing his base station density. DECT provides easily engineered and economic installation of closer and closer cells, whereby the efficiency of the DCS algorithms, DCS, and the high radio link quality is maintained. NOTE: This does not mean that large capacity systems can be implemented on a very limited amount of spectrum. There is a minimum amount of spectrum required to provide an economically defensible infrastructure. This is further explained in annex C. 5.4 Increasing link quality without increasing the load on the spectrum Another basic property of DECT is, that if an operator increases his base station density without increasing his traffic density, he will increase his own radio link quality without causing more average interference to other systems in the same area. For example, with twice as dense infrastructure, the average distance for the wanted signals will be 30 % shorter. Therefore, in an environment with d-4 propagation law, the wanted signals will in average be 6 dB stronger. The average interference (or load on the spectrum) has not increased, since the traffic per subscriber and the subscriber density has not been altered. Therefore, the own average C/I has increased by 6 dB. Since the local load on the spectrum has not increased, it is obvious that the interference to other systems has not increased as a result of the dense base station deployment. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 20 This is an essential property to provide required radio link quality in an environment of local interference from other DECT systems: - any operator can, without increasing the load on the spectrum, always increase his local radio link quality by locally increasing his base station density. NOTE: This does not mean that required link quality can be maintained for systems implemented on a very limited amount of spectrum. There is a minimum amount of spectrum required to provide an economically defensible infrastructure. This is further explained in annex C. See also clause 5.5. 5.5 Means for adjusting to emerging growth of traffic (subscribers) In this clause we discuss means for adjusting to emerging growth of the local traffic. Growth of local traffic may be caused by increased number of users in the system, by new services (for example Internet) or by geographical redistribution of users. It is therefore important that larger multi-cell DECT systems provide means for the operator to monitor the traffic generation, blocking probabilities and early call curtailments at each base station of the system. This enables him to timely adjust his infrastructure to cope with the emerging traffic growth. Increased local load on the spectrum may also be caused by another system increasing its traffic. If the capacity is trunk limited, the solution is to provide more radio resources in the infrastructure, either by installing more base stations or by employing more radios in each base station (one special trunk limited case is a mixture of full-slot connections and double-slot connections, where the double-slot connections will have consistently higher blocking probability than the full-slot connections. It is therefore, in this case, important to provide enough radio resources to meet the Grade of Service (GoS) requirements not only for the full-slot connections but also the double-slot connections). If the capacity is C/I limited, the means to increase the own traffic density is to make the cells smaller by employing more base stations (or more and/or narrower sectors in RLL installations). See clause 5.3. This is an obvious natural action within the operators own control. For indoor systems and outdoor below rooftop public pedestrian street systems, such traffic increases do normally not require any precautions regarding increased interference to other systems. But for above rooftop installations special precautions are required. If the capacity is C/I limited and the own traffic is the same, but the load on the spectrum is increased due to increase of traffic of other systems in the same area, the means to maintain the own required link quality is again to make the cells smaller by employing more base station (or more and/or narrower sectors in RLL installations). See clause 5.4. The potential threat for this situation is mainly when the own installation is an above rooftop installation. Summary: - for public systems and larger office systems the operator should monitor the traffic and the blocking probabilities at each base station of the system. This enables him to timely adjust his infrastructure to cope with emerging local traffic growth; - if the local traffic tends to become trunk limited, more radio resources shall be added; - if the local traffic tends to become interference limited, the local cell density shall be increased (more and narrower cell sectors and/or more cell sites). It is important that an operator is not forced to increase his cell density beyond economic limits because other operators in the same area increase their traffic. Procedures for economic handling of hot spots are described in clause 10. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 21 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6 DECT applications - scenarios | The traffic requirements are based on speech services and the traffic needs for emerging data services are estimated as a factor in proportion to the speech traffic. A reasonable estimate is that the speech traffic per subscriber in offices and residents will be about the same as today and that the additional traffic per subscriber due to use of data services, within a few years, in average will be of the same magnitude as for speech. See also note 3. This expected doubling of the traffic will also apply to RLL applications, but not the public street public pedestrian application, see clause 7. Table 3 shows the estimated busy hour traffic per subscriber figures used for the different applications: Table 3: Estimated average busy hour traffic per subscriber Subscriber Speech service only Speech and emerging data services Office worker 150 mE to 200 mE 300 mE to 400 mE Resident 50 mE to 70 mE 100 mE to 140 mE RLL See office and resident See office and resident Public pedestrian 30 mE 30 mE NOTE 1: The data traffic figures above should be understood as equivalent voice Erlang load. In DECT, 1 E corresponds to a pair of full slots, a duplex pair or a double simplex pair, using 2-level modulation. NOTE 2: There are residents and offices with broadband data, where traffic is higher than indicated above. A single radio residential base station can support about 0,5 Mbps with 2-level modulation and 1 Mbps with 4-level modulation. This is suitable to support an ADSL residential access. NOTE 3: In the estimates below, data traffic is estimated to increase to the same level as the speech traffic that today dominates in DECT applications. However, if higher level modulation options are implemented for DECT, the traffic figures below including data traffic, will correspond to data traffic having increased to twice the level of speech traffic. See clause 7.3.1. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.1 Residential application | A typical scenario for residential DECT applications is a multi-storey apartment block or a single house maybe in a group of villas. The speech traffic generated by this application can be typically 50 mE to 70 mE per household, and the peak hour is usually in the evening. Base stations are normally unsynchronized. In the most densely populated areas, blocks of flats with 4 to 8 storeys, there are 2 000 to 4 000 households per km2. This corresponds to 100 E/km2 to 280 E/km2 or 25 E/km2- 35 E/km2/floor. In villa areas, there can be 500 to 1 000 households/km2. This corresponds to up 25 E/km2 to 70 E/km2. These traffic densities are estimated to be doubled within a few years due to emerging increase of data services. The traffic densities of residential applications are typically 1/10 of the traffic densities in office environments and most residential systems are deployed in other houses than office systems. Therefore, spectrum requirements for the office applications will cover the deployment needs for residential systems as well. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.2 Office/factory application | Metropolitan centres may have exceptional peaks of 40 000 employees/km2, more typical about 10 000 employees/km2. The Wireless PABX (WPBX) user has a speech traffic of 150 mE to 200 mE. This gives an average speech traffic of 1 500 E/km2 to 2 000 E/km2 for metropolitan centre areas. About 40 % of the PABX traffic is internal traffic. These traffic densities, and the other office traffic density figures below, are estimated to be doubled within a few years due to the increase of data services. The WPBX applications can be classified in 3 types depending on traffic densities, described in subclauses 6.2.1 to 6.2.3. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 22 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.2.1 Large companies in a business centre | Even if the average speech traffic load is typically about 2 000 E/km2, the local traffic density within a building can be much larger. Some large multi-store offices may have a very high density of employees, one every 20 m2. If all employees have a DECT handset, this would mean a total traffic of 7 500 E/km2/floor to 10 000 E/km2/floor with a traffic of 0,15 E to 0,2 E per user. This very high local traffic density must sometimes be offered. This will require 22 m to 26 m rectangular grid base station separation with 5 E average traffic per base station. More typical, 25 % of the employees will have wireless access. Then the traffic required would be 2 500 E/km2/floor with 45 m separation between 5 E base stations. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.2.2 Large companies in industrial zones | The most common profile is a company with few buildings in a zone with outdoor parking and some surroundings green zones. A dense zone of this kind can be 4 50 m x 50 m buildings with 5 levels in a 300 m x 300 m area. Assuming the same penetration (25 %) of wireless handsets and 0,2 E average traffic per user and one user per 40 m2, the total traffic generated in such a zone will be 140 E/km2/floor or 700 E/km2. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.2.3 Small/medium size companies | In this category, companies with an average of 20 telephone extensions are considered; In this case, it could be realistic to suppose that each handset is a DECT handset with a traffic of 0,2 E, that is a total traffic of 4 E per company. This traffic can be provided by a single DECT base station. Considering a maximum of 100 companies of this kind in a km2, this will give 400 E/km2. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.3 Public pedestrian application | The public pedestrian DECT application gives local mobility to subscribers in an urban or suburban area. There are two main application areas, indoor public zones like shopping centres, railway stations or airports, and outdoor streets. For each mobile user, the traffic is assumed to be 30 mE. For indoor hot spots public zones like shopping centres, railway stations or airports, there may be crowds with 1 person per m2. Assuming again the penetration of 5 %, the traffic generated is 1 500 E/km2. In these cases, the maximum traffic density handled by DECT for a public application is very similar to the one in the wireless PBX environment, and the infrastructure will have similar base station density as for offices. The street coverage is obtained by positioning the base stations (RFPs or WRSs) at lamp post height along the streets. If it is assumed that a maximum penetration for this application could be the 5 % of the population, this means, for a city of 2 millions of inhabitants over 100 km2, a traffic of 30 E/km2. People are however not always on the streets. An other way to estimate the traffic, is to use an estimated number of pedestrians in a metropolitan centre, 10 000/km2. Having 5 % penetration leads to 15 E/km2. As a further example, the coverage of a typical (not hot spot) base station located in a street, as shown in figure 2, is analysed. 2 m 200 m 200 m DECT user RFP 5 m Figure 2: Example of a typical coverage of a street base station ETSI ETSI TR 101 310 V1.2.1 (2004-04) 23 A large main street with a 5 m wide pavement on each side is taken into account; the base station has a range of 200 m to each side, so that its total coverage is 4 000 m2 of pavements. In the street there is one person every 10 m2, in total 400 people, but only the 5 % of them use a DECT handset, that is 20 people. If for each user the traffic is 30 mE, the average total traffic at the base station will be 0,6 E, corresponding to 30 E/km2, if the streets are separated by 100 m (10 streets + 10 perpendicular streets per km2, each street having 2,5 base stations) and if all streets had the same high pedestrian density. Only a few main streets in a city centre have such high load, therefore for average load over a km2 will be 10 E/km2 to 15 E/km2 as estimated above. The average traffic per base station will be less than 1 E . |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.4 RLL application | RLL is an important DECT application. Below are requirements related to one low density scenario and one high density scenario with (fixed) Cordless Terminal Adaptor (CTA) type of subscriber terminal only (not PPs). It should be noted that effective radio ranges achieved in the DECT RLL application using CTAs, will be considerably greater than when DECT is used in the mobile mode. The signal path is more consistent, it is often line-of-sight and base stations and CTAs may use high gain antennas, whose directionality also reduces multipath signals. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.4.1 Rural area - range requirements | A rural area may consist of a large area where few houses are spread out within a range of 10 km, eventually grouped in small clusters. The typical subscriber density within the area is 5 to 50 subscribers per km2. Traffic per subscriber is 70 mE during busy hour. This means that the total traffic in the area is 0,35 to 3,5 E per km2. For this scenario, the capacity is not an issue, but the range is. Directive antennas and WRSs (see clause A.6), are often applied in order to increase the range of the links. The service and facilities description for DECT RLL, ETR 308 [16] requires a range up to 5 km for a DECT radio link. A line-of-sight (LOS) range up 5 km is feasible with 12 dBi antennas at each end and reasonable antenna heights. Therefore, adding a WRS will provide a 10 km range. A DECT radio access site will typically be supplied from the local exchange, LE, with one or two 2 Mbit links (primary rate access). These will provide 30 or 60 trunks, which with 0,5 % GoS will support 19 E (271 subscribers) or 45 E (643 subscribers) average traffic per site. Table 4 shows how low subscriber densities are supported as a function of the cell range, supposing 271, 643 or 2 000 subscribers per radio site. (2 000 subscribers require six 2 Mbps lines or 180 trunks). Hexagon cells are used. The range R km is equal to the length of the hexagon side, and the cell area is 2,6 x R2 km2. It could be estimated that with 270 subscribers being served per site, the CTA related costs still dominate over the radio site related costs. If so, requiring more than 270 subscribers to be served per site, would not further dramatically reduce deployment costs. We could however expect that with the popularity of Internet, the 70 mE/subscriber may be substantially increased whereby about 300 subscribers could correspond to about 40 E per DAS. Thus about 40 E per DAS could be a required minimum available capacity per operator for economical deployment. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 24 Table 4: Economic support of low subscriber density applications as a function of range Range R km. Hexagon cell 1 km 2 km 3 km 4 km 5 km 10 km Site separation 1,7 km 3,5 km 5,2 km 6,9 km 8,7 km 17 km Subscriber density with 19 E or 271 subscribers per radio site 104 subscr./km2 (7.3 E/km2) 26 subscr./km2 12 subscr./km2 6,5 subscr./km2 4 subscr./km2 (0,3 E/km2) 1 subscr./km2 Subscriber density with 45 E or 643 subscribers per radio site 247 subscr./km2 (17 E/km2) 62 subscr./km2 27 subscr./km2 15 subscr./km2 10 subscr./km2 2,5 subscr./km2 Subscriber density with 140 E or 2 000 subscribers per radio site 769 subscr./km2 (54 E/km2) 192 subscr./km2 85 subscr./km2 48 subscr./km2 31 subscr./km2 8 subscr./km2 Table 4 shows that DECT with suitable antenna site arrangements will support economic deployment of RLL systems with 4 to 250 subscribers per km2 without need to stretch the 5 km range requirement. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.4.1.1 Special provisions for single link ranges beyond 5 km | In EN 300 175, parts 1 [1] to 8 [8], advance timing of the CTAs has been introduced, which allows up to 17 km range with maintained TDD guard space. This feature was not available when ETR 139 [22] was published. LOS ranges of 10 km to 15 km are therefore, in principal possible to a CTA or to a pool of WRSs in a remote village. This however requires higher antenna gain (larger antennas) and higher antenna installation. The higher antenna gains, narrows the transmission beam and also the reception angle, which reduces time dispersion and required fading margins. For example, traditional 2 GHz 2 Mbit/s radio links without equalizers provide reliable services over 15 km to 25 km typically using 30 dBi high gain elevated antennas. The LOS propagation model of ETR 139 [22] requires for a 15 km single link range, antennas at 15 m height with 17 dBi gain at one end of the link and 14 dBi gain at the other end. A 12 dBi patch antenna has an area of about 600 cm2 at 1,9 GHz. A 17 dBi patch antenna has an area of about 2 000 cm2, etc. 6.4.2 Urban area - traffic capacity requirements mainly for speech services Typical urban scenarios are the extension of the fixed network to a new housing area near an existing town, a new town or a new operator in a urban area. The connection density ranges from 500 (villa area) to 2 000 (blocks of flats, 2 to 4 stories) connections per km2; each connection has a traffic of 70 mE, which means a total traffic in the area of 35 E/km2 to 140 E/km2. The highest residential traffic is 140 E/km2 to 280 E/km2 for blocks of flats with 4 to 8 stories. This is for a built up city, but not typical for new housing areas. A business centre metropolitan area may have about 10 000 employees per km2 . The traffic density is 1 500 E/km2 with 150 mE average traffic per employee. Since about 40 % of all traffic is internal in a PABX, the required traffic density is about 1 000 E/km2. If second operators in an area deploying RLL will get 10 % of the total business traffic in a metropolitan area, 100 E/km2 must be supported by DECT RLL. We may conclude that a traffic capacity of 100 E/km2 to 150 E/km2 is required to support speech RLL services. These traffic densities are estimated to be doubled within a few years to 200 E/km2 to 300 E/km2 due to emerging increase of data services. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 25 In developing countries may be up to 30 % of the metropolitan traffic (mainly speech) will need to be served by RLL. This corresponds to 300 E/km2. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 6.5 Summary of traffic requirements | Table 5 gives a summary of the traffic density requirements. These requirements have been related to typical application examples indicating the average traffic required per radio site and the required radio site density (site separation). Table 5: Summary of traffic requirements for mainly speech services Service type (mainly speech) E/site, site separation Traffic load Residential < 1 E 25 E/km2 to 280 E/km2 Office < 5 E, 25 m (rectangular grid) Maximum 10 000 E/km2/floor Public pedestrian hot spots 2,5 E, 40 m (rectangular grid) 1 500 E/km2 at 5 % penetration Public pedestrian street < 1 E, < 400 m (along a street) 15 E/km2 at 5 % penetration RLL 40 E, 8,7 km (hexagon grid) 40 E, 430 m (hexagon grid) 140 E, 1,7 km (hexagon grid) 140 E, 400 m (hexagon grid) 0,6 E/km2 250 E/km2 54 E/km2 Maximum 1 000 E/km2 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 7 ISDN, data and multimedia applications | The DECT standard (EN 300 175, parts 1 [1] to 8 [8]) provides a comprehensive set of interworking profiles for ISDN, data and multimedia applications. There is a rapid world-wide growth of Internet residential and office subscriptions. Therefore, it is foreseen that the present dominance of DECT speech services will within a few years shift so that data services will be as important as speech services. A reasonable estimate is that the speech traffic per subscriber will be about the same as today and that the additional traffic per subscriber due to use of data services in average will be of the same magnitude as for speech. The discussions below lead to the assumption that the increased use of data services in offices and homes will increase the load on the DECT spectrum by a factor of two compared with speech only services. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 7.1 ISDN services | So far two profiles have been defined for DECT/ISDN interworking, the ISDN Intermediate System (IS) and the ISDN End System (ES). The IS standard provides the user with the ISDN B and D channels whereas the ES standard only gives access to ISDN services such as the 64 kbit/s unrestricted bearer service and the ISDN supplementary services. The spectrum requirements for the ISDN interworking profiles can be found in the tables below. Table 6: Intermediate System (IS) spectrum requirements DECT ISDN (IS) Total bearer requirements D 1 full slot 1B (32 kbit/s) 1 full slot 1B (64 kbit/s) 1 double slot NOTE: The standard allows for combinations of multiple B-channels and D-channels. Furthermore, after call establishment both the B-channel and D-channel can be combined in one slot (e.g. after establishment only one full slot is required to carry a 32 kbit/s B-channel and the corresponding D-channel). ETSI ETSI TR 101 310 V1.2.1 (2004-04) 26 Table 7: End System (ES) spectrum requirements DECT ISDN (ES) Total bearer requirements Speech 1 full slot B-channel is transcoded to ADPCM with 32 kbit/s 3,1 kHz audio 1 full slot B-channel is transcoded to ADPCM with 32 kbit/s Unrestricted digital information 1 double slot A double slot occupies the position of two adjacent full slots. It provides an unprotected data rate of 80 kbit/s or in the protected mode 64 kbit/s. ISDN as such does not cause increased load on the DECT spectrum, because an ISDN speech call does not require more spectrum than a "POTS" call. (Both use 32 kbit/s ADPCM speech over the air interface, and the ISDN D-channel information is transferred to the A-field of the full slot duplex bearer during the call). We may assume that people will not speak more in the telephone because they have ISDN, but they will have access to data services over a second line. It is the increased use of data services that will increase the load on the spectrum. ISDN B-channel data services will use a double slot duplex bearer. ISDN D-channel packet data will use a full slot duplex bearer (as the normal speech service). A double slot compared with a full slot will momentarily use twice as much spectrum, but because of the higher data rate, the time to transfer the data will typically be half. Therefore, using double slots for data transfer, will in many cases provide equal or less load on the spectrum than using full slots for the data transfer. The trunk limited blocking probability in a base station will however be larger for a circuit switched double slot than for a full slot. Therefore for system planning more radio resources are needed to avoid trunk limited blocking when double slots are being used. But this is a separate issue than load on the spectrum. NOTE: The blocking probability of a double slot (occupying the positions of two adjacent full slots) is higher than the blocking probability of two non-adjacent full slots for a multi bearer connection. Due to this, recommendations for packing of full and double slots reduce double slot blocking probability. Such rules have been included in the DECT base standards but their implementation is not mandatory. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 7.2 Data services in general | Besides ISDN, data services may also be provided via modems over analogue connections using full slot and double slot (transparent 64 kbit/s) bearers. Data over the DECT air interface may also be transferred using some of the specified family of packet data profiles, which are far more spectrum efficient. The data profiles offer a variety of services varying from low speed messaging to high speed frame relay. The user bitrates available are up to 552 kbit/s using 2-level modulation, and up to more than 4 Mbit/s using higher level modulation options. Two classes of mobility support have been defined for the data profiles. The first class, Class 1, concerns local applications where the terminals are pre-registered off-air with one or more specific FPs. The second mobility class, Class 2, cares for roaming applications. All data profiles make use of the full slot for the data transfer though the number of slots that are used vary, see table below for the 2-level option. Table 8: Required number of bearers for the DECT data profiles DECT data profile Maximum sustainable throughput using 2-level modulation Bearer requirements DPRS 24 kbit/s per bearer 1 full slot per bearer D (transparent and isochronous connections) 32 kbit/s 1 full slot E (low rate messaging services) 1,38 kbit/s (A-field, Cs channel) 17,6 kbit/s (CF channel) 1 full slot The data profiles use single and multi bearer connections in protected and unprotected mode based on full slots. Both symmetric and asymmetric connections are possible. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 27 A reasonable estimate is that the speech traffic per subscriber will be about the same as today and that the additional traffic per subscriber due to use of data services, within a few years, in average will be of the same magnitude as for speech. Therefore, we get the following estimated busy hour traffic per subscriber. Table 9: Estimated busy hour traffic per subscriber Subscriber Speech service only Speech and emerging data services Office 150 mE to 200 mE 300 mE to 400 mE Residential 50 mE to 70 mE 100 mE to 140 mE Public pedestrian 30 mE 30 mE This expected doubling of the traffic also affects RLL applications, but hardly the public street public pedestrian application. NOTE: In the estimates above, data traffic is estimated to increase to the same level as the speech traffic that today dominates in DECT applications. However, if higher level modulation options are implemented for DECT, the traffic figures including data traffic, will correspond to data traffic having increased to twice the level of speech traffic. See clause 7.3.1. 7.3 The DECT 4-level, 8-level, 16-level, 64-level modulation option The latest version of the DECT base standard includes backwards compatible 4-level, 8-level, 16-level and 64-level modulation options as shown in table 10a. Table 10a: Available physical layer bit rates Levels Narrow bandwidth 2 1,152 Mbit/s 4 2,304 Mbit/s 8 3,456 Mbit/s 16 4,608 Mbit/s 64 6,912 Mbit/s The 4-level modulation is π/4-DQPSK, the 8-level modulation π/8-D8PSK, the 16-level modulation 16-QAM and the 64-level modulation 64-QAM. The shaping filter shall be root-raised cosine with Ts = 1/1 152 000 s (Ts = symbol duration) and roll-off (α) = 0,5 for all types of modulation. π/2-DPSK may be generally used as 2-level modulation instead of the GFSK modulation. This will increase the bit rate of single radio DECT equipment by a factor 2, 3, 4 or 6 with retained transmitter bandwidth, carrier spacing and slot structure. Asymmetric data services with user data rates exceeding 4 Mbps are provided by a single DECT radio. A typical sensitivity of -95 dBm is expected for the 4-level modulation if coherent demodulation is implemented, and about -93 dBm with a differential digital detector. This sensitivity is similar to typical sensitivity for 2-level modulation. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 7.3.1 Higher Level Modulation impact on traffic capacity | Due to the retained transmitter bandwith, carrier spacing and slot structure when higher level modulation is used, the Dynamic Channel Selection mechanism is fully functional in environments with mixed modulation techniques and mixed voice and data transmissions. We could expect that the voice service remains with 2-level modulation since normally no shorter slots than full slots are used. Therefore, the voice traffic capacity is not expected to be increased by introducing higher level modulations. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 28 But data traffic capacity could increase by typically a factor 2 in average. The main gain is in implementing the 4-level modulation, giving 2 times larger data rate. Since the sensitivity for 2-level and 4-level DECT receiver detectors in practice will be rather equal, we could expect doubling of the data capacity in single cell or other typical range or trunk (DECT slots) limited installations, by just implementing 4-level modulation. In capacity limited environments, the gain would be lower, because C/I for 4-level modulation will be lower than for 2-level modulation. 8 Multi-system and multi-service DECT applications coexistence analysis for speech services and emerging increase of data related services In this clause an analysis of the coexistence of the different applications described above is made. The analysis supposes a basic 20 MHz spectrum allocation and speech services and emerging increase of data related services with subscriber traffic as indicated in clause 7.2 table 9. The conclusions are based on calculations and a large number of simulations, which are described in more details in annex A. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.1 Interference between residential systems | The critical scenarios in which interference between residential systems could reduce the system capacity, may be when users are close to each other like in adjacent flats or villas (see figure 3). However, interference between residential systems is not critical, since the local load from residential users on the spectrum is very low, < 1 E/base station, much lower than from offices. Application of large numbers non-synchronized mutually interfering residential systems can be up to 3 times more spectrum efficient than if they were synchronized. This is because the very short dummy bearer (down link only), if synchronized, only has 12 different time domain positions, but 60 to 120 non-over lapping positions if unsynchronized. (A dummy bearer only consists of the S + A fields, 96 bits, as described in clause E.2.1. This gives up to 11 520 / 96 = 120 positions during a 10 ms frame. In the calculations below this figure is reduced by a factor of 2 due to unsynchronized packing.) Since the residential speech traffic is only 0,07 E, most of the time only the short dummy bearer is transmitted. Therefore, since the load on the spectrum from a synchronous system is 1 E, the load from an asynchronous system is 12 / 60 = 0,2 E from the dummy bearer plus 0,14 E (2 times 0,07 E) from the speech traffic, which equals 0,34 E. Including foreseen emerging increase of data services 2 times 0,07 E has to be added, which gives 0,48 E average load on the spectrum per household. Residential systems shall not be required to be synchronized. Residential systems provide a very limited load on the spectrum. (a) (b) Figure 3: Coexistence between residential systems ETSI ETSI TR 101 310 V1.2.1 (2004-04) 29 8.2 Interference between residential systems and other applications The coexistence between a residential system and other DECT applications such as Office, public pedestrian and RLL is not critical. The low traffic of the residential system is not an interference risk, and the residential system will have no difficulty to find a good single channel for its connection. This conclusion is related to the conclusions below on interference from and between office systems. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.3 Interference between office systems | As described above the business application is the one with the largest traffic densities, up to 10 000 E/km2/floor for speech services. Simulations have been carried out in a 3 storey building with varying total number of carriers available. They show that with half of the 20 MHz spectrum (5 carriers) the capacity of a stand alone system with synchronized RFPs still will be about 7 000 E/km2/floor with 25 m base station separation. This corresponds to 11 000 E/km2/floor with 20 m separation (see clause A.1.2). This shows that there is local capacity left for other systems. We see from clause 6.2.1 that a more typical local peak speech traffic density is 2 500 E/km2/floor. When different unsynchronized office systems are close to each other (adjacent floors) in the same building, the potential interference between systems could increase the local load on the spectrum by about 20 % (see clause A.1.2). Therefore, in spite of the high local traffic, the natural average isolation between office systems provides effective coexistence of different office systems (see figure 4). A B C > 30 dB > 15 dB > 30 dB > 15 dB > 30 dB NOTE: In the figure typical loss values for external walls and floors are indicated. Figure 4: Coexistence between office systems Since typical loss for external walls is 15 dB, interference between systems in different buildings are very limited, with some exceptions as a base station positioned along the window in front of the street. Anyhow, the average mutual load on the spectrum between systems in different buildings is very low. Synchronization of RFPs within a DECT system (FP) is essential for all high capacity multi-cell systems. In-system synchronization is normal practice for multi-cell office systems, where the RFPs obtain the synchronization over the connection wires to the radio exchange (RFP controller). Synchronization is regarded essential by manufacturers both to provide efficient handover and to meet internal system capacity requirements. Whether or not two systems within a building are synchronized to each other does not influence the interference to systems outside the building. Therefore inter-system synchronization within a building can be left to be agreed between the system owners. From the above information, we can conclude that 10 MHz is required for general speech only office applications, and that 20 MHz of spectrum will be adequate also for adding emerging increase of data services. 8.4 Interference between office and public pedestrian street systems Interference between office systems and a public pedestrian street system is studied for a worst case scenario shown in figure 5. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 30 Figure 5: Coexistence between office-public public pedestrian applications It is very difficult to make accurate simulations of the interference from multi-storey indoor installations to a specific point at street level. It is however easy to estimate an upper bound of the local load on the spectrum, if we suppose that none of the channels used in the surrounding offices can be reused on the street. For instance, the total maximum traffic from 3 floors of a 50 m long and 10m wide building on each side of the street, is 30 E. Assuming 1 terminal per 20 m2, the total number of terminals is 150: 10 50 20 3 2 2 x m m x floors x buildings 150 multiplied by the traffic of each user, 0,2 E, becomes 30 E. Therefore, the maximum load on the street is about 30 E. Some of the 30 simultaneous connections will reuse the same channels, and some extra load is caused due to unsynchronized systems. The total local load on the spectrum at street level will be less than about 40 E. Since we have concluded that the loadable local traffic is 100 E, 60 E is left for the public pedestrian system (see clause 5.1). With the estimated emerging data traffic (another 40 E) added, still 20 E are left. Therefore, also for this simplified upper bound estimation, there is enough spectrum left for a street public pedestrian application, which typically only requires 1 E per base station. In reality only channels from transmissions close to the windows may not be reusable at all at the street and it is also rather unlikely that there is a DECT office subscriber every 20 m2 on all floors on both sides of a street. Nor will the opposite case, potential interference from a public pedestrian street system to offices, cause any problems of coexistence, since the public pedestrian system typically loads the spectrum with less than 1 E per 200 m length of street. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.5 Interference between office and RLL systems | Regarding interference from an RLL system to an office system, a critical situation could be interference from an elevated high traffic RLL access node using high gain directional antennas. In clause 8.7 and clause A.3 are described a realistic high traffic node deployment with 42 E average traffic per node. This traffic is however divided into six sectors with 7 E each. Therefore, the local load on the spectrum in any direction from this node will be limited to 14 E (maximum two sectors are overlapping in any direction). Therefore, the local load from a high traffic public node to private systems close to this node is less than 14 E. Therefore, 100 E - 14 E = 86 E is always locally accessible, which still is adequate for the private users. Note also that it is the outer cells (close to windows) in office applications that might be exposed to some interference from a public outdoor system, but that these outer cells suffer much less interference from the own close by cells than the centre office cells. Furthermore, antennas for the RLL links are usually above the roof top and this inserts a substantial average physical separation to indoor office systems. Regarding interference from an office system to an RLL subscriber, the same conclusion as for the interference from offices to a public pedestrian subscriber can be applied; at least 20 E to 60 E will be locally available. See clause 8.4. Furthermore, antennas for the RLL links are usually above the roof top and this inserts a substantial average physical separation to indoor office systems, as exemplified in figure 6. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 31 Coexistance of DECT RLL/Office 4E 4E 4E 4E 4E 4E 7-14E 4E 4E 4E 4E 4E 4E NOTE: RLL interferes less than another row of office cells does. RLL site with 6 sector antennae arrangement with totally 42 E as exaple. Figure 6: DECT RLL Interference between RLL and office systems will in average not be critical. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.6 Interference between public pedestrian systems | Installations in hot spot areas like railway stations, airports and sport arenas with up to 1 500 E/km2 will be very similar to larger office and factory installations. The difference is that a number of systems will cover the same area, without any natural floor or wall isolation as between office systems. Therefore, the public systems should be synchronized, not to cause unnecessary capacity loss. Else up to 50 % of the capacity could be wasted, and this waste would need to be compensated by installing twice as many base stations for high traffic loads. The high traffic densities may only be a quarter of the traffic density for high traffic office applications. On the other hand, the public pedestrian multi-cell applications are in larger open spaces/halls than normal for office applications, which will require a somewhat less efficient reuse of access channels. Therefore, compared to speech office applications, see table A.1, where 2 carriers supports 2 100 E/km2 , here 3 carriers (7 MHz) will be reasonable for a single operator. 4 carriers (8 MHz) is reasonable for a shared spectrum between a number of operators, because possible different cell sizes may require some extra spectrum. More is not needed since they share the same potential number of customers. For street public pedestrian the load is typically 1 E per base station, which will not provide any mutual interference. The spectrum requirement is a fraction of that required for the hot spots. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 32 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.7 Interference between RLL systems | Various rooftop RLL system scenarios have been simulated, where each RLL base station site, DECT Access Site (DAS) support 6 sectorized cells. Also the CTAs use sectorized gain antennas (see clause A.3). The separation between DASs is 1,7 km, The major conclusions of the specific simulations are: a) Maximum sharable local capacity with 10 carriers is estimated to be at least 300 E for 12 sector DAN clusters and about 160 E to 200 E for 6 sector DAS clusters. This is achievable with use of a rather simple (slow and not very accurate) up-link closed loop power control. b) For two or more systems in the same geographical area, the total capacity/site of all operators becomes close to the above maximum sharable local capacity, if the operators have similar cell sizes. c) Each E corresponds to one speech connection or a data connection with about 32 kbps with 2-level modulation and about 64 kbps with higher level modulation (at least 4-level modulation). 300 E corresponds to 19 Mbps data throughput per DAN with 4-level modulation! d) Having 1 RFP per sector provides a trunk limited average capacity of about 5 E/RFP to 7 E/RFP, and having 2 or 3 RFPs per sector provides roughly about 8 E/RFP to 9 E/RFP of average capacity. e) Synchronization between DASs and between above rooftop RLL systems has a very large positive impact on the system capacity, and should be mandated for nodes with high traffic. f) Employing antenna gain generally increases the wanted signal and decreases interference in systems with instant DCS. Use of directional gain antenna versus omni-directional antennas at the DAS has a large positive impact on the system capacity. g) When several operators are active in one geographical area, sharing the spectrum will lead to a higher capacity than dividing the spectrum between the operators. Up to 3,1 to 4,8 times increase in spectrum efficiency has been found. This is when the cell sizes of the different systems do not differ too much. The lower figure is when the operators have equal local market share, and the higher figure when one operator has a local dominance. h) There needs to be a mechanism to ensure that a dominant operator does not limit the spectrum access of the other operators in case of a hot spot local area with large differences of cell sizes. For example, in the case of the dominant operator having 90 % of the traffic and a second operator has 10 % and nine times larger cell area than the dominant operator, the spectrum efficiency gain over an equal split of the spectrum is reduced to 1,6 instead of 3,1 with equal cell sizes. In this case it was necessary to reduce the number of carriers of the dominant operator from 10 to 8, to provide escapes for the large cell connections. i) The distance between the DASs of the above rooftop RLL system have a limited effect on the traffic capacity per DAS, as long as the different systems in a local area have similar cell sizes. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.7.1 Spectrum requirements for RLL applications | From clause 6.4.1 we conclude that minimum 40 E per DAS should be available for each operator to build mutual price competitive networks. We see from clause 8.7 that 160 E to 200 E per DAS could be provided with 10 carriers. Not to be too optimistic, we suppose that 140 E is the sharable capacity. Therefore, we conclude that 4 carriers (7 MHz) is required for one RLL operator including support of estimated emerging increased data traffic (40 E to 45 E per DAS). Since the maximum sharable traffic, for the specific models used, is 140 E with 10 carriers (20 MHz), if cell sizes of the systems have similar sizes, we may conclude that probably up to say 4 operators may coexist well on 20 MHz of common spectrum. The reason that several operators will be able to share the spectrum, is that the total number of potential customers is limited. Therefore, 4 times more spectrum will not be needed when 4 instead of one operator compete for the same customers. On the other hand we should avoid too hard restriction on co-ordinating cell sizes between operators. Therefore a total of 20 MHz would be realistic including the increase of data traffic and about 4 operators. This also leaves room for the public pedestrian application described in the next paragraph using a DAS infrastructure to feed street mounted WRSs. It is essential that conflict solving rules for emerging local hot spots, like those suggested in clause 10 are imposed as part of the licensing agreement. It is important to see that when locally applying these conflict solving rules, the capacity for a split spectrum case is the bottom level. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 33 It is interesting to note that a public pedestrian street system, employed as a DAS system linked to WRSs (CRFPs) having below roof top local links, has the same interference to RLL systems as if it was an ordinary DAS RLL system. It is interesting that this concept alternatively may be interpreted as an RLL system with local mobility (see clause 8.8.1). 8.8 Interference between public pedestrian systems and RLL systems The largest potential interference between RLL systems and other DECT applications is between above rooftop RLL systems and a public below roof top public pedestrian street system, since the public pedestrian system has outdoor base stations (see figure 7). Such an interference scenario has been simulated, where each RLL base station site, DAS, supports 6 sectorized cells (see clause A.5). The separation between DASs is 1,7 km, and between public pedestrian base stations 300 m, both systems are installed in hexagon grid patterns. There are 33 public pedestrian base stations within the area of one DAS. Public Pedestrian RLL Figure 7: Coexistence between public pedestrian - RLL The RLL traffic, up to 44 E per DAS node, did not affect the public pedestrian traffic at 3 E per public pedestrian RFP. Since public pedestrian street base stations typically have 1 E average traffic per cell, we conclude that for this scenario, the interference to the public pedestrian system is not critical. 1 E average traffic per public pedestrian cell does not affect the RLL system having up to 44 E average traffic per DAS. 3 E average traffic per public pedestrian cell however reduces the RLL traffic (0,5 % GoS) of about 40 E per DAS to about 30 E per DAS. The large difference in cell radii is the major reason why the RLL traffic is more affected than the public pedestrian system. Typical street public pedestrian systems with 1E per cell, do not affect the RLL traffic. 3 E per public pedestrian cell gives reduction of the RLL traffic. The above conclusions relate to intra-system and inter-system synchronization. Suppose the public pedestrian system is not synchronized to the RLL system. Since the RLL system will not differentiate between interference from RFPs and PPs, up-link/down-link mix will not contribute, as between RLL systems (DASs). Therefore without inter-system synchronization, the interference from a 1 E per cell public pedestrian system, would at most to be as from a 2 E per cell inter-system synchronized public pedestrian system. For 2 E per cell the interference to the RLL system starts to be noticeable. The need for inter-system synchronization may need to be considered. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 34 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.8.1 Spectrum load for a system consisting of DASs and WRSs (CRFPs) | The results from the above simulated scenario can also be used to estimate the spectrum load of an RLL system with local mobility using WRSs type CRFP instead of CTAs, where the CRFPs provide local links to PPs. See clause A.6. This system concept can also be described as a public pedestrian system using CRFPs instead of wired RFPs, where the DAS infrastructure provides the above rooftop connection to the CRFPs. The antennas for the local CRFP link are supposed to be below rooftop as for the original RFPs. The CRFP antennas for the longer DAS link is supposed to be similar in position and have antenna gain as for the original CTAs (75 % are in LOS). See clause A.5.2.3.1. The conclusion is that we can use the blocking probabilities for a DAS RLL system (with CTAs and not WRSs) to estimate the GoS and load on the spectrum for the DAS + WRS concept. This is a very interesting result, and will as a first approximation independent of the cell sizes and traffic densities. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.9 Interference from public systems to private users | The worst interference source from a public system is an elevated high traffic node using high gain directional antennas. In clause 8.5 the potential interference between a realistic high traffic node deployment and an office system has been analysed. The clear conclusion is that due to sectorization and the average attenuation between above roof top links and indoor links, interference to offices is not a critical scenario. Potential interference to residential users will be even less, due to the low residential traffic capacity requirements. Therefore, there is no need for special protection of private systems from interference from public systems. Public systems should be allowed to use all available carriers. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 8.10 Summary on coexistence and spectrum requirements | The interference potential between different DECT systems can be summarized by table 10b. Table 10b: The potential interference between DECT applications Interference to Residential Office Public pedestrian hot spots Public pedestrian street RLL Residential low low low low low Office low some some low low Public pedestrian hot spots low some high low low+ Public pedestrian street low low+ low low low+ RLL low low+ low+ some high NOTE: "low+" indicate that there are some circumstances were there is "some" interference. As seen from the table 10b, the worst RLL interference is between above roof-top RLL systems. The simulations given in clause A.3 show that intra-system and inter-system synchronization is a necessity for above roof top RLL installations. Public pedestrian street systems employed as a DAS system linked to WRSs (CRFPs) having below roof top local links, are covered in the table by "RLL". The DECT standard (EN 300 175, parts 1 [1] to 8 [8]) provides for this purpose a cost effective absolute time synchronization option using the Global Positioning System (GPS) satellite system. Other means for mutual frame synchronization are also available in the DECT standard (EN 300 175, parts 1 [1] to 8 [8]). The table also indicates the potential for interference between operators for public pedestrian hot spots, such as railway stations and airports. Local inter-system synchronization is recommended for high capacity cases. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 35 The spectrum requirements based on the simulations in annex A have estimated spectrum requirements for different blocking probabilities, typically between 0,1 and 2 %. The 1 % blocking probability cases have been used for the discussions in the present document. Adjustments to another blocking probability is possible with help of the information in annex A. The estimated total spectrum required for different DECT application scenarios from clause 5.2.2.4 can be summarized as follows. Table 11: Summary of spectrum requirements Scenario Office and Residential Public pedestrian hot spots RLL Total spectrum requirement Shared spectrum, 3 (note 1) RLL operators. Mainly speech services 10 MHz 5 carriers 10 000 E/km2 4,5 E/base 21 m separation 7 MHz 3 carriers 1 500 E/km2 2,5 E/base 41 m separation 16 MHz 8 carriers Up to 120 E sharable per DAS (note 2) area 20 MHz All applications share the spectrum. Conflict solving rules for public operators Shared spectrum, several RLL operators. Speech and estimated emerging data services 20 MHz 10 carriers 20 000 E/km2 10 E/base 22 m separation 8 MHz 4 carriers 1 500 E/km2 2,5 E/base 41 m separation 20 MHz 10 carriers Up to 140 E sharable per DAS (note 2) area 28 MHz Private applications only in 1 880 MHz to 1 900 MHz. Conflict solving rules for public operators NOTE 1: May perhaps be 4, provided very well defined and regulated conflict solving rules. NOTE 2: A DAS area is served from one radio site with sectorized directional gain antennas and up-link power control. The text in Italic in table 11 gives some basic application examples that relate the spectrum requirements to the traffic capacity requirements of clause 6. The separation distances relate to rectangular grids. The traffic served per DAS relates to the specific simulation scenario of clauses A.3.3 and A.3.4. The European initial DECT allocation 1 880 MHz to 1 900 MHz provides 10 DECT carriers. EN 300 175 parts 1 [1] to 8 [8] defines extended DECT carriers up to 1 937 MHz. This ensures interoperability in extended DECT allocations, or in countries with allocations other than 1 880 MHz to 1 900 MHz. Extension up to 1 910 MHz will provide a total of 16 carriers, and extension up to 1 920 MHz, 22 carriers. In many countries and for many scenarios, depending on number of operators and other factors, we can conclude that the initial 1 880 MHz to 1 900 MHz, will support reliable and economic deployment of DECT RLL systems effectively coexisting with other DECT applications. There may be markets with conditions favouring spectrum extension for the public DECT services. A justification for any extension of the DECT spectrum shall be related efficient use of the spectrum. Commercial RLL and point to multi-point non-DECT systems in operation in the 3,5 GHz band have been allocated totally 10 MHz to 30 MHz each, say 20 MHz each in average. Compared to allocating two separate 20 MHz allocations for two operators with traditional RLL technologies, a single 20 MHz shared allocation for the DECT services can for instance support four RLL operators plus support a number of public street system operators and also support the traffic for all private office and residential DECT systems in a city. NOTE: Commercial RLL and point to multi-point systems operating in the 3,5 GHz band, normally have FDD duplex arrangements and not TDD duplex arrangements. Annex F gives information on RF modifications of DECT enabling applications on FDD (paired up-link/down-link) spectrum. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 36 9 Conclusion on spectrum requirements for different scenarios Based on the information in earlier clauses, the following is concluded on use of the DECT spectrum: a) By allowing all services to share the whole spectrum, in general, we will maximize the possible traffic offered, since we maximize the trunking efficiency of locally available access channels. See clause 5.2.2. b) Specifically we oppose to any suggestion to forbid public operators to use part of the total spectrum, since public services blocking office or residential applications is not a critical scenario. c) All public operators should in principle operate on the whole allocation. See clause 5.2.2. Potential problems with implementing very different RLL cell sizes in the same local area, is solved by proposals for conditional local carrier back-off rules when a local conflict occurs. This is much more efficient than having some kind of fixed split of carriers between operators. See clause 10. d) The public license should contain some rules for synchronization and procedures for limiting the traffic in high elevated nodes if local conflicts occur between operators. See clause 10. e) Results from simulations indicate that it is feasible to start implementing all intended DECT services on the current 20 MHz. But since the DECT standard is most suitable for ISDN, data, multimedia and RLL applications, we can foresee a rapid increase of applications in these areas, whereby extended spectrum (8 MHz to 10 MHz) could increase the cost effectiveness of high quality DECT services in a multi-operator environment. See clause 8.10. To retain one of the most important success factors of DECT, the multi-application platform, this extension should be a natural extension of the current 20 MHz band. DECT is an IMT-2000 technology, and is supposed to utilize IMT-2000 spectrum. See clause 4. f) Principally, regulators shall not limit any system to have access to the whole allocated band. The main reason is that we believe that this is the best choice for competition on an unregulated market. But also, if the band is split, we will lose the possibility for large scale realistic verification of the power and efficiency of applying uncoordinated DECT system installations on a common spectrum allocation. It is however reasonable to limit the use of any extended DECT band to public operation, since it is hard to regulate the unlicensed services with conflict solving rules. g) DECT FPs operating on an extended band shall have field programmable software controlled carrier allocation. This will encourage regulators to start with as few restrictions as possible, since it provides a simple means, if required, for eventual local resolution and for refinement of deployment rules once real life experience has been gained. 10 Recommendation on procedures for economic handling of hot spots and emerging traffic increase Below are suggestions for procedures for economic handling of local emerging traffic increase and local hot spots, based on simulations and analysis performed in this report. These suggestions are generally applicable, but as seen from the summary on coexistence, clause 8.10, agreed mutual rules for handling of local hot spot traffic only need to be considered for high traffic density public system, mainly those with above rooftop antenna installations. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 37 |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 10.1 Monitoring | It is standard practice in wired and wireless telecommunications systems to monitor the traffic variations and blocking rates as part of the Operations and Maintenance (O&M) support to an operator. This is required for timely adjustment of the infrastructure as the local traffic increases or varies, due to changed habits of the subscribers, new services visible or not visible for the operator and due to new subscribers. Therefore, the need for monitoring the local traffic and service quality, and having processes for timely modification of the local infrastructure to adjust for partly unpredictable local variations, is nothing specific for DECT. The new element for DECT is that not only the own subscribers, but also the traffic variations from other systems, may influence the need to adjust the infrastructure. This is not a problem as such, as long as the economic impact of non-predictable local adjustments due to traffic from surrounding systems is low compared to other costs. As seen from the summary on coexistence, clause 8.10, the economic impact from traffic of other systems only need to be considered for high traffic density public system, specifically between those with above rooftop antenna installations. One aim for the suggested rules below, is to provide predictable upper bounds for the infrastructure costs at local hot spots, where special co-ordination between operators may be needed for providing mutual efficient use of the spectrum. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 10.2 Adjustment of the infrastructure | The operator should monitor the traffic and the blocking probabilities at each base station of the system. This enables him to timely adjust his infrastructure to cope with emerging local traffic growth: a) if the local traffic tends to become trunk limited, more radio resources shall be added; b) if the local traffic tends to become interference limited, the local cell density shall be increased, by having more sectors per cell site and/or more cell sites. Adding sectors or cell sites is simple in the sense that DCS is used so that the new sectors or cells do not impact the rest of the installation. If the issue is only to increase the own link quality and not increase the own traffic a simple means is to add a WRS at the area with marginal wanted signal. The WRS should have a directional antenna towards the RFP to ensure the link reliability to the RFP. Also adding sectors at a cell site is not very costly, since the transmission capacity to the site will in this case remain unchanged. It is important that an operator is not forced to increase his cell density beyond economic limits because other operators in the same area increase their traffic. One aim for the suggested rules below, is to provide predictable upper bounds for the infrastructure costs at local hot spots. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 10.3 Frame synchronization | DECT is designed not to require frame or slot synchronization between base stations or systems to maintain a high radio link quality. Synchronization between close by base stations does however in general decrease the local load on the spectrum. For high capacity indoor multi-cell systems the vast majority of the close by base stations normally belong to the own system, and synchronization is regarded essential by manufacturers both to provide efficient handover and to meet internal system capacity requirements. Intersystem synchronization (to an absolute reference or mutual between two systems) is essential for above rooftop high capacity applications, and should be mandated for such applications. Intersystem synchronization (to an absolute reference or mutual) is also essential for "hot spot" public pedestrian applications. The DECT standard (EN 300 175, parts 1 [1] to 8 [8]) provides for this purpose a cost effective absolute time synchronization option using the GPS satellite system. Other means for mutual frame synchronization are also available in the DECT standard (see EN 300 175, parts 1 [1] to 8 [8]). For other cases inter system synchronization is typically not critical, and should not be mandated. In order to prevent potential problems, it could be recommended that all public systems, i.e. all systems needing a license, are forced to be locally synchronized to each other, if an operator requires it in a specific local area. This means that means for mutual synchronization must be a part of a public system. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 38 In addition, intra-system synchronization, at least within local clusters, should be mandatory for public systems, although most systems already have intra-system synchronization in order to provide intercell handover. This leads to the following simple rule: - Public systems should provide intrasystem cluster synchronization, and should have either GPS synchronization and a SYNC output port or a complete SYNC port (both input and output). This will allow absolute time synchronization via GPS or wired mutual synchronization, if an operator requires local synchronization between operators. NOTE: For public pedestrian street type (antennas lamp post, below rooftop, 1E per base), synchronization may improve the capacity, but is often not essential. GPS synchronization is feasible if several base stations are part of the same FP. It is not cost effective for single RFP FPs connected directly to a local exchange unless it is possible to transfer frame synchronization signals over the local exchange. Rules in line with the above recommendation have been implemented in the second edition of TBR 006 [10]. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 10.4 Maximum traffic load at RFPs | Simulations indicate that it is desirable for an operator to limit the planned average traffic in any one coverage cell (omnidirectional or sector shaped) to about 30 E (full-slot duplex bearers or equivalent) per 20 MHz total allocation. Exceeding this limit could make the effective range of his cells disproportionally vulnerable to interference from other users of the spectrum. NOTE: The RLL simulations indicate 160 E to 200 E traffic in a DAS with 6 sectors. This is about 30 E per sector cell. Due to overlapping of the sectors, this corresponds up to about 60 E load in a specific geographical direction. The intention is to restrict the maximum load from one antenna on the DECT spectrum in a specific geographical direction. This recommendation must not be used to limit economic infrastructure implementations, but as a tool for optimizing coexistence on the common DECT spectrum when required. Limit figures on traffic per cell for outdoor antenna installations could be part of a package of conflict solving rules, to be used if a local conflict occurs between public operators. The limits may depend on the total amount of allocated spectrum and on the degree of sector overlapping. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 10.5 Sharing infrastructure | The simulations show that maximum spectrum utilization occurs when different operators use similar cell sizes. An optimal way to provide this is to locally share the infrastructure. DECT provides flexible identity structures that can provide broadcast access rights information over a base station from several service providers. Operators should be allowed to locally share the same base station infrastructure. |
17276d18a3f94eabc0ca9dab26c56b19 | 101 310 | 10.6 Carrier back-off | When several operators are active in one geographical area, sharing the spectrum will lead to a higher capacity than dividing the spectrum between the operators. Up to 3,1 to 4,8 times increased local spectrum efficiency has been found. This is when the cell sizes of the different systems do not differ too much and includes effects of varying local distribution of market share between operators. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 39 However, if for above roof top installations the cell sizes differ a lot, and if the operator with the smaller cells provides very high local load on the spectrum, the large cell operator may get an unacceptable high blocking probability, unless he provides as dense infrastructure as the small cell operator. Simulations show that for a case of as much as nine times difference in cell size, both systems get about the same accessibility if the small cell system or both systems back of from 2 different carriers. And still the capacity is about 1,6 times better than for a completely split spectrum between two operators. This leads to the following proposals for conflict solving rules: a) Any public system (and any DECT FPs operating an extended band) shall have field programmable software controlled carrier allocation. This will encourage regulators to start with as few restrictions as possible, since it provides a simple means, if required, for local conflict resolution and for refinement of deployment rules once real life experience has been gained. b) Above roof top system operators shall in case of conflict between them, locally, mutually back off from the same number (2) of carriers (but different carriers). They may back off until the spectrum is locally totally split between them, but going so far is not optimal. In principle only the operators that have conflicts need to back-off. An alternative where each operator always has access to one or two own carriers, seems much less attractive to all parties. All will suffer in all normal cases where back-off is not required. And if there are many operators, so much will be taken from the common spectrum, that the, in average, large economic gain of sharing may be totally lost. By using such conflict solving rules when there are large differences in cell sizes, the local upper bound for the infrastructure cost will be as for the case of totally split spectrum. But in reality, due to varying local distribution of market share between operators, the upper bound may be as if the spectrum was split between only two operators, even if there are, say, four operators in total. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 40 Annex A: Simulation results This annex describes the scenarios and the results of the simulations referred to in the main text of the present document. It is a collection of information from a large number of input documents supplied to the ETSI DECT Project during development of this report. A.1 Simulations of WPBX office systems In this clause the main assumptions and results of the simulations carried out for WPBX systems are summarized. First the simulation scenario is described highlighting the differences, then the reported results are presented. A.1.1 Simulation scenario Terminals are randomly positioned (with uniform distribution) within a reference three-storey building 100 m x 100 m x 9 m, in which 16 base stations are regularly spaced on each storey (figure A.1). Each terminal generates 0,2 E of traffic and the mean duration of the call is 120 s. 1 Af > 15 dB Af > 30 dB 2 3 100 m 100 m Figure A.1: Reference building Two different radio propagation models have been considered: The ETSI model assumes a propagation exponent accounting for the path loss equal to 3,5, an attenuation between floors of 15 dB, and a shadow margin factor uniformly distributed in the range ±10 dB. ( ) ( ) ( ) I d d x number of floors = + + 30 35 15 log A model for more heavy construction buildings, the Ericsson loss Model, has also been used. Ericsson-in-Building loss model: ( ) ( ) ( ) I d d x number of floors = + + 38 30 15 log d m <20 ( ) ( ) ( ) I d d x number of floors = - + + 1 60 15 log 20 40 m d m < < ( ) ( ) ( ) I d d x number of floors = - + + 97 120 15 log d m >40 The shadowing margin is modelled with a log-normal law with zero mean and a standard deviation of 8 dB. In both the models the Rayleigh fade margin is 10 dB, when antenna diversity is applied; the C/I threshold is 11 dB, so the call set-up threshold is 21 dB. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 41 The system spectrum allocation, the radio parameters, such as transmitted power, receiver noise floor, adjacent channel rejection factors etc. and the call procedures, such as set-up and handover for both single and multi-bearer channel allocation models, are in accordance with the DECT specifications (see EN 300 175-3 [3]). Specifically, the parameters of the simulation scenario of annex E of ETR 042 [21] have been used. Base station blind slot information is available at the PPs for the simulations in clause A.1.2, whilst not in clause A.1.2.2. The aim of this work is to evaluate the GoS versus the average traffic per base station and the total number of available DECT carriers (total spectrum). GoS is defined as follows: GOS number of blocked calls + 10 number of interrupted calls total number of calls = x In simulation works dealing with DECT performance (ETR 042 [21]) the desired GoS should be less than 1 %. A.1.2 Simulation results For the simulations in this subclause, DECT capacity in offices, intracell and intercell handover is provided and 20 % of the users are moving. The capacity is expressed in average speech traffic (Erlangs) per base station, as a function of the number of carriers that has been allocated to the system. Table A.1 provides a summary for the 1 % blocking case using the ETSI loss model. Table A.2 is the same summary for a heavy construction building where the Ericsson Loss model has been used. Table A.1: Average traffic per base station (at 1 % blocking probability) in an office application as a function of total number of DECT access channels (the ETSI loss model has been used) No. of carriers/ access channels Average traffic per base station Average number of users (at 0,2 E) per base station Traffic/km2/floor, if 625 m2 per base station (25 m separation) 2/24 1,3 E 7 2 100 E 4/48 3,2 E 16 5 100 E 6/72 4,5 E 23 7 200 E 8/96 5,3 E 27 8 500 E 10/120 5,6 E 28 9 000 E It can be seen from table A.1 that the capacity is C/I limited up to about 6 carriers. For higher number of carriers the capacity becomes trunk limited (maximum 12 simultaneous calls per base station). For table A.2 the limit is at 4 to 5 carriers. Table A.2: Average traffic per base station (at 1 % blocking probability) in an office application as a function of total number of DECT access channels (the Ericsson loss model has been used) No. of carriers/ access channels Average traffic per base station Average number of users (at 0,2 E) per base station Traffic/km2/floor, if 625 m2 per base station (25 m separation) 2/24 2,1 E 11 3 400 E 4/48 4,4 E 22 7 000 E 6/72 5,5 E 26 8 800 E 8/96 6,1 E 31 9 800 E 10/120 6,1 E 31 9 800 E Regarding capacity calculations, the figure average traffic (E) per base station is the essential parameter. The traffic density figures, traffic/km2 and number of users per floor, depend directly on the base station density (base stations per km2 or per floor). The results below may be extended to cover other base station densities, by varying the base station density, but keeping the E/base figures from the tables. We may conclude that with about 20 m base station separation 5 carriers (10 MHz) will provide about 10 000 E/km2. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 42 A.1.2.1 Capacity in large office landscapes with soft partitioning Simulations have also been made for a very large single floor 300 x 300 m office landscape with semi-high soft partitionings, but without interior walls. The propagation model is: ( ) ( ) [ ] L d xMax d dB where is dB mor dB m = + + − 41 20 0 10 0 37 0 59 log , , , / , / . Γ Γ The higher attenuation figure corresponds to a high density of partitions. The results are summarized in table A.3. Table A.3: Average traffic per base station (at 0,5 % blocking probability) in a large (300 m x 300 m) office landscape with soft partitioning as a function of total number of DECT access channels and as a function of total traffic No. of carriers/ access channels (ΓΓΓΓ) Average traffic per base station Number of base stations (base station separation, rectangular grid) Traffic/km2 (total traffic in the office) 5/60 (0,37 dB/m) 4,2 E 12 (87 m) 556 E (50 E) 5/60 (0,37 dB/m) 6,0 E 42 (46 m) 2 778 E (250 E) 5/60 (0,37 dB/m) 5,6 E 90 (32 m) 5 556 E (500 E) 5/60 (0,37 dB/m) 3,7 E 272 (18 m) 11 111 E (1 000 E) 10/120 (0,37 dB/m) 4,2 E 12 (87 m) 556 E (50 E) 10/120 (0,37 dB/m) 6,9 E 36 (50 m) 2 778 E (250 E) 10/120 (0,37 dB/m) 7,8 E 64 (38 m) 5 556 E (500 E) 10/120 (0,37 dB/m) 5,9 E 169 (23 m) 11 111 E (1 000 E) 5/60 (0,59 dB/m) 2,5 E 20 (67 m) 556 E (50 E) 5/60 (0,59 dB/m) 6,0 E 42 (46 m) 2 778 E (250 E) 5/60 (0,59 dB/m) 6,2 E 81 (33 m) 5 556 E (500 E) 5/60 (0,59 dB/m) 4,2 E 240 (19 m) 11 111 E (1 000 E) 10/120 (0,59 dB/m) 2,5 E 20 (67 m) 556 E (50 E) 10/120 (0,59 dB/m) 6,9 E 36 (50 m) 2 778 E (250 E) 10/120 (0,59 dB/m) 7,8 E 64 (38 m) 5 556 E (500 E) 10/120 (0,59 dB/m) 6,4 E 156 (24 m) 11 111 E (1 000 E) We see that the installation is range limited for the low traffic cases, and starts to be come interference limited for the high traffic density cases. We also see that with about 20 m base station separation 5 carriers (10 MHz) will provide about 10 000 E/km2, as for the simulations in clause A.1.2. A.1.2.2 Interference to and from offices The potential Interference to and from different WPBX systems in the same building has also been analysed. Below the main results are presented. Two different scenarios are taken into account: a) a single system in the building; b) three different unsynchronized systems (one per floor). As a first assumption, systems are considered unsynchronized, i.e. frames are not aligned; the shift between the first time-slot of the frames of each system is not greater than one time-slot as shown in figure A.2. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 43 1 2 3 4 5 6 7 . . . . . . . system 1 1 2 3 4 5 6 7 . . . . . . . system 2 1 2 3 4 5 6 7 . . . . . . . system 3 Timeslot on which a transmission occurs Figure A.2: Three unsynchronized systems in the building When a single WPBX system is introduced in the building with a floor attenuation of 15 dB, the maximum capacity of the system in terms of Erlangs per RFP reached with a GoS equal to 1 % is about 5,6 E, that corresponds to 9 000 E/km2/floor; if a higher separation between floors is introduced (i.e. Af = 20 dB), this value becomes 6 E, that is 9 600 E/km2/floor. Note that blind slot information is not provided in this simulation. This explains the slight discrepancy with the results of clause A.1.2. In the second scenario, a different WPBX system is positioned on each floor of the building; terminals can only set-up a call and make handovers with base stations of their system, that is of their floor. Two values on floor attenuation are taken into account: The different systems are unsynchronized. The comparison among the scenarios is shown in figure A.3. 0 0,5 1 1,5 2 2 3 4 5 6 7 Offered traffic (Erlang/RFP) GOS (%) 1 system 1 system Af=20dB 3 systems unsynchronised 3 systems unsinch Af=20dB Figure A.3: Offered traffic per RFP with one and three systems in the building The results obtained by simulations show that coexistence of different WPBX systems, also unsynchronized, is possible with a loss in capacity, in the worst case, less than 20 %; in fact the total capacity obtained is about 7 400 E/km2/floor, instead of about 9 000 E/km2/floor for the reference case of 1 system in the building with Af = 15 dB. Better performance is obtained when the physical separation between different systems is higher, that is when the floor attenuation considered is 20 dB. In fact, in that case, the loss in capacity when 1 system in the building is substituted by 3 unsynchronized systems is almost negligible: The total capacity decreases from 9 600 E/km2/floor to 9 300 E/km2/floor. Table A.4 summarizes the simulation results. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 44 Table A.4: Summary of comparison of capacity for unsynchronized office systems System types Af (dB) Erlangs/RFP Erlangs/km2/floor 1 system 15 5,6 9 000 on three floors 20 6 9 600 3 systems 15 4,6 7 400 unsynchronized 20 5,8 9 300 A.1.3 The impact of up-link power control A.1.3.1 Introduction Power control of subscriber units (PPs and CTAs) has in the DECT (and PWT(US)) standards been added to the Instant Dynamic Channel Selection, iDCS, procedures. It is called PP power control. It is not mandatory, but it provides a number of advantages including increased capacity where the DECT environment is dominated by uncoordinated single cell systems and RLL. A.1.3.2 Power saving PP power control increases the talk time of subscriber units. For this reason a number of manufacturers of residential DECT systems have already since many years used a simple (two step) open loop power control procedure. A.1.3.3 Control of maximum interference and cell sizes DECT RFP down-link per connection power control is not possible due to the iDCS procedure. It is however possible to have a static reduced power for all down-link transmissions from a specific RFP. A DECT system may have the same reduced power on all RFPs, or have different power on different RFPs, which will result in different "cell sizes". Information on reduced RFP power may need to be broadcast to PPs using open loop power control. By introducing PP power control no more power will be emitted during a call than what is needed. It would also be possible to completely control the maximum emitted handset power (and RFP power) by (locally) installing the DECT base stations close enough. A.1.3.4 Capacity impact A.1.3.4.1 Single-radio RFPs and WRSs A.1.3.4.1.1 Residential single cell systems A number of adjacent residential systems appear as a set of mutually unsynchronized RFPs or cells. Since they are unsynchronized, the (in average) lower PP power will reduce the average level of mutual interference and thus reduce the local load on the spectrum. A.1.3.4.1.2 Multi-cell systems Multi-cell systems have all their RFPs synchronized. Since the down-link power is not changed, the down-link capacity will not be changed. Therefore the system capacity is not expected for be very much influenced by the PP power control, which has been confirmed by simulations. A.1.3.4.2 Multi-radio RFPs and WRSs The total capacity of a single-radio RFP is trunk (slot) limited to about 5 or 6 E. A single-radio WRS is trunk limited to about 2 E. The way to increase the local capacity without increasing the number of RFP sites, is the use multi-radio RFPs and WRSs. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 45 In a multi-radio RFP (or WRS) the same time slots will be used simultaneously on different carriers. Therefore it is important to have enough adjacent channel selectivity/power suppression not to cause interference in the RFP between channels using the same time slot. This is not a problem for the down-links, because the down-link power is constant on channels of all radios, and the actual isolation between the channels will be equal to the specified adjacent channel selectivity of the receiver. However, there will be a problem for the up-link when constant up-link power is used, because one subscriber unit can be close to the RFP and another close to the cell range. Therefore the up-link signals received at the RFP on the same time slot (but on different carriers) could differ e.g. 30 dB in field strength, and the specified adjacent channel selectivity will not be sufficient to avoid the weaker signal to be blocked. Thus multi-radio RFPs will not be able to utilize all channels, unless up-link power control is implemented, so that all the up-links are received with equal power at the RFP/WRS. With PP power control it is feasible to increase capacity by placing several synchronized RFPs or WRSs on the same site or spot, as long as they have the same UL/DL slot notations. This could be useful in office and residential environments. But the for RLL systems where the RFP/WRS sites are very expensive, multi-radio RFPs or collocated RFPs are required, and here the capacity increase by introduction of PP power control becomes dramatic (2 times). See clause A.3.4. A.1.4 The impact of higher level modulation options The latest version of the DECT base standard includes backwards compatible 4-level, 8-level, 16-level and 64-level modulation options. This will increase the bit rate of single radio DECT equipment by a factor 2, 3, 4 or 6 with retained transmitter bandwidth, carrier spacing and slot structure. Asymmetric data services with user data rates exceeding 4 Mbps are provided by a single DECT radio. We could expect that the voice service remains with 2-level modulation since normally no shorter slots than full slots are used. Therefore, the voice traffic capacity is not expected to be increased by introducing higher level modulations. For more or less isolated single cell single-radio systems we will get up to 6 times increased data traffic, unless they become range limited for the highest level modulation options. The 4-level modulation option will hardly introduce range limitation compared to the present implementation of 2-level radios. See clause 7.3. For multi-cell systems, and for the total capacity locally available in an environment of several systems, introduction of higher level modulation options could increase the data traffic capacity by a factor 2 in average. The main gain is in implementing the 4-level modulation, giving 2 times larger data rate. Implementing more than the 4-level and the 16-level options provides hardly any higher interference limited capacity, but would of course increase the peak rate at short distances from the RFPs. If some new multimedia services were standardized where voice and data to the same subscriber is mapped on a common slot, e.g. a double slot, than also the voice traffic would gain from the increased available bit rates. Conclusion: When introducing the higher level modulation options, we could use the results from the simulations made with standard 2-level modulation and make the following amendments: - The offered voice traffic is not expected to be increased by introducing higher level modulation options, unless voice and data to a user is mapped on a common slot. - The offered data traffic could be doubled by introducing higher level modulations, e.g. the 4-level option. A.2 Simulations of public street public pedestrian systems In this clause the assumptions and results of simulation studies of the capacity of public pedestrian systems in a suburban environment are described. First the simulation scenario for the public system is described. Thereafter the simulation results are presented. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 46 A.2.1 Simulation scenario A total number of 61 RFPs are placed in a hexagonal grid. The outer RFPs together form a new hexagon. The distance between RFPs is 300 m, whereby the area per cell becomes about 0,08 km2. In total an area of 4,75 km2 is covered. See figure A.4. In this area Poisson traffic is generated. Calls have a negative exponentially distributed holding time, with a mean duration of 120 seconds. 300 m Figure A.4: Reference public pedestrian environment The radio propagation model assumed is a mixture of 75 % LOS and 25 % Near Line Of Sight (NLOS). Which of the two models is to be used for calculating the propagation conditions is determined randomly at the start of the call. There is no preference for LOS or NLOS at an individual PP or RFP. The propagation loss model is: 75 % LOS: ( ) ( ) I d d d m = + < 38 20 10 log ( ) ( ) I d d d m = + > 30 28 10 log 25 % NLOS: ( ) ( ) I d d d m = + < 38 20 10 log ( ) ( ) I d d d m = + > 22 36 10 log Additionally to the loss, shadowing is assumed to have a log-normal distribution with a standard deviation of 8 dB. The assumption is made that a fade margin of 10 dB is required to combat multi path fading. This is based on the assumption of Rayleigh fading, in combination with diversity. The required C/I is assumed to be 11 dB or 13 dB. The latter to investigate the sensitivity of the results to this parameter. Transmit power is 24 dBm, receiver sensitivity -86 dBm (GAP requirement). The antenna gain is 2 dBi at RFPs and 0 dBi at PPs. This gives a basic link budget of 24 + 2 + 86 = 112 dB, excluding fading and shadowing margins. The number of allocated carriers is varied between 1 and 10, assuming a variable spectrum allocation. Adjacent channel interference, set-up and handover procedures and DCS are modelled in accordance with the DECT specification. Blind slot information is available at the PP. The capacity of the DECT system in the above described scenario is studied using the GoS, being defined as follows: GOS Number of blocked ca lls Number ofdropped ca lls Total numb er of call s = + 10 x The desired GoS should be less than 1 %. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 47 A.2.2 Simulation results Capacity and carrier availability The traffic capacity per RFP as a function of the available total number of carriers is shown in figure A.5. The case C/I of 11 dB is assumed to be typical for DECT. When the DECT public pedestrian system, as described in the scenario, can use all 10 carriers, the capacity at 1 % GoS is 7,9 E, corresponding to 100 E/km2. This capacity is higher than what is to be expected based on the Erlang B formula, which gives 5,9 E. This is due to the DCS, which enables a PP to set-up to an other RFP when the strongest RFP has no resources available. The traffic capacity per RFP is more or less proportional to the number of totally available carriers. The figure also shows that 2 to 3 carriers are required to have a reasonable capacity for public pedestrian street application defined in this suburban scenario and in clause 6.3 (about 1 E per RFP). NOTE: A city centre public pedestrian street application with consistent below roof top base station installations, will due to larger isolation between base stations, require less spectrum than indicated in figure A.5. 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 9 10 Number of available carriers Capacity at 1% GOS (Erlang/RFP) 11 dB C/I 13 dB C/I Figure A.5: Capacity at 1 % GoS versus the number of available carriers of the public pedestrian system In figure A.5 the capacity per RFP at 1 % GoS is shown. The capacity is also shown for a C/I of 13 dB. This makes it possible to estimate the sensitivity of the capacity to the required C/I. When the system is purely C/I limited, as is the case for 4 carriers, we find a decrease in capacity of 8 % to 10 % per dB increase in C/I. When more carriers are available, the trunk size is limiting the capacity, and a reduced effect is noticed. For eight to ten carriers a decrease in capacity of 5 % to 7 % per dB increase in C/I is found. A.3 Simulations of above rooftop RLL systems In this clause the assumptions and results of simulation studies of the capacity of above rooftop RLL systems in a suburban environment are described. First the simulation scenarios for the RLL system are described. Thereafter the simulation results are presented. Note that in an update of the present document, simulation results using improved propagation models and scenarios are found in clauses A.3.3 to A.3.5. A summary is found in clause 3.6. A.3.1 Simulation scenarios A.3.1.1 Basic scenario For the above rooftop scenarios it is supposed that a major part of the CTAs are in LOS. In LOS conditions DECT can provide reliable long range links (up to 5 km or more). To provide economic installation, the RFP stations of six cells are installed in at common site called DECT Access Site, DAS, This is possible by using directional antennas for the RFP of each cell, so that each cell gets a sector shape with the RFP placed in the corner of the sector angle. The same principle for creating sectorized cells is frequently used in mobile telephony systems. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 48 Seven synchronized DASs, are placed above rooftop in an hexagonal pattern. The sides of the cells are 1 km, corresponding to a separation distance of 1,732 km between the DASs. See figure A.6. The coverage area becomes 2,6 km2 per DAS. Poisson time distributed traffic is generated within the coverage area of the DASs. The statistics are taken only from the inner DAS. 1,732 km 1 km Figure A.6: Basic above rooftop RLL scenario One DAS consists of six RFPs, each equipped with a directional antenna, and pointing in a direction 60° different from the next RFP. The DAS antenna has an opening angle of 85°. The bore sides of the antennas are directed to the corners of the DAS cell. Redundancy is provided by having an opening angle as large as 85°. Each CTA can see two RFPs, which provides redundancy. This implies that these 6 overlapping sectors are equivalent to about 3 non-overlapping sectors. Figure A.7 shows the antenna diagram. The antenna provides 12 dBi gain. -20 -10 0 10 20 dBi Figure A.7: Antenna diagram with 85°°°° to 90°°°° opening angle and 12 dBi gain The CTAs are also equipped with a directional antenna. The CTA antenna has an opening angle of 90° and 12 dBi gain. This antenna is directed to the nearest DAS. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 49 The radio propagation model assumed is a mixture of 75 % LOS and 25 % NLOS. Which of the two models is to be used for calculating the propagation conditions is random. It is determined when placing the CTA. The propagation loss model is: 75 % LOS: ( ) ( ) I d d d m = + < 38 20 10 log ( ) ( ) I d d d m = + > 30 28 10 log 25 % NLOS: ( ) ( ) I d d d m = + < 38 20 10 log ( ) ( ) I d d d m = + > 22 36 10 log Additionally to the loss, shadowing is assumed to have a log-normal distribution with a standard deviation of 8 dB. Due to the shadowing model used, in combination with other defined conditions, a low number of calls will originate in CTAs out of range. These calls are taken out from the statistics, since no real CTA will be installed in such a way that it is out of range. For multi path fading Rayleigh fading is assumed. For each radio path between a CTA and an RFP separate Rayleigh fading is calculated. When this path is the actual connection between CTA and DAS, diversity is assumed, resulting in the selection of the strongest of two Raleigh faded signals. There is no preference for LOS or NLOS at an individual DAS or CTA. All RFPs of a DAS will have the same loss and shadowing conditions, but different antenna gain and multipath fading, due to the difference in direction. The required C/I is assumed to be 11 dB. Transmit power is 24 dBm, receiver sensitivity -89 dBm (typical for DECT RLL systems). This gives a basic link budget of 24+12+12+89 = 137 dB, excluding fading and shadowing margins. The number of allocated carriers, adjacent channel interference, set-up and handover procedures and DCS are modelled in accordance with the DECT specification. Blind slot information is available at the CTA. The capacity of the DECT system in the above described scenario is studied using the GoS, being defined as follows: GOS Number of blocked ca lls Number ofdropped ca lls Total numb er of call s = + 10 x The desired GoS should be less than 1 %. For the basic scenario, a total of 10 consecutive carriers (20 MHz) are allocated. A.3.1.2 Additional scenarios In addition to the basic scenario, as described above, additions have been made to the scenario: 1) The DASs are completely unsynchronized. 2) The DAS and CTA antenna were either directional or omni-directional. In order to avoid range problems, the distance between DASs was reduced to 300 m. The antenna pattern models include side lobes. The cases given in table A.5 were simulated. Table A.5: Specification of simulated antennas CTA antenna DAS antenna Gain (dBi) Opening angle (°) Gain (dBi) Opening angle (°) 12 90 12 85 12 90 2 360 2 360 2 360 ETSI ETSI TR 101 310 V1.2.1 (2004-04) 50 3) The total number of carriers allocated for the system(s) is varied between 1 and 10; at each location of a DAS a second DAS is added. The second DAS is synchronized to the first. Traffic is equally spread of the DASs. 4) A second system of seven DASs is added to the first set of seven DASs. The second DASs have the same separation distance, and are placed at the intersections of the cells of the first DASs. See figure A.8. Any CTA belongs to either of the two systems with the same probability. The CTA is pointing to the closest DAS of the own system. (This might be further away than the closest DAS.) All DASs of both systems are synchronized. 1 km 1,732 km Figure A.8: Two system above rooftop RLL scenario 5) The required C/I is assumed to be 11 dB or 13 dB. 6) The side of the node cells is 100 m or 1 km, and the DAS node separation 173 m or 1,7 km, whereby the coverage area per DAS becomes 0,026 km2 or 2,6 km2. A.3.2 Simulation results A.3.2.1 Basic capacity simulation results The capacity of the basic scenario with one and two systems is given in table A.6. For one system in this scenario the capacity per RFP is higher than what can be calculated using the Erlang-B formula for 12 servers (trunks). The Erlang-B formula shows a GoS of 1 % at 5,9 E, while the simulations show the same GoS at 40,2 / 6 = 6,7 E per RFP. So to some extent CTAs make use of free channels at adjacent RFPs at the DAS. For the two system case, the simulations show 28,6 / 6 = 4,7 E per RFP. For two collocated synchronized systems, the total capacity per node at 1 % GoS is 2 x 28,6 E = 57,2 E. This is more than the 40,2 E for the single system case. Therefore, it is obvious that the capacity for the single system case is trunk limited and not C/I limited. The total capacity per node of the two systems is the same as the capacity per DAS of one system with two RFPs in each sector cell (not trunk limited capacity). See the last line of table A.6 and compare with figure A.11. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 51 Table A.6: Capacity per DAS for the basic scenario, totally 10 carriers Capacity (Erlang/DAS/system) at GoS Scenario 0,1 % 0,5 % 1,0 % 2,0 % Basic, 1 system 29,0 36,2 40,2 44,3 2 synchronized collocated systems 19,5 24,5 28,6 32,2 1 system, 2 RFPs per DAS sector 39,0 49,0 57,2 (note) 64,4 NOTE: For one system with six 60° DAS sectors, 2 RFPs per sector, 25 % LOS and 75 % NLOS, the capacity per DAS at 1 % GoS is 74 E. A.3.2.2 Capacity and carrier availability It is important to study how the capacity depends on the total number of available carriers. This information is very helpful for estimating the local load on the spectrum and how much is left for other systems. The total number of available carriers is varied from 1 to 10. In figures A.9 to A.11 the capacity per DAS for various numbers of carriers and various GoS is shown for the three cases of table A.6. 0 10 20 30 40 50 0 1 2 3 4 5 6 7 8 9 10 Number of available carries Capacity at indicated GOS (Erlang/DAS) 0,10% 0,50% 1,00% 2,00% Figure A.9: Capacity per DAS versus number of available carriers of the above rooftop RLL system at 0,1 %, 0,5 %, 1,0 % and 2,0 % GoS (1 system with 1 RFP per sector cell) 0 5 10 15 20 25 30 35 0 1 2 3 4 5 6 7 8 9 10 Number of available carries Capacity at indicated GOS (Erlang/DAS) 0,10% 0,50% 1,00% 2,00% Figure A.10: Capacity per DAS/system versus number of available carriers of the above rooftop RLL system at 0,1 %, 0,5 %, 1,0 % and 2,0 % GoS (2 systems with 1 RFP per sector cell) ETSI ETSI TR 101 310 V1.2.1 (2004-04) 52 0 10 20 30 40 50 60 70 0 1 2 3 4 5 6 7 8 9 10 Number of available carries Capacity at indicated GOS (Erlang/DAN) 0,10% 0,50% 1,00% 2,00% Figure A.11: Capacity per DAS (lower bound) versus number of available carriers of the above rooftop RLL system at 0,1 %, 0,5 %, 1,0 % and 2,0 % GoS (1 system with 2 RFPs per sector cell) From figure A.11 we can conclude that the maximum (by different operators) sharable local capacity is about 57 E per DAS when totally 10 DECT carriers are available. For extended number of carriers beyond 10, a lower bound for the local capacity is 5,7 E per carrier. This assumes synchronization and use of directional gain antennas. With 1,7 DAS separation the sharable traffic capacity becomes about 57 / 2,6 = 22 E/km2 when totally 10 DECT carriers are available, and about 200 E/km2 for 0,58 km separation, and about 2 100 E/km2 for 173 m separation. See table A.12. A.3.2.3 Synchronization In tables A.7 to A.9 the results are shown from simulations with 10 carriers where the seven DASs are not synchronized. Table A.7: Capacity per DAS for synchronized and unsynchronized DASs, 1 system with 1 RFP per sector cell (10 carriers) Scenario Capacity (Erlangs/DAS) at GoS 1 system, 1 RFP/sector 0,1 % 0,5 % 1,0 % 2,0 % Synchronized 29,0 36,2 40,2 44,3 Unsynchronized 9,4 13,7 15,5 17,3 Table A.8: Capacity per DAS for synchronized and unsynchronized DASs, 2 co-located systems with 1 RFP per sector cell (10 carriers) Scenario Capacity (Erlangs/DAS/system) at GoS 2 systems, 1 RFP/sector 0,1 % 0,5 % 1,0 % 2,0 % Synchronized 19,5 24,5 28,6 32,2 Unsynchronized 7,9 9,7 10,7 12,1 Table A.9: Capacity per DAS for synchronized and unsynchronized DASs, 1 system with 2 RFPs per sector cell (10 carriers) Scenario Capacity (Erlangs/DAS) at GoS 1 system, 2 RFPs/sector 0,1 % 0,5 % 1,0 % 2,0 % Synchronized 39,0 49,0 57,2 64,4 Unsynchronized 15,8 19,4 21,4 24,2 The capacity per DAS is reduced by more than 60 % for the all cases. This means that the sharable local capacity per DAS may be reduced from 5,7 E to 2,1 E per allocated carrier. Synchronization between DASs is required for high capacity applications. This does not mean that the above rooftop RLL system needs to be synchronized to other DECT systems. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 53 A.3.2.4 Directional versus omni-directional antennas Besides synchronization, also the use of directional or omni-directional antennas is crucial for the spectrum efficiency of above rooftop RLL systems. Directional antennas will have a higher gain, so a larger range is realized. Directional antennas will also radiate into and receive from the wanted direction. Interference to and from other DECT users is reduced. In the scenario to investigate the capacity effects three options are taken into account, as shown in the description of the scenario in clause A.3.1. Table A.10: Capacity per DAS for directional and omni-directional antenna patterns at DAS and CTA, 1 system (1 RFP per sector cell) with synchronized DASs and totally 10 carriers Scenario Capacity (Erlangs/DAS) at GoS DAS CTA 0,1 % 0,5 % 1,0 % 2,0 % dir dir 26,2 35,6 40,7 44,9 dir omni 21,8 27,8 31,2 35,5 omni omni 18,1 21,4 23,2 25,9 In table A.10 the results for the different scenarios is summarized. The figures show that antennas at the CTA and the DAS both have a large, and more or less equal, impact on the capacity of the system. The reduction in capacity in the last line of table A.10, by not using directional antennas, is about 40 % (somewhat less than for not synchronizing the DASs). Use of directional antennas is very beneficial for high capacity applications since a significant increase in capacity is realized, and interference to other systems is reduced. The case with two RFPs in each sector provides redundancy in each sector. For this case the opening angles of the DAS antennas may be reduced, allowing higher antenna gain and even more efficient use of the spectrum. A.3.2.5 Sensitivity to C/I performance The basic scenario has been simulated also with a 2 dB change in required C/I. For C/I limited cases the capacity reduction is typically about 6 % per 1 dB increase of C/I. A.3.2.6 Effect of cell size on the capacity To investigate the influence of the distance between DASs on the capacity per DAS, the radius of the cells was reduced to 100 m, corresponding to a distance between DASs of 173 m. The effect of this reduction, as shown in tables A.11 and A.12, is a somewhat reduced capacity, though the effect is limited (±2 %). This result is depending on the propagation model used. So far no alternative propagation model has been used in these simulations. Table A.11: Capacity per DAS for 173 m and 1,7 km node separation, 1 system (1 RFP per sector cell) with synchronized DASs and totally 10 carriers Capacity (Erlangs/DAS) at GoS Scenario 0,1 % 0,5 % 1,0 % 2,0 % 1,7 km separation 29,0 36,2 40,2 44,3 0,17 m separation 27,3 35,5 39,6 43,9 Table A.12: Capacity per DAS for 173 m and 1,7 km node separation, 1 system (2 RFPs per sector cell) with synchronized DASs and totally 10 carriers Capacity (Erlangs/DAS) at GoS Scenario 0,1 % 0,5 % 1,0 % 2,0 % 1,7 km separation 39,0 49,0 57,2 64,4 0,17 m separation 38,0 46,8 55,6 63,8 A.3.2.7 Multi-operator scenarios When two or three operators are active in the same area with an above rooftop RLL system, several scenarios are possible regarding the locations of the DASs. The two extreme scenarios are co-located DASs or DASs located at the corners of the cells of the other above rooftop RLL systems. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 54 Regarding the use of the spectrum also two alternatives exist. The spectrum can be shared or divided between the two operators. In case of division, the locations of the DASs do not matter, so three scenarios remain: - shared spectrum, DASs co-located; - shared spectrum, DASs located at corners of other system (the most unfavourable position); - spectrum divided between systems. The results of these simulations is shown in table A.13. Table A.13: Capacity per DAS for second operator scenarios, 1 RFP per DAS (all DASs are synchronized) Capacity (Erlangs/DAS/system) at GoS Scenario 0,1 % 0,5 % 1,0 % 2,0 % co-located, 2 systems 19,5 24,5 28,6 32,2 other location, 2 systems 16,0 20,0 22,4 25,3 divided spectrum, 2 syst. 12,4 16,4 18,6 21,3 The figures in table A.13 show a preference for co-locating the DASs. In practice this does not necessarily mean a pure co-location. The same effect will be noticed when the DASs are placed near each other. For "other location" (worst case), the capacity reduction is only about 20 %. The figures also show a very large preference for sharing the spectrum instead of dividing the spectrum. This of course requires synchronization between the operators. The more operators the larger the gain of sharing instead of dividing, see table A.14. Table A.14: Capacity per DAS for three-operator scenarios, 1 RFP per DAS (all DASs are synchronized) Capacity (Erlangs/DAS/system) at GoS Scenario 0,1 % 0,5 % 1,0 % 2,0 % co-located, 3 systems 13 16 19 21 divided spectrum, 3 syst. 8 10 12 13,5 Tables A.13 and A.14 show that the spectrum efficiency can be increased by up to 60 % by not dividing the spectrum between operators. This is for the case where all systems have equal local load on the spectrum. In reality, for RLL, we can expect that there will be many local areas where one of the operators will be dominating. In such areas the capacity can be up to 57,2 E per DAS, which corresponds to 57,2 / 18,6 = 3,1 times (2 operators) and 57,2 / 12 = 4,8 times (3 operators) better spectrum efficiency compared to splitting the frequency band between operators. Therefore, for the 3 operator case, by providing synchronized systems, sharing spectrum will compared to equal division of the spectrum, provide up to between 1,6 and 4,8 times more efficient use of the spectrum. A.3.3 Improved realistic RLL propagation model With more realistic propagation models for fixed WLL, the capacity per DAS node could double compared to results presented in the above simulations using the scenarios defined in clause A.3.1. The main issue is that the propagation model in clause A.3.1 uses a ±8 dB shadowing component on all wanted LOS and NLOS signals and also on all interfering signals without any correlation between wanted and interfering signal. This is normally made for mobile systems, but gives far too pessimistic conditions for an RLL system. See description in table A.15. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 55 Table A.15 A.3.1 and A.3.2 simulations Mobile subscribers Fixed subscribers with LOS or almost LOS installation optimized for best possible wanted signal. No correlation for use of either of the defined LOS and NLOS models for wanted and interfering signals for the same CTA. Low or medium correlation for use of either of the defined LOS and NLOS models for wanted and interfering signals for the same CTA. High correlation for use of either of the defined LOS and NLOS models for wanted and interfering signals for the same CTA. If the wanted signal is LOS, the CTA is either above roof-top or up on a wall (still in LOS), and it is likely that the interferers to the CTA also are LOS, but a substantial part will be NLOS (see note). The interferers to the DAN are also LOS, but a substantial part will be NLOS (see note). If the wanted signal is NLOS (below roof-top) it is very likely that the interferers to the CTA also are NLOS. The interferers to the DAN will be LOS from some of the LOS installed CTAs (see note), but a substantial part will be NLOS. No correlation for the level of shadowing used for wanted and interfering signals for the same CTA. Low correlation for the level of shadowing used for wanted and interfering signals for the same CTA. Not a high correlation for the level of shadowing used for wanted and interfering signals for the same CTA, but the distribution is not generally log-normal. For the LOS case t here is almost no shadowing for the wanted signal but could be added attenuation for the interferes, and due to the way installation is made, there is for the NLOS case often shadowing attenuation both for the wanted and interfering signals. NOTE: LOS installed CTAs on walls will not be interfered from the 180° backwards sector, and will produce no interference in the 180° backwards sector. Table A.16: Void Due to the above considerations, we may conclude that when simulating C/I limited capacity, that it is more correct to have no shadow component, than to use uncorrelated shadow components. A.3.3.1 New simulations By removing the shadowing components from the clause A.3.1 model we got the following results. For comparison, two other propagation/deployment models have been included. A.3.3.2.1 Common parameters/definitions GOS is defined as the blocking probability plus 10 times dropping probability. There are 7 DASs in a clustes. Each DAS has 24 RFPs, 2 per sector. The capacity is indicated per DAS. Each DAS has 12 sectors with 30° horizontal opening angle antennas. The CTAs have 80° horizontal opening angle antennas. CTAs are not evenly distributed per sector. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 56 A.3.3.2.2 Results A.3.3.2.2.1 Customary model (close to model from clause A.3.1) RLL modified Walfish Ikegami with 3dB shadowing for LOS and 8dB for NLOS. 25 % LOS. GOS 1 %: 70 Erlang. This corresponds to 2.9 E/RFP. Blocking 1 %: 85 Erlang (thus significant influence from dropping). A.3.3.2.2.2 The model from clause A.3.1 The A.3.1 model shadowing 8dB, but with 25 % LOS links and 75 % NLOS links. GOS 1 %: around 65 Erlang. This corresponds to 2.7 E/RFP. Blocking 1 %: 81 Erlang (thus significant influence from dropping). A.3.3.2.2.3 No shadowing path loss 100 % LOS GOS 1 %: 198 Erlang. This corresponds to 8.3 E/RFP (close to trunk limitation). Blocking 1 %: 202 Erlang. An additional simulation, but with 6 sectors (85° horizontal opening angle) instead of 12 sectors, and where GOS was calculated only for the down-link, the following results were obtained for 1 % GOS: 1 RFP/sector: 55 Erlang, 2 RFPs/sector: 110 Erlang, 4 RFPs/sector (totally 24 RFPs): 198 Erlang. An interesting observation is that with a total of 24 RFPs, the down-link capacity with only 6 sectors is as large as the capacity for 12 sectors (198 E) where also the up-link limitation is included. This indicates that the up-link is limiting the capacity. See the impact of up-link power control in clause A.3.4. A.3.3.2.2.4 No shadowing, 75 % LOS and 25 % NLOS. If CTA is NLOS, also interferes to CTA are NLOS. For RFPs and LOS CTAs, 75 % of the interferers are LOS and 25 % NLOS. GOS 1 %: 170 Erlang. This corresponds to 7.1 E/RFP. Blocking 1 %: 185 E. A.3.3.2.2.5 Conclusion As seen, the results depend a lot on the selection of propagation model. The last case A.3.3.2.2.4 can be compared with the result of figure A.11 which also has 75 % LOS and 2 RFPs per sector, but only 6 sectors. Figure A.11 indicates 57 E at 1 % GOS. Suppose that going from 6 to 12 sectors increases capacity by about 50 %, corresponding to 57 x 1,5 = 85,5 E for the model in clause A.3.1. Thus we could say that a more realistic model (no shadowing) than in clause A.3.1 could give about 2 to 2½ times higher capacity (from 85 E to 170 E to 200 E). Furthermore, simulations show that decreasing the CTA antenna opening angle from 80° to 25°, increases capacity by about 60 %. This gain can be utilized by increasing the number of RFPs in each sector, or is useful when two operators are having one system each in the same geographical area. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 57 A.3.4 Impact of up-link power control PP up-link power control has been standardized for DECT. See clause A.1.3. Simulation shows that CTA up-link power control increases capacity from about 80 E to 190 E for 12 sectors with 2 RFPs per sector and with a model similar to the model of clause A.3.3.2.2.1. This corresponds to 7,9 E/RFP (close to trunk limitation). With 3 RFPs per sector the capacity increased to about 300 E. This corresponds to 8,3 E/RFP (close to trunk limitation). Note that this 300 E traffic was obtained with a shadowing component in the propagation model, and with capacity per RFP close to trunk limitation. Thus with 4 RFPs per sector we could expect > 300 E traffic, but the DECT standard does not permit more than 3 single radio RFPs per sector (unless more than 10 RF carriers are available). A.3.5 Impact of higher layer modulation options The latest version of the DECT base standard includes backwards compatible 4-level, 8-level, 16-level and 64-level modulation options. This will increase the bit rate of single radio DECT equipment by a factor 2, 3, 4 or 6 with retained transmitter bandwidth, carrier spacing and slot structure. See clause A.1.4. Asymmetric data services with user data rates exceeding 4 Mbps are provided by a single DECT radio. When introducing the higher level modulation options, we could use the results from the simulations made with standard 2-level modulation and make the following amendments: - The offered voice traffic is not expected to be increased by introducing higher level modulation options, unless voice and data to a user is mapped on a common slot. - The offered data traffic could be doubled by introducing higher level modulations, e.g. the 4-level option. A.3.6 Conclusions Various rooftop RLL system scenarios have been simulated and discussed. The major conclusions of the simulations are: - Maximum sharable local capacity with 10 carriers is estimated to be at least 300 E for 12 sector DAN clusters and about 160 E to 200 E for 6 sector DAN clusters. This is achievable with use of a rather simple (slow and not very accurate) up-link closed loop power control. - For two or more systems in the same geographical area, the total capacity/site of all operators becomes close to the above maximum sharable local capacity, if the operators have similar cell sizes. - Each E corresponds to one speech connection or a data connection with about 32 kbps with 2-level modulation and about 64 kbps with higher level modulation (at least 4-level modulation). 300 E corresponds to 19 Mbps data throughput per DAN with 4-level modulation! - Having 1 RFP per sector provides a trunk limited average capacity of about 5 E/RFP to 7 E/RFP, and having 2 or 3 RFPs per sector provides roughly about 8 E/RFP to 9 E/RFP of average capacity. - It is obvious that an isolated DAS site, will support the trunk limited traffic capacity. - Synchronization between DASs and between above rooftop RLL systems has a very large positive impact on the system capacity. - Use of directional gain antenna versus omni-directional antennas at the DAS has a large positive impact on the system capacity. - When several operators are active in one geographical area, sharing the spectrum will lead to a higher capacity than dividing the spectrum between the operators. Up to 1,6 to 4,8 times increased spectrum efficiency. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 58 - The required C/I has a limited impact on the capacity of the above rooftop RLL system (if trunk limited). - The distance between the DASs of the above rooftop RLL system have a limited effect on the traffic capacity per DAS, as long as the different systems in a local area have similar cell sizes. A.4 Simulations of below rooftop RLL systems and other RLL systems Below roof top RLL applications will not have critical impact on spectrum requirements, because the radiation will be limited by surrounding buildings and the local load from such a base station will also be limited. EN 300 175-3 [3] recommends to limit the maximum load from an antenna of a sectorized cell to 36 E, which limits the average local load on the spectrum to 24 E. Furthermore 24 E corresponds to 373 households, and a below roof top installation can hardly reach 373 households. An office with 24 / 0,15 = 160 employees could however occasionally be served this way. Simulations have also been made for a scenario with onmidirectional base station antennas positioned just at roof top level of houses in a residential villa area. The CTAs are non LOS and ranges are limited to about 200m. Simulations are made for up to 10 transceivers per site antenna. The capacity of a single cell is trunk limited up to 6 transceivers (72 trunks) and does not increase capacity by adding transceivers. The maximum capacity is 48 E. The reason is that for this specific case only every second carrier can be used due to the interference in the first adjacent channel. As mentioned above, EN 300 175-3 [3] does not suppose more than 3 transceivers (average 24 E) to be connected to an omnidirectional antenna. Therefore the simulations have no practical importance. If more than 24 E are required from an access node, sectorized directional antennas should be used. A.5 Coexistence between above rooftop RLL systems and a public pedestrian street system The largest potential interference between RLL systems and other DECT applications is between above rooftop RLL systems and a public pedestrian street system, since the public pedestrian system has outdoor base stations. Such an interference scenario has been simulated. A.5.1 Simulation scenario The RLL scenario is the basic 7 DASs RLL above rooftop scenario defined in clause A.3.1, which will cover an area with about 4,8 km diameter. The only difference is that the antenna gain is 8 dBi instead of 12 dBi for the DASs and 6 dBi instead of 12 dBi for the CTAs. The public pedestrian scenario is a 61 cell system with 300 m RFP separation as defined in clause A.2.1, with the exception that the public pedestrian RFPs are below rooftop and only 25 % of the PPs are in LOS, instead of 75 %. The public pedestrian system will cover an area with about 2,5 km diameter. The RLL-public pedestrian propagation is assumed to always be NLOS. The blocking probabilities are calculated for the connections within the area of the inner centre DAS node, with 33 public pedestrian cells. See figure A.12. The RLL and public pedestrian systems are synchronized. The models for LOS and NLOS are as defined in subclauses A.2.1 and A.3.1. 40 E in the RLL DAS corresponds to 40 / 2,6 = 15,4 E/km2. 1 E per public pedestrian cell corresponds to 33 / 2,6 = 12,7 E/km2, and 3 E per public pedestrian cell corresponds to 38 E/km2. A.5.2 Simulation results The simulations gave the following results. A.5.2.1 Interference from the RLL system to the public pedestrian system The RLL traffic, up to 44 E per DAS node, did not affect the public pedestrian traffic at 3 E per public pedestrian RFP. Since street PCM base stations typically have 1 E average traffic per cell, we conclude that for this scenario, the interference to the public pedestrian system is not critical. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 59 A.5.2.2 Interference from the public pedestrian system to the RLL system 1 E average traffic per public pedestrian cell does not affect the RLL system having up to 44 E average traffic per DAS. 3 E average traffic per public pedestrian cell does not affect the RLL system when having 18 E average traffic per DAS. 3 E average traffic per public pedestrian cell however reduces the RLL traffic (0,5 % GoS) from about 40 E per DAS to about 30 E per DAS. Therefore, the additional load on the spectrum for the RLL system is about the same as when adding a second RLL system. Two RLL systems can support 28,6 E each per DAS. Compare with table A.6. 28,6 E per DAS corresponds to 11 E/km2 and 3 E per public pedestrian cell corresponds to 38 E/km2. 500 m 2,5 km 1,7 km RLL system coverage Public pedestrian system coverage 4,8 km Figure A.12: Deployment of above rooftop RLL DAS nodes and street below rooftop street public pedestrian cells A.5.2.3 Conclusions The large difference in cell radii is the major reason why the RLL traffic is more affected than the public pedestrian system. Typical public pedestrian street systems with 1E per cell, do not affect the RLL traffic. 3 E per public pedestrian cell gives reduction of the RLL traffic. The above conclusions relate to intra-system and inter-system synchronization. Suppose the public pedestrian system is not synchronized to the RLL system. Since the RLL system will not differentiate between interference from RFPs and PPs, up-link/down-link mix will not contribute, as between RLL systems (DASs). Therefore without inter-system synchronization, the interference from a 1 E per cell public pedestrian system, would at most to be as from a 2 E per cell inter-system synchronized public pedestrian system. For 2 E per cell the interference to the RLL system is just noticeable. The need for inter-synchronization is discussible. RLL systems with smaller separation distances between the DASs will of course be less affected. A.5.2.3.1 Spectrum load for a system consisting of DASs and WRSs (CRFPs) The results from the above simulated scenario can also be used to estimate the spectrum load of an RLL system with local mobility using WRSs type CRFP instead of CTAs, where the CRFPs provide local links to PPs. This system concept can also be described as a public pedestrian system using CRFPs instead of wired RFPs, where the DAS infrastructure provides the above rooftop connection to the CRFPs. The antennas for the local CRFP link is supposed to be below rooftop as for the original RFPs. The CRFP antennas for the longer DAS link is supposed to be similar in position and have antenna gain as for the original CTAs (75 % are in LOS). See figure A.13. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 60 DAS CRFP PP Figure A.13: RLL system with local mobility Suppose that the CRFPs are in the same positions as the RFPs, then there are 33 CRFPs within the area of one DAS. With 1 E average local link traffic per CRFP, the traffic per DAS will be 33 E, since the DAS above rooftop link will be loaded with 1 E per Erlang of local link load. Therefore, this scenario is almost identical to the already simulated scenario. The only difference is that there are couplings between the above rooftop (RLL) links and the local (public pedestrian) links. But since the simulations show that the blocking probability of the DAS link will dominate and that the low traffic (1 E) local links will not affect that probability, we can use the blocking probabilities for the above rooftop RLL simulations of clause A.3 to estimate the GoS and load on the spectrum for the concept of figure A.13. This is a very interesting result, and will as a first approximation be independent of the cell sizes and traffic densities, since the total traffic per km2 in the DAS links and in the local links always are equal, in this case 12,7 E/km2. A.6 The impact of WRSs on infrastructure cost and spectrum utilization The DECT WRS is an important component for providing economic DECT infrastructures. WRS is an additional building block for the DECT fixed network. A WRS has the function of an RFP that need no wired connection to the FT. The WRS is a physical grouping that contains both FT and PT elements, and that transfers information between an RFP and a PP. The FT element acts towards a PP exactly as an ordinary RFP. The PT element acts like a PP towards the RFP, and is locked to the closest RFP. The WRS contains interworking between its FT and its PT, including transparent transfer of the higher layer DECT services. WRS links may be cascaded. A WRS has to comply with the general FT identities requirements for RFPs. Installing or adding a WRS to a DECT infrastructure is not possible outside the control of the system operator and/or system installer and/or system owner, who provides the required system identities, access rights and authentication/encryption keys. Figure A.14 gives a graphic explanation of the WRS functionality. For more information, see the ETSI technical report on WRS, ETR 246 [14] and EN 300 700 [15]. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 61 RFP RFP PP PP PP PP Handover WRS PP is only software One Access Channel per Active CRFP Access Channel ‘WIRED’ Base Station ‘WIRELESS’ Base Station (WRS) MAX 6E at 1% GOS MAX 2E at 1% GOS (CRFP) Wired connection to Network or Radio Controller Figure A.14: Principle for WRS No access channel is required between the RFP and the WRS when there is no local uplink traffic to the WRS. The number of access channels required and the GoS figure for WRS in the figure relates to the CRFP type. For the REP type, 2 RFP link access channels are required for the first PP link access channel. For the following PP link access channels, 1 or 2 additional RFP link access channels are required per additional PP link channel. The trunk limited capacity is maximum 1 E for the REP WRS is at 1 % GoS. A PP does not see any difference between a WRS and an ordinary wired RFP. Handover is provided between WRSs and between WRS and RFPs, as between ordinary wired RFPs. The impact on the local spectrum utilization of a call relayed via a WRS depends on the scenario. Below are some typical scenarios that exemplify this. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 62 A.6.1 Examples of scenarios with WRS type CRFP (this type is implemented in products) Table A.17 Scenario Relative local load on the spectrum for a WRS call Total local load on the spectrum Total additional local load on the spectrum Impact of WRS calls on other systems Cost savings economic benefit Residential (typical 1 E per RFP) 2x Low Low Low Important Office (up to 6 E per RFP) 2x Medium to High Low (limited line of sight, WRS not economic for high capacity) Low (natural isolation to other systems) Important for small systems, and generally for remote area coverage. Public street Pedestrian (typical 1 E per RFP) 2x Low Low Low Essential, one RFP can relate to 4 CRFPs Public "hot spot" Pedestrian (indoor, up to 6 E per RFP) 2x Medium to High Low (WRS not economic for high capacity) Low Important for remote low traffic spot coverage Public pedestrian (below rooftop) outdoor to indoor WRS coverage and wireless centrex Same or less on the outdoor link, since less power is needed penetrate wall Typically low Typically low Typically low Essential RLL with residential (or small office) mobility (remote link above rooftop, local WRS link indoor) Same (the alternative is to add a separate indoor residential system) High to Critical for the outdoor link 0 0 Essential Provides lower delay and less quantization distortion (QDUs) than a separate DECT indoor system RLL with local mobility/public pedestrian (remote link above rooftop, local outdoor link below roof top) About the same (for the critical remote link) compared to no mobility High to Critical for the remote link Low Some small load on the remote links from the (< 1E) WRS local link Low Provides essential synergy between local mobility RLL and public pedestrian services From the examples of table A.17 we can conclude that implementations of CRFPs typically has no critical impact on the local load of the spectrum. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 63 A.6.2 Examples of scenarios with WRS type REP (not in use) Table A.18 Scenario Relative local load increase on the spectrum for a WRS call Total local load on the spectrum Total additional local load on the spectrum Impact of WRS calls on other systems Cost savings Economic benefit Residential (typical 1 E per RFP) 3x Low Low Low Important Office (up to 6 E per RFP) 3x Medium to High Low (limited line of sight, WRS not economic for high capacity) Low (natural isolation to other systems) Important for small systems, and generally for remote area coverage. Public street public pedestrian (typical 1 E per RFP) 3x Low Low Low Important, one RFP can relate to 2 REPs Public "hot spot" Pedestrian (indoor, up to 6 E per RFP) 3x Medium to High Low (WRS not economic for high capacity) Low Useful for remote low traffic spot coverage Public pedestrian (below rooftop) outdoor to indoor WRS coverage and wireless centrex 2x or less on the outdoor link Typically low Typically low Typically low Essential RLL with residential (or small office) mobility (remote link above rooftop, local WRS link indoor) 2x (the alternative is to add a separate residential system) High to Critical for the outdoor link High to Critical for the outdoor link High to Critical for the outdoor link Important, but only possible for low density REP applications RLL with local mobility / public pedestrian (remote link above rooftop, local outdoor link below roof top) 2x (for the critical remote link) compared to no mobility High to Critical for the remote link High to Critical for the remote link High to Critical for the remote link Important, but only possible low density REP applications. Synergy between RLL and public pedestrian From the examples of table A.18 we can conclude that "not-above-rooftop" implementations of REPs typically has no critical impact on the local load of the spectrum. Implementations of REPs with above rooftop links have critical impact on the local load of the spectrum, except for low density installations of REPs. NOTE: If interlacing is mandated for REP, the spectrum load per simultaneous REP connection, will except for the first connection, be the same as for CRFP. However, for the two critical RLL scenarios above, the average traffic per WRS is about 1E or less. In these cases the spectrum load from the first REP connection is the relevant figure. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 64 Annex B: Coexistence with other technologies B.1 Coexistence on a common spectrum allocation with evolutions and derivatives (PWT) of DECT Analysis and simulations show that the good coexistence performance of the DECT DCS procedures, as a first approximation, is independent of exact carrier positions and carrier bandwidths, as long as the frame structure is the same. Suppose for instance, that one of two neighbour systems have their carrier positions shifted by half a the carrier separation spacing. This means that the inter-system carrier interference power on the same time slot will be reduced by a factor of 2 in each carrier, but two carriers will be interfered. System 1 System 2 Figure B.1: Coexistence of two systems with different carrier positions Figure B.1 illustrates this. Each box indicates the transmission bandwidth with a carrier position in the middle of the box The arrows indicate interference. It is obvious that this gives on one hand shorter average reuse distances to a single interferer, but since the same slot on two carriers are interfered, the average interference load is about the same as if both systems had the same carrier positions. The conclusion of this analysis is supported by simulations of a single system high density application where additional DECT carriers positions were defined on a grid of 1/3 of the standardized carrier positions. This resulted in frequent irregular interference patterns in the frequency domain of the same kind as shown in the figure above. This did not decrease the capacity, on the contrary, in this specific case the traffic capacity increased by up to 20 %, obviously due to the increased flexibility. The conclusion is that standard DECT systems will coexist very well on a common allocation with any possible DECT evolutions with higher or lower carrier bandwidth (higher or lower bit rate) and other carrier positions. DECT and the North American DECT derivative Personal Wireless Telecommunications interoperability standard, PWT [19] and PWT/E [20], also coexist very well on a common spectrum allocation. PWT and PWT/E uses the DECT frame structure, MAC, DLC etc, but has a different modulation and different bandwidth and carrier spacing to meet local regulatory requirements. PWT operates in the US Isochronous Unlicensed PCS band 1 920 MHz to 1 930 MHz. PWT-E is an extension into the licensed PCS bands 1 850 MHz to 1 910 MHz and 1 930 MHz to 1 990 MHz. PWT may also be allowed in some Latin American countries. B.2 Coexistence DECT and GSM 1800 In Europe and many other countries around the world, GSM down-link (base station TX band) has spectrum allocation 1 805 MHz to 1 880 MHz and DECT has 1 880 MHz to 1 900 MHz. The coexistence properties between DECT and GSM1800 have been analysed in the CEPT ERC Report 100 "Compatibility between certain radiocommunications systems operating in adjacent bands; Evaluation of DECT/GSM 1800 compatibility", February 2000 [29]. The report analyses all possible combinations between DECT indoor systems (residential and enterprise applications), DECT outdoor below root-top pedestrian systems, DECT above roof- top WLL systems, GSM indoor systems and GSM above roof-top macro cell deployments (with outdoor and indoor subscribers). ETSI ETSI TR 101 310 V1.2.1 (2004-04) 65 Important scenarios for the recommendations are a) potential interference to GSM when a GSM 1800 mobile station (MS) operates in the same indoor environment as a DECT indoor system, and b) potential interference to DECT when above roof-top DECT WLL systems and GSM macro cell systems operate in the same local outdoor environment. The conclusions for the above two scenarios are given below. Case a) is of general interest, since the main DECT market is for residential and enterprise applications. Case b) is relevant is some countries: a) Potential interference to GSM mobile stations (MS) DECT has very low probability to cause harmful interference to GSM 1800 systems. The potential victims are only the GSM 1800 mobile stations. The probability that DECT will cause harmful interference to GSM 1800 is very low in particular due to the GSM error correction capability. Moreover, GSM can escape temporary interference close to the DECT band edge by intra-cell handover to an other carrier more distant from the DECT edge. This is feasible, since macro cell systems normally have two or more GSM carriers per sector, whereby the GSM 1800 BCCH control channels should use carriers outside the frequency band 1 878 MHz to 1 880 MHz. This proposed planning does not reduce the traffic capacity of the GSM system, but will provide escapes for the few instances when harmful interference could occur to the GSM mobile stations. b) Potential interference to DECT above roof-top WLL systems A guard band is not required to protect DECT WLL systems from GSM 1800 interference, but measures are proposed to facilitate the coexistence when the GSM sub-band 1 878 MHz to 1 880 MHz is used. The proposed measures include avoiding to use the sub-band 1 878 MHz to 1 880 MHz for above roof-top GSM base stations, but rather for below roof-top micro cells or indoor cells. c) General recommendation to protect DECT DECT should be able to detect and escape interference from a single GSM bearer, via its instant Dynamic Channel Selection procedure and intra-cell handover, which implies that, DECT should be able to process a successful handover when the up-link or the down-link is interfered as seldom as every 6th frame. See [3] clause 11.4. This requirement is generally useful, but of prime importance for DECT WLL systems. B.3 Coexistence DECT and UMTS/TDD 3,84 Mcps NOTE: In Europe UMTS/TDD has spectrum allocation 1 900 MHz to 1 920 MHz and DECT has 1 880 MHz to 1 900 MHz. The coexistence properties between DECT and UMTS/TDD 4,84 Mcps have been analysed in the CEPT ERC Report 065 "Adjacent band compatibility between UMTS and other services in the 2 GHz band", November 1999 [28]. The report analyses all possible combinations between DECT indoor systems (residential and enterprise applications), DECT outdoor below root-top pedestrian systems, DECT above roof- top WLL systems, UMTS/TDD indoor systems and UMTS/TDD above roof-top macro cell deployments (with outdoor and indoor subscribers). Important scenarios for the recommendations are a) potential interference to UMTS/TDD when a UMTS/TDD mobile station (MS) operates in the same indoor environment as a DECT indoor system, and b) potential mutual interference between above roof-top DECT WLL systems and UMTS/TDD macro cell systems operate in the same local outdoor environment. The conclusions for the above two scenarios are given below. Case a) is of general interest, since the main DECT market is for residential and enterprise applications. Case b) may become relevant is some countries. Note that no UTRA/TDD systems have yet (2003) been commercially deployed in Europe: a) Potential interference to UMTS/TDD mobile stations (MS): No additional guard bands are needed between DECT and UMTS TDD if UMTS TDD is deployed indoors. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 66 UMTS TDD outdoor base station systems used in the band 1 900 MHz to 1 910 MHz should use interference avoidance techniques (such as intra-cell handover and instant Dynamic Channel Selection, iDCS, in the time domain) to reduce the probability of interference to Mobile Stations entering a location with DECT. Similar considerations arise between adjacent UMTS TDD carriers operating with indoors and outdoors base stations, within the whole 1 900 MHz to 1 920 MHz band. The concern raised with the second bullet above, is based on the fact that UMTS/TDD MSs served from an outdoor macro base station may operate close to the sensitivity limit, and that each UMTS/TDD operator has only one carrier, and no second or third carrier to which intra-cell handover escapes are possible, if interference occasionally becomes too high on the carrier closest to the band edge. Everywhere else around the world, cellular operators have access to more than one carrier. A Monte Carlo simulation would still show a low probability for interference, but there are local environments where a more deterministic model is more correct, and has thus been applied in [28]. As seen from the text of the second bullet, mutual MS to MS interference is of main concern for two UMTS/TDD operators operating on adjacent 5 MHz bands. In reality, larger separation distances are required to MSs from an adjacent UMTS/TDD operator than from DECT MSs. Thus the problem is not emissions from DECT, but as mentioned above, the lack of multiple carriers allocated for European UMTS/TDD operators. Introduction of instant Dynamic Time Slot Selection (including control slots) to the UMTS/TDD standard, would have facilitated the application of UMTS/TDD outdoor infrastructures. The conclusion is that possible future applications of UMTS/TDD in Europe, will be exposed to somewhat higher risk for interference from DECT, than other cellular technologies like GSM (see the GSM section above) or in other parts of the world where spectrum for several carriers is provided for each cellular operator. b) Potential interference mutual interference between DECT above roof-top WLL systems and UMTS/TDD macro cells: UMTS TDD macro base station systems should not be applied on the band 1 900 MHz to 1 910 MHz in areas where DECT WLL systems are installed (Eastern Europe), unless special measures are taken. This problem is, as mentioned above, caused by the single carrier allocation of the UMTS/TDD system in combination with the very wide bandwidth of the UMTS/TDD system and lack of a proper guard band between the systems. The special measures, referred to in the bullet above, is coordinated site engineering including installation of external filters on most the above roof-top radio equipments. B.4 Coexistence DECT and American PCS technologies In many Latin American countries DECT is allocated within 1 910 MHz to 1 930 MHz. (This is the same as the US Unlicensed PCS band). Mobile PCS technologies have their base station transmit band within 1 930 MHz to 1 990 MHz and the handset transmit band within 1 850 MHz to 1 910 MHz. In several Latin American countries DECT FWA (WLL) above roof-top applications are allowed in the band 1 910 MHz to 1 930 MHz. As a guide for these decisions, the Inter-American Telecommunication Commission, CITEL, made an in-depth coexistence study [30] on the mutual coexistence properties between DECT FWA (up to 36 dBm EIRP) and the different cellular PCS technologies at the band boarders 1 910 MHz and 1 930 MHz. Two political camps conducted the study, and it is therefore very long and detailed, and there are two views expressed on almost everything. The study showed however that the potential interference between cellular PCS technologies on adjacent PCS blocks (A, B, D etc) was higher than from DECT FWA to the adjacent PCS blocks. See [30] Part 1, clause 2.3.2. As a result several Latin American countries introduced DECT FWA. DECT enterprise and residential systems are also allowed in many Latin American countries, whereby normally both standard DECT, PHS and equipment meeting the US UPCS isochronous rules are accepted in the whole 1 910 MHz to 1 930 MHz band. Note however, that these DECT residential and enterprise applications were by CITEL not at all considered problematic as regards potential interference to adjacent block cellular PCS systems (See note below). The only concern was if FWA in the UPCS band 1 910 MHz to 1 930 MHz would interfere with the unlicensed residential and enterprise applications in the same band. The CITEL study did not have time to finish that part, which was considered less important. See however [30] Part 3, where it is shown that DECT FWA and indoor UPCS applications (including DECT) coexist well on the same spectrum. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 67 NOTE: The reasons why DECT enterprise and residential applications in the 1 910 MHz to 1 030 MHz are not considered problematic as regards potential interference to the adjacent PCS services, are very similar to the reasons why there are very small risks for DECT to interfere with GSM 1800 (clause B.2): - The main case to be considered is the potential interference to A-block handsets (1 930 MHz to 1 945 MHz Rx band) being in the same indoor location as a DECT system. Potential for interference requires that both the DECT device and the PCS handset use carriers close to the 1 930 MHz block boarder. - Monte Carlo simulations show that the average interference probability is so small that the capacity of the PCS system (or cell) is not affected at all. - For the few cases when interference occurs, the PCS systems have several mitigation techniques: a) Powerful error correcting coding combined with interleaving, which correct for low load interference from the DECT carriers closest to the A-block. A DECT handset provides such low load interference. b) For the remaining cases where the error correction capability is insufficient, the PCS system will provide an intra-cell handover to a PCS carrier more distant from the 1 930 MHz boarder. This is easily made since the A-block handset Rx band is so large, 15 MHz. The same mitigation techniques a) and b) are used to combat potential interference between the A- and B- block PCS systems. Comparing different Monte Carlo simulations makes it reasonable to suppose that average potential interference between adjacent PCS blocks (mutual BS to handset and handset to BS interference) is larger than between the UPCS block and the A-block (DECT handset to PCS handset). This further supports the conclusion that the potential interference to PCS is very small from DECT (or PWT) residential and enterprise applications in the 1 910 MHz to 1 930 MHz (UPCS) band. B.5 Coexistence DECT and PHS DECT and PHS are in some parts of the world, some Asian and Latin American countries, allowed to be implemented on the same spectrum, or partially the same spectrum. There are similarities between DECT and PHS, which makes this possible, but also differences, which makes sharing spectrum less efficient in some cases. The similarity is that that Traffic Channels both for DECT and PHS use instant Dynamic Channel Selection, DCS, which selects least interfered (isochronous) "time window/frequency" combinations as traffic channels. This provides efficient sharing both in the time domain and in the frequency domain within each system type. However, it also provides sharing between DECT and PHS systems when applied in the same local area. The reason for this sharing to work, is that the PHS TDMA frame is 5 ms, which is a sub-multiple of the DECT 10 ms frame. Thus time windows that are free during part of any 10 ms frame time, can be selected by DECT or PHS, whosoever may have the need. This packing (sharing) in the time domain works, but will off course be less efficient than within a single system. A main difference is that PHS requires special carriers (spectrum) for its control signalling, control carriers. These carriers are fixed and must not be interfered by, nor be shared with traffic channels. DECT on the other hand, instant DCS and traffic channels also for the control signalling, and has no need for special spectrum for protected control carriers. Thus the conclusion is that DECT and PHS can dynamically share spectrum for the (user data) traffic channels, but PHS needs part of the spectrum exclusively for its control carriers. In spite of this difference, in some countries both technologies are allowed to share the same common spectrum without any specific protection for PHS control carriers. DECT does not suffer from this. PHS may suffer, depending on application. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 68 Private indoor applications For application of indoor residential and office systems, the risk with a common spectrum is not very evident, because there is normally only one type of system per home and per office, and for these cases the wanted own signal is stronger than from a system from some other home or office. Furthermore, if PHS systems are loading their control carriers, any DECT system would automatically avoid them if they can be heard. On top of that, PHS has implemented a (slow) dynamic control channel allocation mechanism to fit the US UPCS isochronous etiquette rules, where several technologies are allowed to access a common band based on least interfered "time window/frequency" combinations. Public outdoor applications For public outdoor systems, where both technologies normally are used simultaneously in the same area, it is more important to protect the PHS carrier. In for instance China where public pedestrian systems are common, and in some Latin American countries where FWA are used, DECT Forum and the PHS MOU group have jointly helped regulators to find a good compromise (depending on market situation). The typical solution is like the decision in China, where PHS uses the band 1 900 MHz to 1 915 MHz and DECT the band 1 905 MHz to 1 920 MHz. Of a total of 20 MHz each technology gets 15 MHz, of which 5 MHz is protected for exclusive use for each system. B.6 DECT coexisting on the US unlicensed bands, the UPCS band and the 900 MHz and 2,4 GHz ISM bands Relevant unlicensed spectrum in the US are the protected UPCS (Unlicensed UPCS) Isochronous band 1 920 MHz to 1 930 MHz and the unprotected ISM bands 902 MHz to 928 MHz, 2 400 MHz to 2 483,5 MHz and 5 725 MHz to 5 850 MHz, see [2] and [32]. B.6.1 The protected UPCS isochronous band rules - good for real time/isochronous services (e.g. telephony) The UPCS Isochronous rules provide coexistence with DECT equipment, because the basic principles and parameters for instant Dynamic Channel Selection, also called Listen Before Talk, are the same. E.g. an isochronous UPCS channel is defined as a frequency/time-window combination repeated in the time domain every frame of TF ms, where TF = 10/N ms, where N is an integer. This provides instant spectrum sharing of high quality real time service connections both in the frequency and time domains. DECT (and PWT) has TF = 10 ms. Thus DECT and UPCS rules both provide repetitive burst patterns in any repeated 10 ms frame sequence, which enable sharing in the time domain. The US UPCS (Unlicensed UPCS) protected Isochronous band 1 920 MHz to 1 930 MHz is available for the DECT derivative PWT, but presently not for DECT, due to historic non-technical reasons. The US FCC is however currently (early 2004) revising the UPCS Isochronous rules and possibly removing the (artificial) fixed 1,25 MHz channelization and bandwidth limitation that currently (for no technical reason) bars DECT from this band. There is presently (early 2004) no protected spectrum available in the US for standard DECT equipment. A protected spectrum is where autonomous systems follow a set of rules (an etiquette) which makes them compatible to maintain and protect high quality real time service radio links in an environment of uncoordinated system installations. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 69 B.6.2 The unprotected ISM bands - not good for real time/isochronous services Standard DECT equipment can since May 2002 be applied in the US within the ISM bands 902 MHz to 928 MHz, 2 400 MHz to 2 483,5 MHz and 5 725 MHz to 5 850 MHz, see [2] and [32]. Opposite to a protected DECT spectrum having an etiquette whereby high quality real time radio links of compatible but uncoordinated systems are maintained and protected, the ISM bands allow for uncoordinated usage of a variety of incompatible communication devices and also industrial, scientific and medical devices. Therefore maintenance of high quality of service will not be guaranteed when other types of ISM devices (non-DECT devices) are used in the same local area. This applies especially to voice and video services, but is less critical for best effort packet data services, where non-time-critical retransmissions are applied. If a manufacturer nevertheless would implement DECT for the US ISM bands, the band 902 MHz to 928 MHz could be preferred over the 2 400 MHz to 2 483,5 MHz band due to lack of potential interference from IEEE 802.11b WLANs, microwave ovens and Bluetooth devices. The 900 MHz spectrum provides better range than the 2,4 GHz spectrum. The 5 GHz ISM band is of less interest due to range limitations and higher cost and current consumption. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 70 Annex C: The concepts of traffic capacity and efficient use of the spectrum C.1 General It is important, both from operator's, user's and regulator's point of view that the different applications of DECT do not violate reasonable requirements on spectrum efficiency and on the quality of the transferred service. C.2 The relation between infra structure cost and spectrum efficiency Efficient use of the spectrum cannot be determined by such a simple term as e.g. "traffic channels per MHz". For a technology like DECT spectrum efficiency for speech has been defined as E/km2 per floor at comparable (speech) quality and infrastructure cost. See ETR 042 [21] clause 2. The relation to the cost, comes from the fact that the traffic capacity (E/km2) for DECT will be proportional to the base station density (RFPs/km2) (see note). See clause 4.2. Therefore, the capacity is very dependent of the infrastructure cost. Cost efficient implementations at required capacity and service quality is known as a prime goal for all standardization and is beneficial to the general public. Therefore, efficient use of a spectrum has both a cost, a quality, a type of service and a spectrum efficiency (spectrum/connection) component. It is for example very important quality difference between a 4 kbit/s and a 64 kbit/s speech link. NOTE: DECT can maintain the radio link quality at decreasing cell sizes due to the C/I limited DCS and quick seamless inter-cell handover procedures. C.3 Maximizing the application dependent spectrum efficiency The maximum load per cell has to be limited, at least for multi-site above rooftop applications, in order to provide efficient reuse and sharing of the spectrum. Simulations indicate that it is highly desirable for an operator to limit the planned average traffic in any one coverage cell (omnidirectional or sector shaped) to about 10 E (full-slot duplex bearers or equivalent) per 20 MHz of total allocation. Exceeding this limit could make the effective range of his cells disproportionally vulnerable to interference from other users of the spectrum. The intention is to restrict the maximum load from one antenna on the DECT spectrum in a specific geographical direction. This advice should not limit economic infrastructure implementations, but is a tool for optimizing coexistence on the common DECT spectrum. C.3.1 Directional gain antennas Use of directional gain antennas generally increases the spectrum efficiency, as shown in clause A.2.3. The DECT standard (EN 300 175, parts 1 [1] to 8 [8]) recommends to allow general use of up to 12 dBi gain antennas and up to 22 dBi upon (case by case) approval by national authorities. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 71 Sectorized antennas can also provide a common RFP site for several cells, as for the examples with the DAS nodes in clause A.3. Common cell sites provide essential cost savings for important applications. C.3.2 Frame synchronization DECT is designed not to require frame or slot synchronization between base stations or systems to maintain a high radio link quality. See clause E.2.8. Synchronization between close by base stations does however in general decrease the local load on the spectrum. C.3.2.1 Synchronization between RFPs within a DECT system (FP) Synchronization of RFPs within a DECT system (FP) is essential for all high capacity multi-cell systems, and could be mandated (within clusters) for such public applications. In-system synchronization is normal practice for multi-cell office systems, where the RFPs obtain the synchronization over the connection wires to the radio exchange (RFP controller). Synchronization within office systems is regarded essential by manufacturers, both to provide efficient handover and to meet internal system capacity requirements. C.3.2.2 Intersystem synchronization Intersystem synchronization (to an absolute reference or mutual between two systems) is essential for above rooftop high capacity applications, and should be mandated for such applications. Intersystem synchronization (to an absolute reference or mutual) is also essential for "hot spot" public pedestrian applications. The DECT standard (EN 300 175, parts 1 [1] to 8 [8]) provides for this purpose a cost effective absolute time synchronization option using the GPS satellite system. Other means for mutual frame synchronization are also available in the DECT standard (see EN 300 175, parts 1 [1] to 8 [8]). For other cases inter system synchronization is typically not critical, and should not be mandated. In order to prevent potential problems, it could be recommended that all public systems, i.e. all systems needing a license, are forced to be locally synchronized to each other, if an operator requires it in a specific local area. This means that means for mutual synchronization must be a part of a public system. This leads to the following simple rule: - public systems should provide intrasystem cluster synchronization, and should have either GPS synchronization and a SYNC output port or a complete SYNC port (both input and output). This will allow absolute time synchronization via GPS or wired mutual synchronization, if an operator requires local synchronization between operators. NOTE: For public pedestrian street type systems (antennas lamp post, below rooftop, 1E per base), synchronization may improve the capacity, but is often not essential. GPS synchronization is feasible if several base stations are part of the same FP. It is not cost effective for single RFP FPs connected directly to a local exchange unless it is possible to transfer frame synchronization signals over the local exchange. C.3.3 Application of WRS Some WRS applications, for example outdoor to indoor coverage enhancements, decrease the local outdoor load on the spectrum, since no excessive outdoor field strength is required to penetrate the building. Applications of WRS are in most applications not critical for the local load on the spectrum. A CRFP type WRS link always provides less load on the spectrum than an REP type WRS link, but the REP is not critical for the load on the spectrum except for high density WRS installations with above rooftop remote links. The GAP and RAP interworking profiles will use the CRFP type of WRS. See clause A.6. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 72 Annex D: Comparison with systems using fixed channel selection This annex analyses the spectrum required for different single DECT systems compared with the spectrum required by a comparable system using FCA. By comparable technology is meant a duplex 32 kbit/s service transfer and radio receivers with limiter/discriminator detector or differential detector. The modulation type has only secondary influence. D.1 Public pedestrian outdoor suburban application DECT simulations indicate that 61 RFPs placed in hexagonal grid with 300m separation will at 1 % GOS provide 5,2 E average traffic per base with 6 carriers, 72 access channels, allocated for DECT. See figure A.3. We assume that a comparable system with FCA will use a 16 cell reuse pattern for a suburban 2-dimensional outdoor application [18]. We use the Erlang B traffic formula at 1 % GOS to estimate the offered average traffic per base. D.1.1 Traffic when using the same total number of access channels as DECT The number of access channels per base will be 72 / 16 = 4,5. Of these 4,5, one has to be a control channel. Therefore, there are 3,5 traffic channels available per base. 3,5 trunks give 0,7 E average traffic (Erlang B). In this example DECT is 5,2 / 0,7 = 7,4 times more spectrum efficient than the comparable system using FCA. D.1.2 Total number of access channels required for the same traffic per base 5,2 E average traffic per base will require 11 traffic channels per base (Erlang B), plus one control channel, which gives 12 access channels per base and totally 12 x 16 = 192 access channels for the system allocation. In this example DECT is 192 / 72 = 2,7 times more spectrum efficient than the comparable system using FCA. D.1.3 Summary tables Table D.1: Comparison for outdoor suburban case with 72 DECT access channels Outdoor suburban, FCA 16 cell reuse, DECT totally 72 access channels (6 DECT carriers) DECT FCA Equal traffic/base FCA Equal number of access channels Total number of access channels 72 192 72 # of channels per base (incl. 1 control ch.) 11 + 1 3,5 + 1 Average traffic per base 5,2 E 5,2 E 0,7 E DECT spectrum efficiency gain 2,7 times 7,4 times ETSI ETSI TR 101 310 V1.2.1 (2004-04) 73 Table D.2 shows the same calculations with 48 access channels allocated to DECT, see figure A.3. Table D.2: Comparison for outdoor suburban case with 48 DECT access channels Outdoor suburban, FCA 16 cell reuse, DECT totally 48 access channels (4 DECT carriers) DECT FCA Equal traffic/base FCA Equal number of access channels Total number of access channels 48 152 48 # of channels per base (incl. 1 control ch.) 8,5 + 1 2 + 1 Average traffic per base 3,4 E 3,4 E (0,15 E) DECT spectrum efficiency gain 3,2 times (23 times) From tables D.1 and D.2 we can conclude that DECT in outdoor pedestrian applications is typically 3 to 7 times more spectrum efficient than a comparable technology using FCA. D.2 Office multi-floor applications DECT simulations indicate that 16 RFPs per floor placed in rectangular grid on 3 floors will at 1 % GOS provide 4,4 E average traffic per base with 4 carriers, 48 access channels, allocated for DECT (see table A.2). We assume that a comparable system with FCA will use a 32 cell reuse pattern for an office 3-dimensional application. We use the Erlang B traffic formula at 1 % GOS to estimate the offered average traffic per base. By applying the same kind of calculations as for the outdoor case above, we obtain the results given in table D.3. Table D.3: Comparison for indoor 3-dimensional case with 48 DECT access channels Office multi-floor, FCA 32 cell reuse, DECT totally 48 access channels DECT FCA Equal traffic/base FCA Equal number of access channels Total number of access channels 48 352 48 # of channels per base (incl.1 control ch.) 10 + 1 0,5 + 1 Average traffic per base 4,4 E 4,4 E (< 0,4 E) DECT spectrum efficiency gain 7 times > 10 times From table D.3 we can conclude that DECT in an indoor application is typically 7 to 10 times more spectrum efficient than a comparable technology using FCA. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 74 Annex E: DECT instant DCS procedures E.1 Summary of some DECT procedures providing the high traffic capacity and the maintenance of a high quality radio link Some of the essential DECT procedures and features that provide the high traffic capacity and the maintenance of a high radio link quality, are listed below. Handsets (idle locked or in communication) are always locked to closest (strongest) base station. Automatic seamless handover is made as soon as an other base becomes stronger. The seamless handover provides "make before break", which is important for a high quality of voice service. Being locked to the strongest base station is essential for efficient access channel reuse and link robustness, which leads high capacity. Down-link broadcast system information and incoming call alert (paging) is distributed on each down-link dummy and traffic bearer. The more traffic, the more to lock to. There is no specific fixed control carrier that can be interfered so that the whole base station will be out of operation. The short dummy bearers providing down-link broadcast system information and paging on idle base stations are checked at the RFP about every second, during a randomly selected odd frame, to remain on a least interfered access channel. Two dummy bearers with at least one slot separation avoid blind slots at seamless handover, since a GAP PP is not required to be able to switch carrier during the inter slot guard band time. The figures below shows an example on how blind slots are avoided when making a seamless handover from cell 1 to cell 2. If there had been no traffic in cell 2, then the traffic bearer on carrier 5 would have been a second dummy bearer. CELL 1 CELL 2 BS BS Slot 1 Carrier 1 Handover to least interferred access channel 1 2 Slot 0 1 .......... 4 ........................ 11 Base Station 2 = Traffic Channel = Dummy Bearer Slot 0 1 ......... 4 ........................ 11 Base Station 1 Carrier 1 Carrier 5 Carrier 1 Slot 1 Carrier 5 Figure E.1: Example on how to avoid blind slots at seamless inter-cell handover For call set-up or handover, the handset selects a least interfered access channel and makes direct set-up (20 ms) on this traffic channel to the strongest base station. This provides quick bearer access, 50 ms for data. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 75 The handover is decentralized and handset controlled. This avoids complex co-ordination or tricky channel selection requirements on the fixed infra structure. The RFPs however may provide blind slot information to the PPs to speed up the access. E.2 Detailed description of the DECT instant DCS procedures and features E.2.1 Instant DCS or CDCS The principles described in this clause are based on Multi Carrier, Time Division Multiple Access, Time Division Duplex (MC/TDMA/TDD). Figure E.2 shows the TDMA/TDD frame for DECT here with 12 + 12 full slots. normal RFP transmit <<<<------------------------5 ms--------------------- >>>> normal PP transmit <<<<------------------5 ms--------------- >>>> full slot 23 full slot 0 full slot 1 full slot 2 full slot 11 full slot 12 full slot 13 full slot 23 full slot 0 <<<<--------------------------------------------------------------------------------------------------- >>>> one frame 11,520 bits f0 f479 s0 s31 |||| d0 d387 ||||z0 z3 S field D field Z field p0 p31 |||| p32 p419 p423 <<<<-------------------------------------------- Full slot k ---------------------------------------- >>>> d0 388 bits - D32 format (full slot) d387 |||| |||| D field (D32, D08, D80) A B |||| 64 bits |||| 324 bits - D32 format (full slot) |||| a0 a63||||b0 b323 Figure E.2: TDMA slot structure for DECT The basic property of CDCS is that a physical channel is selected, that is least interfered at the moment of selection. The DCS includes the following: - selection of bearers for control signalling; - selection of simplex or duplex traffic bearers; - selection of traffic bearers for handover; - selection of bearers for extension of user data rate of an established connection. Examples for selection criteria for different types of bearers can be found in EN 300 175-3 [3], clause 11.4. In DECT a channel selected for a duplex service is changed only if the quality is degraded or if another base station of the same system becomes stronger, while a down link broadcast or connectionless service shall be kept at a least interfered channel, if needed by repeated moves to new channels. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 76 E.2.2 Dynamic selection of control channels In order to provide for uncoordinated installations in a multioperator environment where a common frequency resource is shared, it is necessary that both traffic channels and control channels are continuously dynamically selected. In this kind of environment it is likely that the same handset has access rights to several systems, e.g. a residential system, an office system and several public systems. Therefore, it is important that each base station continuously broadcasts access rights and other system information. Therefore, call set up attempts by handsets through blind interfering transmissions are avoided, since each handset will know if a suitable service is available by listening only. DECT handsets may transmit only after they have succeeded to lock to a base station with the wanted access rights identity. The broadcast information on a down link control channel is most essential. If the control channel is interfered, call set up is impossible (or may be possible through a complicated escape mechanism). It is against the general philosophy to allocate a special part of the frequency band to control channels. This may impose not wanted restrictions on the control channel structure. Furthermore, it is probably easier to find an interference free channel with unrestricted selection over the entire frequency band. In DECT the down link broadcast and control channel is available as a part of every downlink transmission. Besides traffic bearers a down link dummy bearer is also defined, which only contains the synchronization field and the broadcast and control channel part (A-field) of a traffic bearer. See figures E.1 and E.2 and EN 300 175, parts 2 [2] and 3 [3]. The down link broadcast information has to be continuously transmitted from each DECT base station. The following combinations of downlink traffic channels and dummy bearers are allowed. Table E.1 Downlink traffic channel Dummy bearer None active 1 or 2 active At least one active None or 1 active When 2 active dummy bearers are used, they should be transmitted on different antennas. See clause E.2.6. The dummy bearer is always active at low traffic, but is very short and does not steal essential capacity. e.g. in an environment of unsynchronized systems, a dummy bearer loads the radio environment with a load corresponding to only 10 % of that of a duplex traffic channel. The system is allowed to make frequent short breaks in the dummy bearer transmission to check if it is still on a least interfered channel. If not, a change information is broadcast and the dummy bearer is moved accordingly. This ensures that the downlink broadcast bearer stays at a least interfered channel. When there is much traffic from a base station, no dummy bearers are needed since the broadcast information is derivable from each downlink traffic bearer. E.2.3 The broadcast paging and system information Since the paging and system information is available on every downlink channel, a handset can lock to any downlink transmission and derive the required system information. If it contains the wanted access rights identity, it is possible to make and receive calls. The access rights identity (the system and base station identity) is transmitted in almost every slot, while other system information is transmitted less frequently. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 77 Examples of broadcast system information that has to be derived by a handset before it is allowed to transmit are: - system identity (primary access rights identity); - base station identity; - frame synchronization; - multiframe synchronization; - number of transceivers per base station and the synchronization and the order of the base station receiver scanning of RF-carriers; - frame number for cipher synchronization; - the RF carriers allowed to be used by the system; - FPs capabilities; - secondary access rights information. The base station identity makes it possible to make call set up and handover to the closest and strongest base station. The multiframe synchronization is needed e.g. for the handset current saving, since a paging sequence always starts at a multiframe boundary. The information on used carriers can be used for e.g. local barring of channels to avoid local interference, or for system related barring, or for later extension or decrease of usable frequency bands. A DECT RFP may also inform on preferred channels. The FPs capability informs on e.g. speech codec type, fax, data services, etc. The secondary access rights information provides the means for sharing base stations between different operators. DECT has a powerful and flexible identity and addressing structure that provides for e.g. hosting private user groups in a large public system, hosting public access in private systems, and hosting public access from several service providers in a system owned by one of the public service providers. The same handset can be equipped with access rights to several public and private operators. The identity structure for DECT is found in EN 300 175-6 [6]. E.2.4 Dynamic selection of traffic channels and maintenance of the radio link For simplicity only the set up of a (single) duplex bearer is described. After having locked itself to the strongest of the wanted base stations, the handset makes a list of least interfered channels, which it regularity updates. For a duplex bearer, interference level is measured in the receiver channels of the handset. At call set up the handset selects "the best" channel and sends an access request to the closest (strongest) base station. This request is sent in synchronism with the derived base station receiver RF carrier scanning order. If a response is received on the relevant duplex response slot, half a frame (5 ms) later, the duplex bearer is established. Else an attempt is made on the second best channel etc. The handover is portable controlled. Without interrupting the current connection it regularly scans the other channels and records a ranking list of least interfered channels and of own base stations that are stronger than the original one, and is therefore prepared to perform a very quick bearer handover (20 ms). The base station gives immediate feed back on quality of received slots to the portable. Handover is made as soon as another base station is, say 10 dB, stronger than the one of the current connection. Therefore, in a well engineered system seamless handover is always performed before the link quality degrades. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 78 The concept as implemented for DECT provides a quick seamless handover that does not need centralized control nor complicated procedures. The key is TDMA in combination with the portable controlled DCS. The old link is maintained on one slot in the portable, while the new link is set up to the closest base station on another "best" time slot. When the new link is established, the (new) base station requests the central control to make a seamless switch from the old to the new radio link. This is an important TDMA feature. The nature of CDCS is such that a channel in use can (occasionally) be stolen, and therefore the quick DECT intracell handover increases the capacity and cuts call curtailments drastically. It is important not to depend on the old channel to quickly set up the new. If calls are not set up to and kept to the closest base stations by handover, the capacity of the system and the link quality decreases. E.2.5 MC/TDMA/TDD simple radio multichannel base station MC/TDMA/TDD with a reasonable number of traffic slots (8 to 12 duplex connections) provides a cost effective Standard Base Station concept. This concept as applied for DECT is described in ETR 042 [21]. This Base Station can access all traffic channels (common for all systems). It consists of one single radio that can instantly change carrier frequency from slot to slot. With the standard 12 + 12 time slots chosen for DECT, it offers over 5 E average speech traffic, corresponding to 25 handsets with 0,2 E each. This provides a major system and cost benefit: - the number of base radios needed per 12 offered speech traffic channels is reduced to 1 from to the 12 required for analogue or digital FDMA systems; - the in-system requirements on intermodulation and adjacent channel interference are also reduced since each transmission to and from a Standard Base Station uses always different time slots; - in-system blocking requirements will also be reduced, since escape to another available time slot will give perfect isolation; - asymmetric links are provided with up to 23 time slots in one direction and 1 time slot in the other direction. See clause 7.2; - furthermore, simulations for DECT (12 + 12 time slots) show that for handsets it is not essential to require carrier change within an interslot guard band. These properties will be lost if a low number of slots per frame (e.g. 4 + 4) are chosen. E.2.6 Antenna base station diversity The concept as applied for DECT provides and combines different types of diversity; antenna diversity by changing the antenna radiation pattern, frequency diversity by intra-cell handover to another carrier and macro diversity by intercell handover. Diversity increases capacity, extends the range and decreases the time dispersion effects. Application of antenna base station only diversity is simple for the Standard Base Station and is effective due to TDD. E.2.7 Traffic capacity Two parameters that affect the traffic capacity are the type of modulation and the relative carrier spacing. For DECT the chosen modulation Gaussian Frequency Shift Keying (GFSK), with deviation characteristics equivalent to GMSK with a nominal BT value of 0,5, gives good sensitivity and C/I performance. It allows for a low cost, robust, fast acting, limiter-discriminator detector, with 1-threshold bit-by-bit detection. It also allows low cost IF-filters and low radio frequency stability requirements. This modulation type, giving rather large relative carrier spacing, is optimized for low cost, high capacity, residential and office applications. With relevant diversity techniques, it is suitable for outdoor pedestrian street services with 200 m to 300 m range. 5 km Line of Sight ranges are supported for RLL applications using directional gain (12 dBi) antennas. See clause 6.4.1. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 79 The latest version of the DECT base standard includes backwards compatible 4-, 8-level, 16-level and 64-level modulation options. This will increase the bit rate of single radio DECT equipment by a factor 2, 3, 4 or 6 with retained transmitter bandwidth, carrier spacing and slot structure. The traffic capacity and spectrum requirements for different DECT application scenarios can be found elsewhere in this report. E.2.8 Inter system synchronization due to TDMA and TDD Frame and slot synchronization between base stations within a radio exchange is easily provided. In order to avoid high handover rates and quick changes in the "least interfered channel" lists due to the slot drift from adjacent DECT systems, the frame cycle stability should typically be 5 ppm or less. This corresponds to a drift over 1 slot per 80 seconds. The slow slot drift from unsynchronized neighbours does not introduce a new element, but is elegantly dealt with by the standard seamless (normally intra-cell) handover and channel selection procedures. It is in fact easier to make a seamless handover due to slot drift, than to cure the normal effect of a sudden channel (slot) theft, that occasionally occurs in all DCS Systems. DECT has mechanisms to detect slot drift and make a handover before the user data is corrupted. Slot synchronization between systems is useful, but not a requirement, for maintaining a high radio link quality Unsynchronization between close by office systems in the same building leads to a graceful capacity decrease, which is small compared to the total capacity gain given by using CDCS. For high capacity above roof top installations synchronization is essential for the capacity. For the general pico cell applications, for instance in offices, there is normally no significant difference between the average interference levels from base stations or handsets from neighbour cells. Base stations and handsets are close to each other and their antennas are used at similar levels above the ground or floor. Therefore, TDD has no drawback compared to FDD in this unsynchronized environment. If for a specific public service omni directional base station antennas are installed high above the level where handsets normally are used, it is recommended to at least frame synchronize close by base stations of this kind. Else these base stations would cause much more interference to the up links than the handsets. A frame synchronization (over the line connection) with an accuracy of about 1 ms (DECT), will for this case make the interference performance (when using TDD) similar to the performance when using FDD. The need for synchronization is much less critical for systems using CDCS, than for systems using FCA. An attractive solution for this specific application is to derive the synchronization reference from the GPS but other means for synchronization are also available, as seen from other parts of the present document. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 80 Annex F: RF modifications of DECT enabling applications on FDD (paired up-link/down-link) spectrum DECT, although basically a TDD technology, can also be applied on an arbitrary FDD spectrum, maintaining its unique instant dynamic channel selection provision and other properties. This is possible with standard DECT TDD burst mode controllers by implementing the required duplex frequency shift in the RF-part when switching between transmission and reception. In this way a DECT link provides a combination of TDD and FDD. Such a DECT FDD base station (and handset) does not transmit and receive at the same time and does thus avoid expensive duplex filers at the expense of using the spectrum resource only half the time. However, by off-setting the frame timer of every second DECT base station by 5 ms, the available spectrum will be fully used within a multi-cell system. Further information is found in TR 101 370: "Digital Enhanced Cordless Telecommunications (DECT); Implementing DECT Fixed Wireless Access (FWA) in an arbitrary spectrum allocation" [31]. ETSI ETSI TR 101 310 V1.2.1 (2004-04) 81 History Document history Edition 1 August 1996 Publication as ETR 310 Corrigendum 1 October 1996 Corrigendum to ETR 310 V1.2.1 April 2004 Publication |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 1 Scope | The present document lists the terms used in the ETSI Standards and Technical Reports covering network aspects in general. Included are terms already defined in other technical areas if they have a special meaning in a network aspects context or if an unambiguous definition is essential. The terms are listed in alphabetical order only and are not sorted according to the technical area (services, powering, transfer mode, signalling, interfaces etc.) to which they belong. The list of abbreviations and acronyms include acronyms defined in other contexts and used in network aspect documents. |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 2 References | For the purposes of this Technical Report (TR) the following references apply: [1] ITU-T Recommendation B.13 (1988): "Terms and definitions". [2] ITU-T Recommendation D.000 (2000): "Terms and definitions for the Series-D Recommendations". [3] ITU-T Recommendation E.164 (1997): "The international public telecommunication numbering plan". [4] ITU-T Recommendation E.600 (1993): "Terms and definitions of traffic engineering". [5] ITU-T Recommendation F.500 (1992): " International public directory services". [6] ITU-T Recommendation G.601 (1980): "Terminology for cables". [7] ITU-T Recommendation G.701 (1993): "Vocabulary of digital transmission and multiplexing, and pulse code modulation (PCM) terms". [8] ITU-T Recommendation G.707 (2000): "Network node interface for the synchronous digital hierarchy (SDH)". [9] ITU-T Recommendation G.803 (2000): "Architecture of transport networks based on the synchronous digital hierarchy (SDH)". [10] ITU-T Recommendation G.805 (2000): "Generic functional architecture of transport networks". [11] ITU-T Recommendation G.810 (1996): "Definitions and terminology for synchronization networks". [12] ITU-T Recommendation G.823 (2000): "The control of jitter and wander within digital networks which are based on the 2048 kbit/s hierarchy". [13] ITU-T Recommendation G.902 (1995): "Framework Recommendation on functional access networks (AN) Architecture and functions, access types, management and service node aspects". [14] ITU-T Recommendation H.223 (1996): "Multiplexing protocol for low bit rate multimedia communication". [15] ITU-T Recommendation H.323 (2000): "Packet-based multimedia communications systems". [16] ITU-T Recommendation I.112 (1993): "Vocabulary of terms for ISDNs". [17] ITU-T Recommendation I.113 (1997): "Vocabulary of terms for broadband aspects of ISDN". [18] ITU-T Recommendation I.140 (1993): "Attribute technique for the characterisation of telecommunication services supported by an ISDN and network capabilities of an ISDN". ETSI ETSI TR 101 287 V1.2.1 (2001-09) 6 [19] ITU-T Recommendation I.150 (1999): "B-ISDN asynchronous transfer mode functional characteristics". [20] ITU-T Recommendation I.233.1 (1991): "ISDN frame relaying bearer service". [21] ITU-T Recommendation I.322 (1999): "Generic protocol reference model for telecommunication networks". [22] ITU-T Recommendation I.363 series: "B-ISDN ATM Adaptation Layer (AAL) specification. Type x AAL". [23] ITU-T Recommendation I.371 (1996): "Traffic control and congestion control in B-ISDN". [24] ITU-T Recommendation I.374 (1993): "Framework Recommendation on "network capabilities to support multimedia services". [25] ITU-T Recommendation I.501 (1993): "Service interworking". [26] ITU-T Recommendation I.510 (1993): "Definitions and general principles for ISDN interworking". [27] ITU-T Recommendation I.570 (1993): "Public/private ISDN interworking". [28] ITU-T Recommendation J.1 (1999): "Terms, definitions and acronyms applicable to the transmission of television and sound-programme signals and of related data signals". [29] ITU-T Recommendation M.60 (1993): "Maintenance terminology and definitions". [30] ITU-T Recommendation M.3010 (2000): "Principles for a Telecommunications management network". [31] ITU-T Recommendation Q.9 (1988): "Vocabulary of switching and signalling terms". [32] ITU-T Recommendation Q.65 (1997): "The unified functional methodology for the characterisation of services and network capabilities". [33] ITU-T Recommendation Q.825 (1998): "Specification of TMN applications at the Q3 interface: Call detail recording". [34] ITU-T Recommendation Q.921 (1997): "ISDN user-network interface - Data link layer specification". [35] ITU-T Recommendation Q.1290 (1998): "Glossary of terms used in the definition of intelligent networks". [36] ITU-T Recommendation Q.2931 (1995): "Digital Subscriber Signalling System No. 2 - User-Network Interface (UNI) layer 3 specification for basic call/connection control". [37] ITU-T Recommendation V.56bis (1995): "Network transmission model for evaluating modem performance over 2-wire voice grade connections". [38] ITU-T Recommendation X.200 (1994): "Information technology - Open Systems Interconnection - Basic Reference Model: The basic model". [39] ITU-T Recommendation X.213 (1995): "Information technology - Open Systems Interconnection - Network service definition (Common text with ISO/IEC)". [40] ITU-T Recommendation X.700 (1992): "Management framework for Open Systems Interconnection (OSI) for CCITT applications". [41] ITU-T Recommendation X.903 (1995): "Information technology - Open distributed processing - Reference Model: Architecture (Common text with ISO/IEC)". [42] ITU-T Recommendation Y.101 (1999): "GII Terminology". [43] ITU-T Recommendation Y.110 (1998): "Global Information Infrastructure principles and framework architecture". ETSI ETSI TR 101 287 V1.2.1 (2001-09) 7 [44] ITU Radio Regulations.. [45] ETSI ETR 044: "Network Aspects (NA); Reference events for network performance parameters in an ISDN". [46] ETSI ETR 149: "Network Aspects (NA); Interworking between Metropolitan Area Networks (MANs) and Asynchronous Transfer Mode (ATM) networks for the Connectionless Broadband Data Service (CBDS)". [47] ETSI ETR 155: "Asynchronous Transfer Mode (ATM); Operation Administration and Maintenance (OAM) functions and parameters for assessing performance parameters". [48] ETSI ETR 161: "Broadband Integrated Services Digital Network (B-ISDN); Functional description of Virtual Path (VP) cross-connect". [49] ETSI TR 101 287 (V1.1.1): "Network Aspects (NA); Terms and definitions". [50] ETSI TR 101 615: "Network Aspects (NA); Services and networks architecture evolution for telecommunications". [51] ETSI TR 101 686: "Hybrid Fibre Coax (HFC) access networks; Interworking with B-ISDN networks". [52] ETSI TR 101 694: "Asynchronous Transfer Mode (ATM); Provision of internet applications via ATM based networks and interworking with IP networks". [53] ETSI TR 101 734: "Internet Protocol (IP) based networks; Parameters and mechanisms for charging". [54] ETSI TR 101 619: "Network Aspects (NA); Considerations on networks mechanism for charging and revenue accounting". [55] ETSI TR 102 100: "Network Aspects (NA); Interworking framework". [56] ETSI EG 201 400: "Hybrid Fiber Coax (HFC) access networks; Part 1: Interworking with PSTN, N-ISDN, Internet and digital mobile networks". [57] ETSI ETS 300 349: "Broadband Integrated Services Digital Network (B-ISDN); Asynchronous Transfer Mode (ATM); Adaptation Layer (AAL) specification - type 3/4". [58] I- ETSI ETS 300 353: "Broadband Integrated Services Digital Network (B-ISDN); Asynchronous Transfer Mode (ATM); Adaptation Layer (AAL) specification - type 1". [59] ETSI ETS 300 354: "Broadband Integrated Services Digital Network (B-ISDN); B-ISDN Protocol Reference Model (PRM)". [60] ETSI ETS 300 404: "Broadband Integrated Services Digital Network (B-ISDN); B-ISDN Operation And Maintenance (OAM) principles and functions". [61] ETSI ETS 300 469: "Broadband Integrated Services Digital Network (B-ISDN); Asynchronous Transfer Mode (ATM); Management of the network element view [ITU-T Recommendation I.751 (1996)]". [62] ETSI ETS 300 478: "Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over Asynchronous Transfer Mode (ATM); Framework and protocol specification at the User- Network Interface (UNI)". [63] ETSI ETS 300 479: "Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over Asynchronous Transfer Mode (ATM); Protocol specification at the Network Node Interface (NNI)". [64] ETSI ETS 300 780: "Broadband Integrated Services Digital Network (B-ISDN); Broadband Connection-Oriented Bearer Service (BCOBCS) [ITU-T Recommendation F.811 (1996)]". [65] ETSI EG 201 898: "Services and Protocols for Advanced Networks (SPAN); Relationship between IP and telecommunication networks". ETSI ETSI TR 101 287 V1.2.1 (2001-09) 8 [66] ETSI ES 201 803-1: "Dynamic synchronous Transfer Mode (DTM); Part 1: System Description". [67] ANSI T1.105.06 (1996): "Synchronous Optical Network (SONET) - Physical Layer Specification (Revision of ANSI T1.106-1988)". [68] IEEE 802.3, 2000 Edition (ISO/IEC 8802-3, 2000): "IEEE Standard for Information technology - Local and metropolitan area networks - Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications". [69] ATM-Forum (af-ra-0106.000): "ATM Forum Addressing: Reference Guide". [70] IETF FYI 4 (RFC 2664): "FYI on Questions and Answers - Answers to Commonly Asked New Internet User Questions". [71] IETF RFC 768 (1980): "User Datagram Protocol". [72] IETF RFC 1208 (1991): "Glossary of networking terms". [73] IETF RFC 1953 (1996): "Ipsilon Flow Management Protocol Specification for IPv4 Version 1.0"; P. Newman, W. Edwards, R. Hinden, E. Hoffman, F. Ching Liaw, T.Lyon & G. Minshall". [74] IETF RFC 1983 (August 1996): "Internet Users' Glossary", G. Malkin, Editor". [75] IETF RFC 2663 (1999): "IP Network Address Translator (NAT) Terminology and Considerations"; P. Srisuresh, M. Holdrege". [76] IETF RFC 2828 (2000): "Internet Security Glossary". [77] IETF RFC 2881 (July 2000): "Network Access Server Requirements Next Generation (NASREQNG) NAS Model". [78] Federal Standard FED-STD-1037C (1996): "Telecommunications: Glossary of Telecommunication Terms"; The U.S. Department of Commerce, National Telecommunications and Information Administration, Institute for Telecommunication Sciences (NTIA/ITS)". [79] "Telephony's Dictionary", second Edition; Graham Langley; Telephony Publishing Corporation, 1986, USA; ISBN 0-917845-04-8. [80] ITU-T Recommendation X.680: "Information technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation". [81] ITU-T Recommendation X.690: "Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)". [82] ISO 8859-1: "Information technology - 8-bit single-byte coded graphic character sets - Part 1: Latin alphabet No. 1". [83] ISO 10646: "Information technology - Universal Multiple-Octet Coded Character Set (UCS) - Part 1: Architecture and Basic Multilingual Plane". [84] IETF RFC 1519: "Classless Inter-Domain Routing (CIDR): an Address Assignment and Aggregation Strategy". [85] ETSI ETS 300 415: "Private Integrated Services Network (PISN); Terms and definitions". [86] IETF RFC 791: "Internet Protocol". [87] ITU-T Recommendation I.510: "Definitions and general principles for ISDN interworking". [88] ITU-T Recommendation I.114: "Vocabulary of terms for universal personal telecommunication". [89] ITU-T Recommendations G.825: "The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH)". [90] ITU-T Recommendation I.361: "B-ISDN ATM layer specification". ETSI ETSI TR 101 287 V1.2.1 (2001-09) 9 [91] ISO/IEC 11579-1: "Information technology - Telecommunications and information exchange between systems - Private integrated services network - Part 1: Reference configuration for PISN Exchanges (PINX)". [92] ITU-T Recommendation I.430: "Basic user-network interface - Layer 1 specification". [93] ITU-T Recommendation I.431: "Basic user-network interface - Layer 1 specification". [94] ITU-T Recommendation F.850: "Principles of universal personal telecommunication (UPT)". [95] ETSI ETS 300 455: "Broadband Integrated Services Digital Network (B-ISDN); Broadband Virtual Path Service (BVPS); Part 1: BVPS for Permanent communications (BVPS-P)". [96] IETF RFC 1577: "Classical IP and ARP over ATM". |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 3 Information about the present document | Terms and definitions taken from ITU Recommendations are identified by appropriate reference in parentheses at the end of the definition. The numbers after the Q.9, G.601, G.701, I.112, I.113 and I.114 references are the word numbers in these documents. Where the definition has been based upon, but differs from, a definition in another document, the reference is given followed by "modified". Terms defining general used acronyms such as Asynchronous Transfer Mode (ATM) are written with leading capitals. Some definitions include terms in italics to indicate that these terms are defined elsewhere in the present document. The list of abbreviations and acronyms includes acronyms such as PAL and SECAM normally not used in network aspect contexts but generally used in the relevant standards and technical reports. Also included are acronyms with more than one meaning such as CC for Call Control, Country Code or Cross Connect. For some acronyms it is indicated in brackets in which context they are created, e.g. (Internet), (ATM Forum). Some out-of-date acronyms are marked (deprecated). Many terms are overloaded with several meanings. For instance "virtual circuit" has a generic meaning and also a very specific non-generic meaning in ATM. For these multiple-meaning cases the generic form is presented first and the specific forms follow the generic form as new definitions but marked with area/scope within square brackets after the term in question. In cases where a term is valid within more than one field (and is not valued as a generic definition) the areas for which it applies are given within square brackets as a comma separated alphabetically ordered list During the revision of the document specific concerns were raised regarding the usage of terminology which were found to be worth addressing them in particular. It is considered that these will be enlightening to the reader of the present document and provide a guideline outside the scope of the contained definitions while also conveying the specific generic revision decisions being made. |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 3.1 The distinction between old and new technologies | In older telecommunication definitions many terms were defined with an embedded distinction to some other technology. A classical example would be "analogue link" versus "digital link" which was required to distinguish old analogue FDM systems with then new TDM systems. Thus, the need to create definitions for digital switching only becomes of interest if you know and assume that switching normally used to be done with analogue channels. Furthermore, the use of qualifiers like "emerging" is also part of a definition which will not survive the time. What was emerging and new at the time of the definition will be old in 10 to 20 years time and possibly be amusing to the engineers at that time. A more subtle error of the same kind is to be found when a technology is being associated with a certain bit rate. For most technologies the bit rates they can support is changing over time. So, stating that Ethernet has the bit rate of 10 Mbit/s (which used to be true) would only date the definition to be historic at best. The usage of bit rates other than for examples or when a certain name has been given to denote a speed (i.e. E1, T1 etc.) shall thus be avoided. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 10 |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 3.2 Generic vs. Specific | Many terms have been found to apply only for specific technology areas even though the term bears no reference to that area. In such cases a more generic definition has been included. Also, some definitions have carried a subtle binding to a specific technology or means of implementation while this may be questioned. For those cases the definition was modified or replaced in order to provide a generic definition that only grasps the property while not implicating certain types of implementations. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 11 |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 4 Vocabulary of terms | address mask: bit mask used to identify the bits in an address which correspond to certain specific portions of the address address resolution: Conversion of a network-layer address (e.g. IP address) into the corresponding physical address (e.g., MAC address) (see IETF RFC 1983). addressable entity: entity which is recognizable by the network, to which the network is able to route a call addressing domain: context within which an identifier (name, number, etc.) is unique Abstract Syntax Notation One (ASN.1): language used by the OSI protocols for describing abstract syntax NOTE 1: ASN.1 is defined in ISO documents 8824.2 and 8825.2, and ITU Recommendations X.680-X690, ISO standards 8824.2 and 8825.2, ITU-T Recommendations series X.680 to X.690. access capability [ISDN]: Number and type of the access channels at an ISDN access interface that are actually available for telecommunication purposes (see ITU-T Recommendation I.112-416). access channel (channel) [ISDN]: Channel provided at the User Network Interface (see: channel). NOTE 2: The term "access channel" may be qualified, for example by H, B or D in which case it is appropriate to abbreviate the term to "H-channel", to "B-channel" or to "D-channel". access connection element (subscriber access) [ISDN]: equipment providing the concatenation of functional groups between and including the exchange termination and the NT1 NOTE 3: The term should be qualified by the type of access supported. That is either basic access connection elements or primary rate access connection elements (see ITU-T Recommendation I.112-429). access contention [ISDN]: Conflict between the demands made on a network termination in multipoint access (see ITU-T Recommendation I.112-423). access contention resolution [ISDN]: Arbitration of conflicting demands on a network termination in multipoint access (see ITU-T Recommendation I.112-424). access function: Set of processes in a network that provide for interaction between the user and a network (see ITU-T Recommendation Q.1290). access network: Implementation comprising those entities (such as cable plant, transmission facilities, etc.) which provide the required transport bearer capabilities for the provision of telecommunication services between one or more Service Node Interfaces (SNI) and each of the associated User Network Interfaces (UNI). An access network according to ITU-T Recommendation G.902 does not interpret user signalling. ITU-T Recommendation G.902 (modified), see also ITU-T Recommendation Y.101. Access Network Interface (ANI): Interface between a local switch and an access network within a local network (see ITU-T Recommendation Y.101). access network operator: Network operator to which the customer is physically connected (see TR 101 619). access node: edge node of a network providing access to a network and its services access protocol: Defined set of procedures that is adopted at an Access Network Interface enable the user to employ the service and/or facilities of that network (see ITU-T Recommendation I.112-406 modified). accounting: procedure whereby revenue is shared between operators (see ITU-T Recommendation D.000 modified). acknowledgement (ACK): Type of message sent to indicate that a previously sent message arrived at its destination. (See also: Negative Acknowledgement IETF RFC 1983 modified). activation [ISDN]: Function which places a system, or part of a system, which may have been in low power consumption mode during deactivation, into its fully operating mode (see ITU-T Recommendation I.112-602). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 12 actor: person or an entity who plays a visible role in the IN environment address: String or combination of decimal digits, symbols, and additional information which identifies the specific termination point(s) in a network(s) (see ITU-T Recommendation E.164, modified). address mask [IP]: Bit mask used to identify which bits in an IP address correspond to the network and subnet portions of the address. This mask is often referred to as the subnet mask because the network portion of the address (i.e., the network mask) can be determined by the encoding inherent in an IP address. See also: Classless Inter- domain Routing (see IETF RFC 1983). address resolution: conversion of an address into some other address, possibly of another address format addressable entity: entity which is recognizable by the network, to which the network is able to route a call or message addressing domain: context within which an identifier (name, number, etc.) is unique Adjunct (AD): Entity in the Intelligent Network that is functionally equivalent to a service control point but is directly connected to a service switching point (see ITU-T Recommendation Q.1290). Administrative Domain (AD): Collection of hosts and routers, and the interconnecting network(s), managed by a single administrative organization (see IETF RFC 1983 modified). Administrative Interface [Number Portability]: Interface/information base in which information on ported numbers is available for Network Operators (see TR 101 619). Advice Of Charge (AOC): supplementary service related to the presentation of charging information to the user NOTE 4: AOC appears in three versions AOC-S provides the served user with information about the charging rates at call establishment. In addition, the served user shall be informed if a change in charging rates takes place during the call. AOC-D provides the served user with cumulative charging information during the call. AOC-E provides the served user with charging information for a call when the call is terminated (see TR 101 619). agent: Agent is an element that performs some task on behalf of some party (i.e., a user, machine, application, or another agent) rather than having the party itself perform the task (see ITU-T Recommendation Y.101). aggregate stream: Stream composed of an aggregation of many individual streams (see EG 201 898). alias: name/address that is translated into another name/address NOTE 5: The translation may be done in order to provide shorter and/or easier names to a user. NOTE 6: The translation may be done in order to make a virtual name/address to be widely spread while the real name/address is being kept in some database (see IETF RFC 1983 modified). American Standard Code for Information Interchange (ASCII): standard character-to-number encoding widely used in the computer industry NOTE 7: In more recent times it is being replaced by ISO 8859-1 and ISO 10646. However, ASCII is still widely used to denote binary encoding of alphanumeric text (see IETF RFC 1983). analogue signal: Signal one of whose characteristic quantities follows continuously the variation of another quantity representing information (see ITU-T Recommendation I.112-103). anisochronous: essential characteristic of a time-scale or a signal such that the time intervals between consecutive significant instants do not necessarily have the same duration or durations that are integral multiples of the Unit Interval NOTE 8: Isochronous and anisochronous are characteristics of a signal, while synchronous and asynchronous are relationships (see ITU-T Recommendation G.701 modified and US Fed. Std.1037C. appliance: Generic term used to describe the terminal device employed by the service application. Telephones, TV sets, computers, etc. are examples of appliances (see ITU-T Recommendation Y.101). application: set of capabilities to satisfy a certain set of user's requirements NOTE 9: An example of an application using the telephony service would an the information desk. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 13 application entity: Set of Application Service Elements which together perform all or part of the communications aspects of an application process (see ITU-T Recommendation Q.9 - 2156 modified). application layer [OSI] : Top layer of the ISO OSI network protocol stack. The application layer is concerned with the semantics of work (e.g. formatting electronic mail messages). How to represent that data and how to reach the foreign node are issues for lower layers of the network (see IETF RFC 1983 modified). application process: Sequence of operations that perform the information processing for a particular application (see ITU-T Recommendation Y.101). application program: Logic residing in the Service Control and Service Management realms that directs and/or controls the performance of actions in the network to provide and/or manage the provision of IN service features (see ITU-T Recommendation Q.1290). Application Programming Interfaces (APIs): Interfaces that support the process of creating, installing, testing, modifying application programs (see ITU-T Recommendation Q.1290 modified). Application Service Element (ASE): Coherent set of integrated functions within an application entity (see ITU-T Recommendation Q.9). Application Service Element (ASE): Coherent set of integrated functions within an application entity (see ITU-T Recommendation Q.9-2158 modified). Application Service Object (ASO): Configuration of various groups of application service elements (see ITU-T Recommendation Y.101). architecture: Any ordered arrangement of the parts of a system (see ITU-T Recommendation Q.1290). assigned cell [ATM]: cell which provides a service to an application using the ATM layer service assigned numbers: subset of numbers assigned by an appointed authority association: Logical relationship between entities exercised in performing a function (see ITU-T Recommendation Q.1290). Asymmetrical Digital Subscriber Line (ADSL): Modem technology that converts twisted-pair telephone lines into access paths for data communications. The bit rates transmitted in both directions are different (see ITU-T Recommendation Y.101 modified). asynchronous: characteristic of time scales or signals such that their is no fixed time relationship between its significant instants and any other system timing NOTE 10: Isochronous and anisochronous are characteristics of a signal, while synchronous and asynchronous are relationships (see US Fed. Std.1037C). Asynchronous Time Division (ATD) multiplexing [ATM, B-ISDN]: Statistical time division multiplexing technique in which a transmission capability is organized in undedicated slots filled with packets/cells. Packets/cells from the same source are usually all assumed to be anisochronous (see ITU-T Recommendation I.113-202 modified). Asynchronous Transfer Mode (ATM): Transfer mode in which the information is organized into fixed-sized packets, called cells; the recurrence of cells in a connection is not necessarily isochronous (see ITU-T Recommendation I.113-204 modified). ATM Adaptation Layer (AAL) [ATM]: ATM Adaptation Layer (AAL) enhances the service provided by the ATM layer to support functions required by the next higher layer. The AAL performs functions required by the user, control and management planes and supports the mapping between the ATM layer and the next higher layer. The functions performed in the AAL depend upon the higher layer requirements. (see ITU-T Recommendation I.363). ATM connection: Concatenation of ATM layer links in order to provide an end-to-end transfer capability to access points (see ITU-T Recommendation I.113-505). ATM End System Address (AESA): Address defined by the ATM Forum to be used in ATM networks. The AESA is derived from the ISO Network Service Access Point (NSAP) Address and hence may occur in different formats (see ATM-Forum Spec. af-ra-0106.000 modified). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 14 ATM layer connection: Association established by the ATM layer to support communication between two or more ATM service users (i.e. two or more next higher layer entities, or two or more ATM management entities). The communication over an ATM layer connection may be either bi-directional or unidirectional (see ITU-T Recommendation I.113-506). ATM link: Link provides for the capability of transferring information transparently, and represents the association, between two contiguous connecting points or between an endpoint and its contiguous connecting point (see ITU-T Recommendation I.113-507). ATM Name Server (ANS): Server program which supplies name-to-address translation, mapping from names of ATM end-systems to ATM address. ANS is an extension of the IETF DNS TR 101 694 [52]. ATM traffic descriptor: Generic list of traffic parameters that can be used to capture the intrinsic traffic characteristics of an ATM connection (see ITU-T Recommendation I.113-708). ATM Transfer Capability (ATC): Set of ATM traffic control procedures, tailored to support a service with given traffic characteristics (see ITU-T Recommendation Y.101). attribute: Information concerning a managed object used to describe (either in part or in whole) that managed object. This information consists of an attribute type and its corresponding attribute value (for "single-valued" attributes) or values (for "multi-valued" attributes) of managed object (see ITU-T Recommendation X.700). authentication: verification of the identity of a person or process (see IETF RFC 1983). Autonomous System (AS) [IP]: collection of routers under a single administrative authority using a common "Interior Gateway Protocol" for routing packets NOTE 11: The ISO-term for such a collection of routers is "routing domain" (IETF RFC 1983 modified). availability: measure of the relative degree of access to a particular resource or set of resources NOTE 12: The term is usually measured as the relative availability of the full service as a time fraction. A high availability thus results in low outage time (see ITU-T Recommendation Y.101 modified). backbone: Top level in a hierarchical network (IETF RFC 1983 modified). bandwidth: Difference between limiting frequencies of a continuous frequency band (see US Fed. Std 1037C mod). baseband: Transmission means through which digital signals are sent without frequency shifting. In general, only one communication channel is available at any given time. Ethernet and ISDN are examples of baseband networks IETF RFC 1983 modified. basic access, basic rate access, basic rate interface (BRI) [ISDN]: ISDN user access arrangement that corresponds to the interface structure composed of two B-channels and one D-channel. The bit rate of the D-channel for this type of access is 16 kbit/s (see ITU-T Recommendation I.112 modified). basic call: Call between two users that does not include additional features (e.g. a plain telephone call) (see ITU-T Recommendation Q.1290). Basic Call Process (BCP): Sequence of activities used in processing a basic call attempt (ITU-T Recommendation Q.1290). Basic Call State Model (BCSM): High-level finite state machine model of call processing for basic call control (i.e. a two party non-IN call). The model might only cover a portion of a call attempt, e.g. an originating BCSM or terminating BCSM, or the whole attempted call connection, originating user to terminating user (see ITU-T Recommendation Q.1290 ). Baud (Bd) (as unit of modulation rate): one baud corresponds to a rate of one unit interval per second, where the modulation rate is expressed as the reciprocal of the duration in seconds of the shortest unit interval ETSI ETSI TR 101 287 V1.2.1 (2001-09) 15 Baud (Bd) (as unit of signalling speed equal to the number of discrete signal conditions, variations or events per second): If the duration of the unit interval is 20 milliseconds, the signalling speed is 50 Bauds. If the signal transmitted during each unit interval can take on any one of n discrete states, the bit rate is equal to the rate in Bauds times log2 n. The technique used to encode the allowable signal states may be any combination of amplitude, frequency, or phase modulation, but it cannot use a further time-division multiplexing technique to subdivide the unit intervals into multiple subintervals. In some signalling systems, non-informational-carrying signals may be inserted to facilitate synchronization; e.g. in certain forms of binary modulation coding, there is a forced inversion of the signal state at the centre of the bit interval. In these cases, the synchronization signals are included in the calculation of the rate of Bauds but not in the computation of bit rate. NOTE 13: Baud is sometimes used as a synonym for bit-per-second. This usage is deprecated. (see US Fed. Std. 1037C). bearer service: Type of telecommunication service that provides the capability for the transmission of signals between user-network interfaces (ITU-T Recommendation I.112-202 modified). best-effort relationship: particular kind of connection (relationship) between two nodes A and B for which no commitment exists, but where it is possible that a datagram accepted at node A will arrive at node B NOTE 14: However, there is no guarantee that the datagram will arrive at node B (see EG 201 898). bill: Document from the billing entity to a served user in a decided format informing of the price for the usage of the concerned telecommunication services and resources. It shows the price for a single usage or the accumulated price for a certain period of usage. The information can be specified. It should be noted that the subscription fee and the periodic fee are normally included in the bill (see TR 101 619). billing : See billing process. billing entity: entity responsible for the joint billing activities for one or more providers to the served users (see TR 101 619). billing process: Process of transferring the stored charging information for a user into a bill (see TR 101 619). billing system: Technical entity performing the billing process (see TR 101 619). bit: Acronym for "binary digit" which can have one of two values (0 and 1) (see ITU-T Recommendation V.56 bis, modified). Bit Rate (BR): In a bit stream, the number of bits occurring per unit time, usually expressed in bits per second. NOTE 15: For a n-ary operation, the bit rate is equal to log-n times the symbol rate (in Bauds), where n is the number of significant conditions per symbol in the signal (see US Fed. Std. 1037C). block: Unit of information consisting of a header and/or trailer and an information field (ITU-T Recommendation I.113-301 modified). block payload: bits in the information field within a block (see ITU-T Recommendation I.113-304). branching point: connecting point splitting and/or merging 1 to n connection links NOTE 16: Usually used in the meaning of splitting (i.e. multicast/point-to-multipoint sense). bridge: Device which forwards traffic between network segments based on data link layer (OSI Layer 2) information (see IETF RFC 1983 modified). broadband: relates to a service or system requiring transmission capacity greater than 1920 kbit/s (primary rate) NOTE 17: The term is a qualifier usually to indicate the bandwidth or bit rate needed by a service. The usage has grown popular over the years but has no real connection to bitrate terms. Therefore the use of this term is strongly deprecated. ITU-T Recommendation I.113-101 modified. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 16 broadband communication channel ]B-ISDN]: Specific portion of the information payload capacity, available to the user for ISDN services. A broadband communication channel exists only during a call, as set-up by a signalling or administrative procedure. NOTE 18: The term broadband is a qualifier usually to indicate the bandwidth or bit rate needed by a service. The usage has grown popular over the years but has no real connection to bitrate terms. Therefore the use of this term is strongly deprecated (see ITU-T Recommendation I.113-321 modified). broadcast: Communication capability which denotes unidirectional distribution to all users connected to the network. The user terminal is responsible for selecting which broadcast information to receive. broadcast communication: Unidirectional communication from a single source access point to an unlimited number (more than one) of unspecified destination access points (see ITU-T Recommendation I.140). broadcast connection: Unidirectional connection between one (source) endpoint and an unlimited number (more than one) of unspecified destination endpoints (see ITU-T Recommendation I.140). broadcast network: Network providing a multitude of sound, television or other information signals (see: broadcast). broadcast organization: organization which runs a broadcast network broadcasting service: Radiocommunication service in which the transmissions are intended for direct reception by the general public. This service may include sound transmissions, television transmissions or other types of transmission. (ITU Radio Regulations 36-3 and 36-17). brouter: Device which bridges some packets (i.e. forwards based on data link layer information) and routes other packets (i.e. forwards based on network layer information). The bridge/route decision is based on configuration information (see IETF RFC 1983). bypass switching: space switching from the receiver to the transmitter without involving the network layer bypass switching [DTM]: space switching of slots from the receiver to transmitter on the same port on a per slot basis. Bypass switching does not include time-reorder (see ES 201 803-1). Cable Distribution Network (CDN): Tree-structured coaxial/HFC network to transport a signal to appliances. Originally it was unidirectional and used for TV distribution (see ITU-T Recommendation Y.101 modified). call: logical association between two or more endpoints, offering the possibility to make use of a telecommunication service call contractor: network operator responsible for establishment of a call, which may contain contributions from a number of network operators and/or service providers NOTE 19: In case of carrier selection, the call contractor is either the access network operator or the selected carrier. The arrangement is depending of national regulation and agreements between operators concerned. If the selected carrier is the Call Contractor the access from the calling party to the Access NO is outside the Call Contractor's responsibility (see TR 101 619 [54]). call control: Set of functions used to process a call (e.g. provide service features and establish, supervise, maintain and release connections) (ITU-T Recommendation Q.1290). Call Control Agent Functional entity (CCAF): Functional entity that provides network access functions for users, interacting with Call Control Functional entities in providing services (ITU-T Recommendation Q.1290). Call Control Functional entity (CCF): Functional entities which co-operate with each other to provide network call processing functions (ITU-T Recommendation Q.1290). Call Detail Record (CDR): data record containing call detail information relating to a specific call or call attempt instance NOTE 20: Sometimes the term "Call Data Record" is used for this purpose. However, its use should be avoided. ITU-T Recommendation Q.825 [33]. Call Instance Data (CID): identifier that defines call specific details (i.e. value will change with each call instance) for service independent building blocks in the global functional plane ETSI ETSI TR 101 287 V1.2.1 (2001-09) 17 call management: ability of a user to indicate to the network how to handle incoming calls according to certain parameters such as the originator of the call, the time of day and the nature of the call NOTE 21: Call management is done through the user's service profile ITU-T Recommendation I.114-109 [88] . Call Model (CM): Representation of functions involved in processing a call (see ITU-T Recommendation Q.1290). call reference: Parameter e.g. in ISUP/INAP signalling messages indicating a specific call, globally or within certain limits (see TR 101 619 modified). call segment: Specific portion of the processing of a call (see ITU-T Recommendation Q.1290). Call Segment Model (CSM): Representation of the processing of a call in terms of call segments (see ITU-T Recommendation Q.1290). call/service processing: Execution of logic by a switching or control function to advance a call attempt or a service request (ITU-T Recommendation Q.1290). Capability Set (CS): Set of Intelligent Network capabilities that are to be the subjects of standardization activities and for which the availability of standards Recommendations will be targeted for a particular time frame (see ITU-T Recommendation Q.1290). carrier selection: Possibility for the user to select a Network Operator (NO) different from the access Network Operator. The carrier selection is made either on call-by-call basis or based on preselection of a certain Network Operator. Carrier selection on call by call basis can be managed by access code overriding the default Network Operator access and a preselection (see TR 101 619 modified). CATV: Used as a general term for "cable television" (historically used to indicate "Community Antenna TeleVision" - a centralized installation of television antennas that serves a community of users) (see ITU-T Recommendation J.1 and EG 201 400). CATV based access Network: See: Hybrid Fiber Coax (HFC) access network. cell [ATM]: Packet of fixed length (used e.g. in ATM). cell conformance: Algorithm that identifies cells that conform to negotiated traffic parameters and traffic control procedures at a standardized interface (see ITU-T Recommendation Y.101). Cell Delay Variation (CDV) [ATM]: variation of the actual arrival time of an ATM cell with respect to the theoretical (calculated) arrival time measured between two given points of an ATM connection cell delineation [ATM]: Identification of cell boundaries in a cell stream (see ITU-T Recommendation I.113-306). cell entry event [ATM]: Event which occurs when the last bit of an ATM cell has completed transmission across a measurement point along a connection (see ETR 155). cell exit event [ATM]: Event which occurs when the first bit of an ATM cell has completed transmission across a measurement point along a connection (see ETR 155). cell rate decoupling [ATM]: includes insertion and suppression of idle cell, in order to adapt the rate of valid ATM cells to payload capacity of the transmission system centralized charging method: Means charging outside the switch points in charging centres common to a number of switch points (see TR 101 619). channel, transmission channel: Means of unidirectional transmission of signals between two points. Several channels may share a common infrastructure (see ITU-T Recommendation I.112-108 modified). channel-associated signalling: Method of signalling in which signalling information relating to a multiplicity of circuits or functions or for network management, is conveyed over a single channel by addressed messages (see ITU-T Recommendation I.112-502). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 18 characteristic information: those parts of a format definition of the basic traffic entity of a layer network which is transported unchanged across a connection or circuit NOTE 22: Characteristic information is always defined in relation to a particular layer network. For example, characteristic information on layer 2 may not be characteristic information on layer 3, since it can be changed when a traffic entity instance is moving across a network node (see EG 201 898 [65]). charging: Process by which the usage of resources is converted into charge units which will be billed to the customer. (see: billing process). NOTE 23: The usage parameters are usually given in Call Detail Records. checksum: Computed value which is dependent upon the contents of a block of data. This value is sent along with the data block when it is transmitted. The receiving system computes a new checksum based upon the received data and compares this value with the one sent with the block. If the two values are the same, the receiver has a high degree of confidence that the data was received correctly (see IETF RFC 1983 [74]). circuit, telecommunication circuit: Transmission means which allows communication between two points (see ITU-T Recommendation E.600). circuit switching: relates to a connection between two or more terminals providing resources which are exclusively dedicated to that connection NOTE 24: The Public Switched Telephone Network (PSTN) is an example of a circuit switched network. Classless Inter-domain Routing (CIDR): Proposal, set forth in IETF RFC 1519, to allocate IP addresses so as to allow the addresses to be aggregated when advertised as routes. It is based on the elimination of intrinsic IP network addresses; that is, the determination of the network address based on the first few bits of the IP address IETF RFC 1983. clearing centre: Technical entity to handle the clearing activity for the revenue accounting between a number of interworking and co-operating telecommunication providers Network Operators transfer general accounts for clearing and receive cleared invoices (see TR 101 619). client: Computer system or process that requests a service of another computer system or process. A workstation requesting the contents of a file from a file server is a client of the file server (see IETF RFC 1983). client-server model: communication paradigm in which one side of the communication is a client requesting a service from the other side of the communication which is called a server clock: Equipment that provides a timing signal (see ITU-T Recommendation G.810). clock signal: synchronization signal provided by a clock NOTE 25: The clock signal is used to time the transmissions of a data signals and to identify the optimum detection times of a received data signal. Telephony's Directory, modified. collection connection: on demand, reserved or permanent multipoint-to-point connection transferring user information from a defined number of remote endpoints called leaves toward one endpoint called root. All flows (user and other - if appropriate) are only in one direction common channel signalling: Method of signalling in which signalling information relating to a multiplicity of circuits or functions or for network management, is conveyed over a single channel by addressed messages (see ITU-T Recommendation I.112-503). communication: Transfer of information between two or more users, entities, processes or nodes according to some agreed conventions (see ITU-T Recommendation I.112 modified). communication entity: physical or logical object that is able to take part in an instance of communication compression: representation scheme to reduce the size of data maintaining acceptable quality NOTE 26: Compression schemes are usually designed for a particular type of data or content and may give lower compression and/or quality for other types (see ITU-T Recommendation Y.101 modified [42]). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 19 configuration management: Set of management functions which exercise control over the extensions or reductions of a system, the status of the constituent parts and the identity of their allocation (see ITU-T Recommendation I.113-604, ITU-T Recommendation M.3010). congestion: state of a system or a part thereof which is entered when the traffic load exceeds the capacity of the system which is then no longer able to meet the negotiated QOS objectives for the already established connections and/or for the new connection requests NOTE 27: A system being in congestion may refuse new traffic or may drop established traffic. congestion control: Set of actions taken to relieve congestion by limiting the spread and duration of it (see ITU-T Recommendation I.113-703). connecting point: Point inside a connection where two adjacent links come together. It is located within a level where the information is routed transparently; it provides the connecting functions (see ITU-T Recommendation I.113-508). connection: Association of transmission channels, switching and other functional units set up to provide a means for a transfer of information between two or more points in a telecommunications network (see ITU-T Recommendation Q.9-0011 modified). Connection Admission Control (CAC): set of actions taken by the network at the call set up phase (or during call re-negotiation phase) in order to determine whether a connection can be accepted or rejected (or a request for re- allocation can be accommodated) NOTE 28: Admission can be denied based on bandwidth, security, etc. (see ITU-T Recommendation I.113-704 modified [17]). connection attribute [ISDN]: specified characteristic of an ISDN connection NOTE 29: The value(s) assigned to one or more connection attributes may be used to distinguish that connection from others. (see ITU-T Recommendation I.112-315 [16]). connection control: Set of functions used for setting up, maintaining and releasing a communication path between two or more users or a user and a network entity, e.g. a dual tone multi-frequency receiver (see ITU-T Recommendation Q.1290) connection element [ISDN]: Part of an ISDN connection which has stated values of one or more ISDN connection attributes (see ITU-T Recommendation I.112-317). Connection End Point (CEP) [ATM]: Point located at the level boundary (e.g. between VC level and VP level) where the level service is provided to the next higher level or to the management plane. The CEP provides the connection termination functions (see ITU-T Recommendation I.113-509). connection leg: connection leg of a point-to-multipoint connection is part of a connection between a destination endpoint and the previous branching connection point. If the leaf party connected to the connecting leg is leaving or being dropped, the connection leg is released. connection less: property of data transport where there exist no knowledge regarding a data transmission prior to the data transmission connection oriented: Communication method in which communication proceeds through three well-defined phases: connection establishment, data transfer, connection release (see IETF RFC 1983 modified). connection owner: Party related to the root endpoint, who establishes the connection and as such owns the connection. The connection owner is the only party who may renegotiate the connection characteristics, add and drop new leaf endpoints and release the complete connection. connection type, ISDN connection type: Part of an ISDN connection which has stated values of one or more ISDN connection attributes (see ITU-T Recommendation I.112-316). connectionless: Data communication method in which communication occurs without establishing a dedicated path. Packets between two endpoints may take different routes. IP is a connectionless protocol (see IETF RFC 1983 modified). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 20 connectionless service: service which allows the transfer of information between users without the need for end-to-end call establishment procedures NOTE 30: Connectionless services may be used to support both interactive and distributive services. (see ITU-T Recommendation I.113-105 [17]). Connectivity: capability to establish and maintain data transfer between networks and parts thereof Constant Bit Rate (CBR) service [ATM]: Telecommunication service characterized by a service bit rate specified by a constant value (see ITU-T Recommendation I.113-103). content integrity: property of a system such that information offered at an input is delivered unchanged at an output content provider: Entity which offers information to the user (see TR 101 734). continuity check: Mechanism to test the availability of a certain link or connection. Normally qualified to indicate the object being supervised; (e.g. VP continuity check) ITU-T Recommendation I.113-614 modified. contribution, contribution application: Use of a channel for transferring audio, video or other information to a user for further post-production processing and subsequent distribution (see ITU-T Recommendation I.113-111 modified). control channel: Channel to be used for call signalling and management (see ES 201 803-1 modified). control window: Interval during which an entity involved in call/service processing is subject to the control of the Service Control Function (see ITU-T Recommendation Q.1290). conversational service: interactive service which provides for bi-directional communication by means of real- time (no store and forward) end-to-end information transfer from user to user (see ITU-T Recommendation I.113-114). cordless terminal: Physical entity that provides access to the telecommunication services of a network via a radio or infra red interface (see TR 101 619). Cordless Terminal Mobility (CTM): Scenario of cordless terminals moving within the limits of a certain radio based network or within the limits of co-ordinated radio based networks (see TR 101 619). core network : Portion of the delivery system composed of networks, systems equipment and infrastructures, connecting the service providers to the access network (see also backbone network) ITU-T Recommendation Y.101. core service feature: particular service feature fundamental to the telecommunication service, i.e., in the absence of this service feature, the telecommunication service does not make sense as a commercial offering to the service subscriber customer equipment: equipment owned and operated by customer Customer Premises Equipment (CPE): See customer equipment. Cyclic Redundancy Check (CRC): number derived from a set of data that will be transmitted used at the receiving side to detect errors occurred during transmission NOTE 31: By recalculating the CRC at the remote end and comparing it to the value originally transmitted, the receiving node can detect some types of transmission errors (see IETF RFC 1983 modified [74]). data: User and/or network information stored in the network used in connection with call/service processing An instance of a data object (see ITU-T Recommendation Q.1290). data base: Entity that stores information (see ITU-T Recommendation Q.1290). data link layer: Data link layer (layer 2 in ISO/OSI reference model) provides the functional and procedural means to transfer data between network entities (using the physical layer) and to detect and possibly correct errors that may occur in the physical layer. (see US Fed Std 1037C modified). data management: Establishing, updating and administering data bases in the network (see ITU-T Recommendation Q.1290). data object: Individually addressable unit of information specified in a data template (see ITU-T Recommendation Q.1290). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 21 data template: Specified logical structure for a collection of data objects, including allowable ranges for their values and other data consistency specifications (see ITU-T Recommendation Q.1290). datagram: Datagram is a packet with full address information enabling it to be routed to the endpoint without further information (see EG 201 898). deactivation [ISDN]: Function which places a system, or part of a system, into a non-operating mode where the power consumption of the system may be decreased (low power consumption mode) (see ITU-T Recommendation I.112-601). decryption: Decoding of encrypted information. (see also encryption) (see ITU-T Recommendation Y.101). defect: Limited interruption of the ability of an item to perform a required function. It may or may not lead to maintenance actions depending on the results of additional analysis (see ITU-T Recommendation M.60). digressive charging: Charging which decreases stepwise or continuously during the call (see also Increasing charging TR 101 619). delayed discount: Discount triggered by actions/events occurring after the call execution (see TR 101 619). demand service: Type of telecommunication service in which the communication path is established almost immediately, in response to a user request by means of user-network signalling. NOTE 32: The usage of "on demand service" is also noted (see ITU-T Recommendation I.112-205 [16]). Detection Point: Point in basic call processing at which a processing event may be reported to the Service Control Function and transfer of processing control can occur (see ITU-T Recommendation Q.1290). deterministic : process is said to be deterministic if prior to the occurrence of some event in the process the outcome of that process can be determined deterministic [ATM]: Mode of the asynchronous transfer mode in which a constant information transfer capacity expressed in terms of a predetermined limiting value for a given service is provided to the user throughout a call (see ITU-T Recommendation I.113-209). dialog(ue): Conversation or an exchange of information (see ITU-T Recommendation Q.1290). dialup connection: Temporary, as opposed to dedicated, connection between machines established e.g. over a phone line (analogue or ISDN) (see IETF RFC 1983). digital channel, digital transmission channel: Means of unidirectional digital transmission of digital signals between two points (see ITU-T Recommendation I.112-109). digital circuit, digital telecommunication circuit: Combination of two digital transmission channels permitting bi- directional digital transmission between two points, to support a single communication (see ITU-T Recommendation I.112-112). digital connection: Concatenation of digital transmission channels or digital telecommunication circuits, switching and other functional units set up to provide for the transfer of digital signals between two or more points in a telecommunication network, to support a single communication (see ITU-T Recommendation I.112-310). digital exchange: Exchange that switches digital signals by means of digital switching (see ITU-T Recommendation I.112-116). digital link, digital transmission link : means of digital transmission with specified characteristics between two points digital network, integrated digital network: set of digital nodes and digital links that provides communication between two or more defined points digital section: Whole of the means of transmission of a digital signal of specified rate between two consecutive reference points. The term should be qualified by the type of access supported (see ITU-R Recommendation G.701). digital switching: Process in which connections are established by operations on digital signals without converting them to analogue signals (see ITU-T Recommendation Q.9). digital switching node: node at which digital switching occur (see ITU-T Recommendation Q.9). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 22 digital transmission: Transmission of digital signals by means of a channel or channels that may assume in time any of a defined set of discrete states (see ITU-T Recommendation G.701). digital transmission path: Whole of the means of transmitting and receiving a digital signal of specified rate between two digital distribution frames (or equivalent) at which terminal equipment or switches will be connected. Terminal equipment are those at which the signal originates or terminates. A transmission path is connected through one or more digital sections (see ITU-T Recommendation I.113-501). direct access, direct connection element [ISDN]: Specific access connection element in which the basic access digital section or primary rate access digital section is directly connected to the exchange termination at a V1 or V3 reference point respectively (see ITU-T Recommendation I.112-432). direct debit service: Means that the jobs to bill the users, to receive the billed income and to account the revenue are performed by an entity entitled to manage that for a co-operating group of network and service providers (see TR 101 619 modified). directory number: Catalogue number for a telecommunication subscriber (see TR 101 619). discount: Reduction of the charging for a certain service compared to the generally applicable charging for that service (see TR 101 619). discretely-timed signal: Signal composed of successive elements in time, each element having one or more characteristics which can convey information, for example, its duration, its waveform and its amplitude (see ITU-T Recommendation I.112-104). distributed charging method: It means that charging is distributed partly or completely to the switch points in the network (see TR 101 619). Distributed Computing Environment (DCE): Architecture of standard programming interfaces, conventions, and server functionalities (e.g., naming, distributed file system, remote procedure call) for distributing applications transparently across networks of heterogeneous computers. Promoted and controlled by a consortium called the Open Software Foundation (OSF) (see IETF RFC 1983, IETF RFC 1208 modified). distributed database: Collection of several different data repositories that looks like a single database to the user. A prime example in the Internet is the Domain Name System (see IETF RFC 1983). Distributed Functional Plane (DFP): Plane in the Intelligent Network conceptual model containing functional entities and their relationships (see ITU-T Recommendation Q.1290). Distributed Service Logic (DSL): Logic in the distributed functional plane that is used to realize Service Independent Building blocks (see ITU-T Recommendation Q.1290). distribution service: service characterized by the unidirectional flow of information from a given point in the network to other (multiple) locations NOTE 33: Distribution services are subdivided into two classes: - distribution service without user individual presentation control; and - distribution service with user individual presentation control (see ITU-T Recommendation I.113-1190 [17]). distribution service with user individual presentation control: Distribution service in which the information is provided as sequence of information entities e.g. frames with cyclical repetition, so that the user has the ability to select individual information entities and can control the start and order of the information (see ITU-T Recommendation I.113-120). distribution service without user individual presentation control: Distribution service which users can access without having any control over the start and order of the presentation of the distributed information (see ITU-T Recommendation I.113-1210. distribution, distribution application: Use of a channel for transferring audio, video or other information to a user or a number of users who will not be expected to apply post-production processing to the information (ITU-T Recommendation I.113-110 modified). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 23 domain: part of an entity (a network, an address space etc.) that is managed by a particular commercial or administrative entity domain: Organizations requirements for managing a collection of managed objects in management environment (see ITU-T Recommendation M.60). Domain Name Server (DNS): Server program which supplies name-to-address translation, mapping from domain names to IP address (see TR 101 694). Domain Name System (DNS): General purpose is for distributed, replicated, data query service. The principal use is the lookup of addresses based on names. In the IP case host names are converted to IP addresses. In the Internet the host names are organized in a hierarchy of domains (see IETF RFC 1983 modified). downstream direction: direction from the network towards the user in unidirectional configurations: the direction of the traffic towards the destination DTM network: set of interconnected DTM nodes NOTE 34: A DTM network may be single-domain or multi-domain (see ES 201 803-1 [66]). dynamic arming/disarming: Enabling/disabling of a detection point by a Service Control Function in the course of service control execution for a particular call/service attempt (see ITU-T Recommendation Q.1290). dynamic data: Information subject to change as a result of call/service processing (see ITU-T Recommendation Q.1290). Dynamic synchronous Transfer Mode (DTM): transfer mode in which the information is organized into channels where each channel consists of one or more slots out of the TDM frame NOTE 35: The DTM provides an isochronous network service. E1: Basic building block for the Plesiochronous Digital Hierarchy (PDH) based on the first level hierarchical bit rate of 2,048 Mbit/s (see also: T1). NOTE 36: This is colloquial form. elementary function: Primary or basic function that cannot be further decomposed (see ITU-T Recommendation Q.1290). emulation: Simulation in real time (see ITU-T Recommendation Y.101). encapsulation: Technique used by layered protocols in which a layer adds information to the protocol data unit (PDU) from the layer above (see IETF RFC 1983, IETF RFC 1208 modified). encryption: Encryption is the manipulation of data in order to prevent any but the intended recipient from accessing that data (see IETF RFC 1983 modified). enhanced quality television: Television of a quality superior to existing-quality television, but less than the quality of high-definition television (see ITU-T Recommendation I.113-123). entity: Part, device, subsystem, functional unit, equipment or system that can be individually considered. This corresponds to the concept of Resource in TMN. error check code: specific result of the error detection code mechanism error checking: Examination of received data for transmission errors. See also: checksum, Cyclic Redundancy Check (IETF RFC 1983). Error Detection Code (EDC): Mechanism for error detection (see ITU-T Recommendation I.113-615 modified). ethernet: Standard for LANs. All hosts are connected to a cable where they contend for network access using a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) paradigm (see IETF RFC 1983 modified, ANSI/IEEE Std. 802.3). event: Specific input to and/or output from a given state in a finite state machine model that causes a transition from one state to another (see ITU-T Recommendation Q.1290). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 24 event detection point: Detection point that is dynamically armed (see ITU-T Recommendation Q.1290). exchange: Aggregate of traffic carrying devices, switching stages, controlling and signalling means, and other functional units at a network node that enables subscriber lines, telecommunication circuits and/or other functional units to be interconnected as required by individual users (see ITU-T Recommendation I.112-115). exchange connection: Connection that is established through an exchange. between the terminations on that exchange, of two or more channels or circuits (see ITU-T Recommendation I.112-313). Exchange Termination (ET): Functional group containing at least the layer 2 and layer 3 network-side functions of the ITU-T Recommendation I.420 interface at the T reference point. NOTE 37: This may not be true if concentrators or other intelligent equipment are located in the local line distribution network. NOTE 38: The ET is not the switching function. The extent to which the ET supports call control processing and management is not defined (see ITU-T Recommendation I.112-428 [16]). executive process: Process that controls the execution of other processes (see ITU-T Recommendation Q.1290). existing quality television: Television as defined in conventional 625-line and 525-line standards such as NTSC, PAL and SECAM (see ITU-T Recommendation I.113-122). failure: Termination of the ability of an item to perform a required function (see ITU-T Recommendation I.113-602). Far End Receive Failure (FERF): Specific type of alarm for failure reporting. It indicates that the failure has occurred at or near to the end of the line furthest from the transmitter (see ITU-T Recommendation I.113-616). Fault: Inability of an item to perform a required function, excluding that inability due to preventive maintenance, lack of external resources, or planned actions (see ITU-T Recommendation I.113-603). fault localization: Determination by internal or external test systems of a failed entity (see ITU-T Recommendation I.113-611 modified). fault management cell: Specific OAM cell used for fault management. Various types of fault management cells are defined related to specific functions; e.g. AIS, FERF, Continuity Check (see ITU-T Recommendation I.113-612). feature: See service feature. feature interaction: interference of an entity with the intended and expected behaviour of either of another entity, or of another instance of itself NOTE 39: In the case of service features, interaction occurs either: - when a service feature inhibits or subverts the expected behaviour of another service feature considered separately of another instance of the same service feature; or - when the joint accurate execution of two service features provokes a supplementary phenomenon which cannot happen during the processing of each of the service features considered separately. feedback controls: set of actions taken by the network and by the users to regulate the traffic submitted on ATM connections according to the state of network elements Fiber Distributed Data Interface (FDDI): High-speed (100Mb/s) LAN standard. The underlying medium is fiber optics, and the topology is a dual-attached, counter- rotating token ring (see IETF RFC 1983, IETF RFC 1208). file: Set of related records treated as a unit (see ITU-T Recommendation Q.9). file transfer: Copying of a file from one computer to another over a computer network (see IETF RFC 1983). flow: Number of packets that are sent from a particular source to a particular destination and that are related in terms of their routing and any logical handling policy they may require. Flows can be unicast or multicast, but in any case they are unidirectional (see IETF RFC 1953 modified). flow control: Function which controls the flow of data within a layer or between adjacent layers (see ITU-T Recommendation X.2000. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 25 fragment: piece of a packet EXAMPLE: When a router is forwarding an IP packet to a network that has a maximum transmission unit smaller than the packet size, it is forced to break up that packet into multiple fragments. These fragments will be reassembled by the IP layer at the destination host. See also: Maximum Transmission Unit (see IETF RFC 1983 [74] modified). fragmentation: Process in which a packet is broken into smaller pieces to fit the requirements of a lower layer over which the packet must pass. See also: reassembly, IETF RFC 1983 modified. frame: General term for a delimited amount of data. The occurrence of frames can be synchronous in which case the amount of data is fix (e.g. in transmission systems) or asynchronous where the amount of date may be variable (e.g. in packet switching). frame relay: Transfer of data as a sequence of contiguous bits bracketed by and including beginning and end flag sequences. See frame relaying bearer service. frame relaying bearer service: Frame relaying bearer service provides the bi-directional transfer of variable size Service Data Units (SDUs) from one S or T reference point to another with the order preserved. The SDUs are routed through the network by appropriate layer 2 Protocol Data Units (PDUs) on the basis of an attached label (see ITU-T Recommendation I.233.1). framed interface: Interface where the serial bit stream is segmented into periodic physical frames. Each frame is divided by a fixed partition into an overhead and an information payload portion (see ITU-T Recommendation I.113-311). function: set of processes defined for the purpose of achieving a specified objective NOTE 40: Functions may be ordered in a logical hierarchy (see ITU-T Recommendation I.112-403 [16]). function: Set of processes defined for the purpose of achieving a specified objective (see ITU-T Recommendation I.112-403). Function Element (FE) : Signal representing a functional exchange of layer 1 information at the V1 interface (see ITU-T Recommendation I.112-509). functional entity: Grouping of service providing functions in a single location and a subset of the total set of functions required to provide the service (see ITU-T Recommendation Q.9-7113). Functional Entity Action (FEA): Action performed by a functional entity as a result of a specific stimulus while the functional entity is in a specific state (see ITU-T Recommendation Q.1290). functional group (functional grouping): Set of functions that may be performed by a single equipment (see ITU-T Recommendation I.112-419). gateway: relay mechanism that attaches to two (or more) networks/systems that have similar functions but dissimilar implementations and that enables users on one network to communicate with users on another NOTE 41: In theory, gateways are conceivable at any OSI layer. In practice, they operate at OSI layer 3 (see: bridge, router) or layer 7 (see: proxy server). When the two networks differ in the protocol by which they offer service to hosts, the gateway may translate one protocol into another or otherwise facilitate interoperation of hosts (see IETF RFC 2828 modified [76]). general broadcast signalling virtual channel: Virtual channel independent of service profiles and used for broadcast signalling (see ITU-T Recommendation I.113-410) generic address: Address which identifies a set of Network Service Access Points (NSAPs), rather than a single specific NSAP (see ITU-T Recommendation X.213). geographical and non geographical numbering plan: Geographical numbering plan will use the first digits in the access number for a telecommunication subscription to indicate the geographical area in which the switch point access is located. The non-geographical numbering does not indicate the geographical location of the subscription's switch point access (see TR 101 619). global control: Control of a process whose functions are distributed among several entities (see ITU-T Recommendation Q.1290). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 26 Global Functional Plane (GFP): Plane in the Intelligent Network conceptual model which defines Service Independent building Blocks (SIBs) used in providing service features (see ITU-T Recommendation Q.1290). Global Information Infrastructure (GII): Collection of networks, end user equipment, information, and human resources which can be used to access valuable information, communicate with each other, work, learn, receive entertainment from it, at any time and from any place, with affordable cost on a global scale (see ITU-T Recommendation Y.101). Global Service Logic (GSL): Logic in the Global Functional Plane that is used to realize features (see ITU-T Recommendation Q.1290). grasp: Term used in multicast communication to denote the addition of a new subtree or leaf into an existing multicast distribution tree. The operation thus creates a new (or extends an existing) splitting point of the distribution tree. handover: changing of the path over which information flows between two communicating radio nodes without being disconnected Head End (HE): Element in a CATV system which receives information from a service provider and transmits it towards the end users (see ITU-T Recommendation Y.101 modified). header: Portion of a packet, preceding the actual data, containing control information (see trailer), IETF RFC 1983 modified. hierarchical routing: Complex problem of routing on large networks can be simplified by reducing the size of the networks. This is accomplished by breaking a network into a hierarchy of networks, where each level is responsible for its own routing. home network: Network domain, different from the originating network, containing the (subscriber specific) service data needed during call processing. This domain is called home network because in many cases (but not necessarily) it is the same domain as where the service subscriber resides. hop: Term used in routing. A path to a destination on a network is a series of hops, through routers, away from the origin (see IETF RFC 1983). host: Computer that allows users to communicate with other host computers on a network. Individual users communicate by using application programs, such as electronic mail, Telnet and FTP (see IETF RFC 1983). Hot Billing (HB) : Process to produce a bill immediately after a call release. The input for this is the UMRs produced for the call or similar information (see TR 101 619). hub: device to connect other devices which have to be of the same type Hybrid Fiber Coax (HFC) access network: Access network using FDM transmission technology based on radio frequencies in which fibre links are used for the main distribution path, while coaxial links are used as the final link into the users premises. See also CATV based access network (see ITU-T Recommendation J.1 modified). hybrid interface structure: Interface structure which has a mixture of labelled channels and positioned channels (see ITU-T Recommendation I.113-330). hybrid network [IN]: Overall IN which consists of any concatenation of public and private networks. The user perspective of the services offered by a hybrid network is common and consistent across the public and private network components of the hybrid network. NOTE 42: There are more than one definition which could apply to the term concerned in other areas. hyperlink: Pointer within a hypertext document which points (links) to another document, which may or may not also be a hypertext document. See also hypertext (see IETF RFC 1983). hypertext: Document, written in HTML, which contains hyperlinks to other documents, which may or may not also be hypertext documents. Hypertext documents are usually retrieved using WWW. See also: hyperlink, Hypertext Markup Language, World Wide Web (IETF RFC 1983). Hypertext Markup Language (HTML): Language used to create hypertext documents. It is a subset of the Structured Generalized Markup Language (SGML) and includes the mechanisms to establish hyperlinks to other documents See also: hypertext, hyperlink (see IETF RFC 1983). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 27 idle cell: cell which is inserted or extracted by the physical layer in order to adapt the cell flow rate at the boundary between the ATM layer and the physical layer to the available payload capacity of the transmission system interactive real-time transport connection: connection that is capable of transporting traffic of the type "interactive real-time" (see EG 201 898). IN Conceptual Model (INCM) [IN]: Planning model used for defining the Intelligent Network architecture (see ITU-T Recommendation Q.1290). IN Data Base (INDB) [IN]: Physical entity used for information storage in the Intelligent Network (see ITU-T Recommendation Q.1290). IN Data Base Management System (INDBMS) [IN]: system used for establishing and/or administering information storage in the Intelligent Network NOTE 43: This definition is subject to change (see ITU-T Recommendation Q.1290 [35]). IN supported service [IN]: Service provided using the capabilities of the Intelligent Network (see ITU-T Recommendation Q.1290). increasing charging : Charging which increases stepwise or continuously during the call. See Digressive Charging (see TR 101 619). INFO: Defined layer 1 signal with specified meaning and coding at a basic access user-network interface (see ITU-T Recommendation I.112-507). information flow: Interaction between a communicating pair of functional entities (see ITU-T Recommendation Q.9-7120). information payload capacity: Difference between the interface rate and the interface overhead rate, that is the bit rate of the interface payload (see ITU-T Recommendation I.113-315). in-slot signalling: Signalling associated with a channel and transmitted in a digit time-slot permanently (or periodically) allocated in the channel time-slot (see ITU-T Recommendation I.112-504). instant discount: Discount triggered at the call execution (see TR 101 619). integrated connection: Connection that supports at least two traffic types (see EG 201 898). integrated digital transmission and switching: Direct (digital) concatenation of digital transmission and digital switching, that maintains a continuous digital transmission path (see ITU-T Recommendation I.112-117). Integrated Services Centrex (ISCTX): implementation of a PTNX offering ISDN-like capabilities, as part of public network equipment NOTE 44: An ISCTX is usually located on the premises of a public network operator (see ETS 300 415 [85]). Integrated Services Digital Network (ISDN): Integrated services network that provides digital connections between user-network interfaces (see ITU-T Recommendation I.112-308). integrated services network: Network that provides or supports a range of different telecommunication services (see ITU-T Recommendation I.112-307). Integrated Services Private Branch Exchange (ISPBX): implementation of a PTNX offering ISDN-like capabilities, separate from public network equipment NOTE 45: An ISPBX is usually located on the premises of a private network administrator (see ETS 300 415 [85]). Intelligent Network (IN): Telecommunications network architecture that provides flexibility for facilitating the introduction of new capabilities and services, including those under customer control (see ITU-T Recommendation Q.1290). Intelligent Network Application Protocol (INAP) [IN]: Protocol for Intelligent Network applications contained in layer 7 (application of the OSI model) (see ITU-T Recommendation Q.1290). Intelligent Peripheral (IP) [IN]: Physical entity that implements the Intelligent Network specialized resource function (see ITU-T Recommendation Q.1290). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 28 Inter Carrier Interface (ICI): Interface between networks belonging to different network operators (in North America called carriers) (ITU-T Recommendations SG 4, SG 15). Inter Network Interface (INI) : Interface between two networks. See also Network Node Interface (NNI) (see ITU-T Recommendation Y.101 modified). interaction: mutual or reciprocal action or influence interaction detection: moment when an interaction germination is detected before any interaction manifestation occurs interaction germination: Data modification or initialization which prepares an interaction manifestation either later on in the same call or in a further call. It may take place either at service initialization, or at service activation, or at service subscription, or else during management (data modification). interaction manifestation: moment when an interworking between two services causes a situation viewed as unsatisfactory from any of the actors interaction resolution: Processing of mechanisms designed to solve an unsatisfactory interworking situation, which has germinated either in the same call or in a previous call. This processing is often a consequence of interaction detection. However, it may take place either before (if it is preventative), during or after (if it is curative) interaction germination. interaction spotting : analysis of the new service, in conjunction with already existing service, in order to find as many interaction cases as possible interactive real-time stream: real-time stream related to an interactive application NOTE 46: An interactive real-time stream must use a connection that fulfils the constraints for non-interactive streams plus minimum round-trip delay requirements (see EG 201 898 [65]). interactive service: Service which provides the means for bi-directional exchange of information between users or between users and hosts. Interactive services are subdivided in three classes of services: - conversational services; - messaging services; and - retrieval services (see ITU-T Recommendation I.113-113 [17]). interchange medium: Type of means to interchange data between systems can be either a storage medium, a transmission medium or a combination (see ITU-T Recommendation I.374). interconnection: physical and logical linking of telecommunication networks allowing users of one organization to communicate with users of another organization or to access services provided by another organization interface: Shared boundary between two units (sub systems or devices) (see ITU-T Recommendation Y.101 modified, ITU-T Recommendation Q.9 modified). interface overhead: Remaining portion of the bit stream after deducting the information payload. The interface overhead may be essential (e.g. framing for an interface shared by users) or ancillary (e.g. performance monitoring), see ITU-T Recommendation I.113-313. interface payload: Portion of the bit stream of a framed interface which can be used for telecommunication services. Any signalling is included in the interface payload (see ITU-T Recommendation I.113-312). interface rate; interface bit rate: gross bit rate at an interface, that is, the sum of the bit rates of the interface payload and the interface overhead Example: The bit rate at the boundary between the physical layer and the physical medium (see ITU-T Recommendation I.113-314 [17]). interface specification: Formal statement of the type, quantity, form and other of the interconnections and interactions between two associated systems, at their interface (see ITU-T Recommendation I.112-412). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 29 interface structure, ISDN user-network interface structure: Number and type of the access channels that appear at an ISDN user-network interface (see ITU-T Recommendation I.112-415). Interior Gateway Protocol (IGP): Protocol which distributes routing information to the routers within an autonomous system. The term "gateway" is historical, as "router" is currently the preferred term (see IETF RFC 1983). Intermediate System (IS) [OSI]: OSI system which performs network layer forwarding. It is analogous to an IP router (see IETF RFC 1983). internet: Historically used for a set of interconnected networks (IETF RFC 1983 modified). internet: Collection of interconnected networks using the Internet Protocol (IP) which allows them to function as a single, large virtual network (see ITU-T Recommendation Y.101). internet address: Uniquely identifies a node on the Internet (see IETF RFC 1983). Internet application: Any application normally running on TCP/IP or UDP/IP as described in IETF standards (see TR 101 694). Internet Protocol (IP, IPv4): Internet Protocol (version 4), defined in IETF RFC 791, is the network layer for the TCP/IP Protocol Suite. It is a connectionless, best-effort packet switching protocol (see IETF RFC 1983). Internet Protocol Version 6 (IPng, IPv6): IPv6 is a new version of the Internet Protocol which is designed to be an evolutionary step from its predecessor, version 4 NOTE 47: Version 5 is a stream protocol used for special applications. NOTE 48: There are many IETF RFCs defining various portions of the protocol, its auxiliary protocols, and the transition plan from IPv4. The name IPng (IP next generation) is a nod to STNG (Star Trek Next Generation) IETF RFC 1983 [74] modified. interoperability: Capability to provide successful communication between end-users across a mixed environment of different domains, networks, facilities, equipment etc. (see TR 101 287). interval billing: Billing process in telecommunication performed periodically e.g. in intervals of three months (see TR 101 619). interworking: Ability of equipment to communicate successfully in order to achieve a particular service There may exist intermediate equipment acting as gateways. There are different types of interworking: 1) network interworking: - interactions between different types of networks, end systems, or parts thereof, with the aim of providing an end-to-end communication for a specific service; - refers to the functions and requirements supporting the interworking of networks with different low layer capabilities in order to support the interworking of services across the network boundary, for example, to support 3,1 kHz audio transfer. 2) Service interworking. bearer service interworking: refers to the functions and requirements supporting the communication of terminals operating over different ISDN bearer services within an ISDN teleservice interworking: Refers to the functions and requirements supporting the communication of terminals belonging to different ISDN teleservices (e.g. ISDN teletex to ISDN telefax). Such interworking will involve the use of communication-dependent interworking functions as defined in Recommendation I.510. Teleservice interworking can be supported by interworking functions provided by the network, by a service provider, and/or by terminals. Teleservices interworking and bearer services interworking may also include the support of supplementary services as appropriate. ITU-T Recommendation I.510 modified; ITU-T Recommendation I.501. Intrinsic Burst Tolerance (IBT): Traffic parameter which characterizes the maximum burst duration at a specified peak cell rate, for use together with a Sustainable Cell Rate (SCR) in addition to a Peak Cell Rate (PCR) (see ITU-T Recommendation Y.101). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 30 IntServ Flow : unidirectional flow of IP packets for which in an IntServ (RSVP) reservation is valid NOTE 49: Since RSVP allows senders to share a reservation (resource) a flow can have multiple source addresses(one flow per session). For unicast sessions or if a distinct reservation is made, the flow has only one sender. An IntServ flow is defined by its source address(es), optional source port, destination address and destination port (see TR 101 734 [53]). invalid cell: Cell where the header by the header error control process is declared to contain errors (see ITU-T Recommendation I.113-317). IP (-based) network: general term denoting networks based on the Internet Protocol (IP) suite A network which uses IP as the Layer 3 protocol. IP address: 32-bit address defined by the Internet Protocol in IETF RFC 791. It is usually represented in dotted decimal notation (see IETF RFC 1983). ISDN connection: Connection that is established through an ISDN between specified ISDN interfaces (see ITU-T Recommendation I.112. ISDN customer access (ISDN subscriber access): Equipment providing the concatenation of all functional groups relevant to an individual or group of related access connection elements (i.e. customer equipment and access connection element). NOTE 50: This term should not imply or restrict ownership or responsibility for providing equipment (see ITU-T Recommendation I.112-431 [16]). Isochronous: Essential characteristic of a time-scale or a signal such that the time intervals between consecutive significant instants have durations that are integral multiples of the Unit Interval. NOTE 51: Isochronous and anisochronous are characteristics of a signal, while synchronous and asynchronous are relationships (see US Fed. Std.1037C). jitter: Short-term non-cumulative variations of the significant instants of a digital signal from their ideal positions in time. ITU-T Recommendation G.701-2024 jitter tolerance: In order to ensure that, in general, any equipment can be connected to any appropriate interface within a network, it is necessary to arrange that the input ports of all equipment types are capable of accommodating levels of jitter and wander up to at least the minimum limits defined in the following clauses (see ITU-T Recommendation G.823 modified). NOTE 52: See also ITU-T Recommendations G.825 [89]. labelled channel: Temporally-ordered collection of all block payloads having a common label value (see ITU-T Recommendation I.113-322). labelled deterministic channel: Labelled channel with the property that the aggregated payload capacity of all blocks in each successive interval of specified constant duration is a constant (see ITU-T Recommendation I.113-323). labelled interface structure: Interface structure in which all services and signalling is provided by labelled channels A labelled interface structure can be accommodated within a framed interface or a self-delineating labelled interface (see ITU-T Recommendation I.113-327). labelled multiplexing: Multiplexing of labelled channels by concatenating the blocks of the different channels (see ITU-T Recommendation I.113-325). labelled statistical channel: Labelled channel in which the payload of the successive blocks of the channel is random and/or the block durations are random (see ITU-T Recommendation I.113-324). layer (level): conceptual region that embodies one or more functions between an upper and a lower logical boundary within a hierarchy of functions NOTE 53: The Open System Interconnection (OSI) reference model has seven layers (see ITU-T Recommendation I.112-404 [16]). layer interface: Interface between adjacent layers of hierarchy of layers (see ITU-T Recommendation I.112-410). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 31 leaf, leaf endpoint: endpoint of a point-to-multipoint connection leg: representation within a call processing state model representing a telecommunication path towards some addressable entity (e.g. a path toward a user, intelligent peripheral unit etc.) (see ITU-T Recommendation Q.1290). level: Term level is used when describing the hierarchical structure of a network from a transport viewpoint (see ITU-T Recommendation I.113-511 modified). Library: Assembly of objects, routines, programs, etc. that may be drawn upon for use in the performance of functions (see ITU-T Recommendation Q.1290). line activation: Function which requires the digital line transmission system to be activated but which may also activate the user-network interface (ITU-T Recommendation I.112-604). Line Termination (LT) : Functional group containing at least the transmit and receive functions terminating one end of a digital transmission system (see ITU-T Recommendation I.112-427). line-only activation: Function which requires the activation of only the digital line transmission system and does not activate the user-network interface (see ITU-T Recommendation I.112-605). link connection: Transport entity provided by the client/server association. It is formed by near-end adaptation function, a server trail and a far end adaptation function between connection points. It can be configured as part of the trail management process in the associated server layer (see ETS 300 469). link, transmission link: means of transmission with specified characteristics between two points NOTE 54: The type of transmission path or the capacity is normally indicated, e.g. radio link, coaxial link, or 2 048 kbit/s link (see ITU-T Recommendation I.112-301 [16]). layer network: "topological component" that includes both transport entities and transport processing functions that describe the generation, transport and termination of a particular characteristic information NOTE 55: IP and ATM are examples of layer networks, capable of handling IP and ATM flows respectively. ITU-T Recommendation G.805 modified [10]. Local Area Network (LAN): data network intended to serve an area of only a limited coverage Because of that, optimizations can be made in the network signal protocols NOTE 56: The relevant standards can be found in the IEEE 802.x Series [68], resp. ISO 8802 and IETF RFC 1983 modified [74]. local exchange, ISDN local exchange: Exchange which, in addition to the switching function, contains the exchange termination for the ISDN customer accesses (see ITU-T Recommendation I.112-118). location portability (related to Number Portability): Service that allows the customer to retain his Directory Number when his premises location is moved within a certain area (see TR 101 619). logical channel: Data path access from the user to a packet network (see TR 101 619). Logical Link Control (LLC): Upper portion of the data link layer (layer 2 in OSI model), as defined in IEEE 802.2. The LLC sublayer presents a uniform interface to the user of the data link service, usually the network layer. Beneath the LLC sublayer is the MAC sublayer (see IETF RFC 1983). logical signalling channel: Logical channel for signalling information which is contained within an information channel or a physical signalling channel (see ITU-T Recommendation I.113-408). logical user port: set of VPs at the UNI associated with one single VB5 reference point MAC address: Hardware address of a device connected to a shared media (see IETF RFC 1983). maintenance event: Instantaneous maintenance occurrence that changes the global status of an object (see ITU-T Recommendation I.113-608). Manageability: Characteristic of a set of resources, which allows an enterprise, organization, or consumer to control how these resources are deployed and/or utilized (see ITU-T Recommendation Y.101). managed entity: Physical or logical resource that is to be managed (see ITU-T Recommendation I.113-606). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 32 managed object: See object (ITU-T Recommendation M.60). managed resource/target: Anything that may be subject to (target of) a management activity. These may be physical or logical. These may be related to each others (functionally, hierarchically, by containment, etc...) or independent. management application: Application process participating in systems management. The applications actually implement the management services. management entity: Entity capable of providing management functions (e.g. operation, administration, maintenance and provisioning), see ITU-T Recommendation I.113-605. management function: smallest part of a management service as perceived by the user of the service Management Information Base (MIB): Conceptual repository of management information within an open system. Management information may be shared between management processes and is structured according to the requirements of those processes. The MIB neither restricts the interpretation of management data to a pre-defined set, nor to whether the data is stored in a processed or unprocessed form. However, both the abstract syntax and the semantics of information which is part of the MIB are defined so that they can be represented in OSI protocol exchanges (see ITU-T Recommendation X.700, ITU-T Recommendation M.60). management service: area of management activity which provides for the support of operations, administration, and maintenance of the system being managed management system: Functional system which supports the management of user and/or network information and resources for the proper operation of a service (see ITU-T Recommendation Y.101). manager: role that a management system takes when it is monitoring or controlling managed resources map: To map (over) is to establish a defined correspondence with the quantities or values of another set (see ITU-T Recommendation Q.9). maximum bit rate: Maximum bit rate corresponds to the maximum usable transfer bit rate from the users standpoint (see ETS 300 780). Maximum Transmission Unit (MTU): Largest frame length which may be sent on a physical medium. See also frame, fragment, fragmentation (see IETF RFC 1983). Mbone: Multicast Backbone is based on IP multicasting using class-D addresses (see IETF RFC 1983). mean bit rate: Mean bit rate correspond to the average usable transfer bit rate from the users standpoint (see ETS 300 780). media: Plural of medium (see ITU-T Recommendation Y.101). Media Access Control (MAC): Lower portion of the data link layer (layer 2 in the OSI model). The MAC differs for various physical media (see IETF RFC 1983). mediation device: TMN term indicating a device situated between NE and OS managing information to be transferred between NE and OS (see TR 101 619). medium (plural media): Means by which information is perceived, expressed, stored or transmitted. The term "media" has many meanings depending on the context in which it is used. For unambiguous usage the term should always be accompanied by one of the following expressions: - perception medium; - representation medium; - presentation medium; - storage medium; - transmission medium (see ITU-T Recommendation I.374). merging connection point: connection point merging n to 1connection links ETSI ETSI TR 101 287 V1.2.1 (2001-09) 33 mesochronous: Relationship between two signals whose corresponding significant instants occur at the same average rate. The phase relationship between corresponding significant instants usually varies between specified limits. Telephony's Dictionary. message: traffic type where the instances are datagrams related to events in a controlled system NOTE 57: Messages are usually small, less than 1 kByte. NOTE 58: Signals in the control plane are typical messages (see EG 201 898 [65]). message mode: Mode of service offered by the AAL type 3/4 and 5, where the AAL SDU is passed across the AAL interface in exactly one AAL IDU (see ITU-T Recommendation I.113-523). message transport network: network that in some way is capable of transporting traffic type Message NOTE 59: A signalling network is a typical message transport network (see EG 201 898 [65]). messaging service: Interactive service which offers user-to-user communication between individual users via storage units with store-and-forward, mailbox and/or message handling, (e.g. information editing, processing and conversion) functions (see ITU-T Recommendation I.113-115). meta-signalling: Procedure for establishing, checking and releasing signalling virtual channels (see ITU-T Recommendation I.113-411). metering: Measurement of the usage of resources (e.g. transmission, processing, storage) which can be used for charging. In ETSI sometimes named also "collection of charging information". NOTE 60: The measured usage is being handled as call data record (CDR) data (see TR 101 734 modified [53]). Metropolitan Area Network (MAN): Data network intended to serve an area approximating that of a large city Such networks are being implemented by innovative techniques, such as running fiber cables through subway tunnels. A popular example of a MAN is SMDS (see IETF RFC 1983). middleware: Mediating entity between two information elements. Such an element can be, for example, an application, infrastructure component, or another mediating entity (see ITU-T Recommendation Y.101). mixed document: Document that may contain text, graphics, data, image and moving picture information as well as voice annotation (see ITU-T Recommendation I.113-106). mobility: ability of an entity or element to be used in different systems or environments, with a continuity of services while changing of systems or environment (including geographical position) monitor window : Interval during which an entity performs the monitoring function at the direction of a Service Control Function (see ITU-T Recommendation Q.1290). monitoring cell: Specific OAM cell used for performance monitoring (see ITU-T Recommendation I.113-610). multicast: unidirectional communication from a single source to a subset of the reachable destinations multicast communication: Unidirectional communication from a single source access point to a limited number (more than one) of specified destination access point (see ITU-T Recommendation I.140). multicast distribution tree: Tree like structure that the data distribution path within a network as the data is being transported from one sender unidirectional towards the receivers of the multicast flow or stream. The receivers of the multicast flow or stream is being viewed as leafs in the trees where as the transmitter is being the root of the tree. The distribution tree may be modified under operation to add (see: grasp) or remove (see: prune) tree sections and leafs. multicast group: Set of nodes being a subset of nodes within some network participating in a common multicast session. The group may contain multiple transmitters (IP multicast allows this) and may contain zero or more receivers. Systems allowing for multiple transmitters within some multicast group may allow for a receiver not to listen to all the available transmitters. For such a case may the multicast distribution tree be optimized to only contain the necessary distribution path. multicast group identifier: Identifier used to identify some multicast group. Such an identifier may take the from of an address (see multicast address). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 34 multiconnection call: call which is supported by two or more connections between the users multimedia: Property of a piece of information, an application or user equipment, to handle several types of data. Multimedia is an adjective and must be attached to a noun to define a precise context, e.g. multimedia service, multimedia network, multimedia application (see ITU-T Recommendation I.374). multimedia call: call which offers a multimedia service multimedia service: Service in which the interchanged information consists of more than one type, such as text, graphics, sound, image and video (see ITU-T Recommendation I.113-107). multi-operator/multi-provider environment: Telecommunication area in which a number of network operator and service providers are serving the users (see TR 101 619). multiparty call: call in which three or more users are involved multiparty multiconnection call: call that has both multiparty and multiconnection characteristics multipoint: Communication configuration attribute which denotes that the communication involves more than two network terminations (see ITU-T Recommendation I.113-109 modified). multipoint access: User access in which more than one terminal equipment is supported by a single network termination (see ITU-T Recommendation I.112-422). multipoint-to-multipoint communication: bi-directional asymmetric or bi-directional symmetric communication from multiple ITU-T Recommendation I.140 source access points to multiple destination access points, e.g. conference communication multipoint-to-multipoint connection: Connection between multiple (source) endpoints and multiple (destination) endpoints for bi-directional asymmetric or bi-directional symmetric communication (see ITU-T Recommendation I.140). multipoint-to-point communication: Bi-directional asymmetric, bi-directional symmetric or unidirectional communication from multiple (source) access points to a single (destination) access point, e.g. polling station (and in reverse direction), ITU-T Recommendation I.140. multipoint-to-point connection: Connection between multiple (source) endpoints and a single (destination) endpoint for bi-directional asymmetric, bi-directional symmetric or unidirectional communication (see ITU-T Recommendation I.140). name: Identification of an object. The significance of a name is related to the domain in which it is used. namespace: Commonly distributed set of names in which all names are unique (see IETF RFC 1983). negative acknowledgement (NAK): Response to the receipt of either a corrupted or unexpected packet of information. See also Acknowledgement (see IETF RFC 1983). network: Set of nodes and links that provides communication between two or more defined points (see ITU-T Recommendation I.112-305, Y.101 modified). Network Access Point (NAP): Physical entity that provides network access for users. It contains the Call Control Agent Function and may include the Call Control Function (see ITU-T Recommendation Q.1290). Network Access Server (NAS): new name for "Point of Presence" (POP) network address: Name or number used to identify a node or a nodes interface within the scope of a network. The network address is usually globally unique throughout the network where as there exist several important special cases for which the address is not unique (see: anycast address, broadcast address, loopback address and multicast address). Network Address Translation (NAT) [IP]: Method by which IP addresses are mapped from one address realm to another providing transparent routing to end hosts (see IETF RFC 2663). network charging capabilities : Set of actions and procedures performed by the network in order to determine all the network parameters of a communication, which are required for account management, and to determine the values of these parameters (see ETR 123). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 35 network charging capabilities: Set of procedures performed by the network elements in order to determine all the parameters of one communication session, which are required for assessing the effort provided by the network, and to determine the values of these parameters (see TR 101 734). network connection: Transport entity formed by the series of connections between termination connection points (see ETS 300 469). network determined user busy: Refers to the situation where the network has determined that resources required to complete the call on the called users access interface are not currently available (see ETS 300 780). network interface functions: functions belonging to the Head End in a HFC access network network interworking: co-operation of networks to process, manage and create services, which span multiple networks network layer service: provision of resources by the network for the transmission of data NOTE 61: To provide services above the best effort delivery the mechanisms of the Integrated Services or the Differentiated Services Model can be used (see TR 101 734). Network Node Interface (NNI): Interface at a network node which is used to interconnect with another network node An NNI connecting two nodes in different networks is sometimes referred to as an Inter Network Interface (INI). network operator: network operator is responsible for the development, provisioning and maintenance of real-time networking services and for operating the corresponding networks Network Parameter Control (NPC): Set of actions taken by the network to monitor and control traffic at the inter Network Node Interface, to protect network resources from malicious as well as unintentional misbehaviour by detecting violations of negotiated parameters and taking appropriate actions (see ITU-T Recommendation I.113-706) network portability [Number Portability]: Service that allows the customer to retain the Directory Number when he from the same location is shifting to another network access. The Recipient Network type can be different from the Donor Network type and/or the Recipient Network and the Donor Network can belong to different Network Operators (see TR 101 619 [54]). Network Provider (NP): Term with the same significance as the term "Network operator" (see TR 101 619). Network Termination (NT): functional group on the network side of a user-network interface NOTE 62: In ITU-T Recommendation I.430 and I.431, "NT" is used to indicate network terminating layer 1 aspects of NT1 and NT2 functional groups (see ITU-T Recommendation I.112-418 [16]). Network to Network Interface type A (NNI-A) : Interface between a long-distance backbone network and a local network (see ITU-T Recommendation Y.101). Network to Network Interface type B (NNI-B): Interface between a long-distance backbone network and a peer long-distance backbone network (see ITU-T Recommendation Y.101). networking function: Enables a platform to provide network capabilities for a service (see TR 101 615). Network Operator (NO): Entity which provides the network operating elements and resources for the actual execution of services (see ETS 300 780). node address: Network layer address of a node (ES 201 803-1). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 36 node, switching node, network node: In network topology, a terminal of any branch of a network, or a terminal common to two or more branches of the network. From technical point of view, a configuration of engineering objects forming a single unit for the purpose of location in space, and which embodies a set of processing, storage and communication functions. Specifically: - In a switched communications network, the switching points, including patching and control facilities (e.g. exchanges). - In a data network, the location of a data station which interconnects data transmission lines (e.g. routers). A point in a cable television network, at which signals are switched and distributed (e.g. Hubs) Telephony's Dictionary, ITU-T Recommendation X.903, modified; ITU-T Recommendation J.1 Amd.1. nomadicity: Continuity of access between two information infrastructure components as they move in space (see ITU-T Recommendation Y.101). non real-time stream: collection of non-real-time flows EXAMPLE 2: A set of interleaved ATM cells transporting several files in parallel (see EG 201 898 [65]). non-interactive real-time flow : real-time flow which is serving a non-interactive application EXAMPLE 3: Video-on-demand transmission from repository to video player for direct view (see EG 201 898 [65]). non-interactive real-time stream: collection of non-interactive real-time flows EXAMPLE 3: Several TV channels transported over one physical medium in an interleaved mode (see EG 201 898 [65]). non-interactive real-time transport connection: Connection that in some way is capable of transporting traffic type non-interactive real-time flow (see EG 201 898). non-real-time flow: Flow which is serving a non real-time application (see EG 201 898 modified). non-switched connection: Connection that is established without the use of switching, for example by means of hard-wired joints (see ITU-T Recommendation I.112-312). non-switched connection element, non-switched ISDN connection element: ISDN connection element that is established without switching (see ITU-T Recommendation I.112-319). number: Name expressed as a string of digits. In some cases it may contain location information. number portability: Possibility for a telecommunication customer to retain the directory number when his access is moved to another network type, to another Network Operator, or if he moves his geographical location within the switchpoint area, within the numbering area, within the charging area or anywhere (see TR 101 619). OAM cell: Cell that carries OAM information for the performing of specific OAM functions. The term maintenance cell is often used as synonym for OAM cell (see ITU-T Recommendation I.113-609). OAM flow: Bi-directional information flow for the performance of OAM functions in the network (see ITU-T Recommendation I.113-613). OAM level: OAM functions are organized in five OAM hierarchical levels associated with the ATM and the Physical Layer, to which correspond five OAM flows (see ITU-T Recommendation I.113-512). object: View of one or more resources. The abstract view of such a resource that represents its properties as seen by (and for the purpose of) management (see ITU-T Recommendation M.60). one-step activation: Type of activation which invokes a sequence of actions to activate the digital line transmission system and user-network interface from a single command (see ITU-T Recommendation I.112-606). one-step deactivation: Deactivation of the digital line transmission system and user-network interface invoked by a single command (see ITU-T Recommendation I.112-608). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 37 Open Systems Interconnection (OSI): Suite of protocols, designed by ISO committees, to be the international standard computer network architecture (see IETF RFC 1983, ITU-T Recommendations X.200-, X.600-, X.700-, X.800- series of common texts with ISO). Operations System (OS): TMN term indicating a management system (see TR 101 619). Operations Systems (OS): Physical block which performs operations system functions (OSFs), see ITU-T Recommendation M.3010. Operations Systems Function block (OSF): OSF processes information related to telecommunication management for the purpose of monitoring/co-ordinating and/or controlling telecommunications functions and support functions including management functions (i.e. the TMN itself), see ITU-T Recommendation M.60. optional service feature: service feature added to core features to optionally enhance a service offering originating network: network domain from where the call is set-up OSI Reference Model: Seven-layer structure designed to describe computer network architectures and the way that data passes through them. This model was developed by the ISO in 1978 to clearly define the interfaces in multivendor networks, and to provide users of those networks with conceptual guidelines in the construction of such networks (see IETF RFC 1983 and ITU-T Recommendation X.200). out-slot signalling: Signalling associated with a channel and transmitted in one or more separate digit time-slots not within the channel time-slot (see ITU-T Recommendation I.112-505). packet: Ordered set of bits which may have variable length and which may contain control information (see EG 201 898 modified). packet switching: Communications paradigm in which packets (messages) are routed between hosts. See also circuit switching IETF RFC 1983 modified. packet transfer mode: Transfer mode in which the transmission and switching functions are achieved by packet oriented techniques, so as to dynamically share network transmission and switching resources between a multiplicity of connections (see ITU-T Recommendation I.113-208). payload module: That portion of the information payload, of an interface, within which one or more channels entirely exist (see ITU-T Recommendation I.113-316). Payload Type Identifier (PTI): 3-bit field in the ATM cell header identifying the type of payload. NOTE 63: The use of this identifier is specified in ITU-T Recommendation I.361 [90] . Peak Cell Rate (PCR): Upper limit on the rate at which cells can be submitted on an ATM connection (see ITU-T Recommendation Y.101). perception medium: Nature of the information as perceived by the user (see ITU-T Recommendation I.374). performance management: Set of management functions which enable the performance of the network services to be measured and corrective actions to be taken (see ITU-T Recommendation I.113-617). performance management cell: Specific OAM cell used for performance management (ITU-T Recommendation I.113-618 modified). performance monitoring: Action of continuous or periodic checking of a managed entity to test its normal functioning (see ITU-T Recommendation I.113-619). periodic frame: Transmission segment which is repeated at intervals of equal duration (e.g. 125 µs), and may be delineated by incorporating fixed periodic patterns into the bit stream (see ITU-T Recommendation I.113-310). permanent activation: Activation of a system, or part of a system, that will not be deactivated even it is not required to be fully operating (see ITU-T Recommendation I.112-603). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 38 permanent circuit service, permanent circuit telecommunication service: type of telecommunication service in which the communication path is established in response to a customer request effected by means of an operational or administrative message NOTE 64: Release of the communication path is effected in a similar way to its establishment (ITU-T Recommendation I.112-207 [16]). Permanent Virtual Circuit (PVC): A permanent virtual circuit is a permanent "connection" for an undefined period of time or a permanent "connection" only set up according to calendar statements, periodically or non-periodically. A permanent virtual circuit relates to packet oriented traffic (see TR 101 619). persistent data: Information that endures beyond a single instance of use, e.g. longer than one call attempt (see ITU-T Recommendation Q.1290). personal mobility: ability of a user to access telecommunication services at any terminal on the basis of a personal identifier, and the capability of the network to provide those services according to the user's service profile NOTE 65: Personal mobility involves the network capability to locate the terminal associated with the user for the purposes of addressing, routing and charging of the user's calls (see ITU-T Recommendation I.114-102 [88]). phase: period within a session in which the traffic characteristics do not change NOTE 66: A new phase is entered if the reservation parameters are renegotiated. NOTE 67: If a session can consist of multiple flows, the traffic characterization can be different for each flow. A phase specifies a period of a session or a period of a flow. Since charging parameters (like price per time unit or length of a measurement interval) can depend on the time of day, the entering of a new time period (e.g. business hours) might be also considered as the entering of a new phase (see TR 101 734 [53]). physical frame: Segment of a serial logical bit stream at an interface, partitioned into successive segments (see ITU-T Recommendation I.113-309). physical interface: Interface between two equipments (see ITU-T Recommendation I.112-411). physical interface specification (physical interface): Formal statement of the mechanical, electrical, electromagnetic and optical characteristics of the interconnections and interactions between two associated equipments, at their interface (see ITU-T Recommendation I.112-413). physical link: Unidirectional connection between the transmitter part of one port to the receiver side of another port (see ES 201 803-1). physical plane: Plane in the Intelligent Network conceptual model containing elements and their interfaces that implement functional entities (see ITU-T Recommendation Q.1290). physical signalling channel: Dedicated physical channel (e.g. D-channel) used for signalling information It may be used to carry other information (see ITU-T Recommendation I.113-407). plane: Part of a functional model (see ITU-T Recommendation Q.1290 modified, ITU-T Recommendation I.322). platform: Set of capabilities that enable the provision of services to users (see TR 101 615). player: Player is an organization, or individual, which undertakes one or more roles (see ITU-T Recommendation Y.101). plesiochronous: relationship between two signals such that their corresponding significant instants occur at nominally the same rate, any variation being constrained within a specified limit NOTE 68: There is no limit to the phase difference that can accumulate between corresponding significant instants over a long period of time (see US Fed. Std.1037C). Point In Call (PIC): State in a basic call state model (see ITU-T Recommendation Q.1290). Point Of Initiation (POI): Functional interface between basic call processing and service logic over which service control is initiated (see ITU-T Recommendation Q.1290). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 39 Point Of Presence (POP): Initial entry point to a network for the majority of users of network services. It is the first device in the network to provide services to an end user, and acts as a gateway for all further services. As such, its importance to users and service providers alike is paramount. There is a new term introduced for the POP: Network Access Server (NAS) (see ETF RFC 2881 [77]). Point Of Return (POR): Functional interface between service logic and basic call processing over which call processing control is returned to basic call processing (see ITU-T Recommendation Q.1290). point-to-multipoint communication: Bi-directional asymmetric or bi-directional symmetric communication from one (source) access point to multiple (destination) access points (and in reverse direction) (see ITU-T Recommendation I.140). point-to-multipoint connection: Connection between one (source) endpoint and multiple (destination) endpoints for bi-directional asymmetric or bi-directional symmetric communication (see ITU-T Recommendation I.140). point-to-multipoint ISDN connection: ISDN connection that is established between a single specified ISDN interface, and more than one other specified ISDN interface (see ITU-T Recommendation I.112-320). point-to-point ISDN connection: ISDN connection that is established between two specified ISDN interfaces (see ITU-T Recommendation I.112-320). port: Termination through which signals can enter or leave a network. In the Internet used as a logical address for the application (see ITU-T Recommendation B.13). portability: Ability of an entity or element to be used in different systems or environments (see ITU-T Recommendation Y.101 modified). positioned channel: Channel that occupies bit positions which form a fixed periodic pattern (e.g. B- H- and D-channels in ISDN user network interfaces), see ITU-T Recommendation I.113-328. positioned interface structure: Structure in which all services and signalling are provided by positioned channels Such a structure can exist only within a framed interface (see ITU-T Recommendation I.113-329). post-production processing: Further processing of contributed audio and video information, to change the form or presentation of the information prior to its final utilization (see ITU-T Recommendation I.113-112). presentation medium: Type of physical means which is used to reproduce information to the user (output device) or the acquired information from the user (input device) (see ITU-T Recommendation I.374). price Information unit: Technical entity handling requests for charging information to the served users e.g. Advice Of Charge (see TR 101 619). pricing: correlation between "money" and "goods" or "service" NOTE 69: The term is not generally used in telecommunications, the usual term being "tariffing" (see TR 101 734 [53]). primary rate access: ISDN user access arrangement that corresponds to the primary rates of 1 544 kbit/s and 2 048 kbit/s. The bit rate of the D-channel for this type of access is 64 kbit/s. The typical primary rate interface structures are as given in ITU-T Recommendation I.412 and I.431 (see ITU-T Recommendation I.112 modified). primitive: See service primitive. private: Attribute indicating that the application of an item qualified by "private", e.g. a network, a unit of equipment, a service, is offered to a pre-determined set of users. This attribute does not indicate any aspects of ownership. NOTE 70: This definition does not include legal or regulatory aspects ETS 300 415 [85]. private network: Network which provides services to a specific set of users only (see ITU-T Recommendation I.570). Private Telecommunication Network (PTA): Network serving a pre-determined set of users (different from a public network which provides services to the general public). The attribute "private" does not indicate any aspects of ownership. NOTE 71: This definition does not include legal or regulatory aspects. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 40 NOTE 72: PTNs are sometimes referred to as Corporate Telecommunication Networks (CTNs). PTNs may extend over large geographical areas. This definition does not imply any specific implementation. NOTE 73: It is the intention to align the definition of "PTN" with that of "Private Integrated Service Network (PISN)" as defined by ISO/IEC 11579-1 [91]. This will facilitate the evolution towards the consistent world-wide use of the term "PISN". This will not invalidate the scope of the service standardized by ETSI for PTNs (see ETS 300 415 [85]). Private Telecommunication Network eXchange (PTNX): PTN nodal entity that provides automatic switching and call handling functions used for the provision of telecommunication services. The nodal entity can be implemented by one or more pieces of equipment located on the premises of the private network administrator or by equipment co-located with, or physically part of, a public network. NOTE 74: If applicable, a PTNX provides to users of the same and/or other private telecommunication network exchanges: - telecommunication services within its own area; and/or - telecommunication services from the public ISDN; and/or - telecommunication services from other public or private networks; and/or - within the context of a private telecommunication network, telecommunication services from other private telecommunication network exchanges. NOTE 75: It is the intention to align the definition of "PTNX" with that of "Private Integrated Services Network eXchange (PINX)" as defined by ISO/IEC 11579-1 [91]. This will facilitate the evolution towards the consistent world-wide use of the term "PINX". A PTNX may perform the functions of one or more of the node types given for ISPBX and ISCTX (see ETS 300 415 [85]). protocol: Formal statement of the procedures that are adopted to ensure communication between two or more entities (see ITU-T Recommendation I.112-405 modified). Protocol Data Unit (PDU): Unit of information consisting of protocol control information and possibly user data exchanged between peer protocol layer entities (see ITU-T Recommendation H.223, modified, ITU-T Recommendation Q.921, modified). protocol layer: group of one or more functions within an upper and lower logical boundary within a protocol reference model [layer (N) has boundaries to layer (N + 1) and to layer (N - 1)] based on ITU-T Recommendation Q.9-2160 (definition of "layer") protocol stack: Layered set of protocols which work together to provide a set of network functions (see IETF RFC 1983). prune: Term used to denote the removal of a multicast subtree or leaf from an existing multicast distribution path tree. The operation thus removes (or reduces) a split point of the distribution path tree. public: Attribute indicating that the application of the so-qualified item, e.g. a network, a unit of equipment, a service, is offered to the general public. This attribute does not indicate any aspects of ownership. NOTE 76: This definition does not include legal or regulatory aspects (see ETS 300 415 [85]). public network: Network which provides services to the general public (see ITU-T Recommendation I.570). Q3-interface: TMN term indicating the interface between an OS-device and a Mediation Device or an OS-device and a NE-device (see TR 101 619, ITU-T Recommendation M.3010). quality of service: Collective effect of service performances which determine the degree of satisfaction of a user of the service (see ITU-T Recommendation Y.101). real-time flow: Flow that is serving a real-time demanding application, where the time position of each piece of information in the flow is significant (see EG 201 898). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 41 real-time stream: Collection of real-time flows, e.g. a set of interleaved telephone calls transported in simplex mode. NOTE 77: Real-time streams may recursively be multiplexed into higher-order real-time streams. E.g. SDH/SONET. It must be supported by a protocol that is synchronous or plesiochronous. There are two kinds of real-time streams: - interactive real-time streams; and - non-interactive real-time streams (see EG 201 898 [65]). real-time transport connection: connection that in some way is capable of transporting traffic type Real-time flow NOTE 78: The major requirement for this connection is to support timing integrity. NOTE 79: There are two kinds of requirements: non-interactive real-time transport connection and interactive real-time transport connection (see EG 201 898 [65]). reassembly: process in which a previously fragmented packet is reassembled before being passed to the next higher layer. See also: fragmentation (IETF RFC 1983, modified). recipient network: Network where the ported number is located after being ported (see TR 101 619). reference configuration: Combination of functional groups and reference points that shows possible network arrangements (see ITU-T Recommendation I.112-421). reference point: Conceptual point at the conjunction of two non-overlapping functional groups (see ITU-T Recommendation I.112-420 and Y.101, modified). regenerator section: Portion of a digital section. It is a maintenance sub-entity (see ITU-T Recommendation I.113-503). regenerator section level: Extends between regenerator section endpoints (see ITU-T Recommendation I.113-514). relationship: Complete set of information flows, where they exist, between two functional entities (see ITU-T Recommendation Q.65). reliability: Probability that a product or system will perform as required for a specified period of time (see ITU-T Recommendation Y.101). remote access, remote access connection element: Specific access connection element in which the digital section is not directly connected to the exchange termination but is connected through a multiplexer or concentrator (see ITU-T Recommendation I.112-433). remote login: Operating on a remote computer, using a protocol over a computer network, as though locally attached. See also Telnet (IETF RFC 1983). remote network: Remote network denotes every domain different from the originating network domain. That is, it denotes the same as home and terminating network. This term is used in cases that it makes no difference whether the network is in the terminating or home domain. repeater: equipment essentially including one or several amplifiers and/or regenerators, and associated devices, inserted at a point in a transmission medium NOTE 80: A repeater may operate in one or both directions of transmission (see ITU-T Recommendation G.601-1001 [6]). representation medium: Type of the interchanged data, which defines the nature of the information as described by its coded form (see ITU-T Recommendation I.374). reserved circuit service, reserved circuit telecommunication service: type of telecommunication service in which the communication path is established at a time specified in advance by the user, in response to a user request effected by means of user-network signalling NOTE 81: The duration of communication, or the time of release of the communication path, may also be specified in advance by the user (see ITU-T Recommendation I.112-206 [16]). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 42 resource: Manageable functional parts of telecommunication and support equipment which can be unambiguously defined (see ITU-T Recommendation M.60). retrieval service: Interactive service which provides the capability of accessing information stored in data base centres This information will be send to the user on demand only. The information can be retrieved on an individual basis, i.e. the time at which an information sequence is to start is under control of the user (see ITU-T Recommendation I.113-117). revenue accounting : Technical process of accounting the collected revenue for jointly service provision to a group of users and distribute it to the interworking and/or co-operating service/network providers (see TR 101 619). roaming: Process of changing mobile station's attachment from one Location Area to another within one system or between different systems. Those different systems using the same technology or being based on multi-mode terminals relying on different technologies. role: Role is a business activity that is intended to add value to certain goods/services (see ITU-T Recommendation Y.101). root, root endpoint: endpoint of a point-to-multipoint connection to which all other endpoints (leaf endpoints) are connected Round-Trip Time (RTT): Measure of the current delay on a network (see IETF RFC 1983). route: path through one or more networks between endpoints router: Device that is a gateway between two networks at OSI layer 3 and that relays and directs data packets through that internetwork. The most common form of router operates on IP packets. NOTE 82: Internet usage: In the context of the Internet protocol suite, a networked computer that forwards Internet Protocol packets that are not addressed to the computer itself (see IETF RFC 2828 modified [76]). routing: set of instructions on how to reach a destination routing domain: Set of routers exchanging routing information within an administrative domain. The term routing domain is used in the OSI context. The IP world uses the term Autonomous System (see IETF RFC 1983 modified). RSVP session: session (data flow) defined by destination address (unicast or multicast), optionally destination port number and the protocol ID of the transport-layer protocol NOTE 83: For multicast communication a destination port is not mandatory. For unicast communication a destination port number should be specified in order to distinguish several unicast sessions to the same hosts (see TR 101 734 [53]). segment: Segment is a well defined set of functions, part of one role, owned and operated by one player, part of one (and only one) service provisioning platform, and part of one domain (see ITU-T Recommendation Y.101). selective broadcast signalling virtual channel: Virtual channel allocated to a service profile and used for broadcast signalling (see ITU-T Recommendation I.113-411). self-delineating block: Block with the property that its endpoints can be identified by examining the block itself A defined pattern or flag at the beginning of each block might serve to demarcate the block (see ITU-T Recommendation I.113-302). self-delineating labelled interface: Interface whose entire bit stream consists of a self delineating labelled multiplexing (see ITU-T Recommendation I.113-326). server: Provider of resources (e.g. file server, name server, mail server, etc.), see IETF RFC 1983. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 43 service telecommunication service: set of functions and capabilities offered by a service provider to its customers/users and designed to satisfy a specific telecommunication requirement NOTE 84: In this definition, the "user" and "provider" may be a pair such as application/application, human/computer, customer/operator. NOTE 85: Depending on the layers involved in the service two types can be distinguished: - tele service: all 7 layers are involved; - bearer service: only a transport up to layer 3 it provided; - layer service: service offered by one layer in a layered protocol model to other layers (see ITU-T Recommendation I.112 (93), 201 [16]; ITU-T Recommendation Q.921 (97) [34]). Service Access Point (SAP): Point at which an OSI layer provides services to the next higher layer (see ITU-T Recommendation J.1, ITU-T Recommendation Q.2931). service attribute, telecommunication service attribute: specified characteristic of a telecommunication service NOTE 86: The value(s) assigned to one or more service attributes may be used to distinguish that telecommunication service from others (see ITU-T Recommendation I.112-208 [16]). service bit rate: Bit rate which is available to a user for the transfer of user information (see ITU-T Recommendation I.113-102). service component: Services can be complex and can be made up of a number of service components which may also be optional (see ITU-T Recommendation Y.110 modified). service control: Direction of the functions or processes used to provide a specific telecommunications service (see ITU-T Recommendation Q.1290). service control element: Primitives needed to control a multimedia service, for example to start a call, to add or release a service component (see ITU-T Recommendation I.374). Service Control Function (SCF): Application of service logic to control functional entities in providing Intelligent Network services (see ITU-T Recommendation Q.1290). service control parameters: What a subscriber can control regarding a subscription to a telecommunication service The service control parameters are specified by the service customization parameters. Service Control Point (SCP): Entity in the Intelligent Network that implements a service control function (see ITU-T Recommendation Q.1290). service control service: service enabling a subscriber to change the behaviour of his/her subscription to a telecommunication service after the service provisioning service creation: Activity whereby the capability to provide a supplementary service is brought into being from specification to development and verification (see ITU-T Recommendation Q.1290). service creation deployment: Step which provides for the distribution of service creation components amongst physically disparate service creation environments. This step will also co-ordinate the distribution of completed service to multiple Service Management Functions (SMFs). NOTE 87: This definition is subject to change . Service Creation Environment Function (SCEF): set of functions that support the service creation process, the output of which includes both service logic programs and service data NOTE 88: This definition is subject to change (see ITU-T Recommendation Q.1290 [35]). Service Creation Environment Point (SCEP): Physical entity that implements the service creation environment function (see ITU-T Recommendation Q.1290). service creation management: Activity which provides for the management and integrity of the service creation environment itself. This includes the maintenance and recovery of the service creation environments; the interaction of multiple service creation environments. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 44 service creation platform: Set of service independent objects or functions which allow the creation of services in an Intelligent Network (see ITU-T Recommendation Q.1290). service creation process: Conception, design and implementation of a capability to provide a service (see ITU-T Recommendation Q.1290). service customization parameters: what a subscriber can specify regarding subscription to a telecommunication service, service control service and service monitoring service through negotiation with a service manager NOTE 89: This definition is subject to change . service customization service: This provides customization of the telecommunication service, the service control service and the service monitoring service, which are going to be provided to the subscriber after provisioning The service customization is based on subscriber's requirements during the service provisioning phase. NOTE 90: The wording "service provisioning phase" depends on the outcome of service life cycle model work. service data: Customer and/or network information required for the proper functioning of a service (see ITU-T Recommendation Q.1290). Service Data Function (SDF): Set of functions that provides for the management of service data in accordance with a service data template (see ITU-T Recommendation Q.1290). Service Data Point (SDP): Physical entity that implements a service data function (see ITU-T Recommendation Q.1290). Service Data Template (SDT): specific logical structure for a collection of data objects, including allowable ranges for their values and other data consistency specifications, related to a specific service logic processing program Service Data Unit (SDU): Unit of information that is transferred by a layer across a service access point, i.e. across the upper boundary of the layer (see ITU-T Recommendation Q.2931 (95), J.1; ITU-T Recommendation H.223 (96), modified). service deployment: introduction of a service into the IN-structured network in a subscriber independent way service development: Activity which transform a high level structured design into a detailed structured software design and subsequently develops the necessary software components, data definitions, etc. required to realize that design The major output of this activity is the developed service software and documentation which is ready for more rigorous service verification testing. Service Feature (SF): Specific aspect of a telecommunication service that can also be used in conjunction with other telecommunication services/service features as part of a commercial offering. It is either a core part of a telecommunication service or an optional part offered as an enhancement to a telecommunication service. service independence: Not necessarily specific to one service (see ITU-T Recommendation Q.1290). service independent: Not dependent on the availability of other services; or having freedom to create any service desired (see ITU-T Recommendation Q.1290). Service Independent building Block (SIB): reusable set of functional entity actions and (information flows) used to provide a service feature or a part of a service feature in an Intelligent Network service instance: particular combination of service data and service logic that applies to only one service subscriber service interaction: Interference of an entity with the intended and expected behaviour either of another entity, or of another instance of itself. In the case of services, interaction occurs either: - when a service inhibits or subverts the expected behaviour of another service considered separately (or of another instance of the same service); or - when the joint accurate execution of two services provokes a supplementary phenomenon which cannot happen during the processing of each of the services considered separately. service internetworking: Situation where an individual service is used in a connection which exists partly inside one network and partly inside one or more other networks, or which, for certain operational aspects, routes through more than one network. There are more than one definition which could apply to the term concerned in other areas. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 45 service interworking: joint execution of two or several services service life cycle: Description of both stages and steps involved during the complete life of any service, in a service independent manner. It is considered the basis defining the possible behaviour of a service at all times, the stages identified covering all aspects of the service life, including its "death". Service Logic (SL): Sequence of processes/functions used to provide a specific service (see ITU-T Recommendation Q.1290). Service Logic Processing program (SLP): Software program containing service logic (see ITU-T Recommendation Q.1290). Service Logic Processing program (use) Instance (SLPI): Invocation and application of a particular service logic program in providing a service or a service feature for a specific call/service attempt (see ITU-T Recommendation Q.1290). service management: Service management is concerned with, and responsible for: - subscriber facing; - management of information relating to the contractual aspects of services that are being provided to subscribers or available to potential new subscribers, within the bounds specified by policies produced by the business management (layer); - the proper operation of services; - provisioning of information to the network management required for the proper planning, deployment, provisioning and operation of network resources necessary to support services; - interaction with the business management (layer) for guidelines and policies; and - interaction with service providers NOTE 91: Business management (layer) functionality is not yet fully defined. Service Management Agent Function (SMAF): functional interface between network operators and/or subscribers and network service management functional entities NOTE 92: This definition applies only to Capability Set 1 (see ITU-T Recommendation Q.1290 [35]). Service Management Function (SMF): set of processes that support the management of user and/or network information, including service data and service logic programs that are required for the proper operation of a service NOTE 93: This definition applies only to Capability Set 1, replaced for future work by OSF (ITU-T Recommendation Q.1290 [35]). Service Management Point (SMP): physical entity that implements a service management function NOTE 94: This definition applies only to Capability Set 1, replaced for future work by OS (see ITU-T Recommendation Q.1290 [35]). service management service: commercial offering to subscribers to satisfy their requirements to customize, to control and to monitor the telecommunication service for which it is provided NOTE 95: Definition subject to change. service monitoring data: Data a subscriber can monitor regarding his subscription to a telecommunication service. The service monitoring data are specified by service customization parameters. NOTE 96: Definition subject to change. service monitoring service: service which enables a subscriber to get information about the usage of a subscription to telecommunication service after the service provisioning NOTE 97: Definition subject to change. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 46 service node (SN): Network element that provides access to various switched and/or permanent telecommunication services. It contains one or several of the functions to provide a service (e.g. service control functions, service data functions, specialized resource functions, service switching and control). ITU-T Recommendation Y.101 modified, ITU-T Recommendation G.902 (95) modified. Service Node Interface (SNI): interface between an access network and a service node service plane: Plane in the Intelligent Network conceptual model that contains services, service entities and their relationships (see ITU-T Recommendation Q.1290). service primitive; primitive: Abstract, implementation-independent interaction between a service user and the service provider (see ITU-T Recommendation Y.101). service processing: Execution of service control and basic call processing functions to provide a service (see ITU-T Recommendation Q.1290). service profile: collection of information maintained by the network characterizing a set of services provided by the network to a user service profile management; UPT service profile management: ability to access and manipulate the UPT service profile NOTE 98: UPT service profile management can be performed by the UPT user, UPT customer or UPT service provider (see ITU-T Recommendation I.114-108 [88]). service provider (SP): Actor who provides services to its service subscribers on a contractual basis and who is responsible for the services offered. The same organization may act as a network operator and a service provider. service provisioning: process covering all the activities which relate to creating service instances of a service type, preparing them for operation and eventually withdrawing them service specification: transformation of the service requirements into a description agreed with the customer or the service provider, and definition of a high level design by means of refinement of detailed description requirements and functional analysis service subscriber: Entity that contracts for services offered by service providers (see ITU-T Recommendation Q.1290). Service Support Data (SSD): Set of service specific data parameters for Service Independent Building Blocks (see ITU-T Recommendation Q.1290). Service Switching and Control Point (SSCP): Physical entity that contains the Service Control Function, Service Data Function and the Service Switching/Call Control Functions (see ITU-T Recommendation Q.1290). Service Switching Function (SSF): Set of processes that provide for interaction between a call control function and a service control function (see ITU-T Recommendation Q.1290). Service Switching Point (SSP): Physical entity that implements a service switching function (see ITU-T Recommendation Q.1290). Service Trigger Information (STI): stimulus information for initiating an action. It may be distinguished between Trigger Detection Point (TDP) initiating the Service Logic (SL) and Event Detection Point (EDP) reporting an event to the running SL service type: collection of functions and data distributed across network resources, providing the potential for the offering of a service instance to a customer service user: See user. service verification: Step in the service creation process where the developed service software (including supporting documentation) is rigorously tested to validate that the resulting service application completely satisfies the specification. The principal output of this step is thus the verified service software and supporting documentation required for deployment. session: Period of communication between one user and another or other users, characterized by a clearly defined starting point and a clearly defined termination point (see TR 101 734 modified). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 47 SIG: Signal representing an exchange of layer 1 information between line terminations of a digital transmission system for basic access (see ITU-T Recommendation I.112-508). signal: Physical phenomenon one or more of whose characteristics may vary to represent information (see ITU-T Recommendation I.112-102). signalling: Exchange of information specifically concerned with the establishment and control of connections, and with management, in a telecommunication network (see ITU-T Recommendation I.112-501). Signalling Virtual Channel (SVC): Virtual channel for transporting signalling information (see ITU-T Recommendation I.113-409). simple call: Two party call supported by one connection. The connection can be unidirectional or bi-directional. simulation: imitation of the characteristics and appearance of a particular function single point of control: Control relationship where the same phase or aspect of a call/service attempt is influenced by one and only one Service Control Function (see ITU-T Recommendation Q.1290). single-ended service feature: Feature, e.g. call/service attempt manipulation, that applies to only one of the parties that may be involved on a call/service attempt (see ITU-T Recommendation Q.1290). slot [DTM]: Time slot containing 64 bits of control or user data. The slot may also hold a special code for idle data, error slot and end of packet marker (see ES 201 803-1). sound retrieval service: On-demand (user initiated) retrieval of music and other audio information (see ITU-T Recommendation I.113-118). source traffic descriptor: Set of traffic parameters belonging to the ATM traffic descriptor, which is used during the connection set-up to capture the intrinsic traffic characteristics of the connection requested by the source (see ITU-T Recommendation I.113-709). Specialized Resource Function (SRF): Set of functions that provide for the control and access to resources used in providing services in the Intelligent Network (see ITU-T Recommendation Q.1290). speech digit signalling: Type of channel-associated signalling in which digit time-slots primarily used for the transmission of encoded speech are periodically used for signalling (see ITU-T Recommendation I.112-506). split charging: Charging of the call types to be paid partly by the calling party and partly by the called party (see TR 101 619). splitting point: connecting point splitting 1 to n connection links static arming/disarming: enabling/disabling of a detection point, as directed by a Service Management Function, to cause a specified action by call/service processing whenever a specific point in call/service processing is encountered NOTE 99: This definition applies only to Capability Set 1 (see ITU-T Recommendation Q.1290 [35]). static data: Information that remains unchanged for the duration of a call or incident of use of a service (Usually controlled by a source external to the network), see ITU-T Recommendation Q.1290. statistical; ATM statistical: Mode of the asynchronous transfer mode in which the information transfer capacity specified for a given service provided to the user throughout a call is expressed in terms of values of parameters such as mean, peak and standard deviation (see ITU-T Recommendation I.113-210). statistical multiplexing: Multiplexing in which channels are established on a statistical basis, i.e., connections are made according to probability of need (see US Fed. Std. 1037C). Statistical Time-Division Multiplexing (STDM): Time-division multiplexing in which connections to communication circuits are made on a statistical basis (see US Fed. Std. 1037C). storage medium: Type of physical means to store data (see ITU-T Recommendation I.374). stream: reoccurring transmission of data bound by some timing requirements NOTE 100: Streams may be real-time or non-real-time. Streams are either sequential or parallel over some particular resource (see EG 201 898 [65]). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 48 stream transport: function that enables transmission of streams through a connection NOTE 101: Stream creation includes segmentation, adding of control data and other adaptations to the physical layer protocol (see EG 201 898 [65]). streaming mode: Mode of service offered by the AAL type 3/4 and 5, where the AAL SDU is passed across the AAL interface in one or more AAL IDUs (see ITU-T Recommendation I.113-524). Structured Data Transfer (SDT): supports the transmission of structured data (blocks of user data organized in octets) by using a pointer to the start of a block (see ETS 300 353). Structured Generalized Markup Language (SGML): to be used for creation management, storage and delivery of information products stub network: Stub network only carries packets to and from local hosts. Even if it has paths to more than one other network, it does not carry traffic for other networks (see IETF RFC 1983). subnet: Portion of a network, which may be a physically independent network segment, which shares a network address with other portions of the network and is distinguished by a subnet number (see IETF RFC 1983, IETF FIY 4). subnet address: Subnet portion of an IP address. In a subnetted network, the host portion of an IP address is split into a subnet portion and a host portion using an address (subnet) mask. See also: address mask, IP address, network address, host address (IETF RFC 1983). subnet mask: See address mask (IETF RFC 1983). subnet number: See subnet address (IETF RFC 1983). sub-network: Topological component used to effect routing and management. It describes the potential for sub-network connections across the sub-network. It can be partitioned into interconnected sub-networks and links. Each sub-network in turn can be partitioned into smaller sub-networks and links and so on. A sub-network may be contained within one physical node (see ETS 300 469). sub-network connection: Transport entity formed by a connection across a sub-network between connection points It can be configured as part of the trail management process (see ETS 300 469). subscriber: User of a telecommunication service, normally based on a contract with the provider of a public service ITU-T Recommendation F.500 (92). supplemented call: Basic call with added service features or capabilities (see ITU-T Recommendation Q.1290). Sustainable Cell Rate (SCR): Upper limit on the long term average cell transfer rate of an ATM connection (ITU-T Recommendation Y.101). switch node: Node that contains a switching function (see ES 201 803-1). switched connection: connection that is established by means of switching NOTE 102: A switched connection may be used to support both demand and reserved circuit services ITU-T Recommendation I.112-311 [16]. switched connection element, switched ISDN connection element: ISDN connection element that is established by means of switching (ITU-T Recommendation I.112-318). Switched Multimegabit Data Service (SMDS): High-speed datagram-based public data network service developed by Bellcore originally expected to be widely used by telephone companies as the basis for their data networks. See also Metropolitan Area Network (IETF RFC 1983, IETF RFC 1208). switching: Process of interconnecting transmission channels or telecommunication circuits in multiplex systems (ITU-T Recommendation I.112-113 modified). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 49 synchronous: Signal is said to be synchronous with some other signal if you can predict an event on the first signal by looking at the second signal or vice versa. The signals are required to have the same frequency but may have some phase offset between them. The phase offset may vary over time (see: jitter). Phase variations below 0,1 UI is commonly accepted for synchronous signals (for larger phase variations see: mesochronous). NOTE 103: Isochronous and anisochronous are characteristics of a signal, while synchronous and asynchronous are relationships. Synchronous Digital Hierarchy (SDH): International standard for high-speed communications (ITU-T Recommendation G.707, ITU-T Recommendation G.803 modified). Synchronous Optical NETwork (SONET): Standard for high-speed communications closely related to SDH ANSI T1.105.06-1996 (Revision of T1.106-1988). synchronous time division multiplexing: Multiplexing techniques supporting the synchronous transfer mode (STM) (see ITU-T Recommendation I.113-203). Synchronous Transfer Mode (STM): Transfer mode which offers periodically to each connection a fixed-length word (see ITU-T Recommendation I.113-205). system protection: Action of minimizing the effect of a managed entity by blocking or changeover to other entities (as a result the failed entity is excluded from operation), see ITU-T Recommendation I.113-607. T1: Colloquial term for a digital carrier facility used to transmit a DS-1 formatted digital signal at 1,544 megabits per second (see IETF RFC 1983 modified). tariff: Charged price per usage element or per group of usage elements (see TR 101 619). tariffing: Determination of the prices to be applied for services and service elements (see TR 101 619). TCP/IP Protocol Suite: Transmission Control Protocol over Internet Protocol. This is a common shorthand which refers to the suite of transport and application protocols which runs over IP (see IETF RFC 1983). teleaction service (telemetry service): type of telecommunication service that uses short messages, requiring a very low transmission rate, between the user and the network NOTE 104: Examples of teleaction services are telealarm, telecommand, telealerting (see ITU-T Recommendation I.112-204). telecommunication: 1) The exchange of information over a distance. 2) Any transmission and/or emission and reception of signals representing signs, writing, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems. NOTE 105: In the context of communication via electromagnetical means (see ITU-T Recommendation G.701- 1006 [7]). telecommunication network: See network. teleservice (telecommunication service): Type of telecommunication service that provide the complete capability, including terminal equipment functions, for communication between users according to protocols established by agreement between Administrations and/or RPAs (see ITU-T Recommendation I.112-203). Terminal Equipment (TE) : functional group on the user side of a user-network interface NOTE 106: In ITU-T Recommendation I.430 [92] and I.431 [93], "TE" is used to indicate terminal terminating layer 1 aspects of TE1, TA and NT2 functional groups (see ITU-T Recommendation I.112-417 [16]). terminal mobility: Ability of a terminal to access telecommunication services from different locations and while in motion, and the capability of the network to identify and locate that terminal (see ITU-T Recommendation I.114-101). Terminal MoveAbility (TMA): Enables the terminal to retain its subscriber's unique identity when moved between access points. Access is not permitted while the terminal is being moved. The terminal registers with the network at each new location. ETSI ETSI TR 101 287 V1.2.1 (2001-09) 50 terminating network: network domain to where the call is connected throughput: Number of data bits contained in a block (e.g. between the address field and the CRC field of the LAPD-based frames) successfully transferred in one direction across a section per unit time (see ITU-T Recommendation I.113-303). Time To Live (TTL): Field in the protocol control information which indicates how long this protocol data unit (PDU) should be allowed to live before being discarded. In IP it is primarily used as a hop count (see IETF RFC 1983 modified). timing integrity: characteristic of a connection A-B such that a bit received at node B was sent by node A not earlier than a defined time unit NOTE 107: This relationship needs only to be maintained when data are in transit from A to B. NOTE 108: This relationship, as it is defined above, does not preclude loss of bits in transit. It says that if a bit arrives at B, it is delayed within a certain limit. Thus if all bits shall arrive with a bounded delay, both content and timing integrity must be demanded (see EG 201 898 [65]). token ring: Token ring is a type of LAN with nodes wired into a ring. each node constantly passes a control message (token) on to the next; whichever node has the token can send a message. Often, "Token Ring" is used to refer to the IEEE 802.5 token ring standard, which is the most common type of token ring (see IETF RFC 1983). topology: physical arrangement of network nodes and media within an networking structure traffic contract: Requested QOS for any given ATM connection and the maximum CDV tolerance allocated to the CEQ (see ITU-T Recommendation I.113-710). traffic control: Set of actions taken by the network in all relevant network elements to avoid congestion conditions (see ITU-T Recommendation I.113-701). traffic descriptor: set of values of traffic parameters for a given communication relation traffic parameter: Specification of a particular traffic aspect. It may be qualitative or quantitative. traffic routeing: establishment of a successful connection between any two exchanges or connectionless servers in the network traffic shaping: mechanism that may alter the pattern of an ATM stream of cells on a VPC or a VCC to achieve desired modification of traffic characteristics, maintaining cell sequence integrity of the connection traffic type: traffic for which the same requirements, and thus the same rules and functions apply for all flows of the type NOTE 109: There are four traffic types: message, file, real-time non-interactive and real-time interactive (see EG 201 898 [65]). trailer: Portion of a packet, following the actual data, containing control information (see header). transceiver: Combination of transmitter and receiver (see IETF RFC 1983). transfer mode: Mechanism for transmission, multiplexing and switching in a telecommunications network (see ITU-T Recommendation I.113-201 modified). transit delay: Time difference between the instant at which the first bit of the address field of a frame crosses one designated boundary, and the instant at which the last bit of the closing flag of the frame crosses a second designated boundary (see ITU-T Recommendation I.113-801). transit network: Transit network passes traffic between networks in addition to carrying traffic for its own hosts It must have paths to at least two other networks (see IETF RFC 1983). transmission: action of conveying signals from one point to one or more points NOTE 110: Transmission can be effected directly or indirectly, with or without intermediate storage. NOTE 111: The use of the English word "transmission" in the sense of "emission" is deprecated (see ITU-T Recommendation I.112-106 [16]). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 51 Transmission Control Protocol (TCP): Internet Standard transport layer protocol defined in IETF RFC 793. It is connection-oriented and stream-oriented, as opposed to UDP (see IETF RFC 1983). transmission medium: Type of physical means to transmit data (see ITU-T Recommendation I.374). transmission path level: Extends between network elements assembling/disassembling the payload of a transmission system and associating it with its OAM functions (see ITU-T Recommendation I.113-512). transport protocol: Any transport service protocol running on ATM/AAL5 (see TR 101 694). trigger: Stimulus for initiating an action (see ITU-T Recommendation Q.1290). Trigger Detection Point (TDP): Detection point in basic call processing that is statically armed (see ITU-T Recommendation Q.1290). tunnelling: Tunnelling refers to encapsulation of protocol A within protocol B, such that A treats B as if it was a data link layer. Tunnelling is used to transfer data between administrative domains which use a protocol that is not supported by the internet connecting those domains (see IETF RFC 1983). twisted pair: Type of cable in which pairs of conductors are twisted together to produce certain electrical properties (see IETF RFC 1983). two-party call: call in which exactly two users are involved two-step activation: Type of activation which is initiated by one command to invoke a sequence of actions to activate the digital line transmission system and continued by a second command to invoke a sequence of actions to activate the user-network interface (see ITU-T Recommendation I.112-607). unassigned cell (ATM layer): ATM layer cell which is not an assigned cell unicast: qualifier indicating that an unidirectional communication configuration is involved Uniform Resource Locators (URL): Compact (most of the time) string representation for a resource available on the Internet. URLs are primarily used to retrieve information using WWW. The syntax and semantics for URLs are defined in IETF RFC 1738. See also World Wide Web. (IETF RFC 1983, IETF RFC 1738). Unit Interval: Nominal difference in time between consecutive significant instants of a signal. One Unit Interval is one cycle time of the clock signal. (See also synchronous, isochronous, asynchronous, anisochronous), ITU-T Recommendation G.701 modified. Universal Personal Telecommunication (UPT) service: service which provides personal mobility and UPT service profile management NOTE 112: This involves the network capability of uniquely identifying a UPT user by means of a UPT number. NOTE 113: The general principles of universal personal telecommunication are given in ITU-T Recommendation F.850 [94] (see ITU-T Recommendation I.114-103 [17]). Universal Personal Telecommunication Number (UPTN): number that uniquely identifies a UPT number and is used to place, or forward, a call to that user NOTE 114: A user may have more than one UPT number (for example a business UPT number for business calls and a private UPT number for private calls). In that case, from a network point of view, each UPT number is considered to identify a distinct UPT user, even if they all happens to identify the same person or entity (see ITU-T Recommendation I.114-106 [88]). upstream direction: a) in a bi-directional configuration: direction from the user towards the network; b) in unidirectional configurations: the direction of the traffic towards the source. UPT customer (UPT subscriber): person who, or entity which, obtains a UPT service from a UPT service provider on behalf of one or more UPT users and is responsible for payment of the charges due to that service provider NOTE 115: The general terms "customer" is defined in ITU-T Recommendation D.000 [2] (see ITU-T Recommendation I.114-104 [88]). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 52 UPT routing address: Number used by the network to direct a call according to the user's UPT profile (see ITU-T Recommendation I.114-110). UPT user: Person who, or entity which, has access to universal personal telecommunication (UPT) services and has been assigned a UPT number (see ITU-T Recommendation I.114 modified). usage element: Feature, service or function associated with a telecommunication usage and suitable for payment (see TR 101 619). usage metering: Registration of the telecommunication resources or services used by a served user (see TR 101 619). usage metering data: Data, which represents usage of telecommunication resources or services by a served user (see TR 101 619). usage metering record: Data item for a specific user containing information of resource or service usage (see TR 101 619). Usage Parameter Control (UPC): Set of actions taken by the network to monitor and control traffic at the User Network Interface, to protect network resources from malicious as well as unintentional misbehaviour by detecting violations of negotiated parameters and taking appropriate actions (see ITU-T Recommendation I.113-705). user: Entity which actually uses a service (see TR 101 734). user access, user-network access: Means by which a user is connected to a telecommunication network in order to use the services and/or facilities of that network (see ITU-T Recommendation I.112-402). User Datagram Protocol (UDP): Internet Standard transport layer protocol defined in IETF RFC 768 It is a connectionless protocol which adds a level of reliability and multiplexing to IP (see IETF RFC 1983, IETF RFC 768). user determined user busy: Refers to the case where the user chooses to indicate the busy condition. Busy conditions are described in ITU-T Recommendation I.221 (see ETS 300 780). User Interface Functions (UIF): Functions in an access network, interacting with the user equipment, and providing a RF communication interface with the Head End it is connected to EG 201 400. User Network Interface (UNI): interface at which a customer equipment is connected to a network user, user of a telecommunication network: Person or machine delegated by a customer to use the service facilities of a telecommunication network (see ITU-T Recommendation I.112-401). user-network interface only deactivation: Deactivation of the user-network interface which does not deactivate the digital line transmission system (see ITU-T Recommendation I.112-609). user-user protocol: Protocol that is adopted between two or more users in order to ensure communication between them (see ITU-T Recommendation I.112-407). valid cell: Cell where the header is declared by the header error control process to be free of errors (see ITU-T Recommendation I.113-318). Variable Bit Rate (VBR) service: Type of telecommunication service characterized by a service bit rate specified by statistically expressed parameters which allow the bit rate to vary within defined limits (see ITU-T Recommendation I.113-104). VC connection: Concatenation of virtual channel links that extends between two points where the adaptation layer is accessed (see ITU-T Recommendation I.113-403). VC cross connect: Network element which connects VC links; it terminate VPCs and translates VCI values and is directed by Management Plane functions (see ITU-T Recommendation I.113-519). VC level: Extends between network elements performing virtual channel connection termination functions, and it is shown extending through one or more virtual path connections (see ITU-T Recommendation I.113-516). VC link: Mean of unidirectional transport of ATM cells between a point where a virtual channel identifier value is assigned and the point where that value is translated or removed (see ITU-T Recommendation I.113-402). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 53 VC switch: Network element which connects VC links; it terminates VPCs and it translates VCI values. It is directed by control plane functions (see ITU-T Recommendation I.113-520). vendor or implementation independent: Characteristic that products from different vendors are able to work together in the same environment, and/or, physical units serving as the same functional entity(ies) produced by different vendors can be used interchangeably (see ITU-T Recommendation Q.1290). Very high speed Digital Subscriber Line (VDSL): Modem technology that enables/converts twisted-pair telephone lines to be used as access paths for multimedia and high-speed data communications. VDSL uses higher bit rates than ADSL. These bit rates may or may not be different in both directions (ITU-T Recommendation Y.101). video: Electronic image with the capability to reproduce movement (see ITU-T Recommendation Y.101). videomessaging: Messaging service for the transfer of moving pictures with or without other information (see ITU-T Recommendation I.113-116). Virtual Channel (VC): Concept used to describe unidirectional transport of ATM cells associated by a common unique identifier value (see ITU-T Recommendation I.113-401). Virtual Channel Identifier (VCI): Identifies a particular VC link for a given Virtual Path Connection (VPC) (see ITU-T Recommendation I.150). virtual circuit: virtual circuit is a logically emulated circuit NOTE 116: The term "virtual" indicates that the connection is of an abstract nature (see EG 201 898 [65]). Virtual Path (VP): Concept used to describe unidirectional transport of ATM cells belonging to virtual channels that are associated by a common identifier value (see ITU-T Recommendation I.113-404). Virtual Path Connection (VPC): Concatenation of virtual path links that extends between the point where the virtual channel identifier values are assigned and the point where those values are translated or removed (see ITU-T Recommendation I.113-406). Virtual Path Identifier (VPI): Identifies a group of VC links, at a given reference point, that share the same VPC (see ITU-T Recommendation I.150). Virtual Private Network (VPN): that part of a CTN that uses shared switched network infrastructures provided by one or more third parties NOTE 117: The functionality provided by a VPN includes transit-PTNX functionality and/or end-PTNX functionality. NOTE 118: ISCTX and ICN are examples of VPN components (see ETS 300 415 [85]). VP cross connect: Network element which connects VP links; it translates VPI values and is directed by management plane function (see ITU-T Recommendation I.113-517). VP level: Extends between network elements performing virtual path connection termination functions, and it is shown extending through one or more virtual path connections (see ITU-T Recommendation I.113-515). VP link: Group of virtual channel links, identified by a common value of the virtual path identifier, between the point where the VPI value is assigned and the point where the VPI value is translated or removed (see ITU-T Recommendation I.113). VP switch: Network element which connects VP links; it translate VPI values and is directed by Control Plane functions (see ITU-T Recommendation I.113-518). VP-VC cross connect: Network element that may act as VC cross-connect and/or and VP cross-connect (see ITU-T Recommendation I.113-521). VP-VC switch: Network element that may act as VC switch and/or VP switch (see ITU-T Recommendation I.113-522). video server: Physical entity that stores video contents for retrieval by users (see ITU-T Recommendation Y.101). ETSI ETSI TR 101 287 V1.2.1 (2001-09) 54 wander: Long-term non-cumulative variations of the significant instants of a digital signal from their ideal positions in time (see ITU-T Recommendation G.701- 2025). Wide Area Network (WAN): Network, usually constructed with serial lines, which covers a large geographic area See also: Local Area Network, Metropolitan Area Network (see ETF RFC 1983). work station [TMN]: physical entity that implements the work station function block Work Station Function block (WSF) : WSF provides the means to interpret TMN information for the management information user. The WSF includes support for interfacing to a human user (see ITU-T Recommendation M.60). World Wide Web (WWW, W3): Internet and hypertext-based, distributed information system/service created by researchers at CERN in Switzerland. Users may create, edit or browse hypertext documents. The clients and servers are freely available (see IETF RFC 1983). X-interface: TMN term indicating the interface between OS-devices (see TR 101 619). zone: logical group of network devices 1) collection of terminals, Gateways, and Multipoint Control Units managed by a single Gatekeeper. A Zone may be independent of network topology and may be comprised of multiple network segments which are connected using routes or other devices (see IETF RFC 1983 [74]). 2) ITU-T Recommendation H.323 (99), 3.49 modified [15]. |
c2a9bcd3f800610f3c425de0c4adcad1 | 101 287 | 5 Abbreviations and acronyms | AAL ATM Adaptation Layer AAL-CU AAL Composite User (obsolete, now = AAL2) AAL-IDU AAL Interface Data Unit AAL-PCI AAL Protocol Control Information AAL-SDU AAL Service Data Unit AATF ATM Access Termination Functions ABR Available Bit Rate ABT ATM Block Transfer ACE Access Connection Element ACF ATM Control Functions ACTS Advanced Communications Technologies and Services AD ADjunct ADSL Asymmetric Digital Subscriber Line AE Application Entity AFI Authority and Format Identifier AIS Alarm Indication Signal AL Access Link AL ALignment AMF ATM Mapping Functions AMIMF ATM based MSS Interconnection Management Functions AN Access Network ANI Access Network Interface ANS ATM Name Server ANTF ATM Network Termination Functions AOC Advice Of Charge AP Access point (to the access network) API Application Programming Interface APS Automatic Protection Switching ARP Address Resolution Protocol ASE Application Service Element ASP Applications Support Platform ATAF ATM Transit Access Functions ATC ATM Transfer Capability ATD Asynchronous Time Division ATF Access Termination Functions ETSI ETSI TR 101 287 V1.2.1 (2001-09) 55 ATM Asynchronous Transfer Mode ATMNE ATM Network Element ATM-SDU ATM Service Data Unit AU Administrative Unit AUU ATM-layer-User-to-ATM-layer-User BA Basic rate Access (ISDN) BAsize Buffer Allocation size B-BBC Broadband Bearer Control Channel BC Bearer Control BCD Binary Coded Decimal BCDBS Broadband Connectionless Data Bearer Service BCOBS Broadband Connection Oriented Bearer Service BCP Basic Call Process BCSM Basic Call State Model BER Bit Error Ratio BGP4 Border Gateway Protocol 4 BIP Bit Interleaved Parity B-ISDN Broadband Integrated Services Digital Network B-ISPBX Private Branch EXchange for B-ISDN B-ISUP B-ISDN User Part BM Business Management B-NT Network Termination for B-ISDN B-NT1 Network Termination 1 for B-ISDN B-NT2 Network Termination 2 for B-ISDN BOM Beginning Of Message BPCR Backward Peak Cell Rate BR Billing Report BS Burst Scale B-TA Terminal Adaptor for B-ISDN Btag Beginning Tag B-TE Terminal Equipment for B-ISDN0 BVPS Broadband Virtual Path Service (ETS 300 455 [95]) CA Customer Access CAC Connection Admission Control CAD Computer Aided Design CAM Computer Aided Manufacturing CAMC Customer Access Maintenance Centre CASE Core ATM Switching Equipment CATV Community Antenna TeleVision CBDS Connectionless Broadband Data Service CBR Constant Bit Rate CC Call Control CC Charging Centre CC Country Code CC Cross Connect CCAF Call Control Access (agent) Function (ITU-T Recommendation I.114 [88]) CCAF Call Control Agent Function CCF Call Control Function CCF Connection (call) Control Function (ITU-T Recommendation I.114 [88]) CCITT Comité Consultatif International Telegraphique et Telephonique CDR Call Detail Record CDV Cell Delay Variation CDVT Cell Delay Variation Tolerance CE Congestion Experienced CE Connection Element CE Connection Endpoint CEC Cell Error Count CEI Connection Endpoint Identifier CEP Connection End Point CEQ Customer EQuipment CER Cell Error Rate CES Circuit Emulation Service ETSI ETSI TR 101 287 V1.2.1 (2001-09) 56 CES Connection Endpoint Suffix CF Connection Functions CF Core Function CI Customer Installation CIB CRC Indication Bit CID Call Instance Data CIF Common Intermediate Format CIME Customer Installation Maintenance Entities CL ConnectionLess CLAI CL Access Interface CLATF CL Access Termination Functions CLCP CL Convergence Protocol CLHF CL Handling Functions CLL ConnectionLess Layer CLLR&R ConnectionLess Layer Routing & Relaying CLMF CL Mapping Functions CLNAP CL Network Access Protocol CLNI CL Network Interface CLNIP CL Network Interface Protocol CLNTF CL Network Termination Functions CLP Cell Loss Priority CLR Cell Loss Ratio CLS Connectionless Server CLSF Connectionless Service Function CM Call Model CME Connection Management Entity CMI Coded Mark Inversion CMR Cell Misinsertion Ratio C-n Container - n CN Customer Network CNIS Platforms supporting provision of Communication and Networking of Information Services CO Connection Oriented COH Connection Overhead COM Continuation of Message CON Concentrator CONS Connection Oriented Network Service COTS Connection Oriented Transport Service CP Control Plane CP-AAL Common Part of AAL type CPCS Common Part Convergence Sublayer CPCS-PDU CPCS Protocol Data Unit CPCS-SDU CPCS Service Data Unit CPCS-UU Common Part Convergence Sublayer User-User CPE Customer Premises Equipment CPI Common Part Indicator CPN Customer Premises Network CRC Cyclic Redundancy Check CREn Cell transfer Reference Event n CRF Connection Related Function CRF(VC) Virtual Channel Connection Related Function CRF(VP) Virtual Path Connection Related Function CS Capability Set CS Cell Scale CS Convergence Sublayer CS1 Capability Set 1 (IN) CSCW Computer Supported Cooperative Work CSDN Circuit Switched Data Network CSI Convergence Sublayer Indication CSM Call Segment Model CSMA/CD Carrier Sense Multiple Access with Collission Detection CS-PDU Convergence Sublayer Protocol Data Unit CSTA Computer Supported Telecommunications Applications ETSI ETSI TR 101 287 V1.2.1 (2001-09) 57 CSU Channel Service Unit CTD Cell Transfer Delay CTF Control Functions CTM Cordless Terminal Mobility CTP Connection Termination Point CUG Closed User Group DA Destination Address DAB Digital Audio Broadcast DASH Description of Architecture and Services Harmonization DAVIC Digital AudioVisual Council DBR Deterministic Bit Rate DBS Direct Broadcast Satellite DCE Data Circuit-terminating Equipment DFP Distributed Functional Plane DIFFSERV DIFFerentiated SERVices DIPSS Platforms supporting provision of Distributed Information Processing & Storage Services DIS Draft International Standard DLCI Data Link Connection Identifier DNIC Data Network Identification Code DNS Domain Name Server DNS Domain Name System (Internet) DP Detection Point DPL Distributed Primary Link DPT Dynamic Packet Transport DQDB Distributed Queue Dual Bus DS Differentiated Services (field) DS Digital Section DSAP Destination Service Access Point DSL Distributed Service Logic DSM-CC Digital Storage Media - Command and Control DSP Domain Specific Part DSS Distributed Sample Scrambler DSS1 Digital Subscriber Signalling System No. 1 DSS2 Digital Signalling System No. 2 DSU Data Service Unit DTE Data Terminal Equipment DTM Dynamic synchronous Transfer Mode DTMF Dual Tone Multi-Frequency DVB Digital Video Broadcast DWDM Dense WDM EBCN Explicit Backward Congestion Notification EBTN European Backbone Telecommunication Network EC Error Correction ECTRA European Committee for Telecommunications Regulatory Affairs ED Error Detection EDC Error Detection Code EDP Event Detection Point EFCI Explicit Forward Connection Indication EFCN Explicit Forward Congestion Notification EIF European Infrastructure Forum EII European Information Infrastructure EM Element Management EoM End of Message EPD Early Packet Discards EPII European Project Information Infrastructure ESP End of SPeaker identification ET Exchange Termination ETag End Tag ETR ETSI Technical Report ETS European Telecommunication Standard EURESCOM European Institute for Research and Strategic Studies in Europe F1 ... F5 OAM flows 1 ... 5 ETSI ETSI TR 101 287 V1.2.1 (2001-09) 58 FAM Functional Architecture Model FCS Frame Check Sequence FDDI Fibre Distributed Data Interface FDM Frequency Division Multiplex FE Function Element FE Functional Entity FEA Functional Entity Action FEBE Far End Block Error FEC Forward Error Correction FERF Far End Receive Failure FIFO First In First Out FITL Fiber In The Loop FM Fault Management FMBS Frame Mode Bearer Service FPCR Forward Peak Cell Rate FPLMTS Future Publis Land Mobile Telecommunication Systems (I.114) FR Frame Relay FRM Fast Resource Management FRP Fast Reservation Protocol FTAM File Transfer Access and Management FTP File Transfer Protocol, (Internet) GA Group Address GAHF Group Address Handling Functions GAP Group Addressed PDU GBE Gigabit Ethernet GBSVC General Broadcast Signalling Virtual Channel GCRA Generic Cell Rate monitoring Algorithm GCS Platforms supporting provision of Generic Communications Services GDMO Guidelines for the Definition of Managed Objects GFC Generic Flow Control GFP Global Functional Plane GII Global Information Infrastructure GME Global Management Entity GMM Global Multimedia Mobility GONOW Globalising and Opening Networks; Overview and Workplan GSL Global Service Logic GSM Global System for Mobile Communications GVPI Global Virtual Path Identifier (JAMES project) HB Hot Billing HDLC High level Data Link Control HDSL High bit rate Digital Subscriber Line HDTV High Definition TeleVision HE Head End HE Header Extension HEC Header Error Control HEL Header Extension Length HFC Hybrid Fiber Coax HIC Header Integrity Check HLF Higher Layer Functions HLPI Higher Layer Protocol Identifier HLR Home Location Register (GSM) HOL Head Of Line HTML HyperText Markup Language (Internet) HTTP HyperText Transport Protocol (Internet) IAHC International Ad Hoc Committee (Internet) IBC Integrated Broadband Communication IBT Intrinsic Burst Tolerance ICI Inter Carrier Interface ICI Interface Control Information ICIP Inter-Carrier Interface Protocol ICS Implementation Conformance Statement ID IDentification ETSI ETSI TR 101 287 V1.2.1 (2001-09) 59 IDI Initial Domain Identifier IDP Initial Domain Part IDP Internet Datagram Protocol IDU Interface Data Unit IEC International Electrotechnical Commission IEEE Institute of Electrical and Electronic Engineers IETF Internet Engineering Task Force (Internet) ILMI Interim Local Management Interface (ATM Forum) IMAI Interworking MAN ATM Interface IMF Interworking Management Functions IMPDU Initial MAC Protocol Data Unit IMT2000 International Mobile Telecommunications in the year 2000 IN Intelligent Network INAP Intelligent Network Application Protocol (IN) INCM Intelligent Network Conceptual Model INDB Intelligent Network Data Base INDBMS IN Data Base Management System INFA Intelligent Network Functional Architecture INI Inter Network Interface IntServ Integrated Services IP Intelligent Peripheral IP Internet Protocol IPL Primary Link for Interactive services IPX Internetwork Packet EXchange IRP Internal Reference Point IS International Standard ISCTX Integrated Services CenTreX ISDN Integrated Services Digital Network ISE Integrated Switching Element (JAMES project) ISO International Organization for Standardization ISP Information Service Provision ISP Internet Service Provider ISPBX Integrated Services Private Branch eXchange ISUP ISDN Signalling User Part ISUP ISDN User Part IT Information Type ITP International Transit Portion (JAMES project) ITU International Telecommunication Union ITU-T International Telecommunication Union - Telecommunication Standardization Sector ITU-TSS International Telecommunication Union- Telecommunication Standardization Sector (old term) IWF InterWorking Function IWU InterWorking Unit JAMES Joint ATM Experiment on european Services JPEG Joint Picture Experts Group LAN Local Area Network LAPD Link Access Procedure on the D-channel LCD Loss of Cell Delineation LE Layer Entity LE Local Exchange LEX Local EXchange LFC Local Functions Capabilities LI Length Indicator LI Link Identifier LIS Logical IP Subnetwork (IETF RFC 1577 [96]) LLC Logical Link Control LLC Low Layer Compatibility LLID Loopback Localization IDentifier field (OAM working group) LME Layer Management Entity LOC Loss Of Cell delineation LOC Loss Of Continuity check LOM Loss Of Management LOP Loss Of Pointer ETSI ETSI TR 101 287 V1.2.1 (2001-09) 60 LOS Loss Of Signal LSB Least Significant Bit LSI Large Scale Integration LT Line Termination LTA Long Term IN Architecture MA Medium Adaptor MAC Media Access Control MAC Multiplexed Analogue Components (a TV standard) MAI MSS ATM Interface MAN Metropolitan Area Network MBS Maximum Burst Size (ITU-T Recommendation I.371 [23]) MBS Mobile Broadband System MBS Monitoring Block Size MCD Maintenance Cell Description MCU Multipoint Control Unit ME Mapping Entity MIB Management Information Base MID Multiplexing IDentification MIM Management Information Model MIME Multipurpose Internet Mail Extensions, (Internet) MIN Multistage Interconnection Networks (JAMES project) MIR Maximum Information Rate MMC MSS Management Centre MMF MSS Management Functions MoU Memorandum of Understanding MP Measurement Point MPEG Moving Pictures Expert Group MPI Measurement Point associated with international Interface MPLS Multi Protocol Label Switching MPOA MultiProtocol over ATM MRVT MTP Routing Verification Test MS Multiplex Section MSB Most Significant Bit MSC Mobile-services Switching Center (GSM, I.114) MSN Monitoring cell Sequence Number MSP Maintenance Service Provider MSP Mini cell Start Pointer MSS MAN Switching System MSVC Meta Signalling Virtual Channel MTP Message Transfer Part MUX MUltipleXer NA Network Aspects NAN National Access Network (JAMES project) NAP Network Access Point NAS Network Access Server NDC National Destination Code NE Network Element NEF Network Element Function NFA Network Functional Architecture NHRP NBMA next Hop Resolution Protocol NIC Number of Included Cells N-ISDN Narrowband Integrated Services Digital Network NM Network Management NMB Number of Monitored Blocks NMC Network Management Centre NNI Network Node Interface NNI Network to Network Interface NO Network Operator NOD Network Operations Domain NP Network Performance NP Network Provider NPC Network Parameter Control ETSI ETSI TR 101 287 V1.2.1 (2001-09) 61 NRA National Regulatory Authority NRM Network Resource Management NRTS Non Real-Time Stream NSAP Network Service Access Point NSN National Significant Number NT Network Termination NTF Network Termination Functions NTN Network Terminal Number NTP Network Termination Point NTSC National Television System Committee modulation system. (a TV standard) NTTP Network Termination Test Point NVOD Near Video On Demand OAM Operation Administration and Maintenance OAM Operation And Maintenance OAMC Operation And Maintenance Centre OAN Optical Access Network OFDM Optical Frequency Division Multiplex OMAP Operations and Maintenance Application Part ONP Open Network Provision OS Operating System OSF Operating System Functions OSI Open Systems Interconnection OSPF Open Shortest Path First OSS Operation Support System (ITU-T Recommendation I.114) OTDM Optical Time Division Multiplex OUI Organizationally Unique Identifier PAC ETSI Programme Advisory Committee PAD PADding PAL Phase Alternating Line modulation system. (a TV standard) PAS Publicly Available Specifications PC Personal Computer PC Priority Control PCF Protocol Conversion Functions PCI Protocol Control Information PCM Pulse Code Modulation PCR Peak Cell Rate PCS Personal Communication Services PDH Plesiochronous Digital Hierarchy PDN Packet Data Network PDU Protocol Data Unit PEI Peak Emission Interval PEN Pan European Network PH Packet Handler PHB Per Hop Behaviours PHY PHYsical layer PI Price Information PI Protocol Identifier PIC Point In Call PICS Protocol Implementation Conformance Statement PID Protocol IDentifier PL Pad Length PL Physical Layer PLK Primary LinK PLMN Public Land Mobile Network (ITU-T Recommendation I.114 [88]) PL-OAM Physical Layer Operation And Maintenance (cell) PM Performance Management PM Performance Monitoring PM Personal Mobility PM Physical Medium PMD Physical Media Dependent P-NNI Private Network to Network Interface PNO Public Network Operator ETSI ETSI TR 101 287 V1.2.1 (2001-09) 62 POH Path OverHead POI Point Of Initiation PON Passive Optical Network POP Point of Presence POP3 Post Office Protocol, Version 3 POR Point Of Return POTS Plain Old Telephone Service POTS Plain Old Telephony Service PPD Partial Packet Discard PPP Point to Point Protocol (Internet) PPTU PDU Per Time Unit PRA Primary Rate Access (ISDN) PRM Protocol Reference Model PSDN Packet Switched Data Network PSN Physical layer OAM Sequence Number PSPDN Packet Switched Public Data Network PSS1 Private Signalling System No. 1 PSTN Public Switched Telephone Network PSVC Point-to-point Signalling Virtual Channel PT Payload Type PTI Payload Type Identifier PTN Public Telephone Network PTNX Private Telecommunication Network eXchange PTO Public Telecommunication Operator PTR PoinTeR PVC Permanent Virtual Channel PVC Permanent Virtual Circuit QAM Quadrature Amplitude Modulation QCIF Quarter Common Intermediate Format QoS Quality of Service QSIG Q interface SIGnalling protocol Q-type Q Interface type R Router R2 Regional Signalling System No.2 RACE Research and development in Advanced Communications technologies in Europe RAI Remote Alarm Indication RC Resource Control RDI Remote Defect Indicator REM Rate Envelope Multiplexing RES REServed (field) RF Radio Frequency RFC Request For Comments (Internet) RFH Remote Frame Handler RG ReGenerator RLP Radio Link Protocol RM Resource Management (cell) RPOA Recognized Private Operating Agency RPOA Regulated Private Operating Agency RS Regenerator Section RSC Reed-Solomon burst error correcting Code RSE Reed-Solomon Erasure code RSVP Resource ReserVation Protocol RTFM Real Time Flow Measurement RTMC Real Time Management Co-ordination RTP Real-time Transport Protocol RTS Real-Time Stream RTS Residual Time Stamp RU Remote Unit SA Source Address SAAL Signalling AAL SAP Service Access Point SAPI Service Access Point Identifier ETSI ETSI TR 101 287 V1.2.1 (2001-09) 63 SAR Segmentation And Reassembly (sublayer) SAR-PDU SAR Protocol Data Unit SAR-SDU SAR Service Data Unit SBM Shared Buffer Memory SBR Statistical Bit Rate SBSVC Selective Broadcast Signalling Virtual Channel SC Sequence Count SC Service Component SCC Service Control Customization SCCP Signalling Connection Control Part SCE Service Control Element SCE Service Creation Environment SCEAF Service Creation Environment-Access Function SCEF Service Creation Environment Function (I.114) SCEP Service Creation Environment Point SCF Service Control Functions SCP Service Control Point (IN) SCR SustainableCellRate SDF Service Data Function (I.114) SDH Synchronous Digital Hierarchy SDL Simple Data Link SDL Specification and Description Language SDP Service Data Point SDR Service Detailed Record (Internet) SDT Service Data Template SDT Structured Data Transfer SDU Service Data Unit SECAM Sequentielle Couleur Avec Mémoire (a TV standard) SECB Severely Errored Cell Block SECBR Severely Errored Cell Block Rate SES Severely Errored Second SF Service Feature SFET Synchronous Frequency Encoding Technique SGML Standard Generalized Markup Language SIB Service Independent building Block SIR Sustained Information Rate SL Service Logic SLA Service Level Agreement SLCP Service Logic Control Program SLE Sub-Layer Entity SLIP Serial Line Interface Protocol (Internet) SLMP Service Logic Management Program SLP Service Logic Processing program SLP Submitted Loss Priority SLPI Service Logic Processing program Instance SM Service Management SM Service Multiplexers SMAF Service Management Access (agent) Function (ITU-T Recommendation I.114 [88]) SMAF Service Management Agent Function SMC Service Monitoring Customization SMDS Switched Multimegabit Data Service SMF Service Management Function (ITU-T Recommendation I.114 [88]) SMP Service Management Point SMS Service Management System SMTP Simple Mail Transfer Protocol (Internet) SN Sequence Number SN Service Node SN Subscriber Number SNAP Sub Network Access Protocol SNI Service Node Interface SNMP Simple Network Management Protocol (Internet) SNP Sequence Number Protection ETSI ETSI TR 101 287 V1.2.1 (2001-09) 64 SNPA Sub-Network Point of Attachment SOH Section OverHead SONET Synchronous Optical NETwork SP Service Provider S-PCN Satellite - Personal Communications Network SPF Service Port Function SPL Service Provider Link SPN Subscriber Premises Network SPT Switch Point Termination SRC Strategic Review Committee (ETSI) SRF Specialized Resource Function SRL Simple Ruleset Language SRP Spatial Reuse Protocol SRTS Synchronous Residual Time Stamp SS7 Signalling System number 7 SSAP Source Service Access Point SSCF Service Specific Coordination Function SSCOP Service Specific Connection Oriented Protocol SSCP Service Switching and Control Point SSCS Service Specific Convergence Sublayer SSCS Service Switching Control System SSCS-PDU SSCS Protocol Data Unit SSD Service Support Data SSF Service Switching Function (ITU-T Recommendation I.114 [88]) SSM Single Segment Message SSN Switching or Signalling Node SSP Service Switch Point (IN) SSP Service Switching Point ST Segment Type STB Set-Top Box STC Sub Technical Committee STI Service Trigger Information STM Synchronous Transfer Mode STM-n Synchronous Transport Module-n SVC Signalling Virtual Channel SVC Switched Virtual Channel SVC Switched Virtual Circuit SW Switching System T&CP Transport & Control Platform TA Terminal Adaptor TA Terminal Adaptor TAPI Telephony Application Programming Interface (Microsoft and Intel) TAT Transit Access Termination TB B-ISDN T-type interface TB T reference point in B-ISDN TC Transmission Convergence sublayer TCE Transit Connection Element TCP Transmission Control Protocol TCP Transport Control Protocol (Internet) TCP/IP Transmission Control Protocol/Internet Protocol (Internet) TCRF Transit Connection Related Function TDP Trigger Detection Point TE Terminal Equipment TEI Terminal Endpoint Identifier TETRA TErrestrial Trunked RAdio TEX Transit EXchange TM Terminal Mobility TMA Terminal MoveAbility TMN Telecommunication Management Network TOS Type Of Service (field) TP Termination Point TPE Transmission Path Endpoint ETSI ETSI TR 101 287 V1.2.1 (2001-09) 65 TR Technical Report TS Time Slot TS Time Stamp TS Traffic Shaping TTP Trail Termination Point TUC Total User Cell number TUP Telephone User Part UBR Unspecified Bit Rate UDP User Datagram Protocol UIF User Interface Functions UMI User MAN Interface UMR Usage Metering Record UMTS Universal Mobile Telecommunications System UNI User Network Interface UP User Plane UPC Usage Parameter Control UPF User Port Function UPT Universal Personal Telecommunication UPTN Universal Personal Telecommunication Number URAN UMTS Radio Access Network URL Uniform Resource Locator VBD Voice Band Data VBR Variable Bit Rate VBR-nrt non real-time VBR VBR-rt real-time VBR VC Virtual Channel VC Virtual channel VC-AIS Alarm Indication Signal for VC VCC Virtual Channel Connection VCCE Virtual Channel Connection Endpoint VC-FERF Far End Receive Failure for VC VCI Virtual Channel Identifier VCL Virtual Channel Link VC-n Virtual Container-n VCS Video Conference Service VDSL Very high speed Digital Subsciber Line VHDSL Very High bit rate Digital Subscriber Line VLR Visited Location Register (GSM) VLSI Very Large Scale Integration VOD Video On Demand VP Virtual Path VP-AIS Alarm Indication Signal for VP VPC Virtual Path Connection VPCE Virtual Path Connection Endpoint VP-FERF Far End Receive Failure for VP VPI Virtual Path Identifier VPL Virtual Path Link VPLC VP Link Connection VPN Virtual Private Network VPNC VP Network Connection VPSC VP Sub network Connection VPXC VP Cross Connect VTX VideoTeX WAN Wide Area Network WCT Worst Case Traffic WDM Wavelength Division Multiplexing WTSC World Telecommunication Standardization Conference WWW World Wide Web (Internet) XC Cross Connect X-type TMN interface ETSI ETSI TR 101 287 V1.2.1 (2001-09) 66 History Document history V1.1.1 July 1998 Publication V1.2.1 September 2001 Publication |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 1 Scope | The present document gives a set of requirements, observations and areas of further investigations to be used in order to base further actions in ETSI, regarding services that deal with presenting and restricting calling name information to users connected to PSTN or ISDN. The following supplementary services are within the scope of the present document: - Calling Name Identification Presentation (CNIP) is a supplementary service which is offered to the called user and which provides name information associated with the calling user (calling party name) to the called user; - Calling Name Identification Restriction (CNIR) is a supplementary service which is offered to the calling user to prevent presentation of the user's name information to the called user. The identification of requirements is based on analysing existing or emerging European standards and international recommendations on calling name information. Furthermore, due to the obvious clear analogy with CLI services, European standards on CLI management for PSTN and ISDN users have been taken into account. The CNIP and CNIR services on the PSTN and ISDN are offered in United States of America and Canada, where the market is more developed especially in terms of residential phone services and business applications. These services are considered enhanced CLI services. Within Europe some service providers are performing field trials. The following aspects are excluded from the scope of the present document: a) Interactions with supplementary services; b) Quality of service; c) Charging aspects. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 2 References | The following documents contain provisions which, through reference in this text, constitute provisions of the present document. • References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. • For a specific reference, subsequent revisions do not apply. • For a non-specific reference, the latest version applies. • A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. [1] ETS 300 659-1: "Public Switched Telephone Network (PSTN); Subscriber line protocol over the local loop for display (and related) services; Part 1: On hook data transmission". |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 3 Abbreviations | For the purposes of the present document, the following abbreviations apply: CLI Calling Line Identity CNI Calling Name Identity CNIP Calling Name Identification Presentation CNIR Calling Name Identification Restriction IA5 International Alphabet N°5 IAM ISDN User Part Initial Address Message ISDN Integrated Services Digital Network PSTN Public Switched Telephone Network ETSI ETSI TR 101 480 V1.1.2 (1999-12) 6 |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4 Analysis of requirements | |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.1 General issues | CNI is name information associated with a specific calling party number. The length, format and character set of the CNI should be defined in order to meet the different characteristics of European names. A minimum length should be agreed to facilitate interworking between networks. The provision of a new service that transmits names requires the development or updating of terminals to be able to display the received characters set. In PSTN protocol over the local loop (ETS 300 659-1 [1]) a name parameter coded in IA5 is specified. Observation 1: Further investigation is required into the characteristics of the CNI and the impact on ISDN and PSTN terminals. Although one can imagine that most of the regulations applicable to a CLI number may be extended to a name service, it is clear that a name service may need some more specific regulation. For example, ex-directory subscribers who do not want the association between their number and their name to be published may request even stronger restrictions concerning the delivery of their names than of their numbers, or they may agree to have their names transmitted but not their numbers. Observation 2: Different regulations are expected for calling name services (e.g. for ex-directory subscribers). Depending on national regulations, some networks may define categories of subscriber that have the ability to override the presentation restriction and have the CNI presented (e.g. the police). The ability to have such override category is a national option. Observation 3: The ability to have categories of user that have the possibility to override the presentation restriction of CNI should be taken into account. Both CNI and CLI may be delivered if the called user is subscribed to both CNIP and CLIP. Likewise, both CNI and CLI may be treated as "private" or "public" for that particular incoming call taking into account the network stored values associated with CLI and CNI of the calling user, or regardless the network stored values associated. Observation 4: Allow the capability to provide both CNI and CLI, and if possible invoke restriction or release of one or both with a single command. Observation 5: Evaluate if the override category for CNIR could be related to the override category of CLIP. Observation 6: Due to clear analogy with CLI services, the definition of CNIP and CNIR should be tightly linked with the definition of CLIP and CLIR services. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.2 Description of CNI presentation | As mentioned above, in the present document, the calling name information may apply across analogue interfaces, ISDN basic rate interfaces and primary rate interfaces. In the PSTN, the delivery of the calling name identity to the served user can occur either on-hook: a) prior to ringing; or b) during the ringing phase (e.g. during the first long silent interval). or off-hook. Additional information may be provided with the CNI (e.g. date, time, etc.). Observation 7: In the PSTN, the CNIP supplementary service should allow the capability of providing CNI either in the on-hook or off-hook condition. In the ISDN, the network should deliver the CNI at call set-up time. Observation 8: In the ISDN, the CNIP supplementary service should allow the capability to provide CNI at the same time as a call establishment request. ETSI ETSI TR 101 480 V1.1.2 (1999-12) 7 Care must be taken to safeguard users against incompatible presentation of CNI for PSTN and ISDN in order to allow maximum interworking. Observation 9: Ensure that definitions for CNIP for PSTN and ISDN users are as similar as possible. Considering that different representations of names may be desired by calling users for different calls, a distinction could be made between various name presentation styles, e.g.: 1. personal (perhaps including informal version of first name); 2. formal (perhaps including titles); 3. business (perhaps including function title). It is proposed that the calling user should be able to choose the style of presentation of the calling user name. Observation 10: The calling user could optionally be able to change per call the style of presentation of the calling user's name from the default presentation style to another defined presentation style. Considering that: 1. for fixed line applications, in general, the actual end user may be any member of a select group of physical end users; 2. different physical end users have unique names. it is proposed that the following possibilities be supported: - as a network provider option, the end user is allowed to choose one of the predefined names known to the network, by means of a simple procedure, on a per-call basis; - as a network provider option, the end user is allowed to provide a user -defined name to be used for presentation to the called party. Observation 11: The calling user could optionally be able to select per call the actual name to be presented from a predefined set of names known to the network. The calling user could optionally provide per call the name to be used for presentation to the called party. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.3 Description of CNI restriction | The calling party should have the capability of controling the release of calling name identification on a per-line basis or a call by call basis. Observation 12: The capability to restrict the callers CNI information on a per-line basis or a per call basis should be provided in order to protect customers in certain circumstances. Permanent and temporary restriction of the presentation of the callers CNI must be provided from the service provider to interested parties, however the called party must be informed that presentation has been withheld and thereby have the choice of whether or not to accept the call. A service provider may provide several service options, that apply separately to each analogue line or ISDN number. The following service profile options are possible: - CNIR mode: permanent (invoked for all calls), or temporary (specified by user per call); - Default for temporary mode: presentation restricted, or presentation not restricted. Similarly to the CLIR service, a service definition is required that enables the calling party to prevent presentation of CNI to the called party. Observation 13: Ensure that the CNIR services for PSTN and ISDN users are as similar as possible. ETSI ETSI TR 101 480 V1.1.2 (1999-12) 8 The set of calling identity items presently consists of CLI and CNI, and this set may be expanded in the future. If both CLI and CNI may be presented to the called party, in order to respect a callers' privacy, three types of restriction for the calling user identification presentation can be envisaged, as follows: - Type1: no restriction: name and number are presented, there is no restriction on the calling user identification; - Type 2: partial restriction: either number or name is presented; - Type 3: complete restriction: neither number nor name is presented. It should be evaluated if it is possible to have a single service for blocking both CLI and CNI presentation or two separate but similar services. In the first case, it should be envisaged to harmonize the invocation procedure and, for PSTN service, the invocation code. Observation 14: Further analysis is required into the interaction between CLIR and CNIR in order to evaluate the possibility of having a single service to restrict CNI and CLI presentation |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.4 Procedures | |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.4.1 Provision and withdrawal | CNI services are provided either after prior arrangement with the service provider or are generally available. If the CNIR is provided to all users without subscription, the service provider assigns a default subscription value. Regarding ISDN, the CNI services may apply separately to each ISDN number, per ISDN number and bearer service, or per interface. Observation 15: CNI services provided by the service provider may be provided by prior arrangement or may be generally available. The CNI services may be withdrawn at the served user's request or for administrative reasons. Observation 16: CNI services provided by the service provider to a particular subscriber may be withdrawn by the service provider upon request of that subscriber or for administrative reasons. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.5 Procedure | |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.5.1 Registration and Erasure | Not applicable. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.5.2 Activation, deactivation and interrogation | The CNI services are activated by the service provider at provision and deactivated by the service provider at withdrawal. Observation 17: CNI services can be activated by the service provider at provision and deactivated by the service provider at withdrawal. As an option, the served user could activate and deactivate the CNI presentation service by using an activation or deactivation procedure. The served user should receive a notification. Observation 18: If the served user can activate/deactivate CNI presentation service, a notification should be provided to the served user to confirm the activation/deactivation. As a option, in the case where activation/deactivation is provided to the served user, it should possible for the user to interrogate the status (activated or deactivated) of the CNI presentation service. The served user would receive a notification of the status. Observation 19: If the served user can interrogate the CNI presentation status, a notification should be provided to the served user. ETSI ETSI TR 101 480 V1.1.2 (1999-12) 9 In the associated reference document for CNI restriction service, no user procedures (activation/deactivation/interrogation) are foreseen. Observation 20: No user procedures are foreseen for CNI restriction service. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.5.3 Invocation and operation | The network automatically invokes the CNIP supplementary service during call establishment. The network will provide the served user with the CNI of the calling party, or an indication that the CNI is not available due to restriction, or due to insufficient signalling capability. Observation 21: The network automatically invokes the CNIP supplementary service during call establishment, and the served user does not need to invoke or operate the service. Observation 22: If CNI is not available the called user should receive a notification indicating the cause (i.e. unavailable or withheld). The network automatically invokes the CNIR supplementary service for each outgoing call, and delivers the network stored value or the opposite value if the calling user indicated to the network to change it temporary by using a modification procedure. The calling user should receive a notification from the network. Observation 23: The calling user may decide to change the network stored value of its restriction on per call by using a modification procedure. The calling user should receive a confirmation that the stored value has changed. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.6 Network scenarios | Analysing existing or emerging standards on CNI delivery shows that two different architectures supporting CNI have been identified, as follows: - Names are stored in a centralized database. A query is launched from the destination local exchange to retrieve the calling name based on the received CLI if the called user subscribes to CNIP supplementary service and the calling user has not invoked CNIR. - CNI is sent in the IAM during call establishment. The CNI may be obtained by the originating local exchange for insertion into IAM from either a database local to the switch or from a centralized database. It may be possible for a private network to supply the CNI in the case where a call originates in a private ISDN. Observation 24: Further investigation is required on potential network scenarios supporting CNI delivery. |
f7657cecd2fcbf7e94ddf308a8a71fb6 | 101 480 | 4.7 Interworking considerations | Based on existing and emerging standards, interworking should be allowed between all network types (PSTN, ISDN, mobile and private networks). The presentation restricted/allowed indication should be passed between networks as well as the CNI according to the chosen network scenario. Observation 25: Interworking should be allowed between all network types (PSTN, ISDN, mobile and private network). ETSI ETSI TR 101 480 V1.1.2 (1999-12) 10 Bibliography The following material, though not specifically referenced in the body of the present document (or not publicly available), gives supporting information. ETS 300 089: "Integrated Services Digital Network (ISDN); Calling Line Identification Presentation (CLIP) supplementary service; Service description". ETS 300 090: "Integrated Services Digital Network (ISDN); Calling Line Identification Restriction (CLIR) supplementary service; Service description". ETS 300 648: "Public Switched Telephone Network (PSTN); Calling Line Identification Presentation (CLIP) supplementary service; Service description". ETS 300 649: "Public Switched Telephone Network (PSTN); Calling Line Identification Restriction (CLIR) supplementary service; Service description". TR 101 078: "Network Aspects (NA); Public Switched Telephone Network (PSTN); General aspects of standardization of PSTN services related to the transfer of identification information over the PSTN". ITU-T Recommendation I.251.9 (1995): "Calling Name Identification Presentation service (CNIP)". ITU-T Recommendation I.251.10 (1995): "Calling Name Identification Restriction service (CNIR)". ETS 300 659-2: "Public Switched Telephone Network (PSTN); Subscriber line protocol over the local loop for display (and related) services; Part 2: Off-hook data transmission". ECMA 164: "Private Telecommunication Networks (PTN) - Specification, Functional Models and Information- Name Identification Supplementary services". ISO IEC 13864: "Name Identification Supplementary Services". Bellcore TR-NWT-001188: "CLASSsm Feature: Calling Name Delivery generic requirements ", Issue 1, December 1991". ANSI T1.641-1995: "Telecommunications - Calling Name Identification Presentation - January 1995". ANSI T1.639-1995: "Telecommunications - Calling Name Identification Restriction January 1995". ETSI ETSI TR 101 480 V1.1.2 (1999-12) 11 History Document history V1.1.2 December 1999 Publication |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 1 Scope | In the present document an overview of different access techniques Time Division Multiple Access (TDMA), Direct Sequence Code Division Multiple Access (DS-CDMA), Frequency Division Multiple Access (FDMA) and Frequency Hopping Code Division Multiple Access (FH-CDMA) is made, in order to evaluate some parameters such as occupied band, capacity, minimum power at the receiver in threshold conditions. Although it is possible for P-MP systems to support limited mobility, the present document will only consider fixed radio access. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 2 References | The following documents contain provisions which, through reference in this text, constitute provisions of the present document. • References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. • For a specific reference, subsequent revisions do not apply. • For a non-specific reference, subsequent revisions do apply. • A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. [1] ITU-R Recommendation F.697-1: "Error performance and availability objectives for the local-grade portion at each end of an ISDN connection utilizing digital radio-relay systems". [2] ITU-R Recommendation F.697-2: "Error performance and availability objectives for the local- grade portion at each end of an ISDN connection utilizing digital radio-relay systems". [3] ITU-T Recommendation G.821: "Error performance of an international digital connection operating at a bit rate below the primary rate and forming part of an integrated services digital network". [4] ITU-R Recommendation F.557: "Availability ojective for radio relay systems over a hypothetical reference circuit and a hypothetical reference digital path". [5] ITU-R Report 338-6: "Propagation data and prediction methods required for the line-of-sight radio-relay systems". [6] ITU-R Recommendation PN.530-5: "Propagaton data and prediction methods required for the design of terrestrial line-of-sight systems". [7] EN 301 021: "Transmission and Multiplexing (TM); Digital Radio Relay Systems (DRRS); Time Division Multiple Access (TDMA) point-to-multipoint DRRS in Frequency Division Duplex (FDD) bands in the range 3 GHz to 11 GHz". ETSI TR 101 274 V1.1.1 (1998-06) 7 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 3 Symbols and abbreviations | |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 3.1 Symbols | For the purposes of the present document, the following symbols apply: dB Decibel dBi Decibel gain relative to isotropic radiation dBm Decibel relative to 1 mW GHz Gigahertz J Joule K Kelvin (degrees) kbit/s Kilobit per second kHz Kilohertz km Kilometre Mbaud Megasymbols per second Mbit/s Megabit per second MHz Megahertz ms Milliseconds mW Milliwatt µs microsecond |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 3.2 Abbreviations | For the purposes of the present document, the following abbreviations apply: A Attenuation B Exponent of frequency f in sco-formula taking care of regional effects BRF Bandwidth Radio Frequency BER Bit Error Ratio C Exponent of link range r in sco-formula taking care of regional effects CCS Central Controller Station CDMA Code Division Multiple Access C/I Carrier to Interference CRS Central Radio Station CS Central Station DAMA Demand Assigned Multiple Access DBA Dynamic Bandwidth Allocation D/R The minimum Distance between the centre of the cells with the same frequency-Radius of the cell DRRS Digital Radio Relay Systems DS-CDMA Direct Sequence Code Division Multiple Access Eb Energy per information bit ES Errored Seconds ESR Errored Second Ratio F Noise figure in dB FEC Forward Error Correction f Operative Frequency FDD Frequency Division Duplex FDMA Frequency Division Multiple Access FEC Forward Error Correction FH-CDMA Frequency Hopping Code Division Multiple Access FSK Frequency Shift Keying GOS Grade Of Service GSM Global System for Mobile Communications ISDN Integrated Services Digital Network k Boltzmann constant KQ Product of factors describing climatic and terrain effects ld(n) Base two logarithm of quantity (n) ETSI TR 101 274 V1.1.1 (1998-06) 8 LOS Line-Of-Sight M Cluster size m Levels (states) of the modulated carrier MBER Fade Margin at a certain BER MIPS Million of Instructions Per Second MTBF Mean Time Between Faliures MTTR Mean Time To Restore NFD Net Filter Discrimination N0 Noise power spectral density P(.) Probability (for the event described in brackets) PAMA Pre-Assigned Multiple Access PBER Power threshold level at a certain BER PCM Pulse code modulation P-MP Point to Multipoint P-P Point-to-Point PSK Phase Shift Keying QPSK Quadrature Phase shift Keying R Code rate (R≤1) or rain density (mm/h) Rb Information bit rate r Link range or roll-off factor rc Code rate of convolutional code RF Radio Frequency RLL Radio Local Loop RPE Radiation Pattern Envelope RS Repeater Station Rx Receive sco Multipath Occurrence Factor given in ITU-R SES Severely Errored Seconds SESR Severely Errored Second Ratio SFH Slow Frequency Hopping Tb Bit duration T0 Environmental temperature TDM Time Division Multiplex TDMA Time Division Multiple Access TE Terminal (Subscriber) Equipment TM Transmission and Multiplexing TS Terminal Station Tx Transmit WLL Wireless Local Loop |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4 P-MP applications and deployment | |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.1 Overview of applications | P-MP systems (also known in the market as WLL, RLL systems) are intended for providing access to a network from fixed telecommunications terminals at scattered locations. The terminals are connected to a TS, a TS being able to serve one or a few terminals. The TS has a two-way radio link to a Central Station (CS), which is in turn connected to the network. Normally the CS is connected to a telephone exchange, and the service provided to each terminal is a telephone line; but P-MP systems can also provide Internet access or radio link for command and control purposes. Subscribers are offered the full range of services by the particular public or private network. Subscribers have access to these services by means of the various standardized user network interfaces. P-MP systems provide standard network interfaces and transparently connect subscribers to the appropriate network node. These systems allow a service to be connected to a number of subscribers ranging from a few users to several hundred, and over a wide range of distances. ETSI TR 101 274 V1.1.1 (1998-06) 9 P-MP systems are generally configured as Pre-Assigned Systems or as Demand Assigned Multiple Access (DAMA) Radio Systems. Both methods guarantee transparency to the services transported. The essential additional features of a typical P-MP DAMA versus a P-MP PAMA Radio System are: • efficient use of the radio spectrum; • concentration. Radio is often the ideal way of obtaining communications at low cost and almost independent of distance, and over difficult topography. Moreover, only a small number of sites are required for these installations, thus facilitating rapid implementation and minimizing maintenance requirements of the systems. Concentration means that "m" subscribers can share "n" radio channels (m being larger than n), allowing a better use to be made of the available frequency spectrum and at a lower equipment cost. The term "multi-access" derives from the fact that every subscriber has access to every channel (instead of a fixed assignment as in most multiplex systems). When a call is initiated one of the available channels is allocated to it. When the call is terminated, the channel is released for another call. Concentration requires the use of distributed intelligent control which in turn allows many other operation and maintenance functions to be added. Transparency means that the exchange and the TE communicate with each other without being aware of the radio link. ETSI TR 101 274 V1.1.1 (1998-06) 10 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.2 Interfaces and Services | |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.2.1 Reference model | Figure 1 below is the reference model used by TM4 for the standardization of P-MP systems. CRS CS F G G G G G Baseband interface reference points / F G directional antenna omnidirectional or sector antenna TE TE TE TE TE TE TS TS TS TS TS CCS TE RS Another CRS may be connected to the same CCS Network Node G CCS Central Controller Station CRS Central Radio Station CS Central Station TS Terminal Station RS Repeater Station TE Terminal Equipment System boundary Figure 1: TM4 reference model |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.2.2 Services and facilities | Services and facilities for P-MP systems generally require "service transparency" which means that: "the exchange and the terminal communicate without being aware of the radio link". In practice this means that P-MP systems have to support all the transmission and call-control services which are required for supporting fixed analogue or digital telephony. P-MP frequency bands have been identified and shown in table 1. ETSI TR 101 274 V1.1.1 (1998-06) 11 Table 1: P-MP frequency bands Frequency bands 1 350 MHz - 1 375 MHz and 1 492 MHz - 1 517 MHz 1 375 MHz - 1 400 MHz and 1 427 MHz - 1 452 MHz 2 025 MHz - 2 110 MHz and 2 200 MHz - 2 290 MHz 2 300 MHz - 2 500 MHz 2 520 MHz - 2 670 MHz 3 410 MHz - 3 600 MHz and 3 600 MHz - 3 800 MHz 10 150 MHz - 10 300 MHz and 10 500 MHz - 10 650 MHz 24,5 GHz - 26,5 GHz |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.3 System deployment and radio propagation | Originally, P-MP systems have been deployed for providing telecommunications in rural areas over long distances. In this situation the locations of the stations can usually be chosen to provide a line of sight between the CS and TSs. Where LOS is not possible a RS can be used to extend the range, as well as to serve nearby customers. For these systems conventional P-P planning methods can be used, using path profiles to identify locations which ensure fresnel zone clearance and conventional methods to predict path loss. Propagation impairments which arise will be typical of P-P systems. More recently, P-MP systems are being used to provide "ad-hoc" service in urban areas to customers whose locations are not known in advance. For example, an operator may wish to provide service in a city, illuminating an area of the city from one CS and providing service through TSs. The location of the CS will obviously be chosen to optimize coverage of the required area; but a number of constraints typically apply to the TS Installations. The location of customers is not known in advance, so that coverage can only be predicted statistically (as is the case with a mobile system, for example). It may be difficult to serve more than one subscriber with a TS because market penetration may be low and installation difficulties in urban areas prevent running long cables. Zoning regulations may prevent the use of tall masts for TS antennas to optimize the radio path, and the TS can only be mounted on or very near to the subscriber's premises. So it may be possible that radio paths to some TS will not have good LOS conditions and that there will be a significant degree of shadowing. In addition, multipath propagation may arise due to reflection and diffraction from buildings. Some measurements of typical radio propagation for this type of ad-hoc deployment are reported in annex A. However, for P-MP systems to be operated in frequency bands above 10 GHz good LOS conditions are essential. Hence, in such systems the impact of multipath propagation can be expected to be of minor importance. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.4 Isolated systems | P-MP systems may be deployed to cover a well-defined set of locations which can be reached from a given central point. In this case, provided that enough capacity is available for the traffic demand, only one P-MP system (or more than one operating at different frequencies from the same central point) needs to be deployed. This will be referred to as an isolated deployment. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.5 Cellular deployment | If demand has to be met over a large area which cannot be covered from one central point, either because of propagation constraints or capacity constraints or a combination, CSs may be deployed in a cellular arrangement with frequency re- use to optimize spectrum efficiency. This will be referred to as a cellular, deployment. Cellular deployment consists of a subdivision of the service area in many zones called cells. Each of these cells can be served either by one CRS (Central Radio Station) with a omni-directional antenna or by more CRSs each of these with a sectored antenna. Every CRS has a group of radio channels, that can be reused in other cells or sector properly distanced. ETSI TR 101 274 V1.1.1 (1998-06) 12 This means that the optimum coverage structure has to be properly defined in order to fit the recommendation on quality and availability. As an example, let us consider a radio coverage with CRS using an omni-directional antenna. The fundamental parameters in such a kind of radio coverage is the co-channel reuse factor defined as D R / , where D is the minimum distance between the centres of cells with same frequency and R is the "radius" of the cell. By defining the cluster size M as the number of adjacent cells that use distinct carrier frequencies, it is possible to show that D R M / = 3 for every permitted value of M . In fact, in a hexagonal cell structure (figure 2), only certain values of M are allowed: { } M = 1 3 4 7 9 , , , , , . The actual formula is M i ij j = + + 2 2 where i j , , , , , = 0 1 2 3 . D R M = 1 CRS CRS CRS CRS CRS CRS CRS Figure 2: Cellular structure A reasonable model for propagation path loss between a central station site and a terminal equipment is a model where the loss is the product of an inverse power of the distance and a log-normal random variable to model shadowing effect. Therefore: P P P r G G L T R R T = = ( / ) 4 10 2 10 π λ γ ξ (1) where: PL is the path loss; PT is the transmitter power; PR is the received power; r is the distance between the central station and the terminal; γ is a propagation exponent giving the rate of variation with distance; ξ is a random variable log normal distributed with zero mean value and standard deviation 6 dB < σ < 12 dB, that taking into account the shadowing effect, but only slow fading is considered (the value is expressed in decibels); GT antenna gain at the transmitter site; GR antenna gain at the receiver site. ETSI TR 101 274 V1.1.1 (1998-06) 13 For normal Rician channels, γ is likely to be approximately 2 close to central station site and under LOS conditions. For frequencies below 2 GHz and larger distances i.e. inter-cell propagation, γ is more likely to be near 4. For systems operated at frequencies at or above 10 GHz, LOS conditions are essential and γ = 2 at least for intended paths has to be assumed throughout. However shadowing of interfering paths is more complete than for the low frequencies because diffraction is of minor importance. Because of the directivity of the TS antenna, the total interference level in downlink results less than in uplink and consequently the dimension of the cluster is based only on the uplink. The interference contribution due to a TS can be evaluated by finding the average difference in path loss at the interfered CRS site from the interfering TS. For simplicity, the shadowing component will be ignored even though such hypothesis could lead to some inaccuracies. Referring to figure 2 (cluster with M = 1) the difference in path loss L can be expressed by: L dB r r g ( ) log ( ) = − × × − γ θ 10 1 2 (2) where g G G ( ) ( ( ) / ( )) θ θ = 10 0 LOG is the TS antenna gain reduction due to a θ rotation with respect to the maximum gain direction (where g( ) 0 0 = dB ). It is worth noting that relation (2) can be used even with different cell sizes. Note that the CRS are equipped with omnidirectional antennas. r1 r2 θ B Interfering link Useful link TS A CRS2 CRS1 Figure 3: Example of interference in a TS-CRS connection The signal/interference ratio (measured in dB) at the neighbouring cell (B) is as follow: ( ) C I = -10 × × g Log1 3 / (3) For clusters greater than 1, the difference in path loss has been reported in table 2. Table 2: Difference in path loss for different cluster size Cluster Size L dB / ( ) γ 1 4,77 3 6,02 4 6,99 7 7,78 9 8,45 In the above example, the interference contribution due to a single user placed in the worst site has been calculated; other hypothesis on user sites can be applied such as uniform user distribution as more clearly demonstrated in clause 10. ETSI TR 101 274 V1.1.1 (1998-06) 14 Another important parameter that has to be taken into account is the antenna pattern either for the CRS or for the TS. In particular, with an omni-directional CRS antenna, the radiation diagram does not have a big influence if the worst user site is considered. By using sectored antennas, however, this parameter might assume a great importance for the following reason: Generally speaking, the lower sectoring angle for CRS antenna, the higher the overall C/I that can be obtained with the same number of frequencies. The worst user site is not necessarily related to the higher TS antenna gain direction. Under these considerations, the interference contributions due to the neighbouring sectors has to be carefully evaluated finding out the worst user site for each of the interfering sectors. As an example let us consider the structure in figure 4. By supposing two sectors at the same frequency f A , the worst interfering site lies between point A and point B on the border of the cell. The right point can be obtained only by means of TS and CRS antenna patterns. R BS1 RB S 2 R BS3 RB S 4 f A f A A B Interfering link Figure 4: Example of interference in a TS-CRS connection with 90° sectored antenna In addition, with sectored antennas, the evaluation of each interference contribution between cells (or sectors) should be done by using the antenna's mask in order to take into account the implementation tolerance. After this introduction, it is useful to introduce some guidelines to be taken into account during radio coverage planning. 1) CRS site. The first step is the CRS's site definition which has to be carried out on the basis of LOS constraint. In particular, each candidate site has to be able to cover its area of competence in LOS propagation conditions with the highest reliability (e.g. the highest percentage of candidate users in LOS condition). For this task, the usage of software tools working on geographic data base for LOS prediction is recommended in order to find out the most reliable sites. 2) Coverage structure. Having determined a certain number of candidate sites, coverage structure can be planned on the basis of capacity constrain. In particular, the chosen site(s) has to be equipped by a number of CRSs which have to be able to cope with the capacity of their area of service. In such a task, the usage of sectored antenna and/or dual polarized antenna might be useful in order to split the capacity over different CRSs located at the same site. However, this task could lead to unacceptable solution for the following reasons: - the number of CRSs in each site is too high; - the coverage reliability is too low. In both cases a higher number of sites is required and a new coverage structure has to be found. ETSI TR 101 274 V1.1.1 (1998-06) 15 3) C/I evaluation. By means of the coverage structure just obtained, a C/I evaluation can be carried out for each couple of cells (or sectors) on the basis of the above criteria. If dual polarized antennas are deployed, a proper depolarization factor has to be taken into account on the basis of cells ray and rain depolarization. Nevertheless, a more realistic C/I evaluation can be obtained by means of software tools able to take into account of geographical environment while finding out the worst user site (e.g. cells behind natural obstacles such as hill or mountain have a lower interference contribution). 4) Frequency allocation. In order to make a frequency allocation, a minimum C/I has to be defined. By means of co-channel sensitivity curves provided by the manufacturers; this value could be assumed to be the C/I at which the candidate system has a degradation of 3 dB on the power threshold level or less. After that, the available frequencies can be allocated by hand or by means of software tools pursuing the main goal of having an overall C/I for each cell (or sector) greater than the minimum C/I. The overall C/I can be calculated as follows: C I C I tot i i = − ∑ 1 1 (4) where: C I tot is the overall signal/interference ratio. C I i is the contribution due to the i-th cell (or sector) operating at the same frequency. In addition, the interference due to adjacent channel has to be considered by adding a proper contribution in relation (4) especially for CRSs placed at the same site. This contribution has to be calculated on the basis of spectrum measurement provided by the manufacturers. As previously stated, all values in (4) can be calculated on the basis of the above criteria and take into account the particular access scheme. The procedure explained in chapter 8 provides a different approach for the evaluation of the overall C/I. At the end of the analysis, different kind of results could be obtained - The overall C/I for each cell (or sector) is close to the requirement on the minimum C/I. In this case, a solution has been found and the link budget can be evaluated. However, it could be useful to verify the feasibility of future upgrading for the radio access network just obtained by supposing either a higher capacity requirement or new housing area(s) inside and outside the area of interest. - The overall C/I is higher than the minimum C/I required. This is due either to the low number of cells (or sectors) or to the high number of deployed frequencies. This is not necessarily a drawback. In this case the designer may consider either a more economical deployment or to keep the extra capacity for a future demand growth. - The overall C/I is less than the minimum tolerated C/I. In this case, the following counter measures can be adopted: - deployment of a higher number of frequencies (if available); - increase the number of sites. Sometimes, this action might help to reach a useful result either by exploiting the more finely shared capacity or by exploiting the spatial freedom to guide interference towards different direction; - usage of more directive CRS's antenna such as 90° sectored antennas instead of omnidirectional antennas. At any rate, new coverage evaluation procedure has to be carried out again. ETSI TR 101 274 V1.1.1 (1998-06) 16 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.6 Link budget | In order to verify either quality or unavailability requirements, a link budget for each cell (or sector) has to be calculated on the basis of system features and propagation condition. In particular it is necessary to know the following parameters: - receiver power threshold level; - transmitter output power; - feeder attenuation; - cable attenuation; - co-channel and adjacent channel sensitivity curve; - propagation environment; - antenna gains and RPEs. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.6.1 Quality requirements | Taking into account ITU-R recommendation F.697-2 [2], which is applicable to the local grade portion of an ISDN connection at a bit rate below the primary rate, requirements on error performance can be summarized as follows: - the SESR should not exceed 0,015 % in any month; - the ESR should not exceed 1,2 % of any month. Where: - SESR represents the ratio between the SES (as defined in ITU-T Recommendation G.821 [3] and the overall number of measured seconds; - ESR represents the ratio between the ES (as defined in ITU-T Recommendation G.821 [3] and the overall number of measured seconds. It is worth noting that the SES requirement is equivalent to former requirement (see ITU-R Recommendation F.697-1) [1] recommending that the BER should not exceed 10-3 for more than 0,015 % of any month with an integration time of 1 s. For this reason in the present document we will refer to the former requirement. In order to verify the last requirements, a general expression for link budget calculation has to be considered: P P A G G A A A A Rn TX FS RBS TS C V E K = − + + − − − − (5) where: PRn = Received power level (dBm); PTX = Transmitted power level (dBm); AFS = Free space attenuation (dB); G RBS = CRS's antenna gain (dB); G TS = TS antenna gain (dB); AC = Cable attenuation (dB); A V = Vegetation attenuation (dB); AE = Smooth earth attenuation (dB); AK = Diffraction attenuation (dB). ETSI TR 101 274 V1.1.1 (1998-06) 17 Losses associated with the diplexer are included within equipment specification. All the above attenuation figures have to be included if necessary depending on deployment environment and range of coverage (e.g. for rural application all terms should be included). After having determined the received power level, margins both for BER = 10-3 and for BER = 10-6 can be evaluated M P P A Rn I 10 10 10 3 3 3 - - - = - - (6) where: P10 3 - = Power threshold level at BER = 10-3 AI 10 3 - =Power threshold level degradation due to co-channel and adjacent channel interference for a BER = 10 3 − Both power threshold level degradation terms can be evaluated on the basis of the overall C/I calculated in (4) and using the sensitivity curves provided by the manufacturers. At this stage, the attenuation statistic can be modelled as follows: P A M sC M ( ) / > = - -3 - 10 0 10 3 10 10 × (7) where Sco can be calculated as follows: s K Q f r C B C 0 = × × × (8) where: f = operation frequency expressed in GHz r = link range expressed in km K, Q, B, C = parameters depending on the propagation environment For additional references, see ITU-R Report 338-6 [5] and ITU-R Recommendation PN.530-5 [6]. In an average propagation environment, sC0 can be evaluated as follows: s f r C0 3 14 10 = -8 , × × (9) On the basis of ITU-R Recommendation F.697-2 [2] SESR requirement, the following inequality has to be verified P A M ( ) , > < - -4 10 3 15 10 × (10) Frequency selective multipath fading has to be taken into account even though at the moment this issue is under study (see annex A). The ESR requirement states that the seconds with at least one error should not be more than 1,2 % of any month. In fact this requirement needs a specific simulation to be estimated or a measure to be evaluated. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.6.2 Availability requirements | Annex A of ITU-R Recommendation F.697-2 [2] introduces two unavailability types: system unavailability due to equipment unreliability and propagation unavailability due to rain attenuation (which is significant mainly to high frequencies, above 10 GHz). As far as propagation unavailability is concerned, we will refer to ITU-R F.Recommendation 557 [4] definitions. At any rate, no standards have been developed to provide specific values neither for system unavailability nor for propagation unavailability. ETSI TR 101 274 V1.1.1 (1998-06) 18 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.6.2.1 System unavailability | Annex A of ITU-R Recommendation 697.2 [2] introduces the following relation to evaluate system unavailability: Unavailability MTBF MTBF + MTTR = − × 1 100% (11) where: - MTBF is measured in h; - MTTR is measured in h. The parameter MTBF has to be provided by the manufacture and the parameter MTTR has to be estimated by the operators on the basis of the area of deployment, human resources, user and CRS sites, manufacturer data, etc. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.6.2.2 Propagation Unavailability | As for system unavailability, ITU-R Recommendation F.697-2 [2] does not provide a specific requirement for propagation unavailability. For this reason, from now on we will refer to a general percentage p as a requirement for propagation unavailability and we will show how to verify this requirement. As for quality requirements, a general expression for link budget calculation has to be considered: P P A G G A A A A A A Rn TX FS RBS TS C F V H K r = - + + - - - - - - (12) where, with respect to relation (5), a rain attenuation term A r has been added. In fact, rain causes an additional attenuation which can be expressed as follow: g a r KR = (13) where: - γ r is measured in dB/km; - K and α depend on frequency and polarization; - R is the rain intensity, and is measured in mm/h. The parameter R depends on the location in which the P-MP system is deployed. Usually, R is assumed to be the value at which the probability of having a greater rain intensity is equal to 10-4. From now on we will refer to R0 01 , as the value of rain intensity that can be exceeded with a probability of 0,01 % of an average year. Taking into account that K and α depend on polarization, from now on we will also refer to γ r h for horizontal polarization and to γ r v for vertical polarization. In table 3 the K and α values for both horizontal and vertical polarization are reported. Table 3: Parameters for rain attenuation calculation Frequency (GHz) KH KV α H αV 1 3,87E-05 3,52E-05 0,912 0,880 2 1,54E-04 1,38E-04 0,963 0,923 4 6,5E-04 5,91E-04 1,121 1,075 10 0,0101 8,87E-03 1,276 1,264 11 0,0139 0,0124 1,25 1,25 20 0,0751 0,0691 1,099 1,065 25 0,124 0,113 1,06 1,03 ETSI TR 101 274 V1.1.1 (1998-06) 19 For a different frequency the values of K and α can be obtained by a logarithmic or linear interpolation respectively. In order to calculate the real power attenuation due to rain phenomena, the effective link length Leff has to be introduced: L L L eff = × + × 90 90 4 (14) where L is the real link length measured in km. The power attenuation due to rain phenomena, can be calculated by means of (13) and (14) as follows: A L A L r h r h eff r v r v eff = × = × γ γ (15) where A A r h r v and are measured in dB. In the same way as the rain intensity R , the rain attenuation A A r h r v and calculated by means of R0,01 will be referred to Ar h r v 0 01 0 01 , , and A . However, in order to verify the assumed unavailability requirement p% , the terms ArP have to be calculated which represent the rain attenuation that can be exceeded with a probability p% . With the value Ar0 01 , , it is possible to obtain the rain attenuation ArP as follow: ( ) ( ) A A p A A p r h r h p r v r v p p p = = − + − + 0 01 10 0 01 10 0 12 0 12 0 546 0 043 0 546 0 043 , , , , , , , , × × × × Log Log (16) Now the rain attenuation related to the assumed unavailability requirements, new margins M10 3 - has to be calculated: M P P A M P P A h Rn h I v Rn v I h v 10 3 3 3 10 3 3 3 10 10 10 10 - - - - - - = - - = - - (17) where: P P Rn h Rn v and represent the received power levels calculated by means of relation (12) including the proper rain attenuation (respectively, Ar h r v p p and A ) AIh 10 3 - and AIv 10 3 - represent the degradation on the power threshold level for both polarization. It is worth noting that the terms AIh 10 3 - and AIv 10 3 - have to be evaluated taking into account the following aspects: • Each term in relation (4) has to be now evaluated taking into account that the useful link suffers of rain attenuation but, in some cases, the interfering link could not be attenuated. • Surrounding cells operating on the opposite polarization (if any) will cause an additional C/I contribution to relation (4) due to rain depolarization even thought in most of the cases it is not. ETSI TR 101 274 V1.1.1 (1998-06) 20 After having determined both margins (17), the assumed unavailability objective will be fulfilled if: M M h v 10 3 10 3 0 0 - - ≥ ≥ (18) |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 4.7 Operating principles | The CS radiates a radio carrier from an omnidirectional or sectored antenna over the area in which service is required. A number of traffic channels are multiplexed on this carrier, plus signalling information to control the allocation of these traffic channels to Terminal Stations. The link between the CS and TSs will be referred to as the downlink. Normally there is an upper limit to the number of traffic channels which the CS can support. Each TS is equipped (normally) with a high gain directional antenna pointed towards the CS. It receives the multiplexed traffic channels and demultiplexes the control information and any traffic information directed to a terminal served by the TS. It transmits back to the CS, usually on a separate frequency or on a different time slot (the up-link), traffic and signalling information which is multiplexed (usually) by a similar method to the down-link. A TS will only transmit if it is either signalled to do so by the CS (an incoming call); or if the attached terminal requests service (goes "off-hook" - an outgoing call). Each TS in the service area can access only the number of traffic channels supported by the CS. Because calls are made only intermittently from each TE, the number of TEs which can be supported is much larger than the number of traffic channels, and the system operates a Demand Assigned Multiple Access (DAMA) protocol between CS and TSs. There are several choices for the method by which the traffic channels share the radio carriers (multiplexing on the down-link and multiple access on the up-link). The most common in existing or proposed systems are: - TDMA; - DS-CDMA; - FDMA; - FH-CDMA. In principle systems may share several methods. Thus an FDMA system may allow several active TEs to time-share a radio carrier from a TS, where different TSs use different carrier frequencies to access the CS. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 5 P-MP common characteristics | In order to make an overview of different multiple access techniques (TDMA, DS-CDMA, FDMA and FH-CDMA) used in P-MP systems, some common parameters, characterizing the radio relay link, have to be specified. Table 4: Assumption for analysis Channel Spacing 1,75 MHz, 2 MHz, 3,5 MHz, 7 MHz and 14 MHz Modulation 4 PSK Central station antenna Omnidirectional/Sectored User antenna directional Noise figure 6 dB Even though the most common modulation method is coherent 4PSK, other modulation methods, such as coherent 8PSK and 16PSK or incoherent FSK, are sometimes deployed. ETSI TR 101 274 V1.1.1 (1998-06) 21 In addition, we suppose an uncoded transmission for TDMA systems and coded transmission for DS-CDMA systems ( rc = 1 2 / ). The reason for assuming a convolutional encoding for the case of DS-CDMA systems is that the benefit of FEC are obtained in these systems without any associated reduction in capacity. the assumed bit energy to noise spectral density ratios E N b / 0 for a given BER are reported in table 5. Table 5: Assumed E N b / 0 versus BER E N b / @ 0 3 10 BER = − E N b / @ 0 6 10 BER = − TDMA 8,5 dB 12,0 dB DS-CDMA 4,5 dB 7,0 dB FDMA 8,5 dB 12,0 dB FH-CDMA 8,5 dB 12,0 dB |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6 TDMA systems | |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6.1 Broadband TDMA | Broadband TDMA systems generally permit the time sharing of the same frequency band by different users. The physical layer is normally based on 2 Mbit/s transmission, with a total capacity equivalent to a 2 Mbit/s PCM system but additional signalling to control the radio link. Radio carrier spacing is typically 1,75 MHz or 2 MHz. Systems use frequency-division-duplex, and require an appropriate paired frequency allocation. Some systems are also available using 4 Mbit/s or 8 Mbit/s transmission and providing 60 or 120 traffic channels, with 3,5 MHz or 7 MHz channel spacing. Access is by TDM (downlink), TDMA (uplink), demand assigned, with frequency FDD. The CS transmits, continuously, a frame structure which is based on PCM but with normal PCM slots concatenated to longer radio slots: the downlink radio frame length is typically 1 to 10 ms (depending on system), much longer than the normal 125 µs PCM frame. The uplink is burst-mode: the reason for concatenating PCM slots is to make the active up-slot length longer and reduce the effect on efficiency of the required up-link guard periods. Adjustable timing advance (e.g. GSM) is provided to make sure all incoming bursts at the central station fit exactly in their allocated slots. ETSI TR 101 274 V1.1.1 (1998-06) 22 F2 F36 F37 F38 F39 F40 F0 F1 TS0 TS1 TS2 TS29 TS30 TS31 TS31 5 ms Outbound PCM frame stream Downlink frame Inbound burst Inbound 64 kbit/s stream TS31 Figure 4: TDMA frame format Figure 4 shows diagrammatically a possible frame format for a point-to-multipoint system, and how a single 64 kbit/s user accesses the system. On the down-link, a 2,048 Mbit/s PCM stream, which is augmented with additional control information for radio access, is mapped onto the down frame structure. The down-link frame has 32 slots, but in this example its length is 5 ms instead of the normal PCM frame of 125 µs. Therefore the contents of time slot 31 (for example) of 40 successive PCM frames are stored and loaded into time slot 31 of the TDMA frame. Similarly, on the up-link, a single 64 kbit/s tributary stream will be stored for each 5 ms frame period and loaded into a single, 156,25 µs up-link burst. The timing of this burst will be adjusted so that it is received at the central station in synchronism with the down-link frame. The radio architecture assumes that TS radio transceivers have to be full duplex, and therefore it is not necessary for the downlink and uplink frame lengths to be equal; this may enable a better trade-off of signal delay against minimum overhead in the frame structure. Since the protocol is based on PCM, traffic is carried in 64 kbit/s channels, and the system is therefore fully transparent to normal speech-band services. Certain suppliers provide terminal equipment with full ISDN 2B+D capability. Terminal equipment is capable of supporting either single subscribers, or groups of subscribers, is generally available. Systems operate typically at 1,5 GHz or 2,4 GHz in normal "fixed-"reuse" frequency allocations, and frequency rasters are aligned with microwave P-P systems. Central station to subscriber system range can be typically up to 40 km. Both are installed to obtain a good line-of-sight path. In addition, most systems make provision for a "repeater" mode which allows ranges of several hundred, kilometres to be attained in several "hops". For systems specifically designed for data applications, packet data transmission can be deployed using contention avoidance protocols. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6.2 Narrowband TDMA | A typical 2 Mbit/s P-MP system as described above according to EN 301 021 [7] has a threshold receive sensitivity of -90 dBm and peak transmit power of +35 dBm (though the transmit power would probably not exceed +30 dBm in practice). The total link budget, assuming CS antenna gain of 10 dBi and TS antenna gain of 18 dBi, would be: 30 + 10 + 18 - (-90) = 148 dB. ETSI TR 101 274 V1.1.1 (1998-06) 23 At 2 Mbit/s the symbol rate will be 1 Mbaud with a quaternary modulation scheme. Comparing these figures with the propagation measurements for ad-hoc TS deployment reported in annex A, clearly quite a high proportion of the surveyed points would not receive service because of excessive path loss. Moreover, some measured path impulse responses are significantly longer than the symbol length for a 2 Mbit/s system, so that a high error rate due to intersymbol interference caused by multipath propagation will arise for some TS locations. For optimum operation with "ad-hoc" deployment, a system with a lower gross RF channel bit rate will be preferable. This allows a better link budget, through a smaller channel bandwidth; makes the system less susceptible to multipath distortion because the symbol rate is lower; and makes it feasible and economical to implement an adaptive equalizer to correct any multipath. For example, with a minimum channel bit-rate of 0,32 Mbit/s, the system noise bandwidth is reduced by a factor of 6,25, giving 8 dB increase in the link budget relative to a "2 Mbit/s" system; the symbol length (assuming quaternary modulation) is 4 to 6 times longer (depending on the amount of transmission overhead). The example of GSM, which has approximately the same symbol length, shows that a low-cost equalizer realization is feasible for such a symbol rate. The use of a narrow-band channel leads to a lower system capacity for a single-carrier system. At a minimum bit-rate of 0,32 Mbit/s, five 64 kbit/s traffic channels may be accommodated per carrier. However, the lower bit rate also allows the channel spacing to be significantly reduced. Using frequency stabilization techniques in the CS and TS whereby the transmit and receive channel frequencies are locked to the bit-rate, channel spacing as low as 300 kHz may be employed. If larger system capacities are then required (e.g. if the CS has to support an El link capacity), multiple radio carriers can be radiated. Clearly 6 carriers would be required to support 30 × 64 kbit/s traffic channels, to be equivalent to a conventional 2 Mbit/s P-MP system. On the other hand, it may be useful for the operator to conserve spectrum by installing fewer carriers to reduce system capacity where penetration is low or where dictated by the constraints of cellular frequency planning. The total occupied bandwidth for the narrow-band system would be 1,8 MHz, compared to 1,75 MHz or 2,0 MHz for the conventional approach - that is, the systems will be very similar in terms of occupied bandwidth. Greater effective spectral efficiency may also be obtained by using lower rate coding. It should be noted that, for a given multipath delay spread the processing power of an adaptive equalizer, measured in for example MIPS, has to rise as the square of the system bit rate. This is because the sampling rate varies proportionally to the bit rate, and the number of equalizer taps (assuming a transversal equalizer) also goes up proportionally to the bit rate for a length of impulse response. For speech traffic this is appropriate, as long as an effective service transparency can be provided, for both narrow-band and broad-band systems. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6.3 Isolated performance for broadband TDMA | As stated in previous paragraph, physical layer for a broadband TDMA systems is normally based on 2,048 Mbit/s transmission, with a total capacity equivalent to 32 traffic channels. Some systems are also available using 4,096 Mbit/s transmission and providing 60 traffic channels. The minimum average power level in threshold condition S av can be calculated by means of the following relationship ( ) ( ) S E N Log R Log KT F av b dB b dB = + × + × + 0 0 10 10 (19) ETSI TR 101 274 V1.1.1 (1998-06) 24 where: E N b 0 bit energy to noise spectral density ratio (see table 5); K = × − 1 38 10 23 , J/K Boltzman constant; T0 = 293 K environmental temperature; Rb = 2,048 Mbits, 4,096 Mbit/s transmission bit rate; F = 6 dB noise figure. Substituting these values the following characteristics of TDMA system in absence of interfering cells result as in table 6. Table 6: Broadband TDMA capacity (number of 64 kbit/s channels) and threshold power level without interfering cells BER =10 3 − BER =10 6 − Bands N Sav (dBm) N Sav (dBm) 1,75 MHz 32 -96,3 32 -92,8 2 MHz 32 -96,3 32 -92,8 3,5 MHz 64 -93,3 64 -89,8 7 MHz 128 -90,3 128 -86,8 14 MHz 256 -87,3 256 -83,8 For system supporting packed data transmission for data applications, FSK method should be considered. Table 7 shows the bit energy to noise spectral density ratios Eb/N0 for various FSK modulation schemes with incoherent demodulation. Table 7: Assumed Eb/N0 for FSK modulation schemes versus BER BER =10 3 − BER =10 6 − Modulation Eb/N0 (dB) Eb/N0 (dB) 2 FSk 11,5 15,0 4 FSK 18,5 22,0 8 FSK 24,5 28,0 The corresponding sensitivities are shown in table 8. Table 8: Broadband TDMA capacity and threshold power level without interfering cells for systems using incoherent FSK modulation schemes BER =10 3 − BER =10 6 − Bands Modulation Bit rate (Mbit/s) Sav (dBm) Sav (dBm) 2FSK 1 -93,3 -89,8 1,75 MHz/2 MHz 4FSk 2 -86,3 -82,8 8FSK 3 -78,3 -74,8 2FSK 2 -90,3 -86,8 3,5 MHz 4FSk 4 -83,3 -79,8 8FSK 6 -75,3 -71,8 2FSK 4 -87,3 -83,8 7 MHz 4FSk 8 -80,3 -76,8 8FSK 12 -72,3 -68,8 2FSK 8 -84,3 -80,8 14 MHz 4FSk 16 -77,3 -73,8 8FSK 24 -69,3 -65,8 ETSI TR 101 274 V1.1.1 (1998-06) 25 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6.4 Isolated performance for narrowband TDMA | Due to the lower bit rate, narrowband TDMA systems are able to provide a lower capacity for a single carrier but with lower power threshold level as well. In fact the useful bit rate provided by narrowband TDMA system is, as a reference value, 0,32 Mbit/s. By means of relationship (11), it is possible to obtain the power threshold level for a narrowband TDMA system based on 0,32 Mbit/s basic rate. By means of table 9 it is possible to verify the gain on power threshold level with respect broadband TDMA stated in subclause 4.4. Table 9: Threshold power level for narrowband TDMA based on 0,32 Mbit/s the basic rate (e.g. five channels at 64 kbit/s) Basic Rate Sav @BER =10-3 (dBm) Sav @BER =10-6 (dBm) 0,32 Mbit/s -104,4 -100,8 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6.5 Cellular deployment performance for broadband TDMA | As stated in subclause 4.5, cellular deployment means that a certain number of frequencies are reused in other cells (or sectors) properly distanced. This means that a certain amount of co-channel interference has to be taken into account during link budget calculation. The presence of co-channel interference causes an increment of the power threshold level because it acts like an additional noise power at the input of the receiver. In this context, relation (4) can be evaluated by adding a contribution for each cell (or sector) working at the same frequency on the basis of subclause 4.5 rules. Supposing the interference as a gaussian noise, a general figure on power threshold level with co-channel interference can be evaluated by means of the following equation: ( ) ( ) ( ) S E N Log R Log KT F Log E N R W I C av dBm b dB b dB b b TOT = + × + × + − × − 0 0 0 10 10 10 1 (20) where C I TOT is the overall signal to interference ratio expressed by relation (4), and W is the equivalent noise bandwidth of the receiving filter. At any rate, the best way to evaluate this figure is by means of measured sensitivity curves provided by the manufacturers. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 6.6 Cellular deployment performance for narrowband TDMA | In cellular deployment for narrowband TDMA the same approach as for broadband TDMA can be assumed even though some differentiation are necessary. As stated in subclause 4.4, the use of narrowband TDMA systems neither allows to improve system's capacity nor to reduce the cluster size. However, such systems introduce a very important degree of freedom which means a higher number of available frequencies. Such a feature has a great impact on frequency management due to the fact that the network designer is able to obtain a better trade off between the number of deployed frequencies and user penetration. In fact, to use a broadband TDMA system to cover a low populated area with a small degree of penetration means to obtain a coverage with a low spectral efficiency. On the other hand, the possibility to deploy a number of frequencies closer to the required capacity allows to obtain a better coverage of the whole area and, perhaps, a lower amount of bandwidth occupation. As for broadband TDMA systems, a general figure on power threshold levels with co-channel interference can be obtained from relationship (20). ETSI TR 101 274 V1.1.1 (1998-06) 26 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 7 DS-CDMA systems | In the following we are going to investigate two different kind of DS-CDMA. In fact DS-CDMA systems separate the signals from the different users by assigning a different spreading code to each signal. If pseudo random codes are used (Pseudo Random DS-CDMA) the interference is reduced by a factor equal to the spreading factor. If orthogonal codes are used (Orthogonal DS-CDMA) the interference is, in principle, eliminated. Orthogonal codes only retain their zero mutual interference property when synchronized together. It is therefore necessary to synchronize the terminal station transmitter codes for Orthogonal DS-CDMA systems. The requirement also applies to all of the signals transmitted from the central station but in this case the implementation is trivial. In practice, full orthogonality can not be achieved due to propagation effects (e.g. multipath) which will reduce the capacity of the systems. It is worth noting that many DS-CDMA systems can be thought of as a compromise of the two strategies with different degree of synchronization. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 7.1 Pseudo Random DS-CDMA | Pseudo Random DS-CDMA systems generally conform to the following operating principles. In Code Division Multiple Access (DS-CDMA) systems, subscribers are distinctly coded, prior to transmission, in a way which enables the separation at the receiver site. The physical layer permits a maximum number of users depending upon the user bit rate, available bandwidth and performance requirements. Systems use FDD, and require an appropriate paired frequency allocation. Access is DS-CDMA (Code Division Multiple Access), demand assigned. The CS transmits a frame structure which is based on user data but with normal PCM multiplied by a proper code with a higher rate: the ratio between PCM rate and code rate is defined as processing gain. The downlink radio frame is made by summing individual spread downlink signals in addition to some codes without information (pilot). After call set-up, each user shares the same spectrum simultaneously without the need for fine synchronization of the individual user's transmitted codes. At the receiver site, each data signal is distinguished from the others by means of a correlation process. Since all users share the same spectrum, power imbalances at the CS receiver have to be avoided. This is achieved by automatic power control in the TSs which guarantees that all the users on the up-link will be received at the CS with the same power level. In order to counteract self interference and the interference coming from adjacent cells, DS-CDMA systems encode the user data by means of a channel encoder such as a convolutional encoder before spreading the encoded signal. Speech coding might be a lower rate than the 64 kbit/s assumed as a reference in this report. Certain suppliers provide terminal equipment with full ISDN 2B+D capability. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 7.2 Orthogonal DS-CDMA | As stated in the previous paragraph, in the up-link frame, all user share the same spectrum simultaneously without taking care of time synchronization. If either a time advance or pilots' information is provided at the user site, transmission could be carried out so that, at the CS site, every users are time aligned with each others. In other words, each user will share the channel by taking care of the frame-timing over the air. Moreover, if orthogonal spreading code are used, such a approach will let DS-CDMA removing interference coming from others users. Relationship (21) shows one way to construct orthogonal spreading codes ETSI TR 101 274 V1.1.1 (1998-06) 27 W W W W W - W W W W W - W 2 4 2 2 2 2 2 2 2 2 2 n n-1 n-1 n-1 n-1 = − = = 1 1 1 1 (21) In fact, the rows of the above matrices represent a set of L n = 2 orthogonal spreading sequences with length L n = 2 ; it is possible to show that: ( , ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ψ ψ ψ ψ i L j L b i L kT k T j L T t t dt i j i j b b = = = ≠ + ∫ 1 1 0 1 (22) where T R b b = 1/ is the bit duration. Relation (22) tells us that, thanks to the time alignment, every user can be distinguished from each other without any interference contribution due to the other users. In this case, as stated in (21), the number of simultaneous user is only bounded by the length of the spreading code which is in itself bounded by the available bandwidth. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 7.3 Isolated performance for Pseudo Random DS-CDMA | Taking into account that the CS is always able to send a down-link frame in a orthogonal fashion, Pseudo Random DS-CDMA capacity is bounded by the up-link frame. Therefore in the following analyses only the up-link case will be analysed. The minimum average power level in threshold condition Sav and supposing a perfect power control can be calculated by means of the following relationship E N S R N S W b av b av 0 1 = − × + / (( ) ) / α η (23) where: Sav average received power; α voice activity factor; Rb user bit rate assumed to be 64 kbit/s; N number of 64 kbit/s channels sharing simultaneously the transmission channel; W equivalent noise bandwidth of the receiving filter; η average noise power referred to the noise equivalent bandwidth above defined. The relationship between the received signal power level in threshold condition and the number of simultaneous active users can be derived from (23): ( ) ( ) ( ) ( ) S E N Log R Log KT F Log E N R W N av dBm b dB b dB b b = + × + × + − × − − 0 0 0 10 10 10 1 1 α (24) In addition, the maximum number of simultaneous active users can be derived from (24): N W R E N b b < × + / / α 0 1 (25) where the symbol means the highest integer lower than its argument. ETSI TR 101 274 V1.1.1 (1998-06) 28 It could be shown that DS-CDMA capacity could be improved by exploiting the voice activity factor with the use of variable rate speech encoders. However, it has been decided to consider no voice factor improvement (α = 1) for the following reasons: • Voice band data calls, ISDN calls, or any calls carrying a link access protocol implicitly demand a continuous channel and the percentage of these connections is expected to rise significantly in the future; • Various overhead functions (e.g. power control, synchronization, air interface protocol) require a continuous channel. • No variable rate speech encoders have been taken into account by any standardization body. The amount of adjacent power interference is scaled by the NFD (Net Filter Discrimination). By supposing a raised cosine filtering with a reasonable roll-off factor and by assuming an equivalent noise bandwidth equal to the channel spacing, the value of NFD factor is grater than 15 dB. For this reason it is reasonable to neglect the effect of adjacent channel interference. Assuming a bandwidth W = 3,5 MHz and 7 MHz, the Pseudo Random DS-CDMA characteristics resulting from (24) and (25) are reported in table 10. Table 10: Pseudo Random DS-CDMA capacity (number of 64 kbit/s channels) and threshold power level for a single user without iterfering cells BER = 10-3 BER = 10-6 Bands N Sav (dBm) N Sav(dBm) 3,5 MHz 20 -98,5 11 -102 7 MHz 39 -98,5 22 -98,6 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 7.4 Isolated performance for orthogonal DS-CDMA | Orthogonal DS-CDMA systems, as opposed to Pseudo Random DS-CDMA, are able to perform a synchronous transmission over the up-link frame. So that, although all the users share the same channel simultaneously, the minimum average power level in threshold condition Sav assuming a perfect power control can be calculated by means of the following relationship ( ) ( ) S E N Log R Log KT F av b dB b dB = + × + × + 0 0 10 10 (26) where, with respect to the relation (24), there is not intra-system interference contribution and the system capacity is bounded only by the available bandwidth. The DS-CDMA characteristics resulting from (26) are reported in table 11. Table 11: Orthogonal DS-CDMA capacity (number of 64 kbit/s channels) and threshold power level for a single user without interfering cells BER = 10-3 BER = 10-6 Bands N Sav (dBm) N Sav (dBm) 3,5 MHz 32 -115,3 32 -112,8 7 MHz 64 -115,3 64 -112,8 ETSI TR 101 274 V1.1.1 (1998-06) 29 7.5 Cellular deployment performance for Pseudo Random DS-CDMA In the uplink case, all TSs in surrounding cells (or sectors) operating at the same frequency act together to cause interference to the susceptible CRS. If each CRS is able to support up to N simultaneous users, in the unlikely worst case Y × N interfering subscribers will be present, where Y is the number of surrounding cells (or sectors) operating at the same frequency. On the basis of the previous assumption, in the following analysis only the up link case will be taken into account. In this context, a general figure on power threshold level with adjacent cells (or sectors) can be evaluated by means of the following equation: ( ) ( ) ( ) S E N Log R Log KT F Log E N R W N C I av b dB b dB b b i i N Y = + × + × + − × − − + − = × ∑ 0 0 0 1 1 10 10 10 1 1 (27) Where the summation refers to the Y×N users of the adjacent cells (or sectors). All the contributions to the summation can be evaluated by means of the criteria reported in subclause 4.5 or the procedure shown in clause 10. In addition, the maximum number of simultaneous active users can be derived from (27): N C I W R E N i i N Y b b < + + − = × ∑ 1 1 1 1 0 / / (28) |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 7.6 Cellular deployment performance for orthogonal DS-CDMA | In cellular deployment for orthogonal DS-CDMA systems, all users in the adjacent cells (or sectors) operating at the same frequency act together to cause maximum interference to the susceptible central station as well as Pseudo Random DS-CDMA systems. In fact, although each cell avoids intra-cell interference by means of synchronous transmission over the air, adjacent cells interfere with each other asynchronously. This means that no inter-cell synchronization is deployed so that a general figure on power threshold level for orthogonal DS-CDMA systems in the uplink case can be calculated as follows: ( ) ( ) S E N Log R Log KT F Log E N R W C I av b dB b dB b b i i N Y = + × + × + − × − − = × ∑ 0 0 0 1 1 10 10 10 1 (29) |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 8 FDMA systems | |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 8.1 General characteristics | The basic purpose of FDMA technique is to share the frequency resource among subscribers by use of multiple frequency slots. Technically a frequency slot is occupied by a carrier modulated with the data rate (including FEC if necessary) wanted by a certain subscriber. A standard channel arrangement is to use one partial RF-band for downlink transmission from the CRS to the TS and another partial band (normally but not necessary of the same bandwidth) for uplink transmission from the TS to the CRS. The separation of Tx- and Rx-band in both CRS and TS by a sufficiently large duplex spacing allows to control interference between CRSs and between TSs so that this type of distortion can be neglected when planning cellular configurations. Cellular planning tries to apply frequency reuse in adjacent cells as far as possible. The ideal goal would be to use the total assigned RF band in each cell and if possible even in each sector of the whole cellular configuration. ETSI TR 101 274 V1.1.1 (1998-06) 30 Within a sector a multitude of links can be established, each using an individual RF-carrier which defines the allocated frequency slot. Adjacent carrier interference is controlled by net filter discrimination (NFD). Assuming state of the art signal processing, a carrier spacing within about 1,3 times the symbol rate should provide sufficient NFD to cause the adjacent channel interference to be negligible. Modulation is certainly not restricted to QPSK. For a consistency with the results derived for TDMA and CDMA, the same kind of encoding has been assumed (uncoded QPSK and convolutional encoding). In addition, different kind of encoding has been presented on the basis of an existing standard. In a single cell i.e. without interfering cells there is no strong incentive to use FEC. Notwithstanding FEC can be used to reduce transmit power but the price is some loss of bandwidth efficiency. In an extended cellular arrangement however, capacity is more or less limited by interference which can not be combated by increasing transmit power. In that case FEC is an almost inevitable countermeasure and loss of bandwidth efficiency per carrier, due to FEC redundancy, is more than compensated by increased interference resistance. Due to the nature of FDMA, the downlink signal transmitted by the CS is a multi-carrier signal. The number of carriers can well grow to the order of 100. This shows the necessity to control intermodulation in the high power transmit amplifier. Consequently when verifying the transmit spectrum mask specified for FDMA P-MP systems by conformance testing, a multi-carrier signal should be used, which has to be defined by specifying a standard load in the relevant standard. Some advanced features are made possible in FDMA and can be used to increase system efficiency: • Multirate modems allow to chose carrier frequency and bit rate arbitrarily within certain limits. This allows to fill RF-channels of any bandwidth densely with frequency slots which are tailored to the individual bit rate of the customers. • Different modulation schemes equipped with a variety of FEC of different redundancy and efficiency allow to match each connection, operating in a certain frequency slot, to individual noise and interference conditions. Table 12 shows the bit energy to noise spectral density ratios Eb/N0 for various modulation schemes available in an advanced FDMA system. • Dynamic bandwidth allocation (DBA) allows data rate and hence carrier bandwidth to be matched dynamically to the momentary traffic need of the customer. Table 12: Assumed Eb/N0 for additional modulation schemes versus BER BER = 10-3 BER = 10-6 Modulation (note) Eb/N0 (dB) Eb/N0 (dB) QPSK (1/2) 3,3 5,6 QPSK(3/4) 4,3 6,7 QPSK(7/8) 5,6 7,8 8PSK(2/3) 5,3 7,8 16PSK(3/4) 10,6 12,6 NOTE: Values in brackets: code rate R. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 8.2 Isolated performance for FDMA | In the following the FDMA capacity and the minimum power level in threshold condition Sav will be derived assuming absence of interfering cells. The bandwidth of a modulated carrier is given by the relation: ( ) ( ) B R R R ld M r C b OH = + × × + ( ) 1 (30) ETSI TR 101 274 V1.1.1 (1998-06) 31 where Rb: information bit rate; ROH : Overhead bit rate; R: code rate (R ≤ 1); ld(M): base 2 logarithm of number of levels M of the modulated carrier; r: roll-off factor or roll-off equivalent spacing factor for adjacent carriers (assumed to be 0,2). System capacity within a RF-channel of bandwidth BRF, characterized by the number N of channels transmitting bit rate Rb is given by: N B B RF C = (31) The minimum average power level in threshold condition Sav can be calculated by means of the same relation which holds for TDMA: ( ) ( ) S E N R kT F av b dB b dB = + × + × + 0 0 10 10 log log (32) Eb/N0: bit energy to noise spectral density ratio (see table 12); K = 1,38×10-23 J/K: Boltzmann constant; T0 = 293 K: environmental temperature; Rb : user bit rate assumed to be 64 kbit/s; FdB = 6 dB: noise figure. ETSI TR 101 274 V1.1.1 (1998-06) 32 Table 13: FDMA capacity (number of 64 kbit/s channels) and threshold power level with ROH equal 16 kbit/s BER = 10-3 BER = 10-6 Mod. Band MHz N Sav (dBm) N Sav (dBm) QPSK(1/2) 1,75 18 -115,7 18 -113,4 2,0 20 -115,7 20 -113,4 3,5 36 -115,7 36 -113,4 7,0 72 -115,7 72 -113,4 14,0 145 -115,7 145 -113,4 QPSK(3/4) 1,75 27 -114,7 27 -112,3 2,0 31 -114,7 31 -112,3 3,5 54 -114.7 54 -112,3 7,0 109 -114,7 109 -112,3 14,0 218 -114,7 218 -112,3 QPSK(1) 1,75 36 -110,5 36 -107,0 2,0 41 -110,5 41 -107,0 standard 3,5 72 -110,5 72 -107,0 system 7,0 145 -110,5 145 -107,0 14,0 291 -110,5 291 -107,0 8PSK(2/3) 1,75 36 -113,7 36 -111,2 2,0 41 -113,7 41 -111,2 3,5 72 -113,7 72 -111,2 7,0 145 -113,7 145 -111,2 14,0 291 -113,7 291 -111,2 16PSK(3/4) 1,75 54 -108,4 54 -106,4 2,0 62 -108,4 62 -106,4 3,5 109 -108,4 109 -106,4 7,0 218 -108,4 218 -106,4 14,0 437 -108,4 437 -106,4 |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 8.3 Cellular deployment performance for FDMA system | Due to frequency reuse in surrounding cells, just as in TDMA and CDMA co-channel interference will be present in a certain cell in both downlink and uplink. On downlink the distorted receiver is a TS with a narrow-beam antenna pattern. Due to this angular selectivity the number of interfering CRS/sectors is limited. On uplink the distorted receiver is the CRS/sector with an omnidirectional or sectored pattern. Even in case of sectoring, the beam width is considerably wider than for the TS. Hence in the average the CRS is affected by more sources of interference than the TS which means that the uplink is the capacity limiting link which has to be analysed to investigate performance and or cell capacity. Bearing this in mind, the impact of co-channel interference coming from TSs placed in surrounding cells on power threshold level can be computed. This leads to the same result as given above for TDMA by equation (20): ( ) ( ) ( ) S E N Log R Log kT F Log E N R W I C av dBm b dB b dB b b TOT = + × + × + − × − 0 0 0 10 10 10 1 (33) The last term of equation (33) describes the impact of uplink interference. Computing (C/I)TOT realistically implies the existence of a complete and correct algorithmic procedure for C/I analysis which has to take into account all relevant technical features of the system such as modulation schemes, antenna patterns and polarization. In addition when applying equation (33), a reasonable limit should be introduced for the increase of Sav compared to equation (32) which latter describes the system without interference. Even thought relation (33) is correct for any amount of degradation, a value of 3 dB is proposed which means to allow the cumulative power of interference to be equal to noise power. On the other hand C/I analysis makes only sense in a cell configuration where all links between CRSs and TSs are planned thoroughly by an intelligent planning procedure. This planning procedure has to guarantee sufficient decoupling between links by appropriate allocation of modulation scheme (if available) and frequency to each link. Hence similar to GSM, frequency planning is a very important issue in a fixed cellular P-MP/FDMA system. ETSI TR 101 274 V1.1.1 (1998-06) 33 However, there is a significant difference compared to GSM and to other existing fixed cellular systems. Downlink analysis shows, that it is possible to partition the area of a sector in zones with different minimum C/I. This applies to any cellular system. In a FDMA with advanced features it is possible to allocate robust modulation schemes with lower spectral efficiency to zones with low C/I and less robust modulation schemes with higher spectral efficiency to zones with high C/I. But normally there also occur small partial zones with a C/I which is too low for any modulation scheme. Only such zones have to be decoupled by appropriate frequency allocation with respect to certain CRS. NOTE: To identify those zones properly, thorough down- and up-link interference analysis is necessary. This requires to split off small partial subbands from the RF band and hence reduces the frequency reuse factor below 100 %. The spectral flexibility inherent to FDMA equipped with multirate modems, allows to dimension these subbands individually and with minimum extension. In contrast to GSM not whole cells are frequency decoupled with respect to each other, but partial zones within sectors containing groups of TS have to be decoupled with respect to other sectors. This requires an elaborated combinatorial computer tool for optimum frequency planning. To the present state of knowledge between 40 % and 60 % of RF-channel bandwidth can be reused in each sector of an extended 90° sectored cell configuration. This applies to a system with advanced features as described in subclause 8.1. Assuming 50 % frequency reuse, a cell consisting of 4 sectors has approximately twice the capacity of an isolated cell with omnidirectional antenna which uses the RF-band once. This however is a very rough estimation. One should bear in mind, that the real capacity of an extended cell configuration not only depends on the basic geometrical conditions such as locations of CRSs and width and orientation of sectored antennas, but also on the distribution of TSs including the required traffic (Erlang) values. And in addition the achieved capacity depends on the quality of the applied planning methodology which by appropriate allocation of modulation scheme (if there are different ones) and/or frequency has to provide a maximum of capacity in connection with sufficient decoupling between the whole multitude of links. |
05383d9075e345a323cb3dfd39b55815 | 101 274 | 9 FH-CDMA systems |
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