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d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.4.1 Feature description | A number of applications relies on the use of a reliable user position, which in particular implies the capability to have a confidence level associated to the reported position. This is commonly translated as position integrity into location systems reference frame as position integrity. The concept of integrity is inherited from civil aviation, which is historically the main safety critical application eager to use the GNSS positioning systems. The main core performance indicator of such system is the navigation system error defined as the 95th percentile of the positioning error. Such indicator was however not enough for application such as civil aviation. Indeed, when used for plane approach or landing, an error in a position may have direct implication in the safety of life of the crew and passengers. Therefore an estimation of the position at 95 % was clearly not adapted to such an application. The use of GNSS system by civil aviation implied the definition of different integrity related performance indicators. Among others, two major ones are: • The confidence level of the position provided by the GNSS system is required to be better than 1 to 2 x 10-7 in 150 s in order to be compatible to safety of life application. • In case the position is not correct, the system is able to provide warning to users within the applicable time to alarm of 6 s. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 20 At the technical level, this was implemented through the following concept: • The Positioning Error (PE) is the distance between the computed position using GNSS, and the actual true position. • The concept of Protection Level (PL) is introduced. It can be determined by the GNSS, and is intended to provide an upper bound of the PE. • The case when PL < PE (intended to be as low as possible, especially for civil aviation) is assimilated to Mis- Integrity (MI). In that case the system is expected to warn the user within a given time lap, called Time To Alarm (TTA). • Finally, the probability that PL < PE and that the system does not warn the user within the TTA (i.e. the user exploits a bad PL without knowing it) is called the integrity risk. Note that for what concerns the scope of the present document, all positions are horizontal position, so that PE and PL becomes HPE and Horizontal Protection Level (HPL). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.4.2 Feature metric | The metrics for integrity functions and integrity-related needs from application point of view are: • Horizontal Protection Level (HPL), expressed in meters. • Time To Alarm (TTA), expressed in seconds. • Alarm Limit (AL), expressed in meters. • Availability figure, expressed in percentage of time when HPL < AL. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.4.3 Example of implementation | There are different algorithms designed for protection level computation depending of what is available at user level. In the frame of SBAS development such as Wide Area Augmentation System (WAAS) and European Geostationary Navigation Overlay System (EGNOS), Vertical Protection Level (VPL) and HPL computation have been standardized in RTCA DO-229D [i.2]. For standalone user, different techniques have been developed in the frame of the Receiver Autonomous Integrity Monitoring (RAIM) concept: • The integrity of the navigation solution relies on the confidence level provided to the user on the different error budget potentially impacting the user measurements. • Those contributors can be differentiated in two categories: local effects and system effects: - System effects including Orbit Determination and Time Synchronization (ODTS) correction error and ionospheres error, are monitored by SBAS system in real time. Accurate indicators (User Differential Range Error (UDRE) and Grid Ionospheric Vertical Error (GIVE)) are provided in real time to the users. If the system is not able to provide accurate enough indicators it will issue an alarm on the parameter at fault. - Local effect such as troposphere, multipath, inference are not monitored by the system. The solution is to standardize models enabling to correct and over-bound the residual error with the required confidence level. The definition of such a model has been made possible thanks to the homogeneity of the scenarios encountered in the civil aviation application. For instance, for what regards multipath, the main contributor is coming from the disturbance generated by the local environment of the antenna that is the aircraft itself. The aviation integrity concept has been extensively validated for civil aviation users. However its direct application to terrestrial applications, such as the ones targeted in the present document, and using stand-alone GNSS receivers has already proven itself unsuccessful. Thus, figure 6 presents the results obtained in an urban measurement campaign. On the left side, the HPL is being calculated with the Minimum Operational Performance Specification (MOPS). It can be seen that many non-integrity situations can be observed. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 21 On the right side, the Ksigma parameter from MOPS has been increased so that MI = 0 %. In that case integrity is indeed preserved, however the alert limits are getting huge (several hundred of meters). Ksigma = 6 (nominal) Ksigma so that MI = 0 % Figure 6: Application of civil aviation algorithms to urban application Thus, using the MOPS algorithm, in order to keep an integer positioning (i.e. position is known with a trusted confidence level), HPL needs to be increased up to 800 m. However, as far as typical terrestrial applications are concerned, such "relaxed" safe envelop is useless. For instance, a geo-fencing application may require: • 95th percentile of HPL below 50 m (i.e. 95 % of the time); • 99th percentile of HPL below 100 m; • 99,99th percentile of HPL below 200 m; • An MI rate below 0,001 %. Indeed, for such requirement sets, the billing is based on the following rules: • If the HPL is below 50 m, the lower billing rate within 50 m around the user position; • If the HPL is below 100 m, the lower billing rate within 100 m around the user position; • If the HPL is below 200 m, the lower billing rate within 200 m around the user position; • Otherwise no billing is performed. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 22 An increase of the HPL will then reduce the MI but will also reduce the provision of service capacity. In figure 7, the three values of HPL for the same reported user position give a billing of respectively 200 €, 50 € and 10 €. Figure 7: Integrity / Service provision trade-off For a significant number of applications, the position needs to be reported with a given confidence level. This is usually translated into location system reference frame as positioning integrity. Observations on availability: Some applications might introduce the concept of Alert Limit (AL). This parameter is usually the maximum HPL allowed in the frame of the targeted mission. Whenever the HPL is above the AL, system is said to be non- available, i.e. positioning information cannot be used in the frame of the mission. Consequently, availability figure described in the previous clause can be understood in two ways: • For non-liability critical application, it is basically the percentage of time when location information is available. • For application requiring a confidence level on the location information, availability figure depends on different factors: - 1st, as for non-liability critical application, the percentage of time when location information is available; - 2nd, the percentage of time when HPL is indeed computed and available at user level; - 3rd and last, the percentage of time when HPL > AL (with or without loss of integrity). We therefore understand that availability and integrity are linked: an "artificial" decrease of HPL can improve the availability (3rd component above), but would be detrimental to location integrity (higher MI). On the contrary, increasing HPL allows the mitigate the integrity risk, but location information will have a limited use for some mission (function of required AL). This is illustrated in the following graphs in figure 8. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 23 Figure 8: HPL versus HPE - link with application availability |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.5 Interference mitigation | |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.5.1 Feature description | The specificity of most of the considered transport applications is the combination of challenging requirements and operational environment. As previously exposed, the environment conditions, in particular Multipath and interference, are among the most significant sources of positioning error. Based on this statement, the possibility to efficiently mitigate for these contribution is undoubtedly a key feature expected on a location systems. NOTE: "Interference" is understood as any RF signal perturbating the terminal measurement. It therefore embeds intentional and unintentional jamming, and multipath. Mitigation also addresses the characterization of the jamming and multipath sources. Characterization tackles parameters such as frequency, power, Direction Of Arrival (DOA), delays (for multipath), and finally impact on terminal measurement. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.5.2 Feature metric | Metrics to be used for the interference mitigation features can be of many different types: • Tolerable input RF power (at antenna port). • Interference source isolation capability (in terms of direction of arrival). • Tolerable multipath power. These metrics will anyway be refined once the features themselves are identified and specified. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 24 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.5.3 Example of implementation | Mitigation addresses ways to reduce the impact of interference on the position determination. Figure 9 illustrates the most common means today available to reduce this impact. NOTE: FDAF stands for Frequency Domain Adaptative Filtering. It is a pulsed-interference mitigation technique which is an extension of the regular pulse blanking technique. Indeed, it uses an advanced filtering module to selectively remove the jammed frequency band instead of zeroing the whole signal. Figure 9: Interference mitigation considered means |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.2.6 Additional key features | The list of key features addressed in the present document is limited to the above set. However, it does not mean that any additional key feature is irrelevant to location system. The rationale behind this limited scope is derived from the objective of the present document, which is to demonstrate the relevancy of the proposed standardization work. In order to make it clear, the following list of additional key features which could possibly fall under the scope of the standardization task is proposed: • Time to first fix (TTFF): time needed by a positioning terminal from power ON to the availability of a first position estimate compliant with the accuracy requested at service level. • Vertical accuracy: this feature is the position accuracy projected on the vertical axis. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.3 Mapping of application classes to features | Table 2 provides a mapping between: • on one hand, the application classes previously defined; • on the other hand, the key featured addressed in this clause. This allows to understand how these features support the applications we consider. NOTE: The present mapping is also included in TR 103 183 [i.1], but is repeated here to ease the understanding of the proposed analysis. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 25 Table 2: Location applications versus key features Application Domain Application class Position accuracy Position availability Position integrity Position authentication Interference mitigation AL TTA Mis-Integrity Mis-detection False-Alarm Safe train positioning - high density Train Reliable geo- localization 20 m along track 99,9 % 50 m 6 s 2 x 10-7/150 s TBD Safe train positioning - medium/low density Train Reliable geo- localization 50 m along track 99,5 % 100 m 6 s 2 x 10-7/150 s TBD Level crossing, train length monitor Train Reliable geo- localization 100 m 99,5 % 150 m 6 s 1 x 10-7/hour TBD Road charging Road Location based charging 50,0 % 20 m to 50 m 15 s 1 x 10-5/s < 0,1 % (TBC) < 0,01 % (TBC) TBD Road charging - urban Road Location based Charging 90,0 % 20 m to 50 m 15 s 1 x 10-5/s < 0,1 % (TBC) < 0,01 % (TBC) TBD Waterways charging Maritime Location based charging 90,0 % 20 m 15 s 1 x 10-5/s < 0,1 % (TBC) < 0,01 % (TBC) TBD Pay per use insurance Road PAYD 99,9 % 20 m to 50 m 15 s 1 x 10-5/s < 0,1 % (TBC) < 0,01 % (TBC) TBD Pay as you pollute Road PAYD < 0,1 % (TBC) < 0,01 % (TBC) TBD Car rental pricing Road PAYD < 0,1 % TBC) < 0,01 % (TBC) TBD Fleet management city logistics Road Non-cooperative geo-localization 10 m (95 %) 95 % < 0,1 % (TBC) < 0,01 % (TBC) TBD Recovery after theft Road Non-cooperative geo-localization 10 m (95 %) - 12,5 m 60 s 1 x 10-2/hour < 0,1 % (TBC) < 0,01 % (TBC) TBD Car accident reconstruction Road Reliable vehicle movement sensing 2 m (95 %) 99,5 % 5 m 60 s 1 x 10-5/hour < 0,1 % (TBC) < 0,01 % (TBC) TBD Legal speed enforcement Road Reliable vehicle movement sensing 1 ms-1 (95 %) 99,99 % 7,5 m 30 s 1 x 10-5/hour < 0,1 % (TBC) < 0,01 % (TBC) TBD ETSI ETSI TR 101 593 V1.1.1 (2012-09) 26 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4 Enabling technologies | This clause proposes an overview of the available technologies to implement the features of the location system. It is mainly focused at the terminal level, which traditionally embeds most of the relevant sensors. However, note that some technologies are also available at "system central facility" level (please refer to clause 3.1 Definitions). This point is however left open for a future release of the present document. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1 Terminal level | |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.1 Sensor technologies | This clause proposes an overview of the sensor technologies proposed to be taken on-board as part of this standardization activity. It is highlighted that the standardization activity executed here does not aim at standardising sensors detailed design. However, this inventory is done in order to define a realistic standardization framework. This way, we ensure that: • when minimum performance which will be required in the framework of the present document is not an utopian one, that it will indeed be achievable with a given sub-set of sensor (typically: sub-millimetre accuracy for standalone mass market GNSS receiver is currently out of scope); or • equivalently, when a standardized interface will be defined between two system elements, this definition does envision unrealistic components (typically: given the available data rates and sampling technology, requesting at GNSS receiver output a data flow containing RF signal samples is currently out of scope). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.1.1 GNSS receiver | GNSS receiver is one of the core component of the terminal inside a location system. It is in charge of acquiring and tracking the signal coming from the GNSS receivers, and determine a number of parameters, mainly the position. A GNSS receiver's performance of course depends on its characteristics. Two main categories of receivers, each one with its proper characteristics, are proposed to be considered: • Mass market/low consumption GNSS receivers: - These receivers are the ones commonly encountered in Personal Navigation Devices and GSM/UMTS/LTE mobile handsets. Their main specificities are: low power consumption; reduced size; important number of correlators. • Liability critical receivers: - These receivers can be embedded in particular onto trains in order to for example to support some safety critical automatic train positioning functions. They can also be used for survey purposes (base station localization and time synchronization). In the framework of the first release of the specification, it is proposed to address only the "mass market" GNSS receivers, which covers most of the targeted applications. Only train domain application might tend to use "liability critical receivers". ETSI ETSI TR 101 593 V1.1.1 (2012-09) 27 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.1.2 Inertial Navigation Sensor (INS) | Inertial navigation is based on the sequential processing of measurement performed by Inertial Reference Systems (IRS) sensors. Actually the objective is to transpose measurement results from the Galilean reference frame to reference frame more suited to navigation, such as the Earth Centred Earth Fixed (ECEF) reference frame. This transformation is mainly carried out using gyroscopes measurements. The accelerometer measurements are then expressed in a coordinate system adapted to navigation mode, and then integrated twice to obtain velocity and position. The basic relationship of inertial navigation is given below equation (1) with (m) and (n) respectively indicating "Mobile" (i.e. terminal) and "Navigation" reference frames. { ) ( ) ( ) ( 2 ) ( ) sin( 0 ) cos( 2 ) tan( n Down East North E E East North East n g n g g m f z y x n m n Down East North v v v h R v h R v h R v g f f f R v v v ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎣ ⎡ ∧ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎝ ⎛ ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎣ ⎡ ⋅ − ⋅ ⋅ + ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎣ ⎡ + ⋅ − + − + − ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎣ ⎡ − + ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎣ ⎡ ⋅ = ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎣ ⎡ Φ Φ λ ω λ ω λ η ξ λ 3 2 1 & & & r r (1) • Rλ and RΦ are the radius of curvature and the transverse radius of curvature respectively; • h is the altitude; • λ is the geodetic latitude of the mobile; • v is the velocity of the mobile in the navigation frame; • f is the acceleration measurements from the accelerometers; • g is the local gravity vector; • ωE is the Earth's rotation rate (≈ 7,292 4 ×10-5 rad/s = 4,17 × 10-3 degrees/s). Figure 10 illustrates the above fundamental INS mechanism. Figure 10: INS mechanism Inertial sensor are necessary to obtain the required performances in difficult GNSS environments. Inertial sensor measurements are combined with GNSS measurements generally using Kalman filters. Three axes accelerometers and three axes gyroscopes are necessary. Kalman filters may be of the "Tight" coupling type (hybridisation of GNSS pseudoranges, with accelerations and angles from inertial sensors), or of the "Loose" coupling type (hybridisation of GNSS positions, with positions computed from inertial sensors measurements). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 28 Inertial sensors hybridization can act at different levels of the receiver processing chain: • "Loose" coupling usually acts on Position, Velocity and Time (PVT) level data; • "Tight" coupling implies processing at User Equivalent Range Error (UERE) level; and • "Ultra-tight" coupling acts at lower level, i.e. at tracking loop level. Hybridization algorithms could consider inputs from high-quality Inertial Measurement Unit (IMU) or low cost Micro Electro-Mechanical Systems (MEMS) as well. As far as sensor type is concerned, it is proposed, for the moment, to restrain the panorama to the sensor complying with the following requirements: • at least one gyrometer; • at least two accelerometers. Given this constraint eliminating single-accelerometer units, the end result will be almost exclusively Inertial Navigation Systems with three accelerometers and three gyrometers. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.1.3 Communication network sensors | Most of the applications contemplated, if not all, require the use of mobile communication means. Thus, any kind of fleet management implies the use of a system central facility where the location information is reported and exploited, location based charging applications also suppose the use of the communication links between the remote terminal and the central facility in charge location authentication and billing, Assisted-GNSS positioning device needs to be connected to the location server via telecommunication network in order to be provided with assistance data. Consequently, communication network sensors are part of the location system. It is worth considering also the aid that such mobile communication means may bring in terms of location: either to convey GNSS assistance data, and/or to provide coarse location (either using the network cell ID and associated coverage, or using advanced triangulation techniques, such as OTDOA). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.1.4 Smart antenna | The antenna is a usual component of any GNSS receiver. In the mass market receivers, it is expected to comply with a number of high level requirements, in terms of size, pattern (omni, other), weight, possibility to merge it to the navigation device. However, such constraints forbid the use of very antennas, proposed to be called "smart antenna", able to accomplish very valuable tasks in the frame of the RF local disturbance mitigation. A typical such antenna is presented below. The proposed antenna is actually made of an array of 4 patches distributed as explained in figure 11. Figure 11: Antenna description - schematic (left) and geometric (right) ETSI ETSI TR 101 593 V1.1.1 (2012-09) 29 Indeed, antenna arrays perform a spatial sampling that makes possible the discrimination of sources in the space domain (azimuth and elevation). The use of antenna array algorithms is therefore proposed for two objectives: • Electro Magnetic Interference (EMI) mitigation. Identifying the Direction Of Arrival (DOA) of the interference sources affecting the receiver then allows beam-form the antenna pattern, and minimizes the interference impact in terms of C/N0 loss. This is illustrated in the following figure 12. Figure 12: Interference DOA determination (3 sources) • Multipath (MP) mitigation: If we assume that the space domain is independent of the time domain, we can expect to achieve MP mitigation, even for short delay MP which are usually badly isolated and mitigated with usual techniques (narrow correlator spacing, multiple estimating delay lock loop). Moreover, by combining the energy of the useful signals received by multiple antennas, the antenna arrays are able to significantly improve the performance of GNSS receivers under unfavourable signal conditions. This is illustrated in figure 13. Figure 13: Multipath rejection and characterization Two solutions are investigated to mitigate multipath with an antenna array: • The first one tries to filter the multipaths in the space domain only in order to "clean" the incoming signal of all the multipaths. The time-delay and Doppler estimations of the Line Of Sight (LOS) signal are done after the space filtering step. • In the second approach, a set of parameters (amplitudes, times-delays, Doppler shifts, elevations and azimuths) for all the incoming sources is estimated. The main difference between the approaches is that the parameter estimation in the second approach explores the signal properties on the space, time and frequency domains instead of just filtering the sources in the space domain only. This capability is therefore very useful, not only for the improvement regarding interference rejection, but also for the possibility to characterize the multipath conditions. This is explored and detailed in clause |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.3.3 Protection Level | . ETSI ETSI TR 101 593 V1.1.1 (2012-09) 30 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.1.5 Additional sensors | The list of sensors considered in the present document is limited to the above set. However, it does not mean that any additional sensor is irrelevant to location systems. The rationale behind this limited scope is derived from the objective of the present document, which is to demonstrate the relevancy of the proposed standardization work. In order to make it clear, the following list of additional sensor which could possibly fall under the scope of the standardization task is proposed: • Wi-fi modem. • DVB modem. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.2 Technology combination considered (system classes) | In the framework of the first release of the present document, it is proposed to focus on the following combination of technologies. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.2.1 Type 1: standalone GNSS receivers | This category is quite explicit: it considers terminal imbedding only a GNSS receiver (including a regular antenna). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.2.2 Type 2: GNSS receivers combined with inertial sensor | The hybridization of two navigation systems is the computation of a sought final data (position, speed, heading) from intermediate data provided by these two systems. The idea behind this association is to develop a hybrid system more robust to interference and multipath, and more accurate. In the case of satellite navigation and inertial, the accuracy of short-term inertia is complementary to the long-term accuracy provided by GNSS navigation. In addition: • errors associated with the changing RF environment where the terminal evolves only affect the satellite navigation system; and • the drifts observed on the measurement of the INS are not reflected in GNSS measures. There are several ways to hybridize a GNSS receiver with an INS. These methods depend on the type of measurement available at the output of the GNSS receiver. In case the information of position and velocity are available, integration can follow a "loose" coupling method. In case the raw measurements of the receiver are available (that is to say pseudorange, Doppler measurements, etc.), a "tight" coupling may be executed. Finally, if it is possible to have access to the heart of the chip processing and more particularly to GNSS tracking loops, integration "ultra-tight" can be implemented. The integration method depends on the type of chosen application, on the environment in which the hybrid system will be assessed, and on the targeted complexity of the integrated system. Whatever method is finally chosen, the combination of measures is usually performed through a Kalman filter. Two implementations are possible for each integration method: open loop and closed loop: • Open loop: the INS measurements are corrected by the GNSS measurements when they are available. These corrections are calculated from time to time in the filter data fusion, and are not stored in memory. The INS system operates autonomously, with no need of external information. • Closed loop: some of the filter outputs are sent back to the INS input, in order to correct for sensor errors (bias, scale factor, etc.) and allow more precise navigation. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 31 Figures 14, 15 and 16 summarize the available implementations described above. Figure 14: Loose coupling, open loop Figure 15: Loose coupling, closed loop Figure 16: Tight coupling, open loop NOTE: The diagram of tight coupling with closed loop is derived from figure 16 the same way figure 15 is derived from figure 14. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 32 Table 3: Hybridization techniques advantages and drawbacks Coupling Pros Cons Loose • Most simple hybridization technique • Navigation sensors independence is ensured (open loop) • Provides a navigation solution redundant with the one provided by systems Do not take into account GNSS information if the number of used satellites is below 4 (maybe often the case in urban light or dense) Tight • Position solution more accurate than for loose coupling (using measures with equivalent quality) • Allow user to take advantage of GNSS satellite even if less than 4 satellites are visible • Allow implementation of techniques enabling identification and rejection of erroneous measurement (good for position confidence level) • Do not make available the position solution computable from the secondary navigation system measurements (GNSS) • Complex implementation (nonlinear equations, setting and monitoring of divergence of the filter, etc.) • Forces to have access to satellite ephemeris used in the hybrid solution • Accurate synchronization required Ultra Tight • Improves robustness versus interference and jamming • Important interaction between GNSS receiver and INS • High coupling complexity • Very accurate synchronization required |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.2.3 Type 3: GNSS receivers combined with smart antenna | This category considers terminal embedding a GNSS receiver together with a smart antenna, replacing the regular antenna. This combination is considered relevant for the following reasons: • First, the use of a smart antenna allows significant interference mitigation via the enabled beam forming. This is crucial importance when dealing with constrained environments, such as industrial areas. • Second, the same feature is also (partly) applicable to multipath, allowing a significant reduction of the MP contribution to the GNSS measurement error. • Third and last, this combination offers a very promising mean to characterize the RF environment (including interference and multipath). This characterization is of key importance, in particular for any liability critical application where protection level associated to the position is computed. Indeed, we have seen previously that local error sources are the most impacting one: having a way to bound them enables the determination of a more accurate protection level. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.1.2.4 Additional types of terminal | The list of terminal types considered in the present document is limited to the above set. However, it does not mean that any additional type of terminal is irrelevant to location systems. The rationale behind this limited scope is derived from the objective of the present document, which is to demonstrate the relevancy of the proposed standardization work. Thus, a type of terminal embedding both a GNSS receiver and a communication modem is already considered relevant. It is indeed the main type of terminal considered in any Assisted GNSS techniques, widely addressed in 3GPP. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.2 System central facility level | This clause is to be completed in a future release of the present document. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 33 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.4.3 Telecommunications systems | Different communications systems can be considered to support the connection between the positioning terminal and the location system central facility. Depending on the type of location system considered, this connection can be established either using a wired communications (for instance for types of systems were positioning sensors, system central part and application data are located in a single handset, such as city sightseeing), or using radio communication systems, from Wi-Fi (indoor warehouse assets management) to terrestrial mobile communication systems (road charging) and satellite based systems (e.g. person or animal tracking). To that point of the analysis, it is considered worthwhile listing the characteristics of the main radio communication systems, in order to be able to clearly identify the constraint in terms of coverage, data rates and availability. There are two possible classes of systems and table 4 summarises different possible systems that can be used: • Terrestrial systems. • Satellite based systems. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 34 Table 4: Typical cellular and mobile satellite systems System Mode (sat or terrestrial) and brief description Coverage Services and Possible rates Terminals 2G, 2,5G, and 2,75G systems Terrestrial • GSM • GPRS • EDGE Quasi-Universal in Europe Voice and data GSM: around 10 kbits/s GPRS-EDGE: from 56 kbits/s to 130 kbits/s Handsets/ Handhelds/ PDA/ Smart phones 3G and 3G+ Terrestrial: 3GPP and 3GPP2 Urban/Suburban and rural (around 90 % population in France Voice and data From 300 kbits/s to around 7 Mbit/s Handsets/ Handhelds/ PDA/ Smart phones LTE (4G) Terrestrial Urban/Suburban Voice and data Up to 100 Mbits/s down and 50 Mbis/s up Smart phones Globalstar Satellite: 48 satellites in LEO orbits Second generation under launch Universal up to 70 ° latitude (N and S) (but outdoor coverage) Voice and data Up to 9 600 bits/s Handheld Vehicle mounted terminals Usually multimode terminals Iridium Satellite 66 satellites in polar LEO second generation under design Universal) (but outdoor coverage) Voice and data 1st Generation: up to 9 600 bits/s 2nd Generation: up to 512 kbits/s up and up to 1,5 Mbits/s down Handheld and vehicle mounted terminals for 1st generation Bigger terminals for 2ndgeneration THURAYA 3 Satellites in GEO orbit Middle East /Africa/ India/ Europe/ Australia/ Central Asia Voice and data Voice/fax up to 9 600 bits/s Data up to 60 kbits/s down and 15 kbits/s up for handheld Up to 400 kbits/s laptop like terminal Handheld Vehicle adapted terminals Laptop like terminals INMARSAT 4 3 Satellites in GEO orbit Whole world (sea and lands) Voice and data Up to 20 kb/s handhelds Up to 400 kb/s laptop like terminal Handheld Vehicle adapted terminals (maritime, aircrafts) Laptop like terminals Terrastar TBD TBD TBD MEXSAT TBD TBD TBD WI-FI ETSI ETSI TR 101 593 V1.1.1 (2012-09) 35 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5 Operational environments | As mentioned in the introduction, part of the proposed standardisation work will deal with the definition of operational environments. Indeed, the definition of minimum performance specifications for location systems and terminal highly depends on the environment of the system, and in particular of the terminal. This clause therefore aims at defining a set of operational environment to be used in the framework of the standard production. It first lists the environment characteristics deemed relevant in the fixed technical perimeter, then builds a set of typical environments intended to be representative for a wide diversity of realistic environments, and finally provides characteristics of each of these environments. NOTE: The preliminary definition of location system performance proposed in clause 6 Preliminary system architecture and performance uses the operational environment thus defined as reference environments. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.1 Environment characterisation criteria | An environment can be described by the following criteria: • Mask Angle: A fixed elevation angle referenced to the user's horizon below which satellites are ignored by receiver software. Mask angles are used primarily in the analysis of GNSS performance, and are employed in some receiver designs. The mask angle is driven by the receiver antenna characteristics, the strength of the transmitted signal at low elevations, receiver sensitivity and acceptable low elevation errors (see RTCA DO-229D [i.2]). Θ φ h h φ = azitmuth Θ = elevation h = height of Reception Antenna y x z Figure 17: Elevation mask • Signal Attenuation: Signal attenuation refers to any decrease of GNSS signal power at the level of reception antenna. The attenuation, expressed in decibel (dB), corresponds to the rate between the power of GNSS signal at receiver antenna level and the nominal GNSS signal power - at the emission. • Multipath: Signal arrival at a receiver's antenna by way of two or more different paths such as a direct line-of- sight path and one that includes reflections off nearby objects. The difference in path lengths causes the signals to interfere at the antenna and can corrupt the receiver's pseudorange and carrier-phase measurements. In some cases, the direct line-of-sight signal can be obstructed: the antenna only receives the multipath signal. • Interference: Interference denotes emission of signals in bands close to GNSS's, which are disturbing GNSS signals. These emissions can be transmitted unintentionally or intentionally. Jamming denotes intentional emission of signals with the objective to disturb or interrupt the GNSS services. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 36 • User dynamic: User dynamic corresponds to the dynamic of the mobile target and represents its attitude. It is characterized by the velocity, acceleration and jerk of the terminal. In addition to the above mechanical and electromagnetic characteristics, two additional parameters also need to be considered in order to define the system/terminal environment: • Temperature; • Humidity. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2 Definition of operational environments | This clause defines seven generic user environments. These seven generic environments are sufficient to describe any user environment. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.1 Open area | "Open area" generic environment represents the best use case. The user is in open area with clear sky view. The level of received signal is nominal. The satellites can be viewed in line of sight over 5 degrees of mask angle. This environment is also characterized by the absence of interference or multipath. Some examples of this environment are open sea or land environment without building, tree, natural obstacle or metallic structure. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.2 Rural area | "Rural area" generic environment is mainly characterized by the presence of dense vegetation. A dense foliage along the lane can cause a mitigation, even an obstruction, of the GNSS signal and create multipath conditions. In this type of generic environment the interference occurrence is considered as scarce. Some examples of "Rural area" are parkland, forest or country. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.3 Suburban area | "Suburban area" generic environment is characterized by small blocking structures, buildings or natural geographical obstacles. The risk of interference and multipath is considered as low. Some examples of this environment are small population centre without tall building, residential district, port approach area, inland waterways on a wide river, restricted water. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.4 Urban area | "Urban area" generic environment is characterized by high rise structures, buildings or natural geographical obstacles. It also corresponds to a densely constructed area. The risk of multipath is high. Some examples of this environment are urban canyon, cutting, port area or inland waterways on a narrow river. The risk of interference is considered as medium. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.5 Covered area | "Covered area" generic environment is characterized by a loss of the GNSS signal. Some examples of covered area are in-door conditions, tunnels, stations or bridges. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.6 Asymmetric area | "Asymmetric area" generic environment is characterized by different across-line mask angle. Lane alongside cliff and lane with building or trackside structure on one side only are examples of asymmetric area. It can also be considered as a semi "Urban area". |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.2.7 Industrial area | "Industrial area" generic environment is characterized by the presence of metallic structures, radio sources, cables, overhead lines, gantries, catenaries, intentional or un-intentional jammer. The number of multipath and the related error are high. There is also a high interference risk due to increased radio signal presences related to industrial activity. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 37 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 5.5.3 Generic environments characterisation | Table 5 provides the characterisation of the generic environments according to the aforementioned criteria. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 38 Table 5: Operational environment definition Environment Examples Main characteristics Criteria Characterisation Assessment Open area Open sky Best use case Elevation Mask (°) 0 ° - 5 ° Land environment without building, tree, natural obstacle or metallic structure Clear sky view Multipath null Open sea Absence of interference or multipath Attenuation low Interference risk null User Dynamic Pedestrian, Road, Rail, Maritime Rural area Parkland, forest, country Presence of dense vegetation along the lane Elevation Mask (°) 0 ° - 15 ° Motorway apart from urban canyon Mitigation, even obstruction, of GNSS signals Multipath low Coastal area Multipath conditions Attenuation medium - high Interference risk low User Dynamic Pedestrian, Road, Rail, Maritime Suburban area Residential district Small blocking structures, buildings or natural geographical obstacles Elevation Mask (°) 0° - 30° Port approach area Multipath conditions Multipath medium Inland waterways (wide river) Attenuation low Restricted waters Interference low Small population centre User Dynamic Pedestrian, Road, Rail, Maritime Urban area Urban canyon High rise structures, buildings or natural geographical obstacles Elevation Mask (°) 10° - 60° Cutting Densely constructed area Multipath high Port area Multipath conditions Attenuation medium Inland waterways (narrow river) Interference low User Dynamic Pedestrian, Road, Rail, Maritime Covered area Tunnels GNSS Signal loss Elevation Mask (°) Stations Multipath Bridges Attenuation Interference User Dynamic Pedestrian, Road, Rail, Maritime Asymmetric area Road alongside cliff Different across-line mask angle Elevation Mask (°) 0 ° - 30 ° first side 30 ° - 60 ° second side Road with buildings on one side only Semi- "Urban area" Multipath high Trakcsides structures on one side only Attenuation medium T-junctions Interference low X-roads User Dynamic Pedestrian, Road, Rail, Maritime ETSI ETSI TR 101 593 V1.1.1 (2012-09) 39 Environment Examples Main characteristics Criteria Characterisation Assessment Industrial area Radio sources Metallic environment Elevation Mask (°) 0 ° - 60 ° Cables Intentional or un-intentional jammer Multipath high Overhead lines Multipath conditions Attenuation medium Gantries Interference conditions Interference high Catenaries User Dynamic Pedestrian, Road, Rail, Maritime ETSI ETSI TR 101 593 V1.1.1 (2012-09) 40 Furthermore the user dynamics are proposed to be defined as follows in table 6. Table 6: Operational environment - user dynamics User dynamic Velocity (ms-1) Accelaration (g) Jerk (gs-1) Pedestrian TBD TBD TBD Road TBD TBD TBD Rail TBD TBD TBD Maritime TBD TBD TBD |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6 Preliminary system architecture and performance | |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.1 Introduction | As already exposed in introduction to the present document, the on-going standardization initiative comes from the observation that in many various standardization bodies, performance of location technologies are specified independently from one another leading to: • Inconsistent GNSS-related requirements from one group to the other. • Lack of expertise in given groups leading suboptimal requirements. • Slow market uptake of GNSS technologies. The purpose of such enterprise is to concentrate all the GNSS standardisation efforts in a single group, therefore offering a valuable support to other standardisation groups/bodies for what concerns GNSS. As far as implementation is concerned, the GNSS Minimum Performance Standard (MPS) under construction is seen as dictionary made available for any standardization body willing to include GNSS-related location technology in their technical specification. To that end, the MPS definition has been split into 4 main streams of activities: • Definition of the list of application intended to be addressed by the MPS. Given the objective, the wider is this list, the more exploitable will be the resulting document. This activity should also inventory the key requirements (functional or performance) applicable for each application. • Inventory of the technologies "available" to comply with the specific needs of all applications listed in the previous activity. These technologies are understood as much as sensor technologies (GNSS receivers, network sensors, inertial sensors, hybridization layer), as system layer feature allowing QoS improvements (A-GNSS, D-GNSS, Real Time Kinematic (RTK), integrity functions, authentication functions). • Definition of reference environments. Definition of minimum performance should indeed take into account typical environment associated to the application use cases, since they are major drivers of the achievable performance. In addition, since a specific focus is made in the multi-modal application, changing environment is a key factor to take into account. • Finally, the last activity is the standardization activity which is proposed to be focussed on two aspects: - A standardization of the interfaces between the various possible components of location system. This activity is based on the applications and sensors inventory executed, in order to determine a typical high level reference architecture, and thus define the interface standard. - The definition of the MPS itself: for each application, whose performance is worthy of standardization, and for each considered technology and environment, what is the level of performance to be specified? In addition to the above general objective, it is deemed important to determine how the various releases of the standard will be produced (see clause |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 7.3 Evolution plan | ). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 41 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2 Reference architecture | |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.1 Stage 1 architecture | |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.1.1 Logical reference model | Figure 18 shows the logical reference model for the standardization carried out. Please refer to clause 3.1 Definitions for a definition of the description of the components outside the location system perimeter (outside of the framework of this architecture). Figure 18: Stage 1 architecture |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.1.2 Functional entities | • Application central part: - The application central part is a logical functional entity that makes a request to the location system for the location information of one or more than one target terminal within a specified set of parameters such as Quality of Service (QoS). The application central part may reside inside or outside a terminal. The specification of the application central part internal logic and its relationship to any external user (e.g. Requestor) is outside the scope of the present document. • Location system central facility: - A location system central facility consists of a number of location service components and bearers needed to serve the application central part. The location system central facility may respond to a location request from a properly authorized application central part with location information for the target terminal specified by the application central part if considerations of terminal privacy are satisfied. The location system central facility may enable an application central part to determine the services provided to it by the location system central facility through a process of provisioning. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 42 • Positioning terminal: - The terminal is the object to be positioned by the location system. The ability to control privacy may be required to be given to the terminal user for each location request and/or to the terminal subscriber through the terminal subscription profile to satisfy local regulatory requirements. • Positioning function: - Positioning is the basic function that performs the actual positioning of a specific target terminal. The input to this function is a positioning request from the application central part, with a set of parameters such as QoS requirements. The end results of this function are the location information for the positioned target terminal. • Mobile target: - The mobile target is the entity (vehicle, person, goods, etc.) to which the positioning terminal is attached. In the frame of the location system, the terminal position is supposed to be representative of the mobile target position. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.1.3 Functional Interfaces | Function interfaces are further described in the following clauses, dedicated to stage 2 architecture. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2 Stage 2 architecture | The objective of this clause if to propose a more detailed system architecture in order to support the standardization work proposed. Consequently: • It includes the various components needed in order to implement the location key features defined in clause 5.2 Location systems key features. • It defines the associated main interfaces between these components. In particular, it is targeted to define the message flows. • Proposed architecture needs to be flexible enough in order to be applicable at least for the perimeter of applications addressed in the first release of the standard. The selected architecture is as shown in figure 19. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 43 Figure 19: Stage 2 architecture ETSI ETSI TR 101 593 V1.1.1 (2012-09) 44 The various components shown in figure 19 are described here below: GNSS receiver: This component is in charge of acquiring and tracking the RF signals coming from the various supported GNSS constellations, and measures a given number of parameters related to the terminal position and movement. Further details on the supported measurement are given in the interface description. INS - Inertial Navigation Sensor: This component is in charge of measuring the terminal 3D acceleration and rotations. It can possibly derive some parameters concerning terminal attitude. Further details are given in the interface description. Hybridization layer: The hybridization layer is in charge of processing the location request provided by the Location request broker. This processing implies in particular the activation of the specified sensors (INS, GNSS, others). Further details are given in the interface description. Location request broker: The location requests broker role is to handle the location (and control) requests initially originated by the location system central facility, and to satisfy them by providing the location response and status with the assumption that it receives a continuous flow of location information from the hybridization layer. Communication layer: The communication layer is in charge of establishing the physical link between the location system central facility on one hand, and the terminal including the various selected sensors on the other hand. The communication layer is understood as a very general term: for application such fleet management, it establishes link between central management facility and the deployed assets (in this case, link can be terrestrial telecommunication link, UHF, other), whereas for application such as personal navigation, application central part is inside the terminal itself (device MMI), so that communication is internal to the terminal. Location system central facility: The central facility is in charge of managing the requests coming from a third party application providers, addressing the requests to the positioning terminal(s), and implementing part of the location determination functions. As illustrated above, it can be inside or outside the positioning terminal. Application central part: The application central part is the core of the application in charge for emitting location requests. As illustrated above, it can be inside or outside the positioning terminal. External aiding systems: This designates aiding systems that are inside a given external infrastructure. Typically, this is the case of the Assisted GNSS server that belongs to mobile telecommunication infrastructures. All the above components are expected to exchange a given amount of information according to a given protocol. These interfaces are described in the following clauses. The interfaces 7 and 8 in figure 19 are not described so far (external to the system). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2.1 Interface 6 | Interface 6 takes place between the positioning terminal and the central facility, which is at the origin of the location request. The main transactions occurring on this interface are: • Location request/response: The location can be either: - immediate; ETSI ETSI TR 101 593 V1.1.1 (2012-09) 45 - periodical (hence generating several responses); - or event triggered (e.g. when the positioning terminal sends its location when entering/exiting a specific geographical zone); or - constrained by the minimum QoS to be satisfied. The Location request/response transaction supports the necessary features to ensure privacy management. Typically the OMA Secure User Plane for Location (SUPL) specification, OMA-TS-ULP-V2_0-20100816-C [i.3], is a good basis for such implementation. The transaction may end by an explicit stop message or can stop following a timer or event condition defined in the location request. In this latter case the last response message includes an indication of such terminaison case. • Control/status transaction. A control may change the operational status of the positioning terminal, with an impact on the way the positioning terminal is reporting its position (e.g. if a control requests the positioning terminal to switch in a diagnosis mode, then, the terminal location response may be more verbose). Both these transactions may convey application specific data, fully depending on the application which is addressed. At this stage, the present document just imposes that the interface has the capability to convey such data. Figure 20: Location request/response transaction Location responses can contain for each position fix: • the PVT solution; • the type of location technique applied (standalone GNSS, assisted GNSS, type of hybridisation, etc.); • the QoS attached to the position fix (level of confidence); • PVT solution GNSS input data (for GNSS: Satellite Vehicle (SV) pseudoranges, SVs C/N0, etc.) (optional or/on request); • PVT solution Sensors input data: TBD depending on the sensors (optional or/on request). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 46 Figure 21: Control/status transaction |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2.2 Interface 5 | Interface 5 bears the same semantics as interface 6. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2.3 Interface 4 | The location requests broker role is to handle the location (and control) requests presented above, and to satisfy them by providing the location response and status, on interface 5, with the assumption that it receives a continuous flow of location information from the hybridization layer. Thus the location request broker: • Handles the location requests that may be received in parallel from several applications. • Handles the necessary timers/location history to generate the appropriate location responses for periodical or trigger location requests. • Handles the control/status transactions, by feeding the location responses with the appropriate status and location data depending on the mode requested by the control requests. Bearing this in mind, the interface 6 becomes rather simple. After the necessary initialization phase and possible reset controls received by the Location requests broker, a continuous and periodical location messages flow is exchanged on this interface, until the location request broker sends a stop message. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 47 Location requests broker Hybridization layer Init or reset message Periodic location message (1) Periodic location message (2) Periodic location message (n) Stop Message Figure 22: Interface 4 continuous location message exchange The location message conveys the most detailed location data, whatever the location request to be satisfied. It is up to the location request broker to filter the data if necessary. Thus the location message on interface 5 conveys in any case: • the PVT solution; • the type of location technique applied (standalone GNSS, assisted GNSS, type of hybridisation, etc.); • the QoS attached to the position fix (level of confidence); • PVT solution GNSS input data (for GNSS: SVs pseudoranges, SVs C/N0, etc.); • PVT solution Sensors input data: TBD depending on the sensors; • hybridization layer status information. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2.4 Interface 3 | Interface 3 conveys the necessary data in order to enable the hybridization task. Content of the interface depends on the hybridization depth adopted (see clause 5.4.1.2.2 Type 2: GNSS receivers combined with inertial sensor). Table 7 provides the list of parameters expected to be exchanged on this interface, together with the associated type of hybridization for which they are needed (for information). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 48 Table 7: Interface 3 content Parameter Description Interface direction Unit Associated hybridization depth PINS Position estimate coming from the INS Hyb INS m All VINS Speed estimate coming from the INS Hyb INS m/s All δPos Error on sensor position (from INS) Hyb INS m All δV Error on sensor speed (from INS) Hyb INS m/s All δAtt Error on sensor attitude (from INS) Hyb INS rad All δAccel Error on sensor acceleration (from INS) Hyb INS m/s² All δGyro Error on sensor gyroscopes (from INS) Hyb INS rad/s All PGNSS Position estimate coming from GNSS sensor Hyb INS m All VGNSS Speed estimate coming from GNSS sensor Hyb INS m/s All A same type of transaction is assumed as for interface 4 (init/reset messages, followed by a periodical messages suite, ending with a stop message). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2.5 Interface 2 | Interface 2 conveys the necessary data in order to enable the hybridization task. Content of the interface depends on the hybridization depth adopted (see clause 5.4.1.2.2 Type 2: GNSS receivers combined with inertial sensor). Table 8 provides the list of parameters expected to be exchanged on this interface, together with the associated type of hybridization for which they are needed (for information). Table 8: Interface 2 content Parameter Description Interface direction Unit Associated hybridization depth PGNSS Position estimate coming from the GNSS sensor Hyb GNSS m Loose VGNSS Speed estimate coming from the GNSS sensor Hyb GNSS m/s Loose δPos3D Uncertainty on sensor position (from GNSS) Hyb GNSS m Loose δV3D Uncertainty on sensor speed (from GNSS) Hyb GNSS m/s Loose { } N i i :1 = ρ Pseudorange for the N GNSS satellites used in the position solution Hyb GNSS m Tight { } N i i :1 = ρ& Accumulated Doppler for the N GNSS satellites used in the position solution Hyb GNSS m/s Tight { } N i i :1 = δτ Numerically Controlled Oscillator (NCO) commands for the GNSS code loop discirminator steering (for N tracked Satellites) Hyb GNSS s Ultra-tight { } N i i :1 = δϕ Phase command for the GNSS phase loop discirminator steering (for N tracked Satellites) Hyb GNSS rad Ultra-tight { } N i i dop :1 = Doppler applicable for the N current Line Of Sight (LOS) Hyb GNSS Hz Ultra-tight H Heading Hyb GNSS rad N/A ϕ Carrier phase Hyb GNSS m N/A d Carrier Doppler Hyb GNSS Hz N/A A same type of transaction is assumed as for interface 4 (init/reset messages, followed by a periodical messages suite, ending with a stop message). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 49 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.2.2.6 Interface 1 | The interface 1 takes place between the smart antenna and the hybrization layer. It conveys all data related to interference and multipath mitigation. This data is described in the following table 9. Table 9: Interface 1 content Parameter Description Interface direction Unit { } J i i DoA :1 = Directions of arrival of the J detected jamming signals Hyb Ant rad² { } J i iP :1 = Speed estimate coming from the GNSS sensor Hyb Ant dBW { } J i if :1 = Uncertainty on sensor position (from GNSS) Hyb Ant Hz { } M k k DoA :1 = Directions of arrival of the M detected delayed signals Hyb Ant rad² { } M k k U D :1 = Relative power of the M detected delayed signals (compared to main Desired signal) Hyb Ant dB { } M k k :1 = τ Delays of the M detected delayed signals (compared to main Desired signal) Hyb Ant s |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.3 Performance requirements | Reminder: • GNSS signals considered: GPS L1C/A, L1C, L2C, L5, Galileo E1 (incl. PRS), E6 (incl. PRS), E5, GLONASS G1, G2, QZSS L1C/A, L1C, L2C, L5, SBAS L1. Minimum Performance displayed below has to be understood as "for any GNSS used". • The types of terminal considered below are described in clause 5.4.1.2 Technology combination considered (system classes). • The environments considered below are defined in clause 5.5 Operational environments. • The performance key features successively addressed below are described in clause 5.2 Location systems key features. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.3.1 Horizontal accuracy | The horizontal accuracy performance is specified through the following figures of merit: • Availability rate, expressed as a percentage. It represents the percentage of time when position solution is available. • Various percentiles of the Horizontal Position Error (HPE) distribution. HPE is defined by the horizontal difference in meters between the ellipsoid point reported or calculated from terminal response and the actual position of the terminal in the test case considered. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 50 Table 10: Horizontal accuracy minimum performance Terminal type Figure of merit Open area Rural area Suburban area Urban area Covered area Asymmetric Area Industrial area Type 1 Availability 100 % 100 % 98 % 98 % 0 % 99 % 95 % HPE - mean TBD TBD TBD TBD N/A TBD TBD HPE - 95 % 30 m - TBC 30 m - TBC 60 m - TBC 100 m - TBC N/A 100 m - TBC 120 m - TBC HPE - Max 250 m - TBC 250 m - TBC 250 m - TBC 250 m - TBC N/A 250 m - TBC 300 m - TBC Type 2 Availability 100 % 100 % 100 % 100 % 100 % 100 % 100 % HPE - mean 2 m - TBC 2 m - TBC 5 m - TBC 15 m - TBC Special 3 m - TBC 18 m - TBC HPE - 95 % 3 m - TBC 3 m - TBC 10 m - TBC 25 m - TBC Special 5 m - TBC 30 m - TBC HPE - Max 10 m - TBC 10 m - TBC 50 m - TBC 70 m - TBC Special 15 m - TBC 80 m - TBC Type 3 Availability 100 % 100 % 90 % 85 % 0 % 90 % 95 % HPE - mean Idem type 1 Idem type 1 TBD TBD N/A TBD TBD HPE - 95 % Idem type 1 Idem type 1 40 m - TBC 70 m - TBC N/A 70 m - TBC 70 m - TBC HPE - Max Non-specified Non-specified Non-specified Non-specified N/A Non-specified Non-specified As far as performance assessment of type 2 terminals is concerned, the case of covered area needs to be handled following specific procedure. Indeed, the characteristic of covered area the unavailability of GNSS signals, so that the only way to maintain a position estimate is the use of the inertial navigation information. Consequently, the performance specification is expressed as follows: • Test scenario: the terminal enters a covered area (loss of GNSS signals), with a perfect position estimate at the beginning of the test. • Use case: two use cases are successively considered, one dedicated to gyrometry accuracy (speed is constant) the other to accelerometry accuracy (straight trajectory). They are defined in figure 23. Figure 23: Use case for horizontal accuracy in covered area • Each use case lasts 60 s. • At the end of each test, the positioning error has to be below 10 m (TBC). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 51 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.3.2 Authentication | As indicated in clause 5.2.2 Position authentication, authentication of the reported position is required any time fraud is motivated. The performance of an authentication mechanism is measured as: • the probability to declare the position authentic whereas the terminal is spoofed (mis-detection probability); • the probability to declare the position fake (i.e. frauded) whereas it is authentic (false alarm probability). The minimum performance specification is split in two categories: • position computation for which a GNSS encrypted signal is used. In that case, the authentication mechanism is enabled and usually described by the GNSS Signal-in-Space description. For the moment, it is assumed that a perfect fraud detection is achievable with this type of signals, and focus on the second category of performance. • position computation for which no GNSS encrypted signal is used. In that case, authentication information is an added value compare to the basic positioning enabled through GNSS. It is mostly related to the spoofing detection. Description of available mechanisms to implement authentication is given in clause 5.2.2 Position authentication. To date, only type 2 receivers have the possibility to support position authentication (i.e. GNSS receiver spoofing). In order to measure the authentication performance, the operational environment alone (i.e. SV elevation angle, multipath and interference condition, signal attenuation and user dynamic) is not enough. A threat model needs to be designed to complete the test case. The following scenario in figure 24 is a typical use case often used to challenge authentication critical systems. Figure 24: Authentication performance threat model The use case is as follows: • charging road is path 1; • path 2 is free of charge; • values of R1, R2 and D are respectively 10 m, 10 m and 20 m, all TBC. • Mis-detection performance measurement: - GNSS RF signals are preliminarily recorded while terminal follows path 2; - RF signals are then replayed into GNSS receiver antenna while terminal is using path 1; - Authentication function is in charge of identifying the GNSS receiver spoofing. • False alarm detection measurement: - Terminal follows path 1, with no specific spoofing; - Authentication function should not falsely declare the receiver spoofed. The above threat model has to be considered in addition to terminal operational environment. In other words, the proposed road lay out can be considered in any of the operational environments (open area, urban area, etc.). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 52 Based on this scenario, it is possible to derive minimum performance in terms of mis-detection and false alarm. The determination of these performance is proposed to be tackled in the frame of the standardization actions listed in clause 7 Possible standardization action plan and priorities. 6.3.3 Protection Level As briefly introduced in clause 5.2.4 Position integrity, many application for which the concept of position reliability is a key features adopted the concept of protection level. In the case of 2D positioning (HPL for Horizontal Protection Level) is a smallest distance expected to bound the 2D positioning error, at any time. As previously reminded, the determination of HPL at terminal level depends on the different error budget potentially impacting the user measurements Those contributors can be differentiated in two categories: • GNSS System effects. Best assessment of these effects are provided by SBAS system in real time via accurate indicators (UDRE and GIVE) are provided in real time to the users. If the system is not able to provide accurate enough indicators it will issue an alarm on the parameter at fault. • Local effect such as troposphere, multipath, inference. At civil aviation level, the solution lies in the use of standard models. For other transport applications (road, train), these models do not stand anymore, and the combinations of sensor allow to have an estimate of the various local error components. In any case, whether it is inherited from civil aviation or developed for new applications, the determination of the terminal HPL highly depends on the algorithmic core implemented on-board the terminal. Consequently, in order to issue integrity determination performance (HPL) specification, a number of algorithm have been assessed. Table 11 summarizes the achievable performance function of the terminal type considered. Table 11: Achievable performance function for different terminal types Terminal type Figure of merit Open area Rural area Suburban area Urban area Covered area Asymmetric area Industrial area Type 1 HPL Availability 99 % 99 % 98 % 98 % 0 % 99 % 95 % HPL - 95 % 50 m - TBC 50 m - TBC 100 m - TBC 200 m - TBC N/A 200 m - TBC 250 m - TBC HPL - Max 1 000 m - TBC 1 000 m - TBC 1 000 m - TBC 1 000 m - TBC N/A 1 000 m - TBC 1 000 m - TBC MI 3 % 3 % 3 % 3 % N/A 3 % 3 % Type 2 HPL Availability 100 % 100 % 100 % 100 % 100 % 100 % 100 % HPL - 95 % 15 m - TBC 15 m - TBC 50 m - TBC 95 m - TBC Special 95 m - TBC 120 m - TBC HPL - Max 150 m - TBC 150 m - TBC 500 m - TBC 500 m - TBC Special 500 m - TBC 700 m - TBC MI 0 % 0 % 0 % 0,50 % Special 0 % 0,50 % Type 3 HPL Availability 99 % 99 % 98 % 98 % 0 % 99 % 95 % HPL - 95 % 50 m - TBC 50 m - TBC 70 m - TBC 120 m - TBC N/A 120 m - TBC 150 m - TBC HPL - Max 1 000 m - TBC 1 000 m - TBC 700 m - TBC 700 m - TBC N/A 700 m - TBC 700 m - TBC MI 0,5 % 0,5 % 0,5 % 0,5 % 0,5 % 0,5 % 0,5 % Comments on the HPL performance function of the terminal type: • For type 1 receivers (GNSS only), no specific mean allows the reasonably decrease the HPL or the mis- integrity risk. This is due to the fact that local effects contributions are not mastered. Available standard algorithms (MOPS, from civil aviation) does not properly adapt to ground transport conditions, so that important margin has to be taken in order to issue HPL, with, in addition, no real addition value on the confidence level associated to this level ( non negligible MI). • For type 2 receivers (GNSS + INS), the use of inertial navigation information highly supports the HPL determination. It indeed allows to get an estimate of the local error contributions, and thus issue a more performing and reliable HPL. All hybridization types have been considered (loose, tight, ultra-tight) all providing much improvement compared to type 2 receivers. • For type 3 receivers (GNSS + smart antenna), the use of smart allows not only to characterize some interference sources, but also the multipath delayed signal power and impact on the GNSS receiver. This is described in clause 5.4.1.1.4 Smart antenna. Such feature thus allows to bound the most significant local error components (MP and EMI), and hence contribute to the determination of valuable HPL. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 53 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.3.4 Interferer localization | This clause is for further study. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 6.4 Test principles | Several approaches concerning environment modelling have been reviewed in the previous clauses. It is now proposed to issue a synthesis. Four main streams can be identified: a) Basic models It is the basic approach, followed in many standardization bodies such as OMA or 3GPP. Basic models are used to specify the standard performance. Two major advantage of this method are highlighted: • First of all, in presence of these basic models, receiver performances are very well mastered. It means that the definition of the minimum performance will follow a known path, with limited risks. • In addition, in the frame of receiver testing, test results interpretation will be much more efficient. It would be therefore more convenient to isolate the weak points of the unit under test. b) Complex models This approach consists of using more complex models than the basic ones, aiming at reaching a better representativity of the real life environments. Thus, with such approach, we can extend the range of real environments covered by the model, event if, in any case, the coverage will be limited (i.e. for a significant range of types of environment, the model will not be relevant). The main problem with such approach is that the more complex are the chosen models, the sharper is the environment definition. Since the standard will anyhow have to point on a subset of these environments, it will be very hard to enforce them as reference models. c) RF replay test methods Such approach is interesting since it proposed a trade-off between: • the need to be fully representative of real conditions; and • the compatibility with standards definition: recorded data can be included in the standard specification. However, a major problem to solve is the definition of performance specification to be included in the MPS. Indeed, as far as artificial models are concerned, the prevision of the receiver performance requirement is more or less achievable. If real data are used, the environment in which data have been collected needs to be calibrated. This should allow to determine how challenging the real environment was, and derived the level of performance that needs to be required. d) Real environment testing The last considered approach is the test of the devices in actual real conditions. Such approach has similar attributes as the RF replay strategy: calibration of the real environment. However, including test in real conditions as part of the GNSS MPS is less straight forward than with the RF Replay technique: how should the test procedure be defined, in particular concerning test location? In order to solve this problem, a possible way forward is inspired from the Global Certification Forum (GCF) methods (GCF maintains an independent certification scheme for mobile phones and wireless devices that are based on 3GPP standards): the concept of test house. For certification purposes, GCF uses test cases developed and verified by a relevant standards body. So-called test houses actually are companies independent from GCF, in charge of validating the test platforms. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 54 If such scheme is applied for the GNSS MPS, we could define specific test houses whose responsibility is to define and calibrate test locations. This is also valid for RF replay test method. Figure 25 gives an overview of the above assessment. Figure 25: Reference environment definition approach Based on the above assessment, the following strategy is proposed: • The best way to test a particular feature or a particular behaviour consists in isolating the phenomenon, and check the response of the receiver to a given stimulus, even if quite simple. In that sense adopting very simple approach for testing appears to be a good approach (cf. 3GPP approach). • On the other way some phenomenon are very complex, and difficult to isolate. Tests based on real conditions are appropriate for this. In order to comply with this constraint, it is proposed to push for real life testing for two reasons: 1) It gives the opportunity to push for identified "Test houses" very close to end user conditions. 2) When talking about hybridisation, it is very difficult to replay (and inject) measurements of inertial sensors. The preferred approach is therefore as highlighted in figure 25. Still, despite this rationale, the use of RF Replay technique is clearly a very valuable contribution. In particular, from a practical point of view, it is very convenient in the frame of standard definition since test data can be easily attached to the standard. Consequently, in the short term (before complete test definition of sensors such as intertial is executed) it could be more effective to adopt a "Basic Testing" approach coupled with "RF Replay". This is also highlighted in figure 25, as the "back-up" approach. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 55 |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 7 Possible standardization action plan and priorities | The present document demonstrated both relevancy and achievability of a standardisation initiative addressing the concept of complex location systems used in mass market location based applications. The identified standardisation needs covered mainly the system architecture and performance: • Based on the functional needs collected from a thorough inventory of the location based application, it provided a number of technical evidences supporting the definition of reference architecture applicable to these location systems. Together with this reference architecture, standard interfaces between the identified system components have also been promoted. • Furthermore, the application inventory also revealed a wide disparity of performance needs, function of the considered domain. This pushes for the definition at location system level of a minimum performance standard. This is indeed needed to define the achievable performance, function of the technological enablers and operational environment. Consequently, the following action plan is proposed in order to produce the needed specifications (in clauses 7.1 to 7.3). |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 7.1 Needed technical specifications | The following specifications are intended to fill the gaps left by existing specifications in order to create a more complete set of specification for the design of locations systems addressing different markets. As such the proposed specification will reference existing specifications as far as possible. The following technical specification are proposed to be created: • Technical Specification (TS) for Location System Reference Architecture: - This TS is intended to define the stage 1 and stage 2 reference architecture for location systems. It will be based on the content of clauses 6.2.1 Stage 1 architecture and 6.2.2 Stage 2 architecture of the present document. • Technical Specification for Location Data Exchange Protocol: - This TS is intended to define the location data exchange protocol at location system level. This in particular cover the handling of the requests received from the application central part, and the protocol to be put in place to ensure to proper information delivery. This aspect is briefly addressed in the part of clause 6.2.2 Stage 2 architecture related to interface number 7. • Technical Specification for Location System Minimum Performance: - This TS is intended to define the location system minimum performance requirements. It will thus: establish the classification of the location system (which includes terminal types and central facility), function of the selected technological enablers (as proposed in clause 5.4 Enabling technologies); define the reference environments applicable to the location system specification (see clause 5.5 Operational environments); introduce and describe the possible "key features" supported by the location system; and finally define the minimum performance requirements applicable, function of the terminal type, operational environment and key feature considered. • Technical Specification for Test specification, procedure, scenario and data: - This TS is intended to provide data needed in order to allow implementation of proper testing of the location systems, in particular regarding the minimum performance and signalling protocols. This TS will be built based on the content of clause 6.4 Test principles. All of the above TSs are proposed to be produced in the ETSI TC-SES Satellite Communications and Navigation (SCN) working group, which is deemed the relevant specification group to pursue the standardisation work. ETSI ETSI TR 101 593 V1.1.1 (2012-09) 56 Accordingly, work items will be proposed to kick-off the production of these specifications. As far as implementation plan is concerned, figure 26 illustrates the logical links between the proposed TSs. These interactions indeed drive the implementation plan. Figure 26: Relationship between planned TSs Reference architecture and minimum performance requirements are proposed to be addressed first, since they respectively drive the definition of the data exchange protocol and the test specifications. |
d397fedfd9b02ae777b5d247c5d97147 | 101 593 | 7.2 Perimeter of first release | The first release of the set of TSs is intended to cover all aspect addressed in the present document. Further aspects are proposed to be covered in a subsequent release, as presented in the clause 7.3. 7.3 Evolution plan The following extensions of the standard are proposed: • Consider additional sub-types of terminal (type 1.x, 2.x): - new design (including new sensors); - introduce new types of terminal, function of the supported constellations and therefore possibly issue minimum performance specific for each type of constellation or signal. • Addition of terrestrial telecommunication sensors data, in particular in the authentication feature implies to further definition of threat model, including a cell coverage function of the environment selected. • Evolution of authentication threat model (to reach more complexity), function of authentication mechanism possibly added. • Use of civil aviation integrity service (EGNOS, WAAS). ETSI ETSI TR 101 593 V1.1.1 (2012-09) 57 History Document history V1.1.1 September 2012 Publication |
05203f91df26285fa31ed95e202a38fb | 101 532 | 1 Scope | The present document about "Mechanisms addressing interoperability of multimedia service and content distribution and consumption with respect to CA/DRM solutions" gives an overview and provides guidance on several CA/DRM subjects, presents related activities in standardization bodies and discusses implementation issues. Special attention is paid to existing solutions already introduced to the market with regard to interoperability as well as to emerging software-based solutions, all operated under a trusted environment. Analysis of solutions for interoperable multimedia content distribution and consumption with respect to CA/DRM, suitable for Multimedia platforms (broadcast, broadband or hybrid) and to the content/services delivered over them is the main focus of the present document, addressing: • A review of the status of existing and emerging standards together with other attempts to produce interoperable and interchangeable CA/DRM solutions suitable for multimedia consumption across multiple networks and platforms. • A presentation of the practical framework required for implementation and operation of a CA/DRM system. • An analysis of the interoperability available using current solutions and lessons from all the attempts reviewed. • Emerging market needs. • Concepts for market implementation including business roles, liability and trust. • Regulatory and legal issues. The present document covers all aspects of interoperability involving standardized elements concerning Conditional Access (CA) and Digital Rights Management (DRM) solutions associated with content distribution and consumption across various technical platforms for conventional Broadcast TV (DVB-C/C2, -S/S2, -T/T2) as well as for Broadband TV (including IPTV, WEB-TV) and Mobile TV. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 2 References | |
05203f91df26285fa31ed95e202a38fb | 101 532 | 2.1 Normative references | References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. Referenced documents which are not found to be publicly available in the expected location might be found at http://docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. The following referenced documents are necessary for the application of the present document. Not applicable. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 7 |
05203f91df26285fa31ed95e202a38fb | 101 532 | 2.2 Informative references | References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. [i.1] ETSI TR 102 688-1: "Media Content Distribution (MCD); MCD framework; Part 1: Overview of interest areas". [i.2] ETSI TR 102 688-3: "Media Content Distribution (MCD); MCD framework; Part 3: Regulatory issues, social needs and policy matters". [i.3] Recommendation ITU-T X.1191: "Functional requirements and architecture for IPTV security aspects". [i.4] ETSI TS 187 021: "Security services and mechanisms for customer premises networks connected to NGN". [i.5] ETSI TS 187 003: "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); NGN Security; Security Architecture". [i.6] Recommendation ITU-T J.293: "Component definition and interface specification for the next generation set-top box". [i.7] ETSI TS 102 796: "Hybrid Broadcast Broadband TV". [i.8] IETF RFC 5027: "Security Preconditions for Session Description Protocol (SDP) Media Streams". [i.9] IETF RFC 4046: "Multicast Security (MSEC) Group Key Management Architecture". [i.10] IETF RFC 3830: "MIKEY: Multimedia Internet KEYing". [i.11] IETF RFC 4909: "Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST LTKM/STKM Transport". [i.12] IETF RFC 4535: "GSAKMP: Group Secure Association Key Management Protocol". [i.13] ISO/IEC 14496-12: "Information technology -- Coding of audio-visual objects -- Part 12: ISO base media file format". [i.14] ISO/IEC 23001-7: "Information technology -- MPEG systems technologies -- Part 7: Common encryption in ISO base media file format files". [i.15] ISO/IEC 23009-1: "Information technology -- Dynamic adaptive streaming over HTTP (DASH) -- Part 1: Media presentation description and segment formats". [i.16] ETSI TS 103 162: "Access, Terminals, Transmission and Multiplexing (ATTM); Integrated Broadband Cable and Television Networks; K-LAD Functional Specification". [i.17] Information about gaining access to the DVB Common Scrambling Algorithms (DVB-CSAX). NOTE: Available at http://www.etsi.org/services/security-algorithms/dvb-csa-algorithm. [i.18] ETSI TS 100 289 (V1.2.1): "Digital Video Broadcasting (DVB); Support for use of the DVB Scrambling Algorithm version 3 within digital broadcasting systems". [i.19] ETSI TS 101 699 (V1.1.1): "Digital Video Broadcasting (DVB); Extensions to the Common Interface Specification". ETSI ETSI TR 101 532 V1.1.2 (2015-03) 8 [i.20] ETSI TS 103 197 (V1.5.1): "Digital Video Broadcasting (DVB); Head-end implementation of DVB SimulCrypt". [i.21] ETSI TS 102 474: "Digital Video Broadcasting (DVB); IP Datacast over DVB-H: Service Purchase and Protection". [i.22] ETSI TS 102 825: "Digital Video Broadcasting (DVB); Content Protection and Copy Management (DVB-CPCM)". [i.23] ETSI EN 300 294: "Television systems; 625-line television Wide Screen Signalling (WSS)". [i.24] HDCP Rev 2.2: "High Bandwidth Digital Content Protection (HDCP)". [i.25] CI Plus v1.3 CI Plus version 1.3. [i.26] EC Universal Service Directive 2002/22/EC amended by Directive 2009/136/EC. [i.27] Recommendation ITU-T X.1192: "Functional requirements and mechanisms for the secure transcoding of IPTV". [i.28] Recommendation ITU-T X.1193: "Key management framework for secure IPTV services". [i.29] Recommendation ITU-T X.1195: "Service and content protection (SCP) interoperability scheme". [i.30] DLNA® Guidelines. NOTE: Available to DLNA® members at http://www.dlna.org/dlna-for-industry/guidelines. [i.31] ATIS specifications. NOTE: Available to ATIS members at http://www.atis.org/iif/digitalrm.asp. [i.32] W3C Encrypted Media Extensions (EME). NOTE: Available at http://www.w3.org/TR/encrypted-media/. [i.33] W3C Media Source Extensions (MSE). NOTE: Available at https://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html. [i.34] Open Mobile Alliance (OMA) Mobile Broadcast Services Enabler. NOTE: Available at http://technical.openmobilealliance.org/Technical/technical-information/release- program/current-releases/oma-mobile-broadcast-services-v1-3. [i.35] Open Mobile Alliance (OMA): "BCAST DRM profile based on OMA DRM 2.0". [i.36] Open Mobile Alliance (OMA): "BCAST SmartCard profile". [i.37] IETF RFC 380: "Multimedia Internet Keying (MIKEY)". [i.38] 3GPP TS 23 246: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Multimedia Broadcast/Multicast Service (MBMS); Architecture and functional description". [i.39] 3GPP TS 33 246: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; 3G Security; Security of Multimedia Broadcast/Multicast Service (MBMS)". [i.40] DECE Common File Format (CFF). [i.41] ETSI TS 103 127 (V1.1.1): "Digital Video Broadcasting (DVB); Content Scrambling Algorithms for DVB-IPTV Services using MPEG2 Transport Streams". [i.42] Recommendation ITU-T X.1194: "Algorithm selection scheme for service and content protection descrambling". [i.43] Recommendation ITU-T X.1196: "Framework for the downloadable service and content protection system in the mobile IPTV environment". ETSI ETSI TR 101 532 V1.1.2 (2015-03) 9 [i.44] Recommendation ITU-T X.1197: "Guidelines on criteria for selecting cryptographic algorithms for IPTV service and content protection". [i.45] Recommendation ITU-T X.1198: "Virtual machine-based security platform for renewable IPTV service and content protection". [i.46] Recommendation ITU-T J.1001: "Requirements for conditional access client software remote renewable security system". [i.47] CENELEC EN 50221: "Common Interface Specification for Conditional Access and other Digital Video Broadcasting Decoder Applications". [i.48] MovieLabs group specification for enhanced content protection. NOTE: Available at http://www.movielabs.com/ngvideo/MovieLabs%20Specification%20for%20Enhanced%20 Content%20Protection%20v1.0.pdf. [i.49] ETSI ISG ECI white paper. NOTE: Available at http://portal.etsi.org/ECI/ETSI%20ISG%20ECI%20White%20Paper-v1_20.pdf. [i.50] ATIS-0800001.v003: "IPTV DRM Interoperability Requirements". NOTE: Available at https://www.atis.org/docstore/product.aspx?id=26099. [i.51] ATIS-0800006.v002: "IIF Default Scrambling Algorithm (IDSA) IPTV Interoperability Specification". NOTE: Available at https://www.atis.org/docstore/product.aspx?id=25435. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 3 Abbreviations | For the purposes of the present document, the following abbreviations apply: 3DES Triple Digital Encryption Standard 3GPP 3rd Generation Partnership Project 3GPP2 3rd Generation Partnership Project 2 AAA Authentication, Authorization, Accounting AES Advanced Encryption Standard AMD3 Ammendment 3 API Application Programming Interface ARDP Access Right Distribution Protocol ARIB Association of Radio Industries and Businesses ASIC Application Specific Integrated Circuit ATIS Alliance for Telecommunications Industry Solutions ATTM Access, Terminals, Transmission and Multiplexing AVMSD AudioVisual Media Services Directive B2B Business to Business BB Marlin Broadband specification BCAST OMA Mobile Broadcast services specifications BCMCS 3GPP BroadCast MultiCast Service C&R Compliance and Robustness CA Conditional Access CA/DRM Conditional Access/Digital Rights Management CAM Conditional Access Module CAS Conditional Access System CCSA China Communications Standards Association CE Consumer Electronics CENC Common ENCryption CENELEC European Committee for Electrotechnical Standardisation CFF Common File Format CGMS-A Copy Generation Management System - Analog CI Plus Common Interface Plus ETSI ETSI TR 101 532 V1.1.2 (2015-03) 10 CI Common Interface CISSA Common IPTV Software-oriented Scrambling Algorithm CMLA Content Management License Administrator CMMB China Mobile Multimedia Broadcasting CORAL The Coral Consortium CPCM Content Protection & Copy Management CPE Customer Premises Equipment CPU Central Processing Unit CSA Common Scrambling Algorithm DASH Dynamic Adaptive Streaming over HTTP DCAS Downloadable Conditional Access System DECE Digital Entertainment Content Ecosystem DIS DRM Interoperability Solution DLNA® Digital Living Network Alliance DPA Differential Power Analysis DRM Digital Rights Management DTCP-IP Digital Transmission Copy Protection - Internet Protocol DTG Digital TV Group DTLA Digital Transmission Licensing Administrator DVB Digital Video Broadcasting DVB-C/C2 Digital Video Broadcasting - Cable, First and Second Generation DVB-CA DVB Conditional Access DVB-CBMS DVB Convergence of Broadcasting and Mobile Services DVB-CI DVB Common Interface DVB-H DVB Handheld DVB-NGH DVB Next Generation Handheld DVB-S/S2 Digital Video Broadcasting - Satellite, First and Second Generation DVB-SH Digital Video Broadcasting - Satellite Handheld DVB-T/T2 Digital Video Broadcasting – Terrestrial, First and Second Generation DVD Digital Versatile Disc EBU European Broadcasting Union EISA Extended Industry Standard Architecture EME Encrypted Media Extensions ETSI European Telecommunications Standards Institute EU European Union eUMTS Enhanced Universal Mobile Telecommunications System FCC Federeal Communications Commission FLO Forward Link Only FLUTE File Delivery over Unidirectional Transport GBA Generic Bootstrapping Architecture GSAKMP Group Secure Assciation Key Management Protocol GSM Global System for Mobile HbbTV® Hybrid Broadcast Broadband TV HD High Definition HDCP High-bandwidth Digital Content Protection HSF Harmonized Security Framework HTML HyperText Markup Language HTML5 HyperText Markup Language version 5 HTTP HyperText Transfer Protocol IAB Internet Architecture Board ID Identity IDSA IIF Default Scrambling Algorithm iDTV Integrated Digital Television IEC International Electrotechnical Commission IESG Internet Engineering Steering Group IETF Internet Engineering Task Force IIF IPTV Interoperability Forum IMS IP Multimedia Subsystem IP Internet Protocol IPDC Internet Protocol Datacast IPR Intellectual Property Rights IPSEC Internet Protocol Security ETSI ETSI TR 101 532 V1.1.2 (2015-03) 11 IPTV Internet Protocol Television IPTV-GSI Internet Protocol Television Global Standards Initiative ISDB-T Integrated Services Digital Broadcasting Terrestrial ISG ECI Industry Specification Group Embedded Common Interface ISMA Internet Streaming Media Alliance ISO BMFF ISO Base Media File Format ISO International Organization for Standardization ITU International Telecommunication Union ITU-T International Telecommunication Union-Telecommunication JTC Joint Technical Committee KLAD Key LADder LLP Limited Liability Partnership LTE Long Term Evolution LTKM Long Term Key Message MBMS Multimedia Broadcast Multicast Services MIKEY Multimedia Internet Keying MLDv2 Multicast Listener Discovery version 2 MPEG Moving Picture Experts Group MPEG2 (M2TS) Motion Picture Experts Group 2 Transport Stream MPEG-DASH Motion Pictures Expert Group - Dynamic Adaptive Streaming over HTTP MSE Media Source Extensions MSEC Multicast SECurity MSK MBMS Service Key MSOs Multiple System Operators MTK MBMS Traffic Key NGN Next Generation Networks OIPF Open IPTV Forum OMA Open Mobile Alliance OS Operating System OTT Over-The-Top PKI Public Key Infrastructure QoS Quality of Service RAM Random Access Memory RFC Request For Comments RTP Real-time Transport Protocol RTSP Real Time Streaming Protocol RUIM Removable User Identity Module SARFT State Administration of Radio, Film and Television SCP Service and Content Protection SDP Session Description Protocol SE Secure Element SIM Subscriber Identity Module SPP Service Purchase and Protection SR Special Report SRTP Secure Real-time Transport Protocol STB Set-Top Box STKM Short Term Key Message SW Software TA Trust Authority TC Technical Committee TEE Trusted Execution Environment TISPAN Telecommunications and Internet converged Services and Protocols for Advanced Networking TNT2 Digital Terrestrial Television 2 TR Technical Report TS Technical Specification TTA Telecommunications Technology Association TTC Telecommunications Technology Committee TV Television UHD Ultra High Definition UHDTV Ultra High Definition Television UIM User Identity Module UK United Kingdom ETSI ETSI TR 101 532 V1.1.2 (2015-03) 12 UMTS Universal Mobile Telecommunications System US United States USA United States of America USB Universal Serial Bus USIM Universal Subscriber Identity Module USP Unique Selling Point W3C World Wide Web Consortium WEB-TV Web delivered Television WiMAX Worldwide Interoperability for Microwave Access WM Windows Media WMDRM-ND Windows Media Digitial Rights Mechanism Network Devices |
05203f91df26285fa31ed95e202a38fb | 101 532 | 4 The role and importance of CA/DRM solutions | |
05203f91df26285fa31ed95e202a38fb | 101 532 | 4.1 Introduction | This clause provides background information about why CA/DRM systems are used to provide security for pay TV content and how the integrity of each CA/DRM system is assured by an entity known as a "Trust Authority" which accepts liability for the system and consequently sets rules which govern its use. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 4.2 Basic introduction to CA/DRM systems | Content rights owners, and system operators acting on their behalf, want to restrict consumption of their content to just those users who are explicitly authorized to consume it and to prevent it from being copied or re-transmitted unless the user has been granted the right so to do. The rights owners may wish to apply further restrictions such as a limit to the period of time over which a piece of stored content can be consumed. The purpose of Conditional Access (CA) and Digital Rights Management (DRM) systems is to fulfill the content rights owners' requirements to protect content from misuse according to the rules and rights they wish to impose. The term CA was applied to earlier pay TV security systems in which content consumption is conditional on the system operator authorizing a viewer to have access. These CA systems usually relied on a piece of removable hardware - a viewing (or smart) card as part of their architecture - and did little apart from protect the TV content while it was in a unidirectional broadcast channel. The removable hardware was introduced as an enabler to the concept of renewability - the ability to upgrade and renew important parts of a security platform without having to change out the whole of it. Although not without cost, the replacement of, for example, a viewing card and download of new accompanying software is considerably cheaper than changing a population of terminals and is regarded as a cost effective means to respond to piracy or the threat of it. The detailed design of the removable/replaceable hardware is proprietary, outside the scope of any standard, in order that it can support counter measures that are not known to hackers and so that it can be changed out at a time that suits business requirements. The new accompanying software is delivered using a secure download process. When using a CA module with no viewing card, the renewability can be achieved using a similar process to that for systems that include a viewing card. The application of Digital Rights Management or DRM systems began with a broader scope of applicable content than the traditional CA system, for example to books, images and other media, and implemented many of the usage restrictions, which most modern CA systems are now also able to support. These usage restrictions set, for example, rules to be applied to the storage of content and the means by which it may be exported or consumed from the user device. DRM systems typically have no removable hardware element such as a viewing card; the security system is composed of replaceable software although it may relate to and depend on certain fixed hardware elements. Hence, modern CA and DRM systems can provide similar functionality for a pay TV environment. The fundamental architecture used by CA and DRM systems alike to protect content is one in which content is encrypted using a scrambling algorithm and a key to seed the scrambling. The key, or in some cases an artefact that allows the key to be locally generated, is encrypted so that it can be conveyed securely to the viewer at the point of reception; it is usually integrated into the broadcast channel or otherwise associated to the content. The security system of the viewer decrypts the key and uses it to descramble the content in order to allow the rights granted in terms of consumption, storage and re-transmission to be exercised. In broadcast applications, the key is normally changed periodically in order to make it harder for an attacker to determine what it is or to predict it when it changes. In addition to a removable hardware element, CA systems based on the DVB Common Scrambling Algorithm specifications employ a scrambling algorithm that is designed to be far easier to implement in hardware than software on general purpose processors. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 13 NOTE: Some DRM systems also support the use of the DVB Common Scrambling Algorithm, about which further information can be found in clause 5.2. The design topology, involving fixed and typically removable hardware as well, is intended to make it more difficult for a system to be attacked by someone who seeks to gain an understanding of the software code of the system and to access it. In addition, a specific implementation design of a scrambling algorithm can be protected by registering IPR, operating a license regime for bona fide users and pursuing anyone who violates the terms of the license by legal measures. A high level of resilience and protection is particularly important in a security system in which the content rights owner or system operator is using a unidirectional broadcast system and has no direct bidirectional communication path with the viewer's security system. Although it is important to ensure that scrambling algorithms in use are robust against current threats and those that can be predicted over the expected system lifetime, breaches to security systems are seldom accomplished by the exploitation of a direct attack involving the scrambling algorithm used to encrypt content. In practice, successful attacks are usually achieved by exploiting an inherent weakness in the implementation or in the key management system which allows the keys to be predicted, generated or discovered and transferred to the user's system at the rate at which they are required for the descrambling process. It is of the utmost importance that a security system is designed to prevent unauthorized access to the code or any other aspect of the operation of the security system that might allow a third party to access or otherwise discover the keys that are used; it will be robust against attacks. It is also a necessary feature of a security system that it can be upgraded to respond to evolving security threats and business needs. In order to reconcile these two requirements, upgrades will be accomplished securely such that the viewer's system will only accept software from a verified source so that an upgrade can be trusted. The topics of robustness and trust are discussed in the following clause. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 4.3 Introduction to the role of Trust Authorities | Content security systems necessarily rely on a Trust Authority (TA) for their commercial deployment. The Trust Authority has the following main roles: • publish and maintain a set of compliance rules that define the mandatory behaviour of devices/entities belonging to the content security ecosystem; • publish and maintain a set of robustness rules that define the minimum security level for a device/entity belonging to the content security ecosystem; • provide devices/entities that belong to the content security ecosystem (i.e. that conform to compliance and robustness rules) with the necessary cryptographic key material, e.g. a certificate and associated private key; • monitor the content security ecosystem for early detection of devices/entities that do not conform to compliance and robustness rules or for early detection of security breaches; • take necessary actions (e.g. revocation; compliance and robustness rules update; etc.) to remedy non- compliance or security breaches; and • provide a legal framework for all entities belonging to the content security ecosystem. In addition, some Trust Authorities verify compliance and/or security robustness or appoint external third parties to perform these verifications. The absence of a Trust Authority would result in low- (or even zero-) security level implementations of the content security system that could be easily breached without any efficient means to remove these implementations from the content security ecosystem. Content providers may refuse to provide their content for distribution on such content security ecosystems. For proprietary CA or DRM systems, the role of Trust Authority is often taken by the CA or DRM provider itself. For security systems defined by a standard or a consortium, a dedicated legal entity is generally created or used to play this role (e.g. DTLA for DTCP-IP or CMLA for OMA DRM). ETSI ETSI TR 101 532 V1.1.2 (2015-03) 14 |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5 Current landscape of CA and DRM solutions | |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.1 Introduction | This clause covers the market status of CA and DRM solutions and related information, which either are standardized or being developed by industrial organizations and fora. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2 DVB | |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2.1 About the DVB | The DVB project is a consortium established in 1994 with about 200 members, which devises and maintains DVB standards and conditions in a Joint Technical Committee (JTC) with ETSI, CENELEC and the EBU. See also www.dvb.org. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2.2 DVB-CA | In September 1994, agreement was reached in the DVB project to offer three basic standards aimed at enabling interoperability of content and services across multiple networks using different proprietary CA systems. • DVB Common Scrambling Algorithm (DVB-CSA) [i.17], (DVB-CSA3) [i.18]. • DVB Common Interface (DVB-CI) [i.19] (see also clause 5.2.5 introducing CI Plus). • DVB Simulcrypt (DVB-SIM) [i.20]. These standards are used worldwide for broadcast and their principles are available in many other standards such as ISDB-T, FLO, CMMB, etc. These standards allow interoperability of broadcast service access across operator networks and devices insofar as commercial and business agreements allow such interoperability. DVB is not limited to broadcast; the principles of the approach also apply to IPTV, mobile TV, OTT and other services. The encryption algorithms DVB-CSA v1/DVB-CSA v2 standardized by DVB are based on the same algorithm but with different key lengths. They were not published by the DVB project for security reasons but are available under licence. They were designed to be "hardware friendly", meaning that implementation in software was technically difficult to process. As processor power and speed has improved over time, resistance to software implementation has reduced and the key length is now beginning to be regarded as relatively short. These factors inspired DVB to create a new, more complex and secure version which was standardized as DVB-CSAv3 in 2007. CSAv3 is supported by new terminal equipment now arriving on the market, however migrating to CSAv3 requires the previous generation of terminal equipment to be replaced. The DVB-CSA licensing management for all 3 algorithms is handled by ETSI as the custodian. In addition to the CSA algorithms DVB also standardized a software-oriented scrambling algorithm called CISSA (Common IPTV Software Oriented Scrambling Algorithm) [i.41] which was designed as "software-friendly", meaning that the algorithm is easy to implement in either hardware or software in order to support with a software implementation also terminals that are using general purpose CPUs. Low cost end user devices typically still use a hardware accelerator element. The algorithm uses the AES cipher. CA systems are based on different technologies for management of keys but typically rely on the standardized common scrambling algorithm for content protection. CA systems from different technology providers are mutually incompatible. This means that a user's set-top box with an integrated CA/DRM system is not interoperable with other systems, although interoperability can be provided at the headend level when business agreements require this through the DVB Simulcrypt standard which provides for the synchronization of keys between different CA systems. DVB also developed the Common Interface (DVB-CI) standard. This specifies the hardware interface on the terminal or host equipment and the CA module (CAM) interface and functionality. Typically a viewing (smart)card is used in conjunction with the CAM to personalize the service with viewer subscription products and essential security elements, but it is also possible to embed security credentials in a module. This architecture allows periodic updates to be made to the security system by changing the viewing card (where used) or the entire CA/DRM system can be replaced by changing the CAM. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 15 Terminal devices can accept any compatible CAM allowing multiple CA systems to be used to access various services from multiple service providers when there is no commercial agreement to share the content through Simulcrypt. It is also possible to embed multiple CA systems in the same CAM allowing a single CAM to access several networks with different CA systems. The Common Interface (CI) has not enjoyed lasting support in the international market in the standardized form of 1997. This is largely due to security concerns about the unencrypted digital transport stream interface which could be used for unauthorized copying; there were also concerns about possible circumvention of certain specific national requirements on Protection of Minors (refer also to AVMSD, protection of minors). These concerns led to a lack of support from some network operators and content providers (although it is still in use in for example Switzerland, Austria and the Netherlands). CI Plus was developed to fill these technical gaps. For further details see clause 5.2.5 on CI Plus. Under the title "CA neutral CPE" DVB attempted to standardize all hardware components required for an encryption system and the required interfaces. This was supposed to ensure that the terminal equipment could be relatively easily switched via a software update from one CA system to another. This attempt, which was not the first of its kind in DVB, was not continued due to a lack of support from key market participants and a lack of market demand once a number of other complexities concerning divergent middlewares, network connectivity and liability had become apparent. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2.3 DVB-SPP | In the field of mobile broadcasting, DVB-H was the standard favoured by many market partners for transmission. The key components for the provision of services and contents are located in the "service enabler layer", which was specified by the DVB-CBMS working group under the term DVB-IPDC [IP data cast]. The IPDC suite of specifications defines the security-related components under the term "Service Purchase and Protection (SPP)" [i.21]. Transport encryption is realized at or above IP level. With IPSec and SRTP, DVB uses the open standard procedures of the IETF and with ISMACryp an open procedure of a group of interested parties (ISMA). SRTP and IPSEC scramble at the link (IP) level whereas ISMACryp scrambles at the content level which allows content to remain encrypted further into the device architecture if required. All procedures are based on the AES cypher. Since agreement was not reached on one encryption method, the SPP specification includes three methods as alternatives that are all implemented in the terminal equipment according to the standard. In the current stage of market development, only the system ISMACryp achieved market penetration. For the service-specific key management, the IPDC SPP specification provides for three alternative methods: • the 18Crypt method is based on OMA DRM 2.0, providing a fully standardized solution; • the OMA BCAST Smartcard Profile based on the secure tamper resistant module (USIM/RUIM) and providing a fully standardized solution; or • the DVB Open Security Framework defines a framework enabling any proprietary, vendor-specific or standard solutions to be supported as plug-in. The Open Security Framework approach was used in US and Italy with several millions of devices based on this technology in the field. The Open Security Framework was also adopted by the FLO Forum and standardized as the security framework by the US Telecom Industry Association in charge of US Telecom Standards. This Open Security Framework approach was used in the MediaFlo service deployment. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2.4 DVB-CPCM | The scope of CA systems on traditional transmission paths comprises safeguarding the transmission side and controlling the use of options in terminal equipment. It usually ends at the interfaces of the terminal equipment, where other copy protection systems, such as CGMS-A [i.23] and HDCP [i.24], are used. If other devices are to be connected in the home environment, the problem arises of how to control further use. With the "Content Protection and Copy Management" (CPCM DVB) standard [i.22], the DVB project has developed a system that - with reference to the required DRM functions - permits separation between the transmission side and the functions required in the home area. Content is first protected and distributed on the distribution networks with arbitrary CA/DRM systems. In the terminal equipment, content and the associated rights information can be safely passed to the standardized CPCM system. Within the "authorized domain" that defines the personal environment of the user in terms of rights, content can then be safely transported and used according to the transmitted rights information. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 16 As for any other content protection technology, CPCM requires a Compliance and Robustness Regime (C&R) to be in place prior to being launched to the market. This C&R Regime is still missing despite several attempts to create it. Because of this and despite several companies having produced working implementations of CPCM, it is currently unclear to what extent CPCM is still supported by relevant market players. CPCM may also be perceived as too complex to have cost-effective implementations and to be understood by end-users. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2.5 CI Plus | The DVB-CIv1 (CI version 1) specification (refer to clause 5.2.1) was developed in the mid-90s based on the EISA physical format and no longer corresponds to today's requirements in terms of the following aspects: • German "Protection of Minors Act" (in safe interaction with CA systems); • Copy protection; and • Re-encryption. Consequently, fewer network operators and content providers were using it but EU directives [i.26] require a common interface to be fitted to all iDTVs (integrated digital televisions) with screen size larger than 30 cm; refer also to [i.1] and [i.2]. These factors inspired the creation of a successor interface. Work on this successor began as CIv2 in the DVB project, for which appropriate commercial requirements were adopted in 2006. The subsequent work on the technical specification based on these commercial requirements did not progress within the DVB project due to differing ideas about the techniques to be applied and the timeframe to be met. Instead, some companies decided in mid-2007 to pursue work outside of the DVB Project in a new industry group, which they named "CI+ Forum". In November 2008 this resulted in the first version of the CI Plus specification and the creation of the related certificate issuing organization named Limited Liability Partnership (LLP CI Plus). The CI Plus Specification (V1.3) [i.25], CI Plus Device Interim License Agreement and the CI-Plus Test Specification can be found at: www.ci-plus.com. As the certificate issuer, CI Plus LLP acts as a trust authority for the operation of CI Plus. For secure implementation, one will, as a subcontractor, make use of such a trust authority. The specification was developed in a small, closed group but responsibility for maintenance and development of the specification has now been taken back into DVB with the result that version 1.4 has been finalized for submission to ETSI. Up to v1.4, all specifications use the same form factor for the physical interface and retain backwards or legacy compatibility with earlier versions to the extent of the functionality that the earlier versions provide. V1.4 adds support for multi-stream handling and IP delivered content. The specification can be found at: http://www.dvb.org/resources/public/standards/a165_dvb-ci-plus_v_1_4.pdf. DVB's plans for future versions of the CI Plus interface envisage a new physical form factor based on USB that is expected to make it cheaper to implement in TV devices and CAMs than the current interface. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.2.6 DVB Harmonized Security Framework | The DVB Harmonized Security Framework (HSF) was prepared by a group of security experts to provide clear advice in the form of guidelines to other DVB groups working on commercial requirements for future DVB standards. The first edition of the HSF was approved for use within DVB by the DVB Steering Board in April 2007. The group responsible for its maintenance has been working for the last two years on an update. In the meantime, the advice offered by the original 2007 document remains relevant to the communities working on standards who have need to consider user or system security and data privacy. The HSF notes that "in the last several years, networks and devices capable of the delivery and rendering of premium content have increased in types and number". This is clearly a trend that is continuing as the proliferation of smart devices has gathered pace. The HSF defines overarching security guidelines for DVB Commercial Requirements documents. These guidelines address the generic security aspects, content protection/security, privacy and system security. The stated aims of the HSF are to synchronize "security requirements across different DVB specifications" in order to: • promote interoperability; • facilitate choice; • encourage competition for all stakeholders including security providers, CE manufacturers and broadcasters; ETSI ETSI TR 101 532 V1.1.2 (2015-03) 17 • not favour one particular vendor/operator; • not prevent the introduction of new business models; • not invalidate existing business models and platforms; and • not invalidate existing DVB security specifications. The requirements that are the most pertinent to a report about pay TV security cover: • upgradeability; • global system security (for example designs should ensure that single device hacks cannot being deployed system wide); • minimizing changes to a standard that are necessary to overcome hacks; and • counter measures to allow for revocation and renewal. The HSF makes a special note about standardizing code download security, which it states "may compromise the security of other aspects of the device" and concludes that "DVB should not standardize a code download security mechanism". |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.3 ETSI - TISPAN | TC (Technical Committee) TISPAN (Telecoms & Internet converged Services & Protocols for Advanced Networks) was established in ETSI in 2003 for the standardization of Next Generation Networks (NGN) and services, extending the 3GPP IMS concepts to the fixed networks, and ended its activity in 2012. The work on NGN Release 2 included specifications for IPTV, home networks and terminal equipment. Both the integration of IPTV solutions already available on the market into the NGN and a solution directly based on IMS were provided for IPTV. For the latter, a reference architecture was also defined for terminal equipment. Work on Release 3 includes extensions to IPTV and security issues. The activity in ETSI TISPAN has produced a complete set of documents that provide a comprehensive solution for IPTV support in NGN, both via the exploitation of the intrinsic IMS functionalities or by means of an external platform interworking with the NGN and the Customer Network devices. For the aspects related to content and service protection, the reference document produced by TISPAN is ETSI TS 187 003 [i.5] "NGN Security; Security Architecture", with its last revision in 2011. Its scope is in the main the security of NGN, but limited to its architecture, and one section covers specifically the IPTV service security. The document does not focus on the technologies for content protection, but just provides indications about how this is to be taken into account in the general service security architecture described, defining the essential reference points and the basic functions. For service protection, ETSI TS 187 003 [i.5] goes into more detail and provides a distinct specification for "any content protection" and for the case when OMA BCAST is the service protection solution of choice. For the first case it is requested that the content protection be compliant with the transport technologies specified for TISPAN IPTV. For the second case full reference is made to OMA BCAST specifications and a mapping between the two architectures provided. A framework of specifications for IPTV was produced by TISPAN, including security aspects. In ETSI TS 187 021 [i.4] "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Security services and mechanisms for customer premises networks connected to TISPAN NGN" a section covers aspects of a service and content protection architecture in association with a secure upgrade process. OMA BCAST has been deployed but not on fixed IPTV networks. Deployments of IMS have been made, but none are known that include the IPTV framework. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 18 |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.4 ETSI KLAD System | ETSI TS 103 162 [i.16] defines a standardized key ladder to be used for secure provisioning of cryptographic keys (control words) for descrambling of video content in a multi-CA environment. The standard has three primary technical components: a) a root-key derivation block used for deriving per-vendor unique root-keys from a single non-volatile key; b) a 3-level key ladder using either AES or 3DES; and c) a challenge-response mechanism for authenticating the device or for other uses. The standard was created in response to a desire by the industry to have an interchangeable and multi-tenant security anchor integrated into the SoC, thereby avoiding the costly external security devices (CableCards, CI CAMs) used previously. Assuming an appropriate key management authority has been established in a given market, a device containing a chip implementing the ETSI standard can be sold in a retail environment that would support multiple CA systems and multiple Service Providers while retaining separation between the cryptographic keys used by each security system. A consumer could purchase a device, connect it to a chosen service provider's network and it would 'just work'. When moving to a new location, the customer could take the existing device and connect it to the network of a new service provider. It is understood that there are millions of devices deployed worldwide that include hardware supporting the standard. There are also three primary markets, described below, looking to deploy the entire 'ecosystem': 1) USA: It is the early stages of deployment and service providers are acting as their own Trust Authority which gives them greater flexibility to change CA providers; 2) Korea: The regulator for the cable market is setting up a trust Authority; and 3) China: SARFT is setting up a trust authority. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.5 ETSI ISG ECI | A new Industry Specification Group has been launched by ETSI in April 2014 on Embedded Common Interface for exchangeable CA/DRM solutions. Industry Specification Groups have been established alongside ETSI's Technical Committees and Projects with Terms of Reference and a specific agreement for participation aimed at completing a defined task. Non-ETSI members can participate under certain conditions. The reason to establish the ISG ECI is closely related to the current situation in a rapidly developing and converging area of digital Broadcast and Broadband, including content, services, networks and CPEs with service- and content protection realized by Conditional Access (CA) and Digital Rights Management (DRM) systems, which are essential to protect business models of content owners and PayTV operators. The consumer electronics market for digital TV is fragmented, as Pay TV operators have defined specifications that differ not only per country, but also per platform. The five ISG ECI Founding Members saw the need to address one aspect of fragmentation by considering a standardized environment for a general purpose, SW based, embedded, exchangeable CA/DRM system to allow users to switch security system without changing the hardware platform. The Founding Members of ETSI ISG ECI envisage in the white paper [i.49] that the key benefits of the approach for content security are • Flexibility and scalability due to SW based implementation. • Applicability to content distributed via broadcast and broadband, including OTT. • Support of multi-screen environment. • Opening of the market by avoiding "Lock-in" for platform operators, network/service providers, and consumers. • Open entire eco-system fostering market development. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 19 A number of Work Items and first Group Specifications have been approved within the ISG ECI so far and further activities will address architecture and interfaces for ECI clients in a CPE, including loader mechanisms, light virtual machine and an advanced security functionality based on a chain of trust. The standardization work of ISG ECI is supported by several members of the value chain. The target is that ISG ECI compliant CPEs will enable the end user to consume PayTV content from a broad range of Broadcast and Broadband sources delivered to retail devices (STB and iDTV) as well as to a number of mobile devices, including smart phones and tablets. This will involve creating tiered trust mechanisms and an architecture flexible enough to achieve these aims across a diverse device population. Legal arrangements supporting the trust mechanisms will need to be established in order to create an eco-system based on ECI technologies. These legal aspects are out of scope of the ISG ECI work. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.6 ITU-T | The International Telecommunications Union (ITU) based in Geneva is a United Nations agency involved in worldwide technical aspects of telecommunications. Many of the developed Recommendations are adopted within the ITU by the ITU-T, the responsible Telecommunication Standardization Sector. Due to the broad scope of application and, at times, rather differing market structures in the individual member states, issues such as CA/DRM are always treated by the ITU-T within a wider context, such as IPTV and Security (in ITU-T Study Group 17). Recommendations regarding CA/DRM issues have been mainly taken into account in Asia so far. The ITU-T documents can be distinguished for the following fields of application: • CA/DRM for "classic" broadcasting. • CA/DRM for IPTV and web TV. • CA/DRM for mobile TV. Some documents so far are of a conceptual nature. Chapter 7.4 of the Recommendation ITU-T-Rev. J.293 [i.6] "Component Definition and Interface Specification for Next Generation Set-Top-Box" may be used for discussion on the CA/DRM issue. The approach of a flexible conditional access system (CAS) illustrated therein that is based on hardware and software components addresses requirements such as a security system that can be replaced by software- only download or the implementation feasibility of multiple encryption algorithms. Moreover, the Recommendation ITU-T X.1191 [i.3] (formerly developed as X.iptvsec-1 in the IPTV-GSI and approved by study group 17), entitled "Functional Requirements and Architecture for IPTV Security Aspects", includes requirements for content security and scrambling algorithms as well as the interoperability of Service and Content Protection (SCP). Further parts of the X.iptvsec-series of Recommendation ITU-Ts have been finalized: • X.1192 (former X.iptvsec-2) [i.27]: Functional requirements and mechanisms for the secure transcoding of IPTV • X.1193 (former X.iptvsec-3) [i.28]: Key management framework for secure IPTV services • X.1194 (former X.iptvsec-4) [i.42]: Algorithm selection scheme for service and content protection (SCP) descrambling • X.1195 (former X.iptvsec-5) [i.29]: Service and content protection (SCP) interoperability scheme • X.1196 (former X.iptvsec-6) [i.43]: Framework for the downloadable service and content protection (SCP) system in the mobile IPTV environment • X.1197 (former X.iptvsec-7) [i.44]: Guidelines on criteria for selecting cryptographic algorithms for IPTV service and content protection (SCP) • X.1198 (former X.iptvsec-8) [i.45]: Virtual machine-based security platform for renewable IPTV service and content protection (SCP) Among these mentioned Recommendations X.1193 [i.28] describes a downloadable Service and Content Protection (SCP) system which includes a trusted environment. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 20 Recently more Recommendations with regard to CA/DRM have been developed or are progressing; among new Recommendations specifically Recommendation J.1001 "Requirements for conditional access client software remote renewable security system" [i.46] provides abstract advice relating to secure software updates by security vendors. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.7 Open IPTV Forum (OIPF) | In March 2007, network operators, service providers, manufacturers of terminal equipment and platform operators as well as content providers merged to form the "Open IPTV Forum". This initiative, now merged into the Hybrid Broadcast-Broadband TV Association, is aimed at developing open standards for a complete end-to-end systems approach for IPTV based upon existing technologies and specifications. The security solution specified initially by OIPF was Marlin, a specification developed by an industry consortium of companies. The scope of OIPF covers distribution of services via closed, managed networks and via the open Internet. Special precautions are taken by the network operator in the case of closed, managed networks to ensure the technical quality of transmission. This is not consistently possible for services via the Internet. The first set of specifications (Release 1) was adopted in early 2009. This includes part specifications of audio/video formats, content metadata, protocols for various network interfaces, middleware for interactive applications, and security of services and content (CA/DRM). In a later development, support for CI+ content protection was added. The Forum has defined two different approaches for the security of services and content: • the "terminal-centric" approach defines a complete end-to-end solution based on the Marlin Broadband (BB) specification; and • the "gateway-centric" approach defines a gateway function in the home network that terminates any network- based CA/DRM solutions and implements them into a standardized solution. This standardized solution can be based on DTCP-IP or CI + when external to the terminal, or embedded in the terminal. The current specifications are available at the following link: http://www.oipf.tv/. The Forum currently defines profiles for various applications of the specifications. Implementation should only be based on these profiles. Commercial deployments based on the end to end system have not been reported so far although parts of the specification are referenced by other specifications such as HbbTV®. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.8 HbbTV® | The HbbTV® initiative started in 2008 with activities in France and Germany to define how a web browser in a TV set could be used to add value to broadcast television and enable services linking broadcast and broadband content delivery. The specification is an integration of selected elements from DVB and from the Open IPTV Forum. The first specification was finalized at the end of 2009 and published by ETSI as ETSI TS 102 796 [i.7] (V1.1.1) in June 2010. First implementations appeared in TV sets in 2010 with widespread introduction in products in 2011. Content protection was outside the scope of this version of the HbbTV® specification except that: i) there is a standardized mechanism by which an HTML page can communicate with any content protection solution that may have been included in a terminal; ii) a mapping of that mechanism to the CI+ specification is included; and iii) for broadband delivered content, a definition is provided for the signalling of the type of content protection used. The specification was revised during 2011/12 to add support for delivering video via broadband using MPEG DASH with the resulting specification published by ETSI as ETSI TS 102 796 [i.7] (V1.2.1) in November 2012. This adds MPEG common encryption [i.14] as an option and defines how that option can be used. Deployments of the HbbTV® specification have selected content protection solutions. The first such selection was for the French retail DVB-T specification (TNT2). An agreement was reached between broadcasters and manufacturers that broadcasters would support at least two DRM systems and manufacturers would support at least one of these two. Both constituencies are free to support other solutions as well. Other HbbTV® deployments for retail markets are following the French selection or have indicated the intent to do so. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 21 |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.9 CORAL | CORAL is a cross-industry consortium with the aim of providing interoperability between different DRM systems in terminal equipment. A general infrastructure framework (DRM-Bridge) for content and service providers and manufacturers of terminal equipment will be defined for this. It can be used with different DRM techniques and is thus independent of the DRM technology used in each case. CORAL does not specify its own DRM technology, however. CORAL relies on the concept of service-oriented architecture by defining trusted and secure services and interfaces via which all necessary information can then be exchanged. Establishing and ensuring the reliability of services and terminal equipment is thus a major challenge The rights themselves are not replaced, but references of DRM- information are exchanged with the aid of tokens independently of the particular DRM system. This is achieved by assigning each terminal equipment a unique and certified ID. The certification is tied to roles within the CORAL frame. Based on this framework, interoperability between WM DRM 10, OMA, Marlin and even conditional access systems (CAS) can be provided. The downside of using Coral for television is that the consumer is required to re-download the whole content item in the new format, which can be time consuming and costly to the network. Coral has not been deployed. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.10 Digital Living Network Alliance (DLNA®) | DLNA® aims at the interoperable networking of terminal equipment and PCs for stationary, portable and mobile use. Networking is mainly based on UPnP [universal plug and play]. DLNA®'s area of study is limited to communication between devices within a home network. They do not define any means of delivery to the home. DLNA® has published two sets of guidelines that are related to content protection: Link Protection guidelines [i.30] that aim at protecting content while it is delivered to another device for viewing purposes. These guidelines do not address content copying or moving functions. Implementing these guidelines is optional. When implemented, one technology is mandatory, DTCP-IP and one is optional, WMDRM-ND. There exist some commercial deployments of devices implementing these guidelines. DRM Interoperability Solution (DIS) guidelines [i.30] that aim at permitting the secure transfer of content between home devices that implement different DRM solutions. Implementing these guidelines is optional. When implemented, two solutions are available: DTCP-IP (including content copy and move) and Coral. In practice, these guidelines have not been widely implemented in the marketplace. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.11 ATIS (Alliance for Telecommunications Industry Solutions) | ATIS is an association of telecommunications operators and equipment suppliers in the U.S. ATIS founded the IPTV Interoperability Forum (IIF) back in July 2005 to formulate a framework and requirements as a basis for further specification and standardization of IPTV, especially on Digital Rights Management (DRM) and Quality of Service (QoS). In addition to a number of ATIS IIF IPTV specifications, the following have been published by ATIS [i.31], which deal specifically with DRM and security issues: • IPTV DRM Interoperability Requirements ATIS-0800001.v003 [i.50]. • IIF Default Scrambling Algorithm (IDSA) Interoperability Specification ATIS-0800006.v002 [i.51]. • Secure Download Interoperability Specification. • Application Level Interfaces (API) Interoperability Specification. • Consumer Domain Attachment and Initialization Specification. • Remote Management of Devices in the Consumer Domain. • IPTV Digital Rights Management (DRM) Requirements Update. • Certificate Trust Management Hierarchy. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 22 • Standard Public Key Infrastructure (PKI) Certificate Format. • Security Robustness Rules. • Distribution of Content in the Subscriber's Authorized Service Domain. These and all other ATIS specifications can be downloaded at www.atis.org. No examples of ATIS deployments could be located and it is understood that all ATIS activities in the IIF group have closed down. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.12 IETF (Internet Engineering Task Force) | The Internet is a "loosely" organized international collaboration of autonomous, interconnected networks. The IETF is the organization responsible for the technical development of the Internet. The IETF is an open, global association of network operators, manufacturers of terminal equipment, researchers, network experts and users. The standardization process within the IETF is organized in a variety of working groups and is managed by the Internet Architecture Board (IAB) and Internet Engineering Steering Group (IESG). The IETF does not have a specific IPTV working group, but a variety of specifications on individual aspects of transmission, as well as on IPTV rights management, were developed as part of its activities. Almost all the other organizations mentioned in this clause have entered into liaison statements with the IETF and/or reference to the underlying specifications of the IETF. Some of the specifications dealing with the rights management for IPTV are: • Framework and Requirements for an Access Node Control Mechanism in Broadband Multi-Service Networks (Internet-Draft, Mai 2008). • Access Right Distribution Protocol (ARDP) (Internet-Draft, August 2007). • Requirement of service provider for the Data Broadcasting Service over the internet protocol television. • Security Preconditions for Session Description Protocol (SDP) Media Streams RFC 5027 [i.8]. • Multicast Security (MSEC) Group Key Management Architecture RFC 4046 [i.9], April 2005. • MIKEY: Multimedia Internet KEYing RFC 3830 [i.10], August 2004. • The Key ID Information Type for the General Extension Payload in Multimedia Internet KEYing (MIKEY). • Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST LTKM/STKM Transport RFC 4909 [i.11], June 2007. • GSAKMP: Group Secure Association Key Management Protocol RFC 4535 [i.12], June 2006. • AAA and Admission Control Framework for Multicasting (July 1, 2008). • MLDv2 User Authentication Problem Statement draft-liu-mboned-mldauth-ps-00. • Real Time Streaming Protocol 2.0 (RTSP) (Internet draft, May 5, 2008). All IETF specifications can be downloaded at www.ietf.org. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.13 W3C | The W3C launched a "Web and TV Interest Group" in February 2011 to identify requirements and potential solutions to ensure that Web and TV services interact well. The membership included TV manufacturers, cable and satellite providers and online video distributors. The interest group has established liaisons with multiple W3C working groups, most notably the HTML working group. In 2011 the interest group provided the HTML working group a set of requirements for commercial media support in HTML5. Two specifications address these requirements - the Encrypted Media Extensions [i.32] and the Media Source Extensions [i.33]. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 23 The Encrypted Media Extensions (EME) extend the HTMLMediaElement (video tag, audio tag) to define a common API that can be used to discover, select and interact with a DRM system. EME leaves it unspecified whether the DRM system accessed through the API is within the browser or in the platform. Based on the activities of involved industry fora, most applications will use EME in combination with the new ISO MPEG Common Encryption specification, while most browsers will implement an interface to a platform DRM. The EME specification was published by the HTML Working Group as a Working Draft in February 2014. The Media Source Extensions (MSE) extend the HTMLMediaElement to allow JavaScript to generate media streams for playback. Similar to the Encrypted Media Extensions, there appears to be strong industry interest in using MSE in conjunction with the ISO MPEG Dynamic Adaptive Streaming over HTTP (DASH) specification. The MSE specification was published by the HTML Working Group as a Candidate Recommendation in January 2014. Together, EME and MSE are specifications intended to meet the requirements of the W3C Web and TV Interest Group, enabling both live and on-demand, DRM-protected commercial media delivery to standards-based browsers and other HTML5 application frameworks, and are designed to work with the new MPEG DASH and Common Encryption specifications. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.14 Open Mobile Alliance (OMA) | The Open Mobile Alliance (OMA) is an association of service and product providers from the entire value chain of the mobile sector and adjacent industries. It aims at developing so-called "enablers" for market-ready, interoperable digital services, establishing them as global standards and thus ensuring the global interoperability of terminal equipment, software and content. As part of the OMA work a toolbox of different techniques to support mobile broadcast service (OMA BCAST) was defined. Mobile Broadcast Services Enabler [i.34] defines a technological framework and specifies globally interoperable technologies for the generation, management and distribution of mobile broadcast services over different BCAST distribution systems, (3GPP/MBMS, 3GPP2/BCMCS, DVB-H, DVB-SH, FLO, WiMAX, DVB-T2 and DVB-NGH). It also defines the procedures and parameters for securing services and content. The common feature of all methods is a transport encryption on or above IP level, service-specific key management. Like DVB-SPP, transport encryption favours open standard procedures such as IPSec and SRTP of the IETF and the disclosed ISMACryp method. IP packets (IPSec) to be RTP packets (SRTP) or codec-specific data packets (ISMACryp) are encrypted. The last version of BCAST (BCAST1.3) adds the support of MPEG-DASH-based contents and the support of MPEG CENC encryption for these contents. The common basis of all encryption methods is the AES algorithm. Two variants have been specified for key management. • OMA BCAST DRM Profile [i.35]: - The OMA BCAST DRM profile is based on OMA DRM 2.0 for key management. As a central element for the authentication of the terminal equipment, the method relies on Public Key Infrastructure (PKI), where only the terminal equipment itself is authenticated. This authentication is not transferable, as in the case of a SIM card, to other terminal equipment. A smart card is not mandatory; a variant of the method also works on one-way broadcast channels. • OMA BCAST SmartCard Profile [i.36]: - The OMA BCAST smartcard profile is based on a key management specified in 3GPP for MBMS (Multimedia Broadcast & Multicast Services) and securely implemented in the smartcard (USIM/(R)UIM) connected to the mobile phone. As such, it generally requires a return channel. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 24 |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.15 3rd Generation Partnership Project (3GPP) | The 3rd Generation Partnership Project (3GPP) unites six telecommunications standard development organizations from Europe USA and Asia (ARIB, ATIS, CCSA, ETSI, TTA, TTC). 3GPP covers cellular telecommunications network technologies. 3GPP has specified the multimedia broadcast and multicast service (MBMS) application independent transport service [i.38]. MBMS user services are based on broadcast or multicast services, and are bearer agnostic to enable access via generic IP access systems. It is used on UMTS and eUMTS (LTE) networks. MBMS introduces the concept of a point-to-multipoint service into a 3GPP system. A MBMS User Service is able to securely transmit data to a given set of users. In order to achieve this, a method of authentication, key distribution and data protection for a MBMS User Service has been defined by 3GPP and is called MBMS security [i.39]. MBMS security is used to protect RTP sessions and FLUTE channels. As such MBMS User Service protection is Transport Service independent, in particular, it is independent on whether it is carried over point-to-point bearer or MBMS bearer. The method of authentication is based on HTTP Digest and GBA (Generic Bootstrap Architecture) defined by 3GPP for establishment of keys between the server and the mobile/USIM. The key distribution (Service Keys (MSK) and traffic keys (MTK)) is based on MIKEY defined by IETF [i.37]. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.16 ISO MPEG | On April 2012, ISO/IEC published the 1st edition of MPEG's Dynamic Adaptive Streaming over HTTP (MPEG-DASH) as ISO/IEC 23009-1 [i.15]. ISO MPEG-DASH supports both ISO Base Media File Format (ISO BMFF) and MPEG2 Transport Streams (M2TS). MPEG-DASH is being broadly adopted by consortia and industry for over the top delivery. ISO also published Amendment 3 to the ISO Based Media File Format (ISO/IEC 14496-12 [i.13] AMD3) and Common Encryption for ISO base media file format files, ISO/IEC 23001-7 [i.14]. MPEG-DASH employed the above specifications to support multiple DRM interoperability for streaming services. ISO is in process of publishing the 2nd editions of MPEG-DASH (ISO/IEC 23009-1 [i.15]) and Common Encryption (ISO/IEC 23001-7 [i.14]). The 2nd editions enhance and extend these specifications features, including key rotation and additional encryption schemes. Multiple industry fora referenced these new ISO standards as the basis for protected over the top video streaming specifications. The Digital Television Group (DTG) in the UK, the HD Forum in France, Hybrid Broadcast Broadband TV (HbbTV®) in Europe, the Digital Entertainment Content Ecosystem (DECE) and Digital Living Network Alliance (DLNA®), all adopted DASH and Common Encryption in their specifications, for both streaming and downloading protected content, supporting multiple DRM interoperability. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.17 DECE and ULTRAVIOLETTM | UltraVioletTM is an industry developed solution for downloadable video content, intended to bring the flexibility to downloaded content that consumers have today with optical disks such as DVD. UltraVioletTM was developed by the Digital Entertainment Content Ecosystem (DECE) organization. UltraVioletTM provides for "DRM interoperability" by defining a Common File Format (CFF) [i.40] using the relevant ISO MPEG standards to provide content interoperability using devices running different DRM systems. DECE has not selected a single DRM for enabling interoperability, but supports many, and the list is continuing to increase. Any device manufacturer implements the DRM of its choice from the list, there is no need to implement multiple DRMs in a single device. Once a device receives content and wants to display it, it connects to the user right locker and requests the license for this content according to the DRM used by this device. If the user now uses another device with another DRM, this second device asks the DECE right locker to send the licence for this other DRM. With this approach, the DECE central right locker enables the secure storing of all content purchased by a user and enables access to its content library from any place and any device using any supported DRM. Content can be either downloaded or streamed on any device the user may use either at home or on the move. The content can be stored anywhere in the cloud or provided by any retailer, the right to access it is managed by the DECE central right locker. Once the user has the licence, there is no need to be connected further to consume the downloaded content. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 25 Thanks to this approach and the common encryption and file format, DECE facilitates the access to any content on all registered devices with DECE compliant DRMs, without being concerned about the DRM used by the end-user device. The approach enables full interoperability without the need to either download any DRM or support multi-DRM, and also greatly facilitates the user's ability to exploit purchased rights effectively for life by having a single place where all content purchased are registered and made widely accessible. A list of approved DRMs can be found at appendix C from the System Specification document, presently version "System—2.0r1" accessible at the following URL http://www.uvcentral.com/frontpage. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.18 US DCAS | An attempt to define a Downloadable Conditional Access System (DCAS) solution was proposed several years ago in the US by CableLabs, supported by major US MSOs. This was an attempt to create an alternative to the CableCARD solution for "separable security", a requirement set by the FCC in its Telecommunications Act 1996 in order to encourage competition through a retail market for terminal equipment. Under the proposal, the MSOs set up a consortium (Polycipher) which designed a common architecture in the form of a software stack and dedicated ASIC created by a specially commissioned chip design company (Embedics). All participating CAS providers would have to rely on the same architecture to integrate their security and all manufacturers would have to implement the defined software and hardware. CableLabs was proposed as the entity responsible for testing products and implementations for conformance thereby having trust responsibilities for the host. However there was no entity established to take full liability. After several years of work and large investment, the whole project failed because of disagreements between different sectors of industry about the specification, roles, responsibilities and liabilities. In the meantime, the CableCARD mandate has achieved just 616 000 devices as against over 47 million operator supplied devices. In 2014 the US House of Representatives voted to end the requirement for cable operators to support separable security. In later developments, Comcast and TiVo have recently announced that they are working on a two-way non-CableCard security solution (refer to http://www.fiercecable.com/node/70746/print). Earlier, two other US cable operators, Cablevision from 2011 and Charter from 2012, had decided to establish downloadable security system. These are individual proprietary initiatives and bear no technical relation to the DCAS project. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 5.19 GlobalPlatform® | GlobalPlatform® is a cross industry, non-profit association which identifies, develops and publishes specifications that promote the secure and interoperable deployment and management of multiple applications on secure chip technology. GlobalPlatform®'s objective is to create a standardized infrastructure that accelerates the deployment of secure applications and their associated assets, such as data and cryptographic keys, while protecting them from physical or software attacks. It achieves this by publishing and advancing specifications which address: • the implementation and management of tamper-resistant chips - such as smart cards and other SEs (Secure Elements); • the TEE (Trusted Execution Environment) which ensures that sensitive data is stored, processed and protected in a trusted environment; and • the messaging that enables service providers to connect their backend systems to the SE, TEE and any other actor within a secure application's ecosystem. GlobalPlatform® specifications have been largely deploying in the banking sector for years, and GlobalPlatform® is now extending the scope to other markets as transportation, government, Internet-Of-Things and media content management and protection. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 26 GlobalPlatform® established the Premium Content Task Force in 2012 in response to the growing consumption of premium content on mobile devices and requirement for the content to be hosted in a protected and secure environment. The intention of the taskforce is to address the requirements of premium content providers to protect their services on smart connected devices such as smartphones and tablets, to identify the key business and use cases in this market segment and to work with the relevant technical committees to ensure that GlobalPlatform® specifications can be enhanced to provide compelling solutions to the market. Content management and protection on devices is identified by GlobalPlatform® as a key driver for TEE adoption. The CA/DRM applications are identified as downloadable trusted applications in this environment that could rely on specific API to the TEE and a protection profile to ensure an end-to-end security to the premium content when consumed. A first requirement document addressing the trusted video playback platform has been issued by the group for implementation of a specific API in the TEE specifications, and another requirement document is in preparation enhancing furthermore the trusted media platform with watermarking and other functionalities. The technical specification of the TEE including support of these requirements should be publicly available in the beginning of 2015 year. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 6 Implementation and operation of CA/DRM systems | |
05203f91df26285fa31ed95e202a38fb | 101 532 | 6.1 Introduction | This clause considers the factors that operators, content rights owners and other stakeholders in the provision of services should take into account of in making and keeping the security of their delivery systems at the level necessary to safeguard their business. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 6.2 Effective implementation of systems | When designing and developing a CA/DRM solution, it is crucial to ensure that the solution be as effective as possible, i.e. is able to protect the content while maintaining a good user experience. The goal of a CA/DRM system is to protect the encryption key, manage user and content rights, and deal with output controls. This clause lists important practices that can be followed in order to build a more secure system. The terminology "CA/DRM agent" is used to designate a piece of software and/or hardware that is part of the client environment and which is responsible for the CA/DRM enforcement of security. Personalization The CA/DRM agent requires an identification and a key. The personalization of the agent allows fine-grained identification of the device it operates within, and consequently of the customer. It is important to be able to identify uniquely one specific agent running into one device belonging to one customer associated with specific commercial rights. This unique identification is the root of trust. A hardware based root of trust can be: • an ID burnt into the agent at manufacturing phase; or • an ID built from hardware unique IDs when the agent is purely software and downloaded into the device (e.g. a tablet). For example, it can be using a combination of unique id from the device (e.g. serial number). Protection The CA/DRM agent has to be protected at rest and in use. When at rest, a CA/DRM agent is better stored encrypted in the device. This is to ensure that reverse engineering will not be possible directly. When it needs to be run, it will be authenticated, integrity-checked and decrypted. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 27 When the CA/DRM agent runs (completely or a part of it) in software within the main chipset, there are specific tools that are used to ensure its safety. Safety here means that the running agent will not be successfully attacked while running. Some examples: • obfuscation: The programming code of the agent is changed (without changing the final behaviour) in order to make it unreadable. This is to counter tools for reverse engineering that are able to read machine code; • anti-debug/anti-dump: With such defense, the agent code can detect that it is being debugged and can stop; and • key storage: Decryption keys are stored in the memory when the agent is running. They need to be irretrievable (e.g. split in parts, moving around, etc.). Isolation The CA/DRM agent is a piece of software running within an environment. As such, it shares resources with other programs, and more importantly the resources it uses (e.g. RAM) can be accessed. This is why it can be beneficial to isolate the agent from the rest of the device. There are several levels of isolation that can be envisioned, depending on the capability of the platform. From the least to the most secure: 1) Mainstream OS. No specific isolation is available, the agent shares everything with the other processes within the OS. Its resources are easily readable; 2) Virtual Machine in an open OS. This isolation is purely software based; 3) Security Hypervisor (Virtual CPU). The agent process is separated from the other ones with specific resources; 4) Trusted Execution Environment. Isolation becomes hardware-based but sharing the chipset; or NOTE: Up to now, the agent is not protected against hardware attacks (DPA, etc.). 5) Dedicated hardware secure element. The hardware is physically separated from the main chipset. A component of the agent runs in the main chipset to ensure communication with the hardware secure element. Renewal and Diversification Secure renewal allows CA/DRM agent replacement (parts of it or the whole agent). It can be done by applying patches or by upgrading the complete firmware. When using a hardware removable piece (for example a smartcard), it means replacing it. Diversification allows not using the same agent models, codes, behaviour for all clients. The target is to segment/partition the population of clients. These two concepts are means to counter breaches in the CA/DRM system. Diversification limits the spread of the breach, giving time for renewal to cure it. Output Protection This has to deal with commercial rights associated with the content. CA/DRM is used to securely transmit the rights information to the device. Protected content is encrypted to ensure safe delivery up to the customer device. There it is decrypted such that it is available in clear. Such clear content will still be protected so that it is not sent insecurely to external devices nor to insecure components of the customer device. When building a complete CA/DRM protected solution, output control is used to ensure that clear content: • does not leave the secure video path inside the device; and • leaves the device by using approved only communication channels (e.g. HDCP). ETSI ETSI TR 101 532 V1.1.2 (2015-03) 28 |
05203f91df26285fa31ed95e202a38fb | 101 532 | 6.3 Anti-hacking and counter piracy activities | Operators have to be vigilant to the possibility of hackers attacking their security systems. A successful hack can give rise to several adverse outcomes. For example, existing customers may cancel legitimate accounts and deploy hacked methods to access content instead, resulting in a loss of revenue. Potential customers may adopt the hacked method, resulting in a lack of new revenue. Falling market confidence in the service and the operator will surely follow. Operators therefore have to ensure that they are looking for evidence of hacking activities, ideally before they have any impact; and they have to have the ability to securely upgrade applications or devices before hacking harms their business. The kinds of surveillance likely to be carried out by or for an operator include internet trawling for evidence of blog posts or other website entries pertaining to, for example, individual hackers and pirated software versions. Internet trawling can be carried out from more or less any territory. There is also the possibility of locating physical evidence of hacking through website shops, market stalls and other local "black market" suppliers and through signs of attempts to penetrate networks. The vigilant operator should be mitigating these threats by adopting prudent measures to ensure that they detect evidence early and are able to react effectively. For a reaction to be effective, it will be targeted at the most appropriate level to overcome the hack. Measures can range from a simple change of keys up to a complete security system change - operators have to be prepared for any eventuality in order to preserve their business and this means being ready for a worst-case scenario. Countermeasures are usually prepared by the security provider to the operator. The best prepared security vendors and operators will ensure that it is always possible to completely replace a security system in a relatively short space of time, months rather than years. To be at this level of preparedness, it is necessary to have assured, trusted access to the devices that need to be updated and to have a replacement security system ready to deploy. |
05203f91df26285fa31ed95e202a38fb | 101 532 | 7 Interoperability in practice | |
05203f91df26285fa31ed95e202a38fb | 101 532 | 7.1 Introduction | This clause examines use cases for interoperability in terms of the same protected content being received on devices with different CA/DRM solutions and the interchangeability of the CA/DRM solutions themselves. 7.2 Interoperability when several CA/DRM solutions are simultaneously used The following use cases are typical of those given as example of cases not covered by existing standards: • Receive content from multiple, managed networks (satellite, cable, terrestrial, Internet) using a single device. This is firstly related to the network interfaces of the device as decided by the manufacturer or the operator for a given market. A growing number of television receivers are "Smart TVs" equipped with triple tuners and internet connectivity and have a typical lifespan of 5 to 7 years which means they can be used on different networks, subject to operating system compatibility. Many set top terminal devices are equipped with Ethernet connectivity but only one tuner which means that they will only work on one type of broadcast network. The life span of a set top terminal device is typically 3 years (see http://www.slideshare.net/AminoTV/2012-0322- iptv-wf) according to recent research although some businesses aim to extend the life to 5 years. In this use case it is common that different CA/DRM solutions are used by different operators. Moreover, the operating system and middleware, which are often utilized to provide the USP - unique selling point of an operator - are very likely to be incompatible due to differing business requirements and delivery protocols of operators. Television receivers usually operate under a different business model with a longer lifespan but without an operator specified CA/DRM system. Users wanting to access pay TV content can attach a CI Plus module with viewing card if the service provider supports that option. If the user wants to access more than one pay TV network, it may be necessary to have more than one CI Plus module or a multi-CA module. • Receive content from one operator using a set top terminal device from a different operator over the same or a similar network, for example when people move or simply want to change to an alternative operator while keeping their retailed set top terminal device. In such a case it is likely that the CA/DRM differs from one operator to the other. ETSI ETSI TR 101 532 V1.1.2 (2015-03) 29 • Receive all channels on a set top terminal device equipped for one network operator, including those primarily broadcast on another operator's network. This can be achieved through B2B agreements between the operator of the original network and the one of the alternative network so that the re-broadcasting may occur. In this case the CA/DRM used on the primary network might differ from the one in use on the second network. • Receive foreign channels. This is a similar example to that of receiving channels from other operators in that it is a business decision to select the channels distributed. Operators acquire the rights for content for a specific territory because it suits their chosen business model which may rely on expertise for a particular market, and reception outside the designated territory is therefore not allowed contractually by the content owner unless specific rights are also acquired for that additional territory. As in other use cases, the CA/DRM system used on the primary network might differ from the one in use on the second network. Or • Receive hybrid services unrelated to broadcast. On hybrid devices users have the opportunity to access OTT content distributed over the internet besides services offered by the network operator. The availability of services to users depends on service providers making their services available using the DRM system implemented in the user's device. From a CA/DRM perspective, all the above use cases can be addressed, providing there is a business relationship between service providers, using DVB Simulcrypt and DVB CSA/CISSA for a CA protected content or DECE and MPEG Common Encryption for DRM protected content. DVB Simulcrypt actually enables each network to keep using their existing CA/DRM solutions while requiring each terminal to implement only one CA/DRM, since the terminal will always obtain ECMs or DRM licenses for the CA/DRM it implements. Simulcrypt has been widely and successfully used for many years over satellite networks where some channels are broadcast only once across multiple European countries and received in a large number of networks with various CA/DRM. The use of DVB Simulcrypt avoids having to implement at the manufacturing stage several CA/DRM solutions and the consequent increase in device cost. It has however to be noted that Simulcrypt may pose a risk to the overall security which is set by the weakest CA/DRM solution that is a part of the ecosystem. Should one of these CA/DRM solutions be successfully attacked, all networks and set top device terminals implementing other CA/DRM solutions are compromised. Security can however be recovered by ceasing the Simulcrypt link to the compromised CA/DRM. Some operators consider that DVB Simulcrypt is an excellent solution for migration from one CA/DRM solution to another (e.g. next generation solution of a CA/DRM vendor). An alternative to Simulcrypt is CI Plus. The current version 1.3 is only applicable to transport stream signals and allows support for additional CA/DRM systems in addition to those natively supported in the set top device terminal. Many terminals currently implement a CI Plus interface. Making use of the CI Plus facility comes often at the cost of the CI Plus module. The module price at retail is often seen as high when compared with a complete set top terminal device with embedded security, however there are sometimes subsidies available from operators to reduce the cost to the end user and work is underway within DVB to specify a version with a new, more common form factor. Users wanting access to multiple service providers may need to have more than one module. As shown by the above examples, interoperable solutions for CA/DRM exist and are deployed where there is the business justification for deploying them. The technologies mentioned in this clause have been shown to provide an appropriate balance between standardized security elements and components while leaving operators free to uniquely service their chosen business proposition. |
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