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e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.1.6.1 DMS type 1 | No difference from having one GIP portable and one mobile station operating using the same SIM except that the user only needs to carry one terminal instead of two (and of course does not have to remove/reinsert the SIM). No handover is possible between the GIP and GSM PLMN coverage. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.1.6.2 DMS type 2 | A type 2 DMS may be based on the "basic dual-mode procedures" (preferred mode) or on a new procedure that mixes mode and PLMN selection. It may be able to identify available GSM cells using a background scanning procedure. GIP to GSM seamless handover in the same PLMN can be performed if the DMS can perform the background scanning while in active communication. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.1.6.3 DMS type 3 | If same LAI is used in GIP access network as in surrounding GSM area, there is no need for mode switching as for type 2 DMS because paging will be done on both radio interfaces. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.1.6.4 DMS type 4 | A type 4 DMS can perform seamless handover between GIP and GSM PLMN coverage. Furthermore in the case of multiple service while in activity in one coverage it can support a receive-only service in the other (e.g. a speech call in GIP while receiving a SMS Cell broadcast message in GSM). A type 4 terminal compared to types 2 and 3 has the advantage to maintain the system synchronization with both GSM and DECT coverage. TR 101 176 V1.1.1 (1998-04) 25 |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.1.6.5 DMS type 5 | A type 5 DMS can perform seamless handover between GIP and GSM PLMN coverage. Furthermore it can provide execution of multiple services simultaneously. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.2 Requirements | |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.2.1 User requirements | No special actions by the user shall be necessary to use a DMS. The possibility for the user to manually select the mode of operation must, however, be supported. The user may also choose which mode is the preferred one, as in EN 301 242 [17]. Indications should also be given to the user of which mode is being used. The user of a DMS shall be able to roam between PLMNs operating in any of the DMS's frequency bands of operation. The DMS shall therefore, at PLMN selection, present all available PLMNs within its frequency bands of operation. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.2.2 Operator requirements | The use of GIP/GSM dual-mode operation is optional for the operator. DMSs must therefore be able to, functionally, work as single mode terminals in single mode networks. When GIP/GSM dual-mode operation is used, it shall be possible to provide coverage in one frequency band independently of the coverage in the other frequency band(s). Operators may benefit from the advantages of having a picocellular access network without the need to plan that part of the network with the same accuracy as the micro and macro cellular parts of it. Instead they would make use of the fact that there is no need for detailed frequency planning of the DECT access network and the fact that the DECT access may be implemented in specific environments. The full possibility of forcing the DMS into a specific cell, band or mode in the same way as it is for a MB MS is then not required. Possibly a mechanism that makes it possible for the network to indicate preferred mode is sufficient. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.2.3 DMT specific requirements | The radio requirements for DECT and GSM differs. A DMS and the GIP/GSM dual-mode network shall meet the requirements for each mode of operation respectively. Type approval of DMSs will be covered by the respective test specifications and some additional test for the dual-mode functionality. The radio requirements for DMTs are covered in TR 101 072 [16], EN 301 439 [18], and clause 5. No new requirements are identified for DMSs. The DMS supports frequency hopping in GSM mode and dynamic channel selection in DECT mode. Frequency hopping and dynamic channel selection between the modes can not be supported. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.2.4 Security requirements | It has to be ensured for GIP/GSM dual-mode operation that the same level of security is maintained over the DECT mode as is specified for the GSM mode. This is ensured by GIP since this profile is specified to meet the security requirements of GSM (see ETS 300 370 [9]). |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3 Functional description | To identify the necessary amendments of the DECT and GSM phase 2 specifications, functional descriptions of different procedures and solutions are given below. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.1 Idle mode procedures | The idle mode procedures will not be different for GIP/GSM terminals or networks when the DMS is in either DECT or GSM mode. Only the fact that operation in more than one mode may be available has to be taken into account. Specific DMS idle mode procedures are needed for switching between DECT and GSM modes. TR 101 176 V1.1.1 (1998-04) 26 |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.1.1 PLMN and Mode selection | Different PLMN and mode selection procedures have to be defined for the different DMS types. For DMSs of type 1 (manual switching between the two modes) the user first selects mode. PLMN selection is then performed in the selected mode as defined in ETS 300 930 [21]. For DMSs of type 2 a parameter value must be set for which mode (DECT or GSM) is the preferred mode [17]. The preferred mode is automatically selected if there is a network available to which the terminal has access rights. The preferred mode parameter can be set by the user. If the operator needs to be able to control the mode selection for the DMS, this can be done by simply introducing ways to transport a value for the preferred mode parameter from the GIP/GSM dual-mode network to the DMS. This mechanism is much simpler to implement than enforcing the network to handle DECT cells in the same way as DCS and GSM micro cells are prioritized in GSM multi band operation. In the selected mode the type 2 DMS listens to the radio interface and collects the available PLMNs in a list: if the HPLMN is available, the mode is the preferred one and the selected PLMN is the HPLMN. If the HPLMN is not available in the preferred mode, the DMS switches to the non preferred mode and collects the available PLMNs in a list: if the HPLMN is available, the mode is the non preferred one and the selected PLMN is the HPLMN. If the HPLMN is not available in the non preferred mode either, the DMSs compares the two lists of PLMNs available in the two modes and selects a PLMN as described in ETS 300 930 [21]. If the selected PLMN is available in the preferred mode, this mode is selected. NOTE: The DMS may also use background scanning to look for HPLMN in the mode other than the one it is in. After selecting PLMN and mode, PLMN re-selection (as specified in ETS 300 921 [24] and ETS 300 930 [21]) is performed only in the active mode. If no PLMNs are found in the active mode, the DMS switches to the non preferred mode and performs PLMN selection. For DMSs of type 3, 4 and 5 (which can listen to both radio interfaces) the PLMN and mode selection can be performed as follows: - the DMS listens to both radio interfaces and collects list of available PLMNs in both modes; - the DMS selects a PLMN following the procedures defined in ETS 300 930 [21] based on a common list of PLMNs available in both modes. For PLMNs that normally has equal priority in the PLMN selection procedure, a higher priority can here be given to those PLMNs that are available in the preferred mode; - if the selected PLMN is available in both modes, the preferred mode is selected. NOTE: For a type 3-5 DMS, to select the preferred mode means that actually only one of the modes is used for execution of the GSM services. The other mode may be on in order for the DMT to be prepared for a mode handover or PLMN reselection. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.1.2 Cell selection | The DMS would select the mode to operate in, as indicated in the previous subclauses, and then select a suitable cell in that mode. The DMS would need to be locked to a DECT cell and camped on a GSM cell at the same time, e.g. in order to receive suitable DECT handover candidates and GSM neighbour cells in case a handover becomes necessary. After a suitable cell has been selected, any necessary registration will be performed. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.1.3 Cell re-selection | The DMS will cell re-select according to which mode it is in. In the case of DMS of type 3, 4 and 5, if a preferred suitable cell is found in the other mode the DMS may change mode automatically based on the timer similar to the one defined in [17] or, in case different location areas, the GSM hysteresis parameter CRH may used also for change of mode. Decision of preferred cell could be based on the DECT radio parameters if these are made comparable to the GSM field strength and priority parameters. NOTE 1: Similar considerations could seem to apply also for type 2 DMSs but the difference between type 2 and 3 in this case is that a type 2 DMS is not required to perform more idle mode procedures than just network identification. TR 101 176 V1.1.1 (1998-04) 27 NOTE 2: There is no need to generalise the neighbourhood cell list concept and mix GSM and DECT cell identities and channels. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.1.4 Location areas | No special requirements are specified for the allocation of location areas among the cells in a GIP/GSM dual-mode network. It shall therefore be possible to use the same or different location areas for cells in different frequency bands irrespective of their location. Location areas for GSM micro cellular architectures were very briefly discussed in TR 101 072 [16]. Several possibilities for relating the DECT RFPs to GSM location areas exist: - the RFPs of a single FP may relate to several GSM location areas; - all RFPs of a single FP relate to the same GSM location area but different FPs relate to different GSM location areas; - several FPs relate to the same GSM location area but this location area contain only DECT cells; - a GSM location area contain both DECT and GSM cells. The advantage of having DECT and GSM cells in the same location area is that the DMS would (usually) not cause any extra signalling in the PLMN due to a change between DECT and GSM mode. As long as the terminal knows which its preferred mode is, it would respond to pagings in this preferred mode. The advantage of having DECT and GSM cells in separate location areas is that there would be a natural hysteresis when the DMS changes between DECT and GSM mode. Even if the DMS may be locked to DECT cell and camped on a GSM cell at the same time, it shall not perform location registration in both location areas. When the location areas of the DECT and GSM cells are different, a change of mode should be based on the CRH (CELL_RESELCT_HYSTERESIS) parameter (see ETS 300 930 [21]) rather than on the principle of preferred mode as in EN 301 242 [17]. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.2 Connected mode procedures | |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.2.1 Monitoring | The DMS shall use the normal GSM monitor and reporting procedures when in GSM mode. Even if the DMS can listen on both radio interfaces, it may need to report only on GSM channels using the normal GSM monitor and reporting procedures. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.2.2 Handover | Handover between DECT and GSM modes of a DMS in a GIP/GSM dual-mode network can be described based on the GIP external handover procedure in ETS 300 370 [9] and the GSM basic external intra-MSC handover procedure in GSM 03.09 [20]. Handover examples are illustrated in annex A. Handover is initiated by the DMS based on identification of a bad radio link or identification of a much better one. As in GIP, ETS 300 370 [9], the portable initiation leads to a handover command from the network. Any DMS will only send measurement reports from cells within its modes of operation. Handover commands to cells outside the modes of operation will therefore not occur. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.3.3 Frequency and power capabilities | The network should be informed by the DMS of its frequency and power capabilities to ensure that all procedures, e.g. the handover algorithm, gets accurate information. TR 101 176 V1.1.1 (1998-04) 28 |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.4 Technical realization and amendments | The technical realization and the identified modifications/amendments of existing standards necessary to support DMSs and GIP/GSM dual-mode operation are given here. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.4.1 Handover | Type 5 DMT is not required for GIP-GSM handover. Type 2 is enough for GIP→GSM handover and type 4 is enough for GSM→GIP handover (or at least the possibility to evaluate link quality of the second mode and transport these measurements on the first link). GSM handover candidate identities are included in handover candidate procedure. If GSM identities are to be included in the handover candidate messages only to DMSs (and not to GIP PPs), the network (at least FPs) must know that the terminal is a DMS. It must be possible for the network (at least FPs) to identify terminal capabilities (at least distinguish PPs from DMSs). DMS shall interpret handover candidate indication as HO command. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 6.4.2 Identities | For a GIP PP, the IPEI is mapped to the IMEI [9] and the PP identity can be handled in the EIRs in the same way as the identities of the GSM MSs. The only difference is that the first two digits of the TAC in the IMEISV are coded as 10 making it possible to distinguish GIP PPs from GSM MSs. I would be possible assign DMSs IMEISVs either as for GSM MSs or as for GIP PPs but it will then not be possible to distinguish a DMS from a GSM MS or a GIP PP, at least not from the IMEISV. The problem of identifying the different future types of multi mode terminals, where one of the modes is GSM, should be considered in general. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 7 Network selection for multi-subscription DMTs | This clause covers the general network selection problem that occurs for a terminal with several subscriptions, on what principles should it operate when selecting mode/network/subscription/service? Neither the existing basic dual-mode procedure (based on the definition of a preferred mode) nor the existing PLMN selection procedure is capable of handling network and mode selection simultaneously. The considerations is based on the most general case; a GIP/GSM DMT with both GSM and DECT (ARI class A,B,C) subscriptions. One way to achieve a mixed mode/network selection would be to first create a list of the subscriptions in the DMT arranged in order of priority. Either the priority could be fully according to the users preferences or a default order could be used, e.g. 1) residential DECT subscriptions (ARI class A); 2) business DECT subscriptions (ARI class B); 3) public DECT subscriptions (ARI class C); 4) GSM subscription (ARI class D or PLMN). At power up, the DMT type 2 would go into the preferred mode and select the network on which it can use the subscription with highest priority. In case the subscription in use does not have the highest priority, the DMT would perform background scanning looking for a network in the other mode on which it can use a subscription with higher priority. Among the subscriptions with the same priority, network selection would be performed according to DECT or GSM principles. Type 3-5 DMTs would scan both radio interfaces and compare the networks available in both modes and select mode and network according to where it can use the subscription with the highest priority. TR 101 176 V1.1.1 (1998-04) 29 Use of the GSM subscription in the HPLMN would be handled as a subscription with higher priority than the use of the GSM subscription in a VPLMN. Similarly in case a DECT IPUI is paired with several PARKs, then one of the IPUI- PARK pairs could be considered to be of higher priority. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8 Conclusions | |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.1 Remarks on dual-mode terminal types 3, 4 and 5 | In the following paragraph the functional behaviour of the three types of advanced dual-mode terminals is summarized. The advantages / disadvantages with respect to reachability and handover between DECT and GSM are discussed and compared to a basic type 2 DMT. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.1.1 DMT Type 3 | This terminal is able listen in both modes at the same time but in case the DMT is in active communication in one mode the other mode is blocked. To the network, such a terminal would then seem to be out of coverage in one mode. Compared to a type 2 DMT, the type 3 DMT offers the user the possibility to be reachable on two telephone numbers at the same time. To guarantee full reachability even when the DMT is in active communication in one mode, "call forwarding on not reachable" will have to be permanently activated as it may not be possible for the terminal to react on an incoming call. A DMT type 3 can be used to enhance a type 2 DMT with SMS capabilities. The handover capabilities are the same for a type 2 and type 3 terminal. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.1.2 DMT Type 4 | A type 4 terminal is able to listen in both modes at the same time. In case of active communication in one mode the other mode can still listen. Unless the terminal is able to react to an incoming call on the non-active radio interface via the active radio interface, this terminal will appear to be out of coverage just like a type 3 terminal. But such a solution seems not reasonable. It is more practical and requires less changes to implement a common IN functionality behind the DECT / GSM networks to support reachability via DECT or GSM for a type 4 terminal. While in active communication on one side, measurement results for the non-active air interface could be sent via the active air interface. This means that a seamless handover between DECT and GSM could be possible. The type of handover would have to be serial, like in GSM. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.1.3 DMT Type 5 | This type is capable of handling the complete functionality of both modes at the same time. Concerning reachability call forwarding is still needed in situations where there is only coverage in one mode. But the terminal offers the possibility to be in active communication in both modes at the same time (e.g. multiparty between different modes/ speech and data) and is more flexible than a type 4 terminal concerning handover DECT / GSM. So this is the most promising type of DMT if it were not for the potential cost of such a terminal. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.1.4 Commonalities | Finally, it turns out that all types of terminals have to rely on call forwarding to offer continuous reachability of the user. Therefore the only real disadvantage of a type 2 terminal seems to be its missing capabilities for a seamless handover between DECT and GSM and its lack of ability to receive GSM SMS in DECT mode. These features may be offered by a type 3, 4 or 5 terminal. Besides the application of the advanced terminals as double location registered terminal these terminals could also be used like a type 2 terminal but capable of performing a seamless DECT / GSM handover and receiving GSM SMS. TR 101 176 V1.1.1 (1998-04) 30 |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.2 Acceptance of degradations | Regarding the acceptable degradation the idea should be to keep everything as close to existing requirements as possible. Of course, almost every shortcoming of a particular type of terminal could be cured by some network settings but it should be avoided that operators have to base their network planning on the functionality of dual-mode terminals. One particular problem is the out of coverage behaviour for type 3 and type 4 terminals while in active communication in one mode. Whereas in case of a type 2 terminal the operator could rely on attach / detach to save spectrum, in case of a double location registered terminal (except type 5) he may not be able to rely on this. From the users point of view a DMT type 3 or 4 with out-of-coverage behaviour may be acceptable since the user can rely on call forwarding on not reachable. In case a DMT of type 3- 5 is not used as a double location registered terminal but as a type 2 terminal which is capable of performing a handover between DECT and GSM or is capable of receiving GSM SMS in DECT mode, the necessary degradations are less severe. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.3 Further standardization | The following requirements were identified that needs to be specified in a new dual-mode standard (or to be included in existing standards) which must then serve as the basis for a TBR or Harmonized Standard together with the relevant DECT and GSM standards: A service description for type 3-5 DMT functionalities should be written that goes into greater detail than the basic dual- mode standard, EN 301 242 [17]. The requirements on acceptable degradation, e.g. decreased pageability, for double location registered terminals (type 3, also 4 and 5) must be described. The requirements for DMTs type 4 and 5 regarding unwanted transmitter emissions in the GSM/DCS 1800 receive bands must be described. New procedures for network/mode selection for multiple subscription terminals and for multiple registrations are required. The requirements for GIP/GSM dual-mode operation concerning the idle mode procedures (cell selection, cell re- selection, location area management) and active mode procedures (e.g. handover) has to be described in a specific standard or as an update of the GIP standards (see ETR 341 [10]). The GSM standards are likely to be affected as well. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4 Testing and type approval | Type approval and testing issues have already been looked at in clause 5. It is important that a type 3, 4 or 5 DMT, when manually switched to DECT or GSM mode, meets all of the type approval requirements associated with a single mode DECT PP or GSM MS. However, the principle followed for type approval of type 2 DMTs, that of type approving each mode separately, with minimum testing of the automatic mode selection mechanism, would not be sufficient. This is particularly the case for type 5 DMTs. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.1 Radio testing and type approval | |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.1.1 Type 3 DMTs | Type 3 DMTs may exist in two radio configurations: type 3a, which has dual transceivers, and therefore is able to simultaneously receive when idle in both modes, and type 3b, which has only one transceiver, and which is therefore not able to simultaneously receive when idle in both modes. A type 3 DMT is the most straightforward of the advanced DMTs to type approve, in that it will require little or no modification of the existing type approval requirements for DECT, GSM, and type 2 DMTs. The approach adopted could be very similar to that of type 2 DMT. Since type 3 terminals do not receive in one mode when transmitting in the other, unless performing background scanning, existing receiver sensitivity requirements could be met for both modes. In any case, receiver sensitivity can only be tested when the DMT is in active communication, which for type 3 DMTs TR 101 176 V1.1.1 (1998-04) 31 means that the other mode is no longer receiving, unless performing background scanning, which is similar to type 2 DMTs. A type 3 DMT should not emit more spurious emissions than a type 2 DMT performing background scanning. It would be acceptable to test spurious emissions when manually switched to each mode, as for type 2 DMTs (except when performing background scanning while in active communication, in which case the same test conditions as for type 2 DMTs would apply). EMC emissions/immunity can also be tested exactly as for type 2 DMTs. This avoids attempting to combine the DECT and GSM spurious emissions tests, which is just as difficult and unnecessary for type 3 DMTs as it is for type 2. In conclusion, for radio type approval, a type 3 DMT can be treated exactly as a type 2 DMT, in that the existing radio essential requirements of TBR 6 [25], TBR 19 [27], TBR 31 [30] and Harmonized Standard EN 301 439 [18] would apply without modification. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.1.2 Type 4 DMTs | A type 4 DMT, in terms of radio configuration, is one which has 2 transceivers, which is capable of receiving on one mode while transmitting on the other, but which is incapable of transmitting on both simultaneously. Radio testing could, for the most part, be performed separately for each mode when manually switched to that mode. Since a type 4 DMT is registered to a network on both modes at the same time, the receiver sensitivity of both receivers should meet the existing requirements for DECT and GSM, whether or not the DMT is transmitting in one of the modes. However, it is only possible to test receiver sensitivity using the existing TBR and Harmonized Standard tests while the DMT is transmitting (loopback is required). Therefore, the existing tests give no indication as to the performance of a receiver of one mode while the other mode is transmitting. The existing receiver sensitivity tests can be used, but will need to be executed while the DMT is receiving in both modes (not manually switched to one mode). Consideration will need to be given to the need to develop a receiver sensitivity test which does not involve transmission of the DMT, in order to verify that receiver sensitivity requirements are met at all times. For testing spurious emissions requirements, it should be sufficient to test each mode separately, while manually switched. While the DMT is (transmitting in one mode and) receiving in both modes, there will be some additional spurious emissions compared with when the DMT is manually switched one mode, for the simple reason that there are two receivers active as opposed to one. These extra emissions must be allowed for, so the existing DECT or GSM tests can not be run when receiving in both modes. The risk associated with these emissions does not justify the complication of writing combined DECT/GSM spurious emissions tests to allow for this. EMC tests should be performed while the DMT is receiving in both modes, and not when manually switched to one mode. In conclusion, for radio type approval, the existing tests of TBR 6 [25], TBR 19 [27] and TBR 31 [30] should be applied separately while manually switched to each mode, except: EMC and receiver sensitivity tests should be tested while receiving in both modes, and the need for a new test method for receiver sensitivity, not involving loopback or transmission, should be considered. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.1.3 Type 5 DMTs | Type 5 DMTs, which have dual transceivers which can be active simultaneously, will require significant investigation, and modification, of existing type approval requirements for DECT and GSM. Therefore they will be the most costly to type approve. Transmitter requirements of DECT and GSM could, in theory, be tested while manually switched to each mode. But it may be considered necessary to test each transmitter while both are active. While the existing requirements should not be relaxed in this case, there may be a need for extra requirements, and there will almost certainly be a need to modify the existing DECT and GSM test cases to take account of the new test environment of having two transmitters active. In this case, it would not also be necessary to apply the existing tests while manually switched to each mode. Existing receiver requirements of DECT and GSM should not be relaxed. However, each receiver should be tested while both transmitters are active. Existing test methods may need to be modified because of the new test environment. New requirements will almost certainly be necessary, to sufficiently protect each receiver from the other mode's transmitter in very close proximity. It should not be necessary to also apply the existing receiver tests while manually switched to each mode. TR 101 176 V1.1.1 (1998-04) 32 Spurious emissions requirements and tests of both DECT and GSM will need to be combined. New maximum limits will need to be devised, with suitable protection of each mode's operating frequencies from the other. Maximum emissions outside the DECT and GSM bands (from whichever transmitter source) will probably need to be less than the sum of the exiting limits for DECT and GSM, but may need to be greater than the existing DECT or GSM limits in order to avoid prohibitively extra expense in designing a type 5 DMT. EMC requirements and tests will need a similar combination, but this should be easier as they are already almost identical. In particular, the maximum emissions may need to be revised. In conclusion, much standardization work is required before type approval of type 5 DMTs can proceed. There is no technical reason which should prohibit type approval of this type of DMTs. The problem is simply that much more standardization is required, which will involve compromise. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.2 Acoustic and telephony testing and type approval | There are no additional acoustic or telephony requirements, or tests, which are necessary for type approval of advanced DMTs. Existing type approval requirements in TBR 10 [26], TBR 20 [28] and TBR 32 [31] will be applied without modification. Wheras it might be necessary to relax certain DECT acoustic requirements for type approval of early type 1 or type 2 DMTs, this should not be necessary for types 3, 4 or 5, (or later type 1 or 2 designs) as DMT manufacturers should develop the capability of designing DMTs to meet both the DECT and GSM requirements. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.3 Protocol testing and type approval | |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.3.1 Type 3 DMTs | It is possible to design a type 3a DMT which does not degrade idle mode performance on either air interface. If initial registration on each mode is performed sequentially, the type 3a DMT will behave like a normal single mode terminal, responding immediately to the first paging which occurs on either air interface. It will probably be designed to behave like an out of coverage MS or PP while the DECT or GSM mode respectively is transmitting. Performing the complete registration procedure on one mode first, and then on the other, is necessary, because registration usually involves several idle mode procedures which can not be interrupted. A type 3b DMT will miss paging messages more frequently than a type 3a DMT, and will possibly have a reduced update rate of broadcast information, due to its need to switch its single receiver between DECT and GSM. However, the impact that this will have on the performance of type approval tests under laboratory conditions is not clear. A type 3b DMT which is tested when registered on both modes may perform better than a type 3b DMT which is only registered on the mode being tested, as it may not need to scan the other mode as thoroughly when it knows on which timeslot and frequency to find the broadcast information of the network it is registered to. On the other hand, a type 3b DMT which is only registered in one mode will probably behave similarly to a type 2 DMT, in that it will perform background scanning for the other mode. In summary, it should be possible to perform the existing protocol tests in TBR 19 [27], TBR 22 [29], TBR 31 [30] and Harmonized Standard EN 301 440 [33] on both type 3a and type 3b DMTs. Investigations need to be made concerning the tests performed following power on. Some relaxations of response timing requirements may have to be made for both modes. It might be sufficient to test Layer 3 or NWK layer of the protocol while subscribed on both modes, and the lower layers when manually switched to one mode at a time. A special test may need to be written to ensure that a type 3 DMT behaves correctly in one mode when a call is made/answered in the other. If it is to behave as though it is out of coverage, it should be verified that location updating is performed if the periodic location update timer (if running) expires during the call, for example. There is no need to test type 3 DMTs against type 2 requirements on excessive signalling due to switching between networks, because if it is registered on two networks, and looses coverage in one, it does not as a result perform any extra signalling in the other. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.3.2 Type 4 DMTs | Type approval of type 4 DMTs should be similar to that of type 3a DMTs, where protocol requirements are concerned. Some relaxations of response timing requirements necessary for type approval of type 3 DMTs may not be necessary for type 4 DMTs. Since a type 4 DMT, with two receivers always active, will be able to monitor information broadcast in TR 101 176 V1.1.1 (1998-04) 33 one mode while in active communication in the other, therefore it may be able to apply procedures such as location updating or cell re-selection slightly faster than a type 3 DMT. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.3.3 Type 5 DMTs | A type 5 DMT should be able to meet all of the existing DECT and GSM protocol requirements in TBR 19 [27], TBR 22 [29], TBR 31 [30] and Harmonized Standard EN 301 440 [33], while registered in both modes. In particular, it should be able to meet all the requirements of one mode while there is signalling being performed or a call active on the other (worst case scenario) There should be no need for a compromise on protocol requirements with type 5 DMTs. An extra test case may need to be performed to verify correct handling of an incoming voice call in one mode while a voice call is already active in another. The exact handling of the call may vary from terminal to terminal, or may be user configurable - it may involve auto-answering or simply alerting, and providing call waiting notification to the user, or it may involve release or rejection because the user is busy, but in each case the appropriate protocol signalling shall be performed - it shall not be acceptable to ignore the pagings, like a type 4 DMT. |
e02eba098cd1221ec7283147ddcee9f5 | 101 176 | 8.4.3.4 DECT GIP/GSM DMTs | A single mode DECT PP which implements the DECT/GSM Interworking Profile as contained in ETS 300 370, is required to be type approved according to TBR 6 [25], TBR 10 [26], TBR 22 [29] (for GAP operation) and TBR 36 [32] (for GIP operation). A DECT GIP PP is required to support GAP. TBR 22 [29] is applied when the GIP PP has a normal DECT subscription, and TBR 36 [32] is applied when the GIP PP has a SIM card inserted with a valid or test GSM subscription. DECT GIP/GSM dual-mode terminals, regardless of the type of DMT, will need to be type approved according to TBR 36 [32]. TBR 36 [32] should be applied in the same manner, and under the same test conditions (manually/automatically switched, with one or two subscriptions etc.), as TBR 22 [29] will be applied. Indeed, the type approval according to TBR 36 [32] may be more straightforward than for TBR 22 [29], as there are no lower layer test suites in TBR 36 [32]. DECT GIP/GSM DMTs which have a single subscription (DMSs) will certainly have additional requirements concerning mode and PLMN selection, cell selection and re-selection, and handover between modes (on the same PLMN). There may be requirements on the possibility of being location registered on both modes. These requirements may vary according to the type of DMT on which the DMS is based. None of these possible requirements have been elaborated. Many of them are likely to be considered essential to the operation of the DMS and to the protection of the PLMN, and therefore may be included in the essential requirements of a TBR or Harmonized Standard, with an associated test. TR 101 176 V1.1.1 (1998-04) 34 Annex A: GIP/GSM external handover The reference configurations for GSM, GIP and GIP/GSM external handovers are given in figure A.1. MSC FP-1 BSS-A FP-2 BSS-B GIP external handover G IP/GSM handover G SM basic external intra-M SC handover M S D M S P P Figure A.1: Illustration of external handovers related to GIP/GSM The information flows for the successful external handover procedures are given in clauses A.1 to A.3. TR 101 176 V1.1.1 (1998-04) 35 A.1 Basic external intra-MSC handover procedure The following figure is the same as figure 4 of GSM 03.09 [20] (v5.0.0) and describes the procedure for a successful basic external intra-MSC handover. MS BSS-A MSC-A BSS-B MS A-Handover-Required A-Handover-Request A-Handover-Request-Ack A-Handover-Command RI-HO-Command RI-HO-Access RI-HO-Complete A-Handover-Complete A-Handover-Detect A-Clear-Command A-Clear-Complete Figure A.2: Basic external intra-MSC handover procedure TR 101 176 V1.1.1 (1998-04) 36 A.2 DECT/GSM interworking profile external handover overview The following figure is the same as figure 30 of ETS 300 370 [9] (2nd ed) and gives an overview of DECT/GSM external handover. PP FP-1 MSC FP-2 PP Handover-Required Handover-Request Handover-Request-Ack Handover-Command MM-INFO-ACC CC-SETUP CC-CO NNECT-ACK Handover-Complete Handover-Detect Clear-Command Clear-Complete MM-INFO -REQ CC-CONNECT CC-RELEASE CC-RELESE-COM Figure A.3: DECT/GSM interworking profile external handover overview A.3 GIP/GSM handover A procedure for handover from GIP to GSM can be defined using the first half of the GIP external handover procedure before the second half of the GSM basic external intra-MSC handover procedure, see A.3.1, and a procedure for handover from GSM to GIP can be defined using the first half of the GSM basic external intra-MSC handover procedure before the second half of the GIP external handover procedure, see A.3.2. Since the GSM handover is serial (first link dropped before second link established) and GIP handover is parallell (first link not released until setup of second link is confirmed), GIP/GSM handover can actually be performed by a type 2 DMT if some restrictions is imposed on the GIP part of the procedure. Due to different synchronization and cell broadcasting mechanisms a DMT at least type 4 would be beneficial for an efficient GIP/GSM handover. TR 101 176 V1.1.1 (1998-04) 37 A.3.1 GIP to GSM handover Two cases are distinguished depending on the capabilities of the DMS to operate in one or two modes simultaneously. The information flow in figure A.4 is relevant for both cases. DMS FP MSC BSS Handover-Required Handover-Request Handover-Request-Ack Handover-Command MM-INFO-ACC RI-HO-Access RI-HO-Complete Handover-Complete Handover-Detect Clear-Command Clear-Complete MM-INFO -REQ CC-RELEASE CC-RELESE-COM DMS Figure A.4: GIP to GSM handover NOTE: The term handover candidate is used in the DECT sense, i.e. a potential new FP or GSM cell. A.3.1.1 Basic procedure - DMT type 2 The DMS is locked to a GIP system. It continuously measures the quality of the received signal field strengths and identifies that it needs to change from the current FP. The decision is based on that the DECT link becomes too bad. Prior to initiation of GIP/GSM handover, the DMS should obtain handover candidates from the current FP. This enables the DMS to determine to which BSS a GIP/GSM handover may be attempted. The DMS requests from the FP a handover reference. This request implicitly informs the FP that an external handover is about to take place. As a result of this indication, the FP requests for a handover attempt by signalling to the MSC. The request contains information, available in the FP, on what target cell has been chosen as most appropriate. The MSC allocates the network resources needed at the terrestrial links as well as in the handover candidate BSS. Upon successful completion of the resource allocation, the MSC informs the FP that resources were allocated and the handover attempt may continue. The FP returns the previously requested information (information on the GSM base station and frequency) to the DMS which then switches mode and initiates a setup to the handover candidate BSS. It must be ensured that the same level of ciphering is enabled on the new link. With a successful connect procedure, the BSS informs the MSC about the handover in the access part. As a result, the MSC switches the network connection to the BSS and initiates a release of the link to the FP which initiates a call release to the DMS. The type 2 terminal will not be able to receive, and confirm, the release command but this does not affect any connection at this point. TR 101 176 V1.1.1 (1998-04) 38 The above case describes a portable initiated handover, i.e. what is most efficient when the DMS leaves DECT coverage and needs to change to the GSM radio interface in order to continue. Network initiated GIP/GSM handover can be performed using the DECT handover candidate indication procedure (the DMS must interprete this as a command to make handover to the indicated BSS). A.3.1.2 Advanced procedure - DMT type 4 and 5 Prior to initiation of GIP/GSM handover, the DMS should obtain handover candidates from those broadcasted by the serving GSM cell. This enables the DMS to determine to which GSM cell a GIP/GSM handover may be attempted. The DMS continuously measures the quality of the received signal field strengths of both the DECT and the GSM systems. Based on these measurements, the DMS or the FP identifies that the DMS needs to change mode. The decision can be based either on that the DECT link becomes too bad or that a GSM link would better (i.e. means to compare DECT and GSM link qualities must be defined). The DMS requests from the FP a handover reference. This request implicitly informs the FP that an external handover is about to take place. The request contains information on what target cell has been chosen as most appropriate. As a result of this indication, the FP requests for a handover attempt by signalling to the MSC. The MSC allocates the network resources needed at the terrestrial links as well as in the handover candidate BSS. Upon successful completion of the resource allocation, the MSC informs the FP that resources were allocated and the handover attempt may continue. The FP returns the previously requested information to the DMS which then initiates a setup to the handover candidate BSS. It must be ensured that the same level of ciphering is enabled on the new link. With a successful connect procedure, the BSS shall inform the MSC about the handover in the access part. As a result, the MSC switches the network connection to the BSS and initiates a release of the link to the FP which initiates a call release to the DMS. (Only a type 5 DMT can then confirm the release of the DECT link). The above case describes again a portable initiated handover. The decision to make the handover is based on a comparison between the qualities of the DECT and GSM links. The comparison can be made either in the terminal (as in DECT) or in the FP (as in GSM) if the GSM measurements are transferred over the DECT link. Network initiated GIP/GSM handover can be performed using the DECT handover candidate indication procedure (the DMS must interprete this as a command to make handover to the indicated BSS). TR 101 176 V1.1.1 (1998-04) 39 A.3.2 GSM to GIP handover DMS BSS MSC FP DMS Handover-Required Handover-Request Handover-Request-Ack Handover-Command RI-HO-Command CC-SETUP CC-CONNECT-ACK Handover-Complete Handover-Detect Clear-Command Clear-Complete CC-CONNECT Figure A.5: GSM to GIP handover For a GSM to GIP handover to be possible, the DMS must be able to measure the quality of the received field strength of also the DECT links when active on a GSM link. For this a DMT of at least type 4 is needed. The serving GSM cell could indicate that DMSs should evaluate also DECT cells for future handover purposes and the DMS then reports also these measurements back to the GSM BSS which decides if to initiate the handover. Even if DMSs can be made to evaluate DECT cells without being ordered to do it, the BSS is only prepared to receive measurements on DECT cells that are being covered by the serving GSM cell. If a handover is required by the BSS, the MSC sets up the terrestrial links to the FP and a GSM handover command is sent to the DMS. The DMS then switches to DECT mode and initiates a call set-up to the FP. The FP indicates the detection and completion of the handover to the MSC which initiates a release of the connection to the BSS. TR 101 176 V1.1.1 (1998-04) 40 History Document history V1.1.1 April 1998 Publication ISBN 2-7437-2133-2 Dépôt légal : Avril 1998 |
721ffbed19b6b6d314418f85c6c0e29e | 101 516 | 1 Scope | The present document provides the abbreviations and acronyms to be used throughout the GSM specifications. All abbreviations are presented in the singular, but are equally applicable to the plural. |
721ffbed19b6b6d314418f85c6c0e29e | 101 516 | 2 References | The present document has no references. |
721ffbed19b6b6d314418f85c6c0e29e | 101 516 | 3 Abbreviations and acronyms | For the purposes of the present document, the following abbreviations and acronyms apply: A A3 Authentication algorithm A3 A38 A single algorithm performing the functions of A3 and A8 A5/1 Encryption algorithm A5/1 A5/2 Encryption algorithm A5/2 A5/X Encryption algorithm A5/0-7 A8 Ciphering key generating algorithm A8 AB Access Burst AC - Access Class (C0 to C15) - Application Context ACC Automatic Congestion Control ACCH Associated Control CHannel ACK ACKnowledgement ACM - Accumulated Call Meter - Address Complete Message ACU Antenna Combining Unit ADC - ADministration Centre - Analogue to Digital Converter ADN Abbreviated Dialling Number ADPCM Adaptive Differential Pulse Code Modulation AE Application Entity AEC Acoustic Echo Control AEF Additional Elementary Functions AGCH Access Grant CHannel Ai Action indicator AoC Advice of Charge AoCC Advice of Charge Charging supplementary service AoCI Advice of Charge Information supplementary service ASE Application Service Element ASN.1 Abstract Syntax Notation One ARFCN Absolute Radio Frequency Channel Number ARQ Automatic ReQuest for retransmission ATT (flag) ATTach AU Access Unit AuC Authentication Centre AUT(H) AUThentication ETSI ETSI TR 101 516 V5.0.2 (2001-10) 6 (GSM 01.04 version 5.0.2 Release 1996) B BA BCCH Allocation BAIC Barring of All Incoming Calls supplementary service BAOC Barring of All Outgoing Calls supplementary service BCC Base Transceiver Station (BTS) Colour Code BCCH Broadcast Control CHannel BCD Binary Coded Decimal BCF Base station Control Function BCIE Bearer Capability Information Element BER Bit Error Rate BFI Bad Frame Indication BI all Barring of Incoming call supplementary services BIC-Roam Barring of Incoming Calls when Roaming outside the home PLMN country supplementary service Bm Full-rate traffic channel BN Bit Number BO all Barring of Outgoing call supplementary services BOIC Barring of Outgoing International Calls supplementary service BOIC-exHC Barring of Outgoing International Calls except those directed to the Home PLMN Country supplementary service BS - Basic Service (group) - Bearer Service BSG Basic Service Group BSC Base Station Controller BSIC Base transceiver Station Identity Code BSIC-NCELL BSIC of an adjacent cell BSS Base Station System BSSAP Base Station System Application Part BSSMAP Base Station System Management Application Part BSSOMAP Base Station System Operation and Maintenance Application Part BTS Base Transceiver Station C C Conditional CA Cell Allocation CAI Charge Advice Information CB Cell Broadcast CBC Cell Broadcast Centre CBCH Cell Broadcast CHannel CBMI Cell Broadcast Message Identifier CC - Country Code - Call Control CCBS Completion of Calls to Busy Subscriber supplementary service CCCH Common Control CHannel CCF Conditional Call Forwarding CCH Control CHannel CCITT Comité Consultatif International Télégraphique et Téléphonique (The International Telegraph and Telephone Consultative Committee) CCM Current Call Meter CCP Capability/Configuration Parameter CCPE Control Channel Protocol Entity Cct Circuit CDUR Chargeable DURation CED called station identifier CEIR Central Equipment Identity Register CEND end of charge point CEPT Conférence des administrations Européennes des Postes et Telecommunications CF - Conversion Facility - all Call Forwarding services CFB Call Forwarding on mobile subscriber Busy supplementary service ETSI ETSI TR 101 516 V5.0.2 (2001-10) 7 (GSM 01.04 version 5.0.2 Release 1996) CFNRc Call Forwarding on mobile subscriber Not Reachable supplementary service CFNRy Call Forwarding on No Reply supplementary service CFU Call Forwarding Unconditional supplementary service CHP CHarging Point CHV Card Holder Verification information CI - Cell Identity - CUG Index CIR Carrier to Interference Ratio CKSN Ciphering Key Sequence Number CLI Calling Line Identity CLIP Calling Line Identification Presentation supplementary service CLIR Calling Line Identification Restriction supplementary service CM Connection Management CMD CoMmanD CMM Channel Mode Modify CNG CalliNG tone COLI COnnected Line Identity COLP COnnected Line identification Presentation supplementary service COLR COnnected Line identification Restriction supplementary service COM COMplete CONNACK CONNect ACKnowledgement C/R Command/Response field bit CRC Cyclic Redundancy Check (3 bit) CRE Call RE-establishment procedure CSPDN Circuit Switched Public Data Network CT - Call Transfer supplementary service - Channel Tester - Channel Type CTR Common Technical Regulation CUG Closed User Group supplementary service CW Call Waiting supplementary service D DAC Digital to Analogue Converter DB Dummy Burst DCCH Dedicated Control CHannel DCE Data Circuit terminating Equipment DCF Data Communication Function DCN Data Communication Network DCS1800 Digital Cellular System at 1800MHz DET DETach DISC DISConnect DL Data Link (layer) DLCI Data Link Connection Identifier DLD Data Link Discriminator Dm Control channel (ISDN terminology applied to mobile service) DMR Digital Mobile Radio DNIC Data network identifier DP Dial/Dialled Pulse DRX Discontinuous reception (mechanism) DSE Data Switching Exchange DSI Digital Speech Interpolation DSS1 Digital Subscriber Signalling No1 DTAP Direct Transfer Application Part DTE Data Terminal Equipment DTMF Dual Tone Multi-Frequency (signalling) DTX Discontinuous transmission (mechanism) ETSI ETSI TR 101 516 V5.0.2 (2001-10) 8 (GSM 01.04 version 5.0.2 Release 1996) E EA External Alarms EBSG Elementary Basic Service Group ECM Error Correction Mode (facsimile) Ec/No Ratio of energy per modulating bit to the noise spectral density ECT Explicit Call Transfer supplementary service EEL Electric Echo Loss EIR Equipment Identity Register EL Echo Loss EMC ElectroMagnetic Compatibility eMLPP enhanced Multi-Level Precedence and Pre-emption service EMMI Electrical Man Machine Interface EPROM Erasable Programmable Read Only Memory ERP - Ear Reference Point - Equivalent Radiated Power ERR ERRor ETR ETSI Technical Report ETS European Telecommunication Standard ETSI European Telecommunications Standards Institute F FA - Full Allocation - Fax Adaptor FAC Final Assembly Code FACCH Fast Associated Control CHannel FACCH/F Fast Associated Control Channel/Full rate FACCH/H Fast Associated Control Channel/Half rate FB Frequency correction Burst FCCH Frequency Correction CHannel FCS Frame Check Sequence FDM Frequency Division Multiplex FDN Fixed Dialling Number FEC Forward Error Correction FER Frame Erasure Ratio FH Frequency Hopping FN Frame Number FR Full Rate ftn forwarded-to number G GCR Group Call Register GMSC Gateway Mobile-services Switching Centre GMSK Gaussian Minimum Shift Keying (modulation) GPA GSM PLMN Area GPRS General Packet Radio Service GSA GSM System Area GSM Global System for Mobile communications GSM MS GSM Mobile Station GSM PLMN GSM Public Land Mobile Network GT Global Title ETSI ETSI TR 101 516 V5.0.2 (2001-10) 9 (GSM 01.04 version 5.0.2 Release 1996) H HANDO HANDOver HDLC High level Data Link Control HLC High Layer Compatibility HLR Home Location Register HOLD Call hold supplementary service HPLMN Home PLMN HPU Hand Portable Unit HR Half Rate HSN Hopping Sequence Number HU Home Units I I Information frames (RLP) IA Incoming Access (closed user group SS) IAM Initial Address Message IC Interlock Code (CUG SS) ICB Incoming Calls Barred (within the CUG) ICC Integrated Circuit(s) Card IC(pref) Interlock Code of the preferential CUG ICM In-Call Modification ID IDentification/IDentity/IDentifier IDN Integrated Digital Network IE (signalling) Information Element IEC International Electrotechnical Commission IEI Information Element Identifier I-ETS Interim European Telecommunications Standard IMEI International Mobile station Equipment Identity IMSI International Mobile Subscriber Identity IN Interrogating Node ISC International Switching Centre ISDN Integrated Services Digital Network ISO International Organization for Standardization ISUP ISDN User Part (of signalling system No.7) ITC Information Transfer Capability ITU International Telecommunication Union IWF InterWorking Function IWMSC InterWorking MSC IWU InterWorking Unit K k Windows size K Constraint length of the convolutional code Kc Ciphering key Ki Individual subscriber authentication key ETSI ETSI TR 101 516 V5.0.2 (2001-10) 10 (GSM 01.04 version 5.0.2 Release 1996) L L1 Layer 1 L2ML Layer 2 Management Link L2R Layer 2 Relay L2R BOP L2R Bit Orientated Protocol L2R COP L2R Character Orientated Protocol L3 Layer 3 LA Location Area LAC Location Area Code LAI Location Area Identity LAN Local Area Network LAPB Link Access Protocol Balanced LAPDm Link Access Protocol on the Dm channel LCN Local Communication Network LE Local Exchange LI - Length Indicator - Line Identity LLC Low Layer Compatibility Lm Traffic channel with capacity lower than a Bm LMSI Local Mobile Station Identity LND Last Number Dialled LPLMN Local PLMN LR Location Register LSTR Listener SideTone Rating LTE Local Terminal Emulator LU - Local Units - Location Update LV Length and Value M M Mandatory MA Mobile Allocation MACN Mobile Allocation Channel Number MAF Mobile Additional Function MAH Mobile Access Hunting supplementary service MAI Mobile Allocation Index MAIO Mobile Allocation Index Offset MAP Mobile Application Part MCC Mobile Country Code MCI Malicious Call Identification supplementary service MD Mediation Device MDL (mobile) Management (entity) - Data Link (layer) ME - Maintenance Entity - Mobile Equipment MEF Maintenance Entity Function MF MultiFrame MHS Message Handling System MIC Mobile Interface Controller MM - Man Machine - Mobility Management MME Mobile Management Entity MMI Man Machine Interface MNC Mobile Network Code MO Mobile Originated MoU Memorandum of Understanding MPH (mobile) Management (entity) - PHysical (layer) [primitive] MPTY MultiParTY (Multi ParTY) supplementary service MRP Mouth Reference Point MS Mobile Station ETSI ETSI TR 101 516 V5.0.2 (2001-10) 11 (GSM 01.04 version 5.0.2 Release 1996) MSC Mobile-services Switching Centre, Mobile Switching Centre MSCM Mobile Station Class Mark MSCU Mobile Station Control Unit MSISDN Mobile Station International ISDN Number MSRN Mobile Station Roaming Number MT - Mobile Terminated MT (0,1,2) - Mobile Termination MTM Mobile-To-Mobile (call) MTP Message Transfer Part MU Mark Up MUMS Multi User Mobile Station N N/W Network NB Normal Burst NBIN A parameter in the hopping sequence NCC Network (PLMN) Colour Code NCELL Neighbouring (of current serving) Cell NCH Notification CHannel NDC National Destination Code NDUB Network Determined User Busy NE Network Element NEF Network Element Function NET Norme Europeenne de Télécommunications NF Network Function NIC Network Independent Clocking NM Network Management NMC Network Management Centre NMSI National Mobile Station Identification number NPI Number Plan Indentifier NSAP Network Service Access Point NT - Network Termination - Non Transparent NTAAB New Type Approval Advisory Board NUA Network User Access NUI Network User Identification NUP National User Part (SS7) O O Optional OA Outgoing Access (CUG SS) O&M Operations & Maintenance OACSU Off-Air-Call-Set-Up OCB Outgoing Calls Barred within the CUG OD Optional for operators to implement for their aim OLR Overall Loudness Rating OMC Operations & Maintenance Centre OML Operations and Maintenance Link OS Operating System OSI Open System Interconnection OSI RM OSI Reference Model ETSI ETSI TR 101 516 V5.0.2 (2001-10) 12 (GSM 01.04 version 5.0.2 Release 1996) P PABX Private Automatic Branch eXchange PAD Packet Assembly/Disassembly facility PCH Paging CHannel PCM Pulse Code Modulation PD - Protocol Discriminator - Public Data PDN Public Data Networks PH - Packet Handler - PHysical (layer) PHI Packet Handler Interface PI Presentation Indicator PICS Protocol Implementation Conformance Statement PIN Personal Identification Number PIXT Protocol Implementation eXtra information for Testing PLMN Public Lands Mobile Network PNE Présentation des Normes Européennes POI Point Of Interconnection (with PSTN) PP Point-to-Point PPE Primative Procedure Entity Pref CUG Preferential CUG Ps Location probability PSPDN Packet Switched Public Data Network PSTN Public Switched Telephone Network PUCT Price per Unit Currency Table PW Pass Word Q QA Q (Interface) - Adapter QAF Q - Adapter Function QOS Quality Of Service R R Value of Reduction of the MS transmitted RF power relative to the maximum allowed output power of the highest power class of MS (A) RA RAndom mode request information field RAB Random Access Burst RACH Random Access CHannel RAND RANDom number (used for authentication) RBER Residual Bit Error Ratio RDI Restricted Digital Information REC RECommendation REJ REJect(ion) REL RELease REQ REQuest RF Radio Frequency RFC Radio Frequency Channel RFCH Radio Frequency CHannel RFN Reduced TDMA Frame Number RFU Reserved for Future Use RLP Radio Link Protocol RLR Receiver Loudness Rating RMS Root Mean Square (value) RNTABLE Table of 128 integers in the hopping sequence RPOA Recognised Private Operating Agency RR Radio Resource RSE Radio System Entity ETSI ETSI TR 101 516 V5.0.2 (2001-10) 13 (GSM 01.04 version 5.0.2 Release 1996) RSL Radio Signalling Link RSZI Regional Subscription Zone Identity RTE Remote Terminal Emulator RXLEV Received signal level RXQUAL Received Signal Quality S S/W SoftWare SABM Set Asynchronous Balanced Mode SACCH Slow Associated Control CHannel SACCH/C4 Slow Associated Control CHannel/SDCCH/4 SACCH/C8 Slow Associated Control CHannel/SDCCH/8 SACCH/T Slow Associated Control CHannel/Traffic channel SACCH/TF Slow Associated Control CHannel/Traffic channel Full rate SACCH/TH Slow Associated Control CHannel/Traffic channel Half rate SAP Service Access Point SAPI Service Access Point Indicator SB Synchronization Burst SC - Service Centre (used for SMS) - Service Code SCCP Signalling Connection Control Part SCH Synchronization CHannel SCN Sub-Channel Number SDCCH Stand-alone Dedicated Control CHannel SDL Specification Description Language SDT SDL Development Tool SDU Service Data Unit SE Support Entity SEF Support Entity Function SFH Slow Frequency Hopping SI - Screening Indicator - Service Interworking - Supplementary Information (SIA=Supplemenatary Information A) SID SIlence Descriptor SIM Subscriber Identity Module SLR Send Loudness Rating SLTM Signalling Link Test Message SME Short Message Entity SMG Special Mobile Group SMS Short Message Service SMSCB Short Message Service Cell Broadcast SMS-SC Short Message Service - Service Centre SMS/PP Short Message Service/Point-to-Point Smt Short message terminal SN Subscriber Number SNR Serial NumbeR SOA Suppress Outgoing Access (CUG SS) SP - Service Provider - Signalling Point - SPare SPC Signalling Point Code SPC Suppress Preferential CUG SRES Signed RESponse (authentication) SS - Supplementary Service - System Simulator SSC Supplementary Service Control string SSN Sub-System Number SS7 Signalling System No. 7 STMR SideTone Masking Rating STP Signalling Transfer Point ETSI ETSI TR 101 516 V5.0.2 (2001-10) 14 (GSM 01.04 version 5.0.2 Release 1996) SVN Software Version Number T T - Timer - Transparent - Type only TA Terminal Adaptor TAC Type Approval Code TAF Terminal Adaptation Function TBR Technical Basis for Regulation TC Transaction Capabilities TCH Traffic CHannel TCH/F A full rate TCH TCH/F2,4 A full rate data TCH (≤2,4kbit/s) TCH/F4,8 A full rate date TCH (4,8kbit/s) TCH/F9,6 A full rate data TCH (9,6kbit/s) TCH/FS A full rate Speech TCH TCH/H A half rate TCH TCH/H2,4 A half rate data TCH (≤2,4kbit/s) TCH/H4,8 A half rate data TCH (4,8kbit/s) TCH/HS A half rate Speech TCH TCI Transceiver Control Interface TC-TR Technical Committee Technical Report TDMA Time Division Multiple Access TE Terminal Equipment Tei Terminal endpoint identifier TFA TransFer Allowed TFP TransFer Prohibited TI Transaction Identifier TLV Type, Length and Value TMN Telecommunications Management Network TMSI Temporary Mobile Subscriber Identity TN Timeslot Number TON Type Of Number TRX Transceiver TS - Time Slot - Technical Specification - TeleService TSC Training Sequence Code TSDI Transceiver Speech & Data Interface TTCN Tree and Tabular Combined Notation TUP Telephone User Part (SS7) TV Type and Value TXPWR Transmit PoWeR; Tx power level in the MS_TXPWR_REQUEST and MS_TXPWR_CONF parameters U UDI Unrestricted Digital Information UDUB User Determined User Busy UI Unnumbered Information (Frame) UIC Union Internationale des Chemins de Fer UPCMI Uniform PCM Interface (13-bit) UPD Up to date USSD Unstructured Supplementary Service Data UUS User-to-User Signalling supplementary service ETSI ETSI TR 101 516 V5.0.2 (2001-10) 15 (GSM 01.04 version 5.0.2 Release 1996) V V Value only VAD Voice Activity Detection VAP Videotex Access Point VBS Voice Broadcast Service VGCS Voice Group Call Service VLR Visitor Location Register VMSC Visited MSC, (recommendation not to be used) VPLMN Visited PLMN VSC Videotex Service Centre V(SD) Send state variable VTX host The components dedicated to Videotex service W WS Work Station WPA Wrong Password Attempts (counter) X XID eXchange IDentifier Z ZC Zone Code ETSI ETSI TR 101 516 V5.0.2 (2001-10) 16 (GSM 01.04 version 5.0.2 Release 1996) History Document history Edition 1 March 1996 Publication as GTS GSM 01.04 V5.0.2 October 2001 Publication |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 1 Scope | The present document provides a collection of information and guidance relating to: - the choice of naming schemes; - the relationship of names to services; - the role of the proposed ENUM system; and - the resolution of names in the process of routing for the routing of public telephone calls (i.e. calls where the called party is identified by an E.164 number) to a terminating IP network or an IP network that supports a gateway back to an SCN. The calls may originate from or transit public IP based or SCN based networks. NOTE: This is intended to be approximately equivalent to the public telephone service defined in ITU-T Recommendation E.105. The present document is applicable to all networks that support the public telephony service and is therefore written on the basis that the E.164 numbering scheme is used for calling and called party identification. Nevertheless the underlying principles could also be applied with minor adaptation to private network numbering schemes. The present document applies to calls to most types of number structures within E.164 [13], and includes the support of carrier selection and number portability. It does not specifically address the support of mobility or roaming, although it would apply to the routeing of a call to the home mobile network. The types of IP network considered include but are not limited to TIPHON Release 3. Because the routing aspects of the present document focus mainly on routing between networks for the support of a common service (public telephony), the report has a different emphasis from the main emphasis of TIPHON Release 3, which is focused on the provision of customized services to the customers of a single service provider. The present document covers only the routeing between networks. It does not include the routeing inside a terminating network. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 2 References | For the purposes of this Technical Report (TR), the following references apply: [1] ETSI TS 101 314: "Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON); Network architecture and reference configurations; TIPHON Release 2". [2] ETSI TS 101 324: "Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON); Numbering; Scenarios 1, 2, 3 and 4". [3] ETSI TR 101 327: "Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON); Guide to numbering options for public networks based on VoIP technology". [4] ETSI TR 101 287: "Services and Protocols for Advanced Networks (SPAN); Terms and Definitions". [5] ETSI TR 102 081: "Network Aspects (NA); Number Portability Task Force (NPTF); Signalling requirements to support number portability". [6] ETSI TR 101 697: "Number Portability Task Force (NPTF); Guidance on choice of network solutions for service provider portability for geographic and non-geographic numbers". [7] ETSI TR 101 119: "Network Aspects (NA); High level description of number portability". [8] ETSI TR 101 118: "Network Aspects (NA); High Level Network Architecture and Solutions to support Number Portability". ETSI ETSI TR 101 326 V2.0.0 (2002-02) 6 [9] ETSI TR 101 122: "Network Aspects (NA); Numbering and addressing for Number Portability". [10] ETSI EG 201 367: "Intelligent Network (IN); Number Portability Task Force (NPTF); IN and Intelligence Support for Service Provider Number Portability". [11] ITU-T Recommendation H.225.0: "Call signalling protocols and media stream packetization for packet-based multimedia communication systems". NOTE: See annex G: "Communication between Administrative Domains". [12] ITU-T Recommendation Q.769.1: "Signalling system No. 7 - ISDN user part enhancements for the support of number portability". [13] ITU-T Recommendation E.164: "The international public telecommunication numbering plan". [14] ITU-T Recommendation E.105: "International Telephone Service". [15] ISO 3166: "Codes for the representation of names of countries and their subdivisions". [16] ITU-T Recommendation E.191: "B-ISDN addressing". [17] ETSI ETR 316: "Broadband Integrated Services Digital Network (B-ISDN); Numbering and addressing in B-ISDN". [18] IETF RFC 2543: "SIP: Session Initiation Protocol". [19] IETF RFC 2131: "Dynamic Host Configuration Protocol". [20] IETF RFC 1715: "The H Ratio for Address Assignment Efficiency". [21] IETF RFC 1035: "Domain names - implementation and specification". [22] ITU-T Recommendation H.323: "Framework and wire-protocol for multiplexed call signalling transport". [23] ITU-T Recommendation H.248: "Gateway control protocol". [24] IETF RFC 2871: "A Framework for Telephony Routing over IP". [25] IETF RFC 2327: "SDP: Session Description Protocol". [26] ITU-T Recommendation Q.931: "ISDN user-network interface layer 3 specification for basic call control". [27] ETSI TS 101 878: "Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 3; Service Capability Definition; Service Capabilities for a simple call". |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 3 Definitions and abbreviations | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 3.1 Definitions | For the purposes of the present document, the following terms and definitions apply: address: string or combination of digits and symbols which identifies the specific termination points of a connection/session and is used for routeing called number: normally, name written as a numerical string identifying the called party or called terminal ETSI ETSI TR 101 326 V2.0.0 (2002-02) 7 contact ID: intermediate identifier for the destination of the next point of resolution, i.e. the destination of the next hop for the signalling messages NOTE: The form of the Contact ID may vary and may or may not depend on the protocol and the technology used in the transport plane. destination network: network to which a call is currently being routed NOTE: For service resolutions that take place before the home network is reached, the destination network is the home network. For service resolutions performed by the home network (e.g. call forwarding or the support of roaming) this is the visited network. E.164 number: number conforming to the numbering plan and structure specified in ITU-T Recommendation E.164 NOTE: See ITU-T Recommendation E.164 [13]. ENUM: telephone number mapping NOTE: IETF working group. home network name: network on which the customer's service application is provided whether by the network operator or a separate service provider, e.g. the network on which the customer has a subscription NOTE: This is in most cases the network through which the customer is assigned its E.164 number. internet named telephony: service that supports conversational voice and uses Internet names for the identification of the called party name: combination of alpha, numeric or symbols that is used to identify end-users NOTE: A name may be portable between Service Providers. public telephony: service that conforms to ITU-T Recommendation E.105, i.e. it supports conversational voice and uses E.164 numbers for the identification of the called party NOTE: From the perspective of the present document, the only point of significance is the use of E.164 numbers. The issue of whether any quality requirements should be applied to public telephony or whether E.164 numbers should be allocated only to services that achieve a certain threshold of quality is outside the scope of the present document. See ITU-T Recommendation E.105 [14]. Routeing Number (RN): within TIPHON, specific number that is used by the networks to route the call NOTE: The Routeing Number conveys information in a form more readily usable by the network (e.g. to route calls to a ported number). routeing: set of instructions on how to reach a destination Second Level Domain name (SLD): part of the names in the DNS below the TLD NOTE: Under the country code TLDs, there is a wide variation in the structure, in some countries the structure is very flat, in others there is substantial structural organization. In some country domains the second levels are generic categories (such as, AC, CO, GO, and RE), in others they are based on political geography, and in still others, organization names are listed directly under the country code. Top Level Domain name (TLD): part of name structure in the Domain Name System (DNS) under the control of the Internet Corporation for Assigned Names and Number (ICANN) NOTE: In the DNS naming of hosts (computers) there is a hierarchy of names. The root of system is unnamed. Below the root, there is a set of what are called "top-level domain names" (TLDs). They include the generic TLDs (EDU, COM, NET, ORG, GOV, MIL, and INT and new ones that are under creation), and the two letter country codes such as .UK, .DE and .JP from ISO-3166 [15]. transit network: network between two networks, e.g. between the originating network and the terminating network NOTE: A transit network is not always present in a call, but in some calls there may be more than one transit network present. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 8 |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 3.2 Abbreviations | For the purposes of the present document, the following abbreviations apply: ACK ACKnowledge ALG Application Layer Gateway CR Call Routing DHCP Dynamic Host Configuration Protocol DNS Domain Name Server ICANN Internet Corporation for Assigned Names and Number ID IDentifier IETF Internet Engineering Task Force IP Internet Protocol ISDN Integrated Services Digital Network ISP Internet Service Provider ISUP ISDN User Part ITU International Telecommunication Union LAN Local Area Network NAT Network Address Translators NOA Nature Of Address PSTN Public Switched Telephone Number RN Routeing Number RTP Real Time Protocol SC Service Control SCN Switched Circuit Network SDP Session Description Protocol SIP Session Initiation Protocol SLD Second Level Domain SMS Short Message Service TCP Transmission Control Protocol TLD Top Level Domain TRIP Telephony Routing over IP Protocol TSAP Transport layer Service Access Point UAC User Agent Client UAS User Agent Server UCI Universal Communications Identifier UDP User Datagram Protocol UPT Universal Personal Telephony URL Uniform Resource Locator VoIP Voice over the Internet Protocol |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4 The choice of naming system | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.1 Introduction to naming and addressing | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.1.1 Naming | A name is a "combination of characters and is used to identify end users (character may include numbers, letters and symbols)". NOTE: According to ITU-T Recommendation E.191 [16]. An end user is "a logical concept which may refer to a person, a persona (e.g. work, home etc.), a piece of equipment (e.g. NTE, phone etc.), an interface, a service (e.g. freephone), an application (e.g. video on demand), or a location". ETSI ETSI TR 101 326 V2.0.0 (2002-02) 9 A name is distinct in function from an address, which " identifies the specific termination points of a connection and is used for routeing". Addresses are essential for communication as the end points always have to be identified in a way that can be used for routing, but names are not essential. Names are added for some services to make it easier for users to identify the distant end-point or to provide an identification system that is independent of the structure of the networks or the current location of the entity to be communicated with. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.1.2 Addressing | An address is defined as "a string or combination of digits and symbols that identifies the specific termination points of a connection and is used for routeing". An address is a specification of the location of the entity in terms of network structure. It includes information about the location within the network and may also include the identity of the network itself and its location in the topology of interconnected networks. An address identifies the interface at which the connection is to be delivered without regard to whether the connection continues beyond that interface. It contains location information and in telecommunications this is expressed in terms of the network structure in order to achieve as high as possible a degree of aggregation that reduces the complexity of routing tables in switches or routers. NOTE 1: According to ETR 316 [17]. Addresses differ from names in that addresses contain explicit network information and this information is what makes them usable for routing. In order to route a call or a packet, the called name must be translated into an address that identifies the location in network terms and so can be used in the routing process. When a name is ported from one location or one service provider to another, the address associated with the name changes. Unfortunately the distinction between name and address is not followed consistently and entities that are names, or closer to names than addresses, are often spoken of as addresses. A Uniform Resource Locator (URL) pointing to a company's web page is often called an Internet address, but is actually based on a domain name. NOTE 2: Often the word "address" is used to mean "containing location information" but this is not sufficient for the purposes of the distinction between names and address in telecommunications. Here the critical issue is whether the location information is specified in terms of network structure. For example, An E.164 number may contain location information if numbering is related to geographical areas, but such a number may be a name rather than an address if the structure that provides the location information does not relate explicitly to network structure. This would be the case for example if there is number portability between competing networks. NOTE 3: Where a communications system is structured in terms of layers with each layer offering a service to the layer immediately above and using the services of the layer immediately below, the identities offered to the layers tend to have the properties of names. Yet when viewed from the layer above, the same identifiers have the properties of addresses. This difference in perspective may explain why the term "address" is used for email and SIP (see IETF RFC 2543, [18]) identifiers e.g. "email address" and SIP "address". |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.1.3 IP addresses | IP addresses are allocated to interfaces, but different communication streams using different protocols may share the same interface. These streams are differentiated using port numbers which are carried in the protocol (e.g. TCP, UDP or RTP) that runs on top of IP. The combination of an IP address and a port number uniquely identifies the source or destination of a stream of packets flowing between two end points. Each application protocol has a "well known" fixed port number assigned to it plus a range of port numbers for dynamic assignment to communication streams. IP addresses are divided, in principle, into two parts: - the identity of the network (the network part); - the identity of the interface attached to the network (the host address, which is the destination of the IP packet). IP address allocations are normally made through ISPs to end networks. The allocations to ISPs are made in blocks and are organized as far as practicable to be aggregatable so that traffic on a particular route is likely to have addresses in contiguous blocks. This is important to reduce the size of the routeing tables in routers where several contiguous blocks that share the same route require only one entry. The size of these routeing tables is a potential bottleneck in the growth of the Internet as router technology is only just keeping ahead of the traffic growth. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 10 ISPs normally allocate blocks of addresses to end networks. Where the end networks have permanently connected terminals e.g. PCs connected to a LAN, the addresses may be allocated permanently to the terminals. Conversely where terminals are likely to be disconnected frequently and where dial-up access is used, IP addresses are normally allocated dynamically, e.g. using the Dynamic Host Configuration Protocol (DHCP) (see RFC 2131 [19]). Addresses are allocated from a pool only while the customer is logged-on. After logging-off the same address will be allocated to another user. There are two versions of IP protocols, whose address formats differ significantly: - IPv4, a 32-bit address, which is used throughout the Internet but which is considered to be in increasingly short supply and whose allocations are being controlled carefully. - IPv6, a 128-bit address, which is just starting to be used and should provide more than adequate capacity for the future if it is administered effectively. IPv4 is the version of the IP protocol in general use. Use of IPv6 is only just beginning. Because the address lengths are different, the two addresses are not compatible and a long process of migration is beginning. There are two main drivers for moving to IPv6: - Avoiding problems when IPv4 addresses reach exhaustion. - Obtaining benefits from features that IPv6 offers that are not available in IPv4. There is however a disadvantage. The IPv4 header has a variable length with the minimum being 192 bits. The IPv6 header has a fixed length of 320 bits, with the possibility of additional extension headers that are normally used only by the end nodes. The fixed header length simplifies the packet handling in routers but the increased length reduces the efficiency of transmission unless header compression is applied. UDP has a 64 bit header and TCP a 224 bit header. Therefore the maximum reduction in efficiency is 33 % (100 x (1 - ((192 + 64) / (320 + 64)))) for a zero length packet. However for speech for a 4 kbit/s speech codec with a packetization delay of 40 ms the speech packet would have a length of 4 000 x 0,04 = 160 bits and the efficiency reduction would be 24 %. For data using TCP the minimum reduction for a zero length packet would be 21 %. Thus the reduction in efficiency is greater for speech than data. A significant uncertainty is the speed with which IPv6 will be introduced generally in the Internet world. Here there are two extremes and a continuum of possibilities between them. - The first extreme is that ISPs will perceive some real operational advantage in using IPv6 and will introduce it as soon as possible in order to capitalize on these advantages. - The other extreme is that ISPs will regard the introduction of IPv6 as an avoidable expense and will delay its introduction as long as possible, i.e. until the shortage in IPv4 addresses begins to be felt. Although IPv4 has a theoretical capacity of some 4 billion (4 x 109) addresses, in practice a realistic maximum is probably some 200 million hosts. The lower practical limit is the result of the structuring of the address space and is a prediction based on observations of the points at which other numbering schemes reach saturation (see RFC 1715 [20] by Christian Huitema). It is very difficult to obtain a well founded estimate of the current world-wide situation on allocations or when the effects of exhaustion will first be experienced. According to a paper on the IANA part of the web site (see http://www.iana.org/assignments/ipv4-address-space) of the Information Sciences Institute, there were in October 2000 some 102 unallocated/8 IP addresses out of the maximum total of 256. There were 23 allocations to the Regional Internet Registries who currently handle the allocations to ISPs and large users. The demand for allocations from these RIRs is doubling every year according to RIPE, suggesting that a further 2-3 years' growth can be accommodated without making other changes. However the remaining 131 values are allocated to organizations and large corporate and eventually some of this space could be released if necessary. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 11 There are many "variables" that make estimation of the remaining life of IPv4 difficult to quantify including: - the use of Network Address Translators to increase the utilization of IPv4 address space, - WAP proxy server deployment (similar to NATs in terms of saving IP address space), - the impact of dynamic address assignment in an "always on" environment, - the possible impact of Windows 2000™ which includes IPSec and may lead to an increase demand for secure end to end communication, (currently the use of NAT inhibits end to end IPSec), - new demands from the "plug and play" (auto configuration) market. In conclusion it does appear likely that some effects of IPv4 address exhaustion will begin to be felt in the 2004-2006 timeframe. During the migration period, various techniques including dual stack will be used to provide interworking between IPv4 and IPv6. Some of these techniques require interworking equipment that itself needs IPv4 addresses. When eventually IPv4 becomes seriously exhausted, new allocations will be possible only from IPv6. This will mean that equipment with only IPv6 addresses will be able to communicate only with other equipment that have IPv6 addresses and therefore communications with the unmodified IPv4 world will not be possible. This will be a significant commercial issue and therefore there is a body of opinion that the introduction of IPv6 should be encouraged in order that it can become as widespread as possible before IPv4 exhausts so that the loss of compatibility will be minimized. The TIPHON standards do not specify the choice of version of IP protocol and are compatible with either version because the TIPHON standards generally apply above the network layer. Thus the choice of Internet Protocol version and any interworking between versions is outside the scope of TIPHON. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.2 Naming schemes | There are two common naming schemes: - E.164 names (numerical strings) defined by ITU-T Recommendation E.164 [13]. This scheme is a mixture of names and addresses. It started primarily as an addressing system but has migrated to become more of a naming system because location and operator portability are functions of names rather than addresses. - Internet names of the form "user@domain" defined by RFC 1035 [21]. NOTE: The prefixes "http:", "sip:" etc denote the protocol and are not parts of the domain name. The choice of identification scheme is related to the nature of the service because a service description needs to specify which type of name is used. This is important because: - users need to know how to identify their correspondents; - the choice of identification system determines the set of potential correspondents that can be reached; - interconnected networks need to have a common method of identifying communicating users. For many services, names are used as the identification system, but some services allow addresses to be used as an alternative to names (e.g. http allows users to identify web sites by IP addresses or domain names), and some services use only addresses. In the past services and hence name types were related to technology. For example telephony could be provided only on circuit switched technology and Telex had its own naming scheme and own technology. However, third generation mobile technology is designed to support multiple services and there is therefore the possibility of supporting more than one type of name. For Tiphon Release 3 compliant systems, only E.164 names and related national numbers (e.g. 0800, 112) are supported. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 12 |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.2.1 E.164 | The international public telecommunication numbering plan is defined in ITU-T recommendation E.164 [13], and numbers which comply with it are referred to as E.164 numbers. It includes PSTN, ISDN and mobile networks and supports various services including public telephony, some special telephony services such as international freephone, fax, some data services and the GSM Short Message Service (SMS). According to the ITU-T recommendations, some telephony services such as national freephone in a strict sense do not use E.164 numbers although their numbering is compatible with E.164 and thought by most people to be E.164 numbers. The E.164 number is not necessarily identical to the dialled number as dialling prefixes and arrangements for local dialling are not part of ITU-T Recommendation E.164 [13]. For various historical reasons, E.164 numbers are a mixture of names and addresses, but the trend is to reduce the degree of address information and make them more names than addresses (i.e. to reduce the network specific information). Various parts of E.164 [13] include structures related for example to geography. This structure may in the past have been related precisely to network architecture but the relationship to network architecture has reduced or been removed for example by operator and location portability. For routeing in switched circuit networks (i.e. when network information is needed), routeing numbers are used to add at least some location information. A routeing number may be: - a separate E.164 number or E.164-like number (i.e. a number similar in format to E.164 numbers and compatible with the E.164 [13] plan but not formally part of the plan) that contains the necessary network information; - a non-E.164 number that contains the necessary routeing information; - or a routeing prefix added to the front of the E.164 number. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.2.2 Internet "names" | Within IP based networks, there are separate naming and addressing schemes. Names normally have the form: User@domain IP addresses are completely separate binary strings and there are different forms depending on whether IPv4 or IPv6 is being used. Table 1 shows some examples of the relationship between names and addresses for telephony and current web applications. It includes the differences between the Tiphon and Internet telephony. Table 1: Examples of names and addresses Telephony on switched circuit network Email Tiphon Release 3 solution for telephony on IP Internet telephony Name E.164 number user@domain where domain may be a host name E.164 number user@domain, possibly with an E.164 alias for incoming calls from the switched circuit networks Address Routeing E.164 number, or (routeing prefix +E.164 number) (see note) IP address IP address IP address NOTE: There is also additional lower level addressing information in equipment numbers. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.2.3 Coding of names | Table 1 refers to the naming scheme used, i.e. allocated to the users of a service, and not to the carriage of the names by a signalling protocol which would depend on the specification for the protocol. For example, an E.164 name could be coded in the form of <E.164 number>@domain. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 13 |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.3 The relationship of naming to services | Normally each service that uses names specifies a single type of name that is used. However a type of name may be used by several different services. Sometimes these services are distinguished by different ranges as is the case of ITU-T Recommendation E.164 [13]. Where there is a separate method to identify different services, the same value of a name of the same type may be used for different services. For example a given E.164 number may be shared for both telephony and fax if the terminal can distinguish the services; equally under Internet naming the same value of user@domain may be used for both email and various SIP (see RFC 2543 [18]) based services. A user may therefore have several names for different services, e.g. GSM users have three different E.164 names for voice fax and data services on GSM. This is not very user friendly because business cards become cluttered up with the different names. A reasonable long term objective could be to work towards having one name per person for private use and perhaps a separate name for business use, however this goal is constrained by the need for compatibility with existing systems. Work within ETSI on the Universal Communications Identifier (UCI) is considering these possibilities. Figure 1 shows an example of the relationship of named entities to name types and values for different services. Services Name type Name value Person/ Terminal E.164 User@domain Named entity Other services Telephony Fax Email Mobile/SMS Multi - service Service specific ITU ICANN ICANN = Internet Corporation for Assigned Names and Numbers Figure 1: Naming relationships from a caller's perspective A single name can also support several different users. Examples are an E.164 name for a telephone service in a house shared by several occupants, or an E.164 name used by a call centre, or an email name used by several people who fulfil the same function in an organizations (e.g. sales@company.com). Although one name of the form "user@domain" may be used for several services, a given name may be used only for services supported on a single host because the name will be mapped by DNS to an IP address of an interface on the host. In most cases the host is operated or connected to a single service provider. Therefore a user that wishes to use one service provider for one set of services and another for another set will need different names. The IETF has distinguished names and addresses and introduced the public DNS to support the resolution of names into addresses, however the IETF does not define services or service capabilities in the way that ETSI and ITU-T do, because it assumes that users assemble their own services using application protocols. In other words, services are created at the edge of networks and are not embedded in them. This means that there is a lack of clarity in relating services defined in ITU-T/ETSI to work in IETF. This lack of clarity in turn leads to some confusion over the choice of naming schemes for voice in IETF. From the perspective of ETSI, voice communications that use Internet names (e.g. what the press calls PC-PC communications) are a different service from public telephony, we call this "Internet named telephony". Internet named telephony will require interworking with the public telephony service and this interworking will have to enable callers on the public telephony service to identify called parties on the Internet telephony service. This is service interworking and there are two alternative methods of handling its numbering: - to allocate hitherto unused E.164 numbers for this interworking (each customer of Internet telephony who requires interworking would need to be allocated an E.164 number to use in parallel with their existing Internet name); - to use a database of associations between E.164 numbers already allocated for the public telephony service and the Internet name used for Internet telephony (this is ENUM). ETSI ETSI TR 101 326 V2.0.0 (2002-02) 14 Figure 2 shows the differences between the approaches of Tiphon and the IETF. The aim of Tiphon is to support the existing public telephony services, which use different parts of E.164, on IP technology. This technology could include Internet at the transport layer but does not necessarily do so. In contrast, the IETF is supporting a different "service" with interworking using ENUM as a method to translate E.164 numbers to Internet names. More information about ENUM is given in a later clause. Switched circuit networks IP Networks including Internet Common service model Switched circuit networks Internet Public telephony E.164 Internet telephony User@domain Different services model - by association (ENUM), or - by allocation in parallel with Internet names Public telephony services E.164 Public telephony services E.164 New features ENUM Area worked on by Tiphon Area worked on by IETF Service interworking Involves E.164 numbers either Figure 2: The different approaches to telephony There are several different forms of public telephony service that use different ranges of numbers within ITU-T Recommendation E.164 [13]. For example in addition to the basic geographic telephony service there are mobile services, freephone, shared cost and premium rate services. These different forms are shown by the stacked boxes in the diagram. NOTE: The issue of whether any quality requirements should be applied to public telephony or whether E.164 numbers should be allocated only to services that achieve a certain threshold of quality is outside the scope of the present document. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.4 The choice of naming for Tiphon | Tiphon is aiming to produce standards that meet the needs primarily of new and old "telcos" who wish to offer new services on IP-based technology or migrate existing services from circuit switched technology to IP-based technology. (The commercial framework for TIPHON is assumed to be networks where service providers create and control services and the services and networks can be accessed only by authorized users. This is the traditional telco approach to communications and differs fundamentally from the Internet model where "services" are created at the network edges and the network provides universal interconnectivity). This aim makes it essential that Tiphon supports the existing services that use E.164 so that users of these services can be migrated transparently from switched circuit to IP technology without any number or name changes. In other words, Tiphon has specified E.164 as the numbering scheme for its public telephony because it is supporting the same public telephony services that already use E.164. This approach is wholly consistent with the principle that services should be defined in a way that is technology- independent. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 15 Tiphon is developing an architecture and meta-protocol (abstract message descriptions and information flows) for the support of a range of service capabilities. This work is protocol independent. It is also developing "profiles and deltas" that will specify how existing protocols can be used/adapted for these information flows and service capabilities. The protocols covered include H.323 [22], SIP [18] and H.248/Megaco [23]. A service capability in TIPHON is a unit of technical functionality that can be mixed-and matched to implement part of a (non-standardized) service application. It is important to understand that a service capability is defined only as a technical function from the perspective of network implementation and is not an element of service defined from the perspective of the user. Also the same service capability may be part of more than one service application (e.g. user registration or user profile) in one or more service offerings. This approach to services in TIPHON means that services are defined initially for use only between the customers of the same service provider. Access to customers of a different service provider may be achieved only if a service level interconnection is established. Thus TIPHON views a service such as public telephony, much of whose value lies in the ability of any customer to call any customer of any other service provider in the world as an exception rather than the norm. The common standard that TIPHON provides for service capabilities is, however, intended to help the establishment of such service level interconnection agreements. The service capability definitions in TIPHON do not specify a naming scheme. The implication is that the choice of naming scheme should be specified as a separate part of the service description of a particular service and as part of any relevant service level interconnection agreement. The following three naming schemes may be used in TIPHON: - public telephony numbers E.164 defined by ITU; - internet names defined by ICANN; and - unspecified private naming schemes. Although the service capabilities defined in TIPHON Release 3 do not specify a particular naming scheme, they have been written to ensure that they are, inter alia, suitable for use in supporting public telephony based on ITU-T Recommendation E.164 [13]. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.5 The relationship of the present document to ENUM | ENUM is the name of a chartered working group in IETF. It is attracting a great deal of attention in relation to numbering and is supported by several large manufacturers. ENUM is the name given to a set of standards that define a protocol for Telephone Number Resolution. The function of the ENUM protocol is to map telephone numbers, defined in ITU-T Recommendation E.164 [13], to one or more Internet resources using the existing DNS system. Here a "resource" is an Internet destination that has an associated application protocol such as an email address or a SIP address. ENUM can also support mapping to resources outside the Internet such as fax and mobile numbers. The system is based on telephone numbers because these numbers are widely known and can be input from any telephone keypad. The name "ENUM" is used to describe both: a) a protocol for interrogating and receiving a response from DNS that could be used for public or private numbering applications; b) a global public service for resolving already allocated E.164 numbers, including the administrative methods for populating the part of DNS used by ENUM. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 16 The main functions of the global public ENUM service are intended to: - enable calling users or entities to make a selection from the range of services that are available for communicating with a particular person or entity when the calling user knows only their telephone number; - enable users to access Internet based services and resources from ordinary telephones where they are only able to input digits; - enable users to specify their preferences for receiving incoming communications (e.g. specifying a preference for voicemail messages over live calls or indicating a destination for call forwarding). ENUM will give much improved user control over communications. Figure 3 shows an example of ENUM used from an IP terminal. Terminal Internet telephony based on SIP Mobile telephony Public telephone service (may be implemented on switched circuits or IP) Internet terminal Internet terminal Service selection ENUM Caller A Called B ENUM Service in DNS Information on services used by Called B Services List of services, associated names and preferences E.164 number For Called B Telephone Telephone Mobile terminal Mobile terminal Called B@domain Mobile E.164 Geographic E.164 Mobile E.164 Called B@domain Geographic E.164 NOTE: Query to DNS be sent from caller’s terminal or from within a network Area of choice Figure 3: Example of ENUM used from a terminal Figure 4 shows an example of ENUM used from a Switched Circuit Network (SCN). In this case, the functionality to provide access from a simple telephone and the mechanism to allow the caller to select the required option is assumed to be built into a network that is part of the PSTN. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 17 Analogue telephone Analogue telephone Internet telephony based on SIP Public telephone service Internet terminal Internet terminal Caller A Called B Information on services used by Called B Services ENUM Service in DNS ENUM Service in DNS List of services, associated names and preferences E.164 number For Called B Telephone Telephone Called B@domain Geographic E.164 Called B@domain Geographic E.164 PSTN Figure 4: Example of ENUM used from a network The ENUM service can hold E.164 numbers that are supported on IP as well as on SCN. An example would be when the access network that provides the public telephone service to the number concerned is IP based. In practice, a prime role of ENUM may be to facilitate the migration of traffic from circuit switched networks to the Internet. When presenting a telephone number to the DNS, the digits are reversed and dots are inserted between each digit (this will be done by software and not by the human user). ENUM is designed for users that have exclusive use of an E.164 number. It does not specify how shared E.164 numbers (e.g. a household with one line and E.164 number but several occupants each with their own SIP addresses for Internet telephony) are supported. The issues currently under discussion are: • what exactly will be the form of the top level part of the name to be resolved by DNS. IETF has proposed .e164.arpa and this proposal is being discussed with ITU-T; • which organizations will be registries and run the DNS servers for E.164 numbers. The intention is that each government will select the registry for numbers under its own country code but selections had not been made at the time the present document was written; • what control will be exercised over the submission of E.164 numbers and associated information for storage in DNS. The aim is to ensure that only the legitimate user of an E.164 number can submit and alter information and that records are updated when E.164 numbers are ported or cease. This is difficult to achieve especially in countries where there is no national database of customer information. The issues are also related to privacy laws that differ from country to country. The resolutions considered in the present document could use a database that uses the ENUM protocol. However the fundamental difference between the global public ENUM service and the resolutions discussed here is that ENUM can use E.164 numbers that have already been allocated for service on one network (the circuit switched network) for directing calls that will be delivered on a different network (e.g. the Internet). In contrast the present document considered the use of E.164 numbers for the delivery of calls on the same networks for which or through which the numbers have been allocated. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 18 |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.6 The use of aliases | An alias is an alternative name. Aliases are commonly used in email where there may be multiple alternative values of "user" in "user@domain". This type of alias is local to the end system since other networks only use the value of "domain". Aliases of this type are supported in H.323 [22]. Users may have more than one name type and more than one name value, where these names are not just local aliases but are recognized by the networks. An example would be an E.164 number and an Internet name. In this case in the terminology of the present document, the user is using two services, public telephony and Internet named telephony, and the choice of name used to call the user is in effect selecting the service by which to call him. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.7 Master IDs and personal numbering | There is no "master ID" and no ultimate personal number. There are various personal numbering services and TIPHON is supporting global personal numbering under the code +87810, which is a subset of the numbering range for Universal Personal Telephony. There is always a translation between a personal number and some other form of identification such as a name or an address. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 4.8 Relationship to back end services | Figure 5 shows the relationship of the customer ID used in support systems such as service management systems and billing to: - the user name; - the end IP addresses and port numbers for the signalling and media paths. Customer ID User name Port # Signalling Port # Media Customer ID User name End IP address Port # Signalling Port # Media End IP address End IP address End IP address Signalling path Media path Figure 5: Relationships at the ends of the call ETSI ETSI TR 101 326 V2.0.0 (2002-02) 19 The figure shows the relationships for both ends of a call. Additional IP addresses and port numbers may be used at different points in the signalling and media paths, especially if network address translators are used. In the back end system, the customer ID is related to the account ID. This relationship is outside the scope of the present document. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 5 Types of resolution and their order | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 5.1 Introduction | The purpose of this clause is to distinguish the various different resolutions that may be encountered in an SCN to IP call. It is written for the public telephony service and so assumes that the E.164 number is the principal identifier for a telephony correspondent whatever the technology used (SCN or IP), however the principles that would apply in a private domain would be similar. The term "E.164 number" is used loosely to mean the number that would be dialled or built up immediately from the dialled number (i.e. by expanding a local number). There are three types of resolution regardless of the underlying technology of the network: - search resolution to determine the E.164 number (name) from any information about the called party; - service resolution to resolve any options for how the call should be carried and to determine ultimately the name or other identity of the destination network from the called E.164 number (examples are freephone numbers and number portability). There are three different types of service resolution and they are explained further in clause 5.3; - routing resolution to determine the information needed for routing the signalling and media streams. The search resolution always takes place first, if it is needed, and is performed at the calling end only. Each network whose call control function handles the signalling may perform: - a service resolution followed by a routing resolution; or - a routing resolution only. These resolutions may be carried out repeatedly by successive networks, but normally a service resolution for a particular service capability will be carried out only once. In SCNs, the network is generally unaware whether it is doing a service resolution or a routeing resolution. The range of numbers that contains the called number determines whether a network needs to perform a service resolution. Normally a network will perform a service resolution if it can before performing a routing resolution. For example, a network in one country will perform a service resolution on its own national freephone numbers but only perform a routing resolution for calls to a national freephone number in another country. Service resolutions for different services may be undertaken successively by different networks, e.g. a call to an international freephone number terminated on a ported geographical number. Service and routing resolutions may be combined in practice. A network that is traversed by the call, but where the call control function does not handle the signalling, will not perform any resolution. An example of this is where signalling packets are routed across a network using an IP address that has already been established for an interface in a network closer to the destination. The resolutions are summarized in table 2. The "From" column shows the information that is converted in the resolution process and the "To" column shows what it is converted to. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 20 Table 2: Types of resolution Resolution type From To Carried out by Public or internal Comment Search Resolution Any information Called E.164 Calling terminal or calling party Either Address book, or Directory, or Search engine Service Resolution Called E.164 name Destination network name or other identity, which may be the home network of the called E.164 number or their visited network Service control in any network Either Specific to service or geographical area (NOTE: a service may be specific to a network) Not specific to IP technology Routeing Resolution Called E.164 name or Destination network name or other identity, which may be the home network of the called E.164 number or their visited network Routeing information for next hop Call control in any network Normally internal Local or national or global Not specific to IP technology Process may be repeated as signalling progresses hop-by-hop A service resolution is objective or absolute in that it always returns the same result irrespective of the location from which the resolution request is made. In contrast, a routing resolution is subjective or relative in that the result depends on the location from which the resolution request is made. Figure 6 shows an example of the sequence of resolutions for a call to a ported freephone number. The caller first uses a directory service (search resolution). Then the call is passed from the originating network, which determines that, because the called number is in a number range of another country, only a routing resolution is needed to reach a network in the terminating country. This network detects that the called number is in a range that supports number portability and so performs an originating network number portability service resolution followed by a routing resolution. The call then passes via a national transit network to the terminating network. The terminating network detects that the number range is used for non-geographic freephone numbers and therefore that a service resolution is needed to determine the destination followed by a routing resolution to reach it. Caller Directory service Routing resolution Service resolution number portability Routing resolution Routing resolution Routing resolution Service resolution freephone Search resolution Network A Network B Network C Network D Figure 6: Example of a sequence of resolutions ETSI ETSI TR 101 326 V2.0.0 (2002-02) 21 |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 5.2 Search resolution | The function of the first resolution is to find the E.164 number (sometimes called the directory number) for the called party. This step may be skipped if this number is already known, or it may be carried out by: - an address book or directory in the terminal; - an address book or directory in the calling network; - a public directory function; - a search engine. A search engine may be a successor to the current directory enquiry service to provide a user friendly public service interface for finding correspondents. There is likely also to be a user friendly customized terminal specific systems like an address book for commonly called numbers. The search resolution will take some or any information and provide the E.164 number. The query is made from the calling terminal and the response is returned to the calling terminal or calling party. NOTE: The details of this resolution are out of scope of the present document. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 5.3 Service resolution | This resolution supports the particular service that is using a range of E.164 numbers. It resolves the called E.164 number to a home network name and optional location information. NOTE 1: Practices vary in different countries. In general the provision of location information enables the calling network to make more optimal routing decisions. The main function of the home network name is to give information on the identity of the call control entity for the called party. This resolution may be needed: • to support number portability; • to support personal numbering; • to support non-geographic services such as national or international freephone; • to support call redirection services. The resolution may be local, regional or national and is not normally related to IP technology specifically because services are not normally technology specific. The resolution capability would normally be available to all operators that need to route calls into the domain that requires the resolution. The information needed for the resolution is may be public and in some cases may be provided through a public reference database. Real-time resolutions may also be public services, but are more commonly provided by the operators for themselves using information downloaded from the public reference database. Any IP network that supports a service that requires a service resolution will need access to the resolution system. NOTE 2: There is as yet no standardization for queries to a real-time resolution service, although there is a work item for standardizing a protocol for the resolution service. For Tiphon compliant systems, the form of the destination network identity should be a URI. There are two reasons for using a URI: • The URI may be used in a SIP address with the form <E.164 number>@<home network>. • The URI enables cheap standardized hardware to be used for resolving the home network name to an address. There are two options for the form of the URI below the sled: <home network id>.<service capability>.SLD.TLD <service capability>.<home network id>.SLD.TLD ETSI ETSI TR 101 326 V2.0.0 (2002-02) 22 Both options may be implemented and some operators may prefer one and some the other. For different service capabilities, different forms of <home network id> could be used including a numerical form with a standard letter prefix if necessary. The home network ID can also include identities within the home network e.g. "Bracknell.CW" or "London.BT". The values of SLD and TLD would need to be chosen carefully because fast responses are needed to minimize the call set-up time, there would be advantage in using the same values for all service capabilities because this would enable the domain name services and the networks around them to be organized to produce fast responses. In terms of the use of TLDs, the most appropriate value of .TLD could be .arpa, which is set aside by the IAB for infrastructural support. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 5.4 Routing resolution | The function of routing is to determine the direction in which a network should send a signalling packet. The routing resolution resolves from a called E.164 name or home network name to an IP address for routing the packets. Routing is discussed in more detail in the following clauses. Routing is subjective because, unless the routing is capable of reaching the far end point, the destination to be reached depends on where the routing resolution is taking place. Routing destination therefore differ from service resolutions which are normally objective, i.e. they give the same result wherever you are starting from. Because routing is subjective, routing resolutions can normally only be internal to a network. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 6 Routing in SCNs | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 6.1 Introduction | Within the SCN, numbers are used to identify ( or to name) destinations. In many cases today, the address of the destination and the name are identical. The number is used to route the call to the terminating switch. It is therefore convenient for routeing, to attach numbering blocks (43 1 979 xxxx) or numbering ranges to switches (a numbering range is consecutive blocks of numbers which follow the same routeing instructions e.g. 43 1 979 2xxx to 43 1 979 5xxx). Block sizes depend on national policy and differ from country to country and also within countries. The most common block size is 10,000 numbers. A disadvantage of this approach is the uneconomic use of the available numbering space, if the demand is less than the block size. Consequently in areas where there is a shortage of numbers and in rural areas smaller block sizes such as 1,000 are increasingly being used. The mechanism that performs the analysis of numbers looks to see if a given number fits into a numbering block or numbering range and extracts the given set of routeing instructions for this numbering block, to be executed in call set-up. The information stored in switches that relates number blocks to routeing instructions is referred to as "routeing tables". Because the analysis needed for the application of routeing tables is costly in terms of switch processor power and because of the problem of maintaining up-to-date routeing tables, the route to the final destination is evaluated in most cases step by step. The process of number analysis is distributed amongst switches, with each switch normally knowing only the route to the next switch (next hop). The next switch may repeat and refine the analysis process. Eventually the call is routed to the terminating switch that serves the called party. The terminating switch translates from the number (name) attached to the called party and the hardware address of the line card. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 6.2 Routeing numbers | Routeing numbers have been introduced to provide more flexibility and provide routeing control in cases where the called party is at a terminating switch that is not identified by the block that contains the called party number. This situation occurs either: - where the number has been ported away from the switch identified by the number block; or - where number blocks are not used (e.g. in mobile services or where numbers are allocated individually). ETSI ETSI TR 101 326 V2.0.0 (2002-02) 23 Routeing numbers may also be used to route calls to the correct termination point in the case where the same set of dialled digits is used for access to a particular service even though the service may be delivered from a number of different points in the network (e.g. 112 calls). In these cases a routeing number is used instead of the called party number for the routeing of the call. The routeing number is normally generated by either: - a query to an IN database (e.g. a Home Location Register in mobile networks to obtain the Mobile Station Roaming Number, which is the routeing number, or a number portability database in some number portability solutions); or - on-switch processing (e.g. in some onward routeing number portability solutions). A routeing number is either: a) added in front of the called party number in the field in the signalling system that carries the called party number; or b) placed instead of the called party number in the field in the signalling system that carries the called party number, with the called party number being carried in a separate field; or c) placed instead of the called party number in the field in the signalling system that carries the called party number, with the called party number no longer being carried. With a), the routeing numbers are added to the routeing tables. With b) changes to the routeing tables in the switches may not be needed if the routeing number is chosen to match the number structure already stored in the routeing tables. NOTE: Older signalling systems (e.g. early versions of ISUP) allow only one number to be transported, therefore the combined approach is used. New signalling systems (e.g. the latest version of ISUP) allow both numbers to be transported, but this opens another problem. Some networks use the called party number field for the routeing number, and put the called party number in the new field, others leave (for other compatibility reasons) the called party number in the old field and put the routeing number in the new field (both approaches are conforming to ITU-T Q.series). Compatibility is achieved by giving additional information indicating what changes have been made possibly by using the Nature Of Address (NOA) parameter. A routeing number in an SCN network may be used to identify either: - the home network (i.e. the equivalent of the home network name); or - routing information for the next hop. A routeing number may not need to be forwarded in signalling if a new routeing number is generated at the next switch. 7 Resolutions in Tiphon Release 3 networks at the meta-protocol level The function of the service and routing resolutions are to provide the routing information for packets to be passed forwards on the correct path with sufficient information to reach their next destination. This means identifying where the packets should be routed to. This destination may be the end destination or an intermediate destination where a further routing resolution (or combination of service and routing resolutions) will take place. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 24 The TIPHON architecture (see TS 101 314 [1]) defines five functional layers: - Services; - Service Control; - Call Control; - Bearer Control; - Media Control. The Services functional layer contains the Call Routing function (CR). This function provides the service and routing resolution functions (i.e. the translation functions) referred to in the present document. These functions may or may not be co-located with the functions in the Service Control functional layer, e.g. they may be in remote databases. The Service Control function (SC) in the Service Control functional layer accesses the various resolution functions at the Services functional layer to obtain and assemble the information needed for call control. The Call Control functional layer provides the signalling messages and maintains state information for the call. Figure 7 lists the service capabilities specified in TS 101 878 [27] and identifies what resolutions they involve. Service capability Resolution Simple call establishment Routing Calling user identity generation - Calling user identity conveyance - Calling user identity delivery - Call rejection - Number portability Service Emergency Calls Service QoS Bearer selection Alternative Media Path Figure 7: Resolutions involved in service capabilities |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 8 Other issues | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 8.1 Firewalls | Firewalls are devices that are placed at the boundary of networks to protect the networks from denial of service attacks and unwanted traffic. Firewalls are used mainly to protect company intranets and web sites, i.e. they are used on end networks. However the need for protection and access control to support charging in transit networks may lead to firewalls being used more widely on interconnected networks that provide VoIP services. Firewalls work by examining the IP addresses and port numbers used within incoming and outgoing packets and allowing only certain ranges of addresses and port numbers through. This examination adds delay that degrades the quality of real-time communications, and firewall developers are being challenged by the need to keep this delay adequately low for conversational voice. It is quite difficult to formulate policies for firewalls that will provide adequate protection whilst not rejecting too much wanted traffic. A group in IETF called MIDCOM is developing requirements for the control of "middle-boxes" including firewalls by the devices that handle the call signalling. This will enable the signalling to instruct firewalls to open "pinholes" (particular IP address: port number combinations) that relate to calls that are in progress. These pinholes are then closed when a call is terminated. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 25 |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 8.2 NATs | Network Address Translators (NATs) are devices that enable a small number of public IP addresses to be pooled and shared by a larger number of terminals. The terminals inside the area served by a NAT have private IP addresses. The NAT changes the values of the public address in the incoming packets to a private address, and changes the value of the private address in an outgoing packet to a public address. Because NATs hide the internal private addresses of a network, they provide some protection. NATs are used widely at present both to hide internal addresses and to reduce the demand for public IP addresses. Because NATs change the values of IP addresses in packets they interfere with the operation of applications that are aware of IP addresses. The SIP signalling messages may contain end IP addresses in the call-ids, and these addresses will need to be altered as the SIP messages cross a NAT. This is a messy situation and requires an Application Layer Gateway (ALG) to make the necessary changes. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 9 Application to SIP and H.323 | |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 9.1 Application to SIP | In SIP the call control and service control functions are performed by proxy servers which interrogate: - redirect servers; or - location servers. depending on the type of resolution needed. A SIP server resolves a SIP address to the URL for the next hop. This may be either a service resolution or a routing resolution. A redirect server would perform either service or routing resolutions, whereas a location server would normally perform a routing resolution to reach the location where the called terminal has registered. It is recommended that a public SIP address for the support of public telephony would have the form: <E.164 number>@<home network name> where: <E.164 number> is the called E.164 number. Although this is the form of SIP address, users would be likely not to put this address on their business cards but to put only their E.164 number. SIP addresses may also have the form: <E.164 number>@<server> where <server> is the domain name of the SIP server for the range of numbers that contains the called E.164 number. Different SIP servers will be used for different ranges of numbers and these ranges may equate to services or geographic regions or networks. The URL for the next hop may be a domain name or an IP address. If it is a domain name, then DNS will have to be used to resolve it to an IP address. EXAMPLE: Consider the routing in figure 8, which is the same as the example in clause 5.1. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 26 Caller Directory service Routing resolution Service resolution number portability Routing resolution Routing resolution Routing resolution Service resolution freephone Search resolution Network A Network B Network C Network D Figure 8: Example of a sequence of resolutions Suppose all networks use SIP, although some could use H.323. After the search resolution, network A knows only the called number not the home network name. Network A would interrogate its routing (redirect) server with: SIP:<called E.164>@<Network A server> and would obtain the URL for a public number portability server in the area served by network B. Suppose the URL is in the form of an IP address. This is network A's routing resolution. Network B would interrogate the public number portability server with: SIP:<called E.164>@<Public number portability server> and receive the URL of the SIP server in network D. This URL is the home network name. Suppose this is in the domain name form rather than an IP address. This is the service resolution for number portability. Network B would subsequently interrogate its internal DNS with the URL for network D and obtain an IP address for the server in network C. This is Network B's routing resolution. Network C would interrogate its internal DNS with the URL for network D and obtain an IP address for the server in network D. This is network C's routing resolution. Network D would interrogate the freephone server with: SIP:<called E.164>@<Network D freephone server> and receive the URL of the terminal. Suppose this is in the domain name form rather than an IP address. This is the service resolution for the freephone service. Network D would then perform a routing resolution using its internal DNS to obtain the IP address of the called terminal at its current location. This example assumes step-by-step routing. Depending on the information available to the servers and the connectivity at the IP level some steps could be skipped. |
4d2b6408477b3a9c7c52f0bed4182205 | 101 326 | 9.2 Application to H.323 | In H.323 the call control and service control functions are performed by the gatekeeper. The name for a terminal (endpoint) is called the alias address because the name is considered to be an alias of the transport address. Various forms of alias address are defined in ITU-T Recommendation H.225.0 [11] including E.164 numbers and H.323 Ids that have the form of a email address. Endpoints are identified by the Transport Address, which consists of an address relating to the network protocol being used (e.g. an IP address) and a TSAP (Transport layer Service Access Point) identifier. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 27 The gatekeeper therefore provides the resolution from alias address to transport address. This resolution may be either a service resolution and routing resolution combined, or just a routing resolution. Annex G of H.323 defines communications between different administrative domains that use H.323. It defines the exchange between border elements of templates that define: - the range of alias address identifiers that can be reached; - pricing information; - protocols to be used. Annex G is broadly equivalent to TRIP (see RFC 2871 [24]), which is used for the exchange of routing information to support SIP. A border element may indicate the gatekeeper to be used for the next step of the routing process. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 28 Annex A: Overview of SIP The main function of SIP is to enable a calling host to establish a media path defined by IP addresses and port numbers to a called host that is identified by a SIP address. The SIP address is the same form (user@domain) as an email address, except that the value of "user" could be either a name such as "john_smith" or a telephone number. Domain indicates the user's home network. Once the media path is defined, the media communications (session) are controlled by the Session Description Protocol (SDP). NOTE 1: See RFC 2327 [25]. In SIP all communications are between clients and servers: - User Agent Clients (UAC) send SIP messages; - User Agent Servers (UAS) receive SIP messages; - proxy servers in networks act as both clients and servers and pass requests and responses to and from other servers; - redirect servers accept a SIP request, map the address into zero or more new addresses and return these addresses to the client; - registrar servers accept registration requests. Figure A.1 shows the operation of SIP in proxy mode. NOTE 2: SIP can also operate in redirect mode without proxies, but proxies would normally be used in the provision of services. The calling UAC sends a request (INVITE) message indicating the SIP address of the called party and the type of media communications to which they are being invited. The proxy server in the network sends this message to a redirect server that indicates the URL of the next server to which the message must be sent. The next proxy server accesses a location server to determine the current location of the called party in the form of a URL or IP address. The called party sends a response message (200 = success) to the calling party indicating whether or not they accept the session and giving a Call-id. If the session is accepted then the call identity is given as "call-id@host". "host" may be either a URL or an IP address and it indicates the destination for the requested media session. The calling party sends an ACK message and the media session is then established directly between the calling and called parties using SDP. Either the caller or the called parties may terminate the session using a BYE message. UAC UAS Proxy Server Redirect server Location server UAS UAC Response contains Call-id@host Host is URL or IP address of called terminal URL of next server URL of next UAS SIP address of called user Session controlled by SDP Media packets sent to IP address of called UAS obtained from response Proxy Server Uses information from registration Calling party Called party Figure A.1: SIP in proxy mode ETSI ETSI TR 101 326 V2.0.0 (2002-02) 29 The request and response messages contain a "record-route" header that enables proxy servers to add their identity in the form of a URL to a list of the proxy servers that the message has traversed. This list is then used to force all response messages to take the same route as the request messages so that the proxy servers can keep track of the calls. The proxy servers may be either: - stateless, in which case they finish their task and then forget what they have done; or - stateful, in which case they keep a record of their action until a sequence of actions is completed, i.e. they know that a call is in progress until the call is terminated. Where calls are charged by the minute, the proxy servers will have to be stateful to create a call record for billing and will therefore have to use the record-route function. SIP provides no control over the routeing of the SDP session media packets, which may take a different route compared to the SIP packets. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 30 Annex B: Overview of H.323 H.323 is the ITU-T's standard for "Visual telephone systems and equipment for local area networks which provide a non-guaranteed quality of service". H.323 defines the signalling and the components of the system, but it does not define the LAN or transport layer, and therefore can be used for voice and multi-media provided over IP. The signalling concepts in H.323 are based on ISDN access signalling (see ITU-T Recommendation Q.931 [26]). H.323 is a "system" standard that makes reference to: - ITU-T Recommendation H.225.0 [11]: Call signalling protocols and media stream packetization for packet based multimedia communications systems; - H.245 Control of communications between visual telephone systems and terminal equipment; - various standards in the H-series on video codecs; - various standards in the G-series on audio codecs. H.323 defines the signalling between: - endpoints, which are terminals or gateways, and - gatekeepers, which may manage the communications of terminals. Figure A.2 shows the general structure: Terminal Gatekeeper Gateway Circuit switched network Terminal Terminal H.323 / H225 over LAN or IP Figure A.2: H.323 There are four stages in a communication (see ITU-T Recommendation H.323 [22], section 7.3.1): - signalling between the calling endpoint and the gatekeeper to obtain admission to the network; - signalling between the calling and called endpoints to establish the call. This signalling may go either direct or via the gateway; - establishment of the media control channel using the in-band H.245 protocol. This signalling may go either direct or via the gateway; - the media communications themselves using the same transport addresses as the media control channel. Each endpoint of an information flow is identified by a Transport Address, which consists of an address relating to the network protocol being used (e.g. an IP address) and a TSAP (Transport layer Service Access Point) identifier, which allows multiplexing of flows for a single terminal. Endpoints may have separate transport addresses for signalling and media. Endpoints may also have alias addresses which include E.164 numbers, Internet names and other identifier strings. The gateways provide translation between aliases and transport addresses if incoming traffic is sent to an alias address. ETSI ETSI TR 101 326 V2.0.0 (2002-02) 31 History Document history V1.1.1 September 2000 Publication (Historical) V2.0.0 February 2002 Publication |
742a006b51c193eadf6cd79c84cff6ad | 101 159 | 1 Scope | The present document is a guide how to implement and test Digital Enhanced Cordless Telecommunications (DECT) systems operating at frequencies outside the frequency-bands described in TBR 6 [11]. The need to have this arises if DECT equipment is to be adapted to national requirements of countries which do not allow to use the basic 1 880 to 1 900 MHz DECT frequency band. The present document is thereby also a guide for approval of such DECT systems in the above mentioned countries. |
742a006b51c193eadf6cd79c84cff6ad | 101 159 | 2 References | References may be made to: a) specific versions of publications (identified by date of publication, edition number, version number, etc.), in which case, subsequent revisions to the referenced document do not apply; or b) all versions up to and including the identified version (identified by "up to and including" before the version identity); or c) all versions subsequent to and including the identified version (identified by "onwards" following the version identity); or d) publications without mention of a specific version, in which case the latest version applies. A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. [1] EN 300 175-1: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 1: Overview". [2] EN 300 175-2: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 2: Physical layer (PHL)". [3] EN 300 175-3: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 3: Medium Access Control (MAC) layer". [4] EN 300 175-4: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 4: Data Link Control (DLC) layer". [5] EN 300 175-5: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 5: Network (NWK) layer". [6] EN 300 175-6: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 6: Identities and addressing". [7] EN 300 175-7: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 7: Security features". [8] EN 300 175-8: "Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 8: Speech coding and transmission". [9] EN 300 176-1: "Digital Enhanced Cordless Telecommunications (DECT); Approval test specification; Part 1: Radio". [10] EN 300 176-2: "Digital Enhanced Cordless Telecommunications (DECT); Approval test specification; Part 2: Speech". [11] TBR 6: "Digital Enhanced Cordless Telecommunications (DECT); General terminal attachment requirements". [12] EN 300 444: "Digital Enhanced Cordless Telecommunications (DECT); Generic Access Profile (GAP)". ETSI TR 101 159 V1.2.1 (1998-06) 6 [13] ETR 056: "Digital European Cordless Telecommunications (DECT); System description document". [14] ETS 300 700: "Digital European Cordless Telecommunications (DECT); Wireless Relay Station (WRS)". [15] ETS 300 765-1: "Digital Enhanced Cordless Telecommunications (DECT); Radio in the Local Loop (RLL) Access Profile (RAP); Part 1: Basic telephony services". [16] ETS 300 765-2: "Digital Enhanced Cordless Telecommunications (DECT); Radio in the Local Loop (RLL) Access Profile (RAP); Part 2: Advanced telephony services". [17] ETR 246: "Digital European Cordless Telecommunications (DECT); Application of DECT Wireless Relay Station (WRS)". [18] ETR 308: "Digital Enhanced Cordless Telecommunications (DECT); Services, facilities and configurations for DECT in the local loop". [19] ETR 310: "Digital Enhanced Cordless Telecommunications (DECT); Traffic capacity and spectrum requirements for multi-system and multi-service DECT applications co-existing in a common frequency band". [20] ETS 300 822: "Digital Enhanced Cordless Telecommunications (DECT); Integrated Services Digital Network (ISDN); DECT/ISDN interworking for intermediate system configuration; Interworking and profile specification". [21] ETR 185: "Digital European Cordless Telecommunications (DECT); Data Services Profile (DSP); Profile overview". [22] ETR 178: "Digital European Cordless Telecommunications (DECT); A high level guide to the DECT standardization". [23] TBR 22: "Attachment requirements for terminal equipment for Digital Enhanced Cordless Telecommunications (DECT) Generic Access Profile (GAP) applications". [24] 91/263/EEC: "Council Directive of 29 April 1991 on the approximation of the laws of the Member States concerning telecommunications terminal equipment, including the mutual recognition of their conformity" (Terminal Directive). [25] 91/287/EEC: "Council Directive of 3 June 1991 on the frequency band to be designated for the co- ordinated introduction of digital European cordless telecommunications (DECT) into the Community". [26] 91/288/EEC: "Council Directive of 3 June 1991 on the co-ordinated introduction of digital European cordless telecommunications (DECT) into the Community". [27] 90/388/EEC: "Council Directive of 28 June 1990 on competition in the markets for telecommunications services". ETSI TR 101 159 V1.2.1 (1998-06) 7 |
742a006b51c193eadf6cd79c84cff6ad | 101 159 | 3 Definitions and abbreviations | 3.1 Definitions For the purposes of the present document, the following definitions apply: Fixed Part (DECT Fixed Part) (FP): A physical grouping that contains all of the elements in the DECT network between the local network and the DECT air interface. Portable Part (DECT Portable Part) (PP): A physical grouping that contains all elements between the user and the DECT air interface. PP is a generic term that may describe one or several physical pieces. 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: CTA Cordless Terminal Adapter CTR Common Technical Regulation DAS DECT Access Site DCS Dynamic Channel Selection DECT Digital Enhanced Cordless Telecommunications ERO European Radio communications Office EUT Equipment Under Test FDD Frequency Division Duplex FP Fixed Part FS Fixed Service FSS Fixed Satellite Service FWA Fixed Wireless Access GAP Generic Access Profile GPS Global Positioning System ISDN Integrated Services Digital Network LOS Line Of Sight NLOS Near Line Of Sight P-MP Point-to-Multipoint POTS Plain Old Telephone Service PP Portable Part PSTN Public Switched Telephone Network RAP RLL Access Profile RF Radio Frequency RFP Radio Fixed Part RLL Radio in the Local Loop TBR Technical Basis for Regulation TDD Time Division Duplex TE Terminal Equipment UMTS Universal Mobile Telecommunications System WLL Wireless Local Loop WRS Wireless Relay Station ETSI TR 101 159 V1.2.1 (1998-06) 8 |
742a006b51c193eadf6cd79c84cff6ad | 101 159 | 4 Introduction to DECT services and applications | DECT is a general radio access technology for short range wireless telecommunications. It is a high capacity, pico- cellular digital technology, for cell radii ranging from about 10 m to 5 km depending on application and environment. It provides telephony quality voice services, and a broad range of data services, including Integrated Services Digital Network (ISDN). It can be effectively implemented in a range from simple residential cordless telephones up to large systems providing a wide range of telecommunications services. The DECT instant or continuos dynamic channel selection, provides effective coexistence of uncoordinated installations of private and public systems on the common designated DECT frequency band, and avoids any need for traditional frequency planning. See ETR 310 [19] for further explanation. Figure 1 gives a high level graphic overview of applications and features of DECT. A list of all ETSI standards and ETSI technical reports for DECT are given in ETR 178 [22]. Annex A of ETR 178 [22] contains a list of the essential standards and reports. The DECT standardization has developed a modern and complete standard within the area of cordless telecommunications. The European wide allocation of the frequency band 1 880 - 1 900 MHz, has been reinforced by the Council Directive 91/287/EEC [25]. Spectrum allocation for DECT has also been adopted by many other countries worldwide. DECT carriers have been defined for the whole spectrum range 1 880 - 1 939 MHz in the basic DECT standards EN 300 175, parts 1 to 8 [1] - [8] and TBR 6 [11]. This allows DECT services to be introduced in countries where the basic DECT frequencies 1 880 - 1 900 MHz are not available. For rapid introduction DECT, Common Technical Regulations (CTRs) have been established for DECT relating to harmonized DECT standards, Technical Bases for Regulation (TBRs) and ENs. TBRs contain the technical requirements of a CTR. Approval to a CTR gives access to a single European market through a simplified legal procedure. The Council Recommendation 91/288/EEC [26] recommends that the DECT standard should meet user requirements for residential, business, public pedestrian and radio in the local loop applications. The standard should also provide compatibility and multiple access rights to allow a single handset to access several types of systems and services, e.g. a residential system, a business system and one or more public systems. The public applications should be able to support full intersystem roaming of DECT handsets. The DECT standard provides these features. Of special importance is the Generic Access Profile (GAP) and the related TBR 22 [23], which define common mobility and interoperability requirements for private and public DECT speech services. For a more comprehensive overview of the DECT standardization see ETR 178 [22]. The European Commission has elaborated an amendment of Directive 90/388/EEC [27] on competition in the market for telecommunications services. This Directive defines DECT as an important alternative to the wired Public Switched Telephone Network (PSTN)/ISDN network access. Furthermore any restriction on the combination of DECT with other mobile technologies are to be withdrawn. The emerging deregulation of fixed services will also speed up fixed-mobile convergence in service offerings from operators. The different DECT interoperability profile standards are designed to facilitate provision of mixtures of fixed and mobile services through a single infrastructure. The aim of the present document is to provide technical requirements that can be applied for DECT approval in countries having a spectrum allocation for DECT, different from the European allocation. The present document consists of references to the relevant ETSI DECT standards (TBR 6 [11]) and amendments required for application in a general spectrum allocation band. ETSI TR 101 159 V1.2.1 (1998-06) 9 DECT Multiple configurations PP PP PP PPs PP FP FP FP W R S Residential Office RLL/PCS Public RLL Business Residential Multiple environments Robust self planned real time radio channel selection Coexistence Multiple access rights Seamless handover Features Cost effective Mobility Security High capacity Inter - operability Quality voice ISDN TACS NMT AMPS X.25 LAN GSM PSTN IEEE 802 Multiple network access Telephony Fax Images Data Video ISDN Evolutionary services Multiple services Figure 1: Overview of DECT applications and features ETSI TR 101 159 V1.2.1 (1998-06) 10 |
742a006b51c193eadf6cd79c84cff6ad | 101 159 | 5 Requirements | This clause defines the minimum required functions and parameters for DECT equipment operating in the frequency band FL to FU. FL defines the lower edge of the assigned frequency band and FU defines the upper edge of the frequency band. The technical requirements are contained in TBR 6 [11] together with the amendments which are defined in this clause. 5.1 Carrier positions Examples of carrier allocations and carrier positions are given in annex A. The frequencies to be used can be software controlled by the DECT base stations. They are indicated in a broadcast message to the portables. DECT equipment should be capable of working on all assigned channels. This normally provides the most efficient use of the spectrum, but it is possible to limit specific applications, or a specific system, to part of the spectrum if this is suitable due to local circumstances. 5.2 General requirements A summary of the main technical requirements of TBR 6 [11] is given in table 1. Table 1 Parameter Characteristic/ Value Reference accuracy and stability of Radio Frequency (RF) carriers RFP: ± 50 kHz PP: ± 100 kHz 7.2, 7.3, 7.4, 7.5 packet timing jitter ± 1 µs 8.3 reference timing accuracy of a Radio Fixed Part (RFP) max 10 ppm 8.4 packet transmission accuracy of a PP 5 ms ± 2 µs 8.5 transmission burst power-time template 9 transmitted power max 250 mW 10 RF carrier modulation digital modulation 11 unwanted emissions due to modulation emission mask 12.2 unwanted emissions due to transmitter transient emission mask 12.3 unwanted emissions due to intermodulation 1 µW 12.4 spurious emissions when allocated a transmit channel 250 nW below 1 GHz 1 µW above 1 GHz 12.5 radio receiver sensitivity -83 dBm at BER = 10-3 13.1 radio receiver reference BER 10-5 at -73 dBm 13.2 radio receiver interference performance BER < 10-3 13.3 radio receiver blocking See table 2 13.4 radio receiver intermodulation performance BER < 10-3 13.6 spurious emissions when the PP has no allocated transmit channel 2 nW 13.7 efficient use of the radio spectrum channel handling 17.1, 17.2, 17.3 antennas with directivity 12 dBi H.2 The tests cases in table 1 shall be performed, where relevant, on the two supported carriers nearest to the band edges and on one carrier inside the band. The applicant shall declare the band edge limits FL and FU and the carriers supported. ETSI TR 101 159 V1.2.1 (1998-06) 11 For the blocking requirements, table 2 shall be applied instead of the requirements given in table 12 of TBR 6 [11]. Table 2 Frequency (f) Continuous wave interferer level For radiated measurements dB µV/m For conducted measurements dBm 25 MHz ≤ f < FL - 100 MHz 120 -23 FL - 100 MHz ≤ f < FL - 5 MHz 110 -33 f - FC > 6 MHz 100 -43 FU + 5 MHz < f ≤ FU + 100 MHz 110 -33 FU + 100 MHz < f ≤ 12,75 GHz 120 -23 The Equipment Under Test (EUT) shall operate on the declared frequency allocation with the low band edge FL MHz and the high band edge FU MHz. ETSI TR 101 159 V1.2.1 (1998-06) 12 Annex A: Examples for frequency band allocations A.1 DECT carrier numbers and carrier positions around 1,9 GHz DECT is specified for the whole frequency range 1880 –1939 MHz. For the frequency band 1880 - 1900 MHz 10 RF-carriers with centre frequencies Fc are given by: Fc = F0 - c * 1,728 MHz, where:F0 = 1897,344 MHz c = 0, 1, 2, ....., 9 For carriers from 1899,072 to 1937,088 MHz the carrier frequencies are defined by: Fc = F9 + c * 1,728 MHz, where:F9 = 1881,792 MHz c = 10, 11, 12, ....., 32 RF-band number = 00001 (see EN 300 175-2 [2], subclause 4.1.1 and EN 300 175-3 [3], subclause 7.2.3.3.1) The above carrier frequencies are explicitly given in table A.1. Table A.1: Carrier numbers and carrier positions Carrier number c Rf-band number Carrier freq. MHz Carrier number c Rf-band number Carrier freq. MHz 9 - 1881,792 17 00001 1911,168 8 - 1883,520 18 00001 1912,896 7 - 1885,248 19 00001 1914,624 6 - 1886,876 20 00001 1916,352 5 - 1888,704 21 00001 1918,080 4 - 1890,432 22 00001 1919,808 3 - 1892,160 23 00001 1921,536 2 - 1893,888 24 00001 1923,264 1 - 1895,616 25 00001 1924,992 0 - 1897,344 26 00001 1926,720 10 00001 1899,072 27 00001 1928,448 11 00001 1900,800 28 00001 1930,176 12 00001 1902,528 29 00001 1931,904 13 00001 1904,256 30 00001 1933,632 14 00001 1905,984 31 00001 1935,360 15 00001 1907,712 32 00001 1937,088 16 00001 1909,440 Examples of current spectrum allocations for DECT in different parts of the world are: 1880 – 1900 MHz, 1900 – 1920 MHz and 1910 – 1930 MHz. The DECT fixed part (base station) broadcast messages indicate the locally relevant carrier to ensure that portables and WLL subscriber units set up calls only within the locally allocated band. New or modified bands can locally be defined when needed. ETSI TR 101 159 V1.2.1 (1998-06) 13 History Document history V1.1.1 February 1998 Publication V1.2.1 June 1998 Publication ISBN 2-7437-2213-4 Dépôt légal : Juin 1998 |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 1 Scope | The present document applies to the physical layer and associated signalling of the air interface of Autonomous Satellite Signalling Channels (ASSCs) between user Satellite Terminals (STs) and Gateways (GWs), or between STs, for satellite access systems where inbound and outbound channels are independent from each other. In these systems, the inbound channels of a Satellite Terminal are those channels carrying data, and transmitted from the Satellite Terminal to Gateways or to other Satellite Terminals. The outbound channels of a Satellite Terminal are those channels carrying data, and received by the Satellite Terminal from the Gateways or other Satellite Terminals. The inbound and outbound channels may be of any type. These satellite access systems are designed to provide end-users with multi-services such as data transfer, telephony and associated services, data gathering, etc. These systems are designed to offer two way links for traffic between end-user Satellite Terminals and service providers connected to Gateways, or between end-user Satellite Terminals. In these systems, the inbound channels from Satellite Terminals and the signalling to and from the Satellite Terminals are transmitted through the same satellite. In these systems, the inbound channels from Satellite Terminals and the outbound channels towards Satellite Terminals may be transmitted through the same satellite or via different satellites, and to and from the same gateway or different gateways. These satellite access systems are operated through geostationary satellites, in the Fixed Satellite Service frequency bands. In these systems, the STs are designed usually for unattended operation. The interfaces of GWs with the terrestrial networks and the interfaces of STs with the user terminals or local networks are outside the scope of the present document. |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 2 References | For the purposes of this Technical Report (TR) the following references apply: [1] ETSI EN 301 428 (V1.2.1): "Satellite Earth Stations and Systems (SES); Harmonized EN for Very Small Aperture Terminal (VSAT); Transmit-only, transmit/receive or receive-only satellite earth stations operating in the 11/12/14 GHz frequency bands covering essential requirements under article 3.2 of the R&TTE directive". [2] ETSI EN 301 443 (V1.2.1): "Satellite Earth Stations and Systems (SES); Harmonized EN for Very Small Aperture Terminal (VSAT); Transmit-only, transmit-and-receive, receive-only satellite earth stations operating in the 4 GHz and 6 GHz frequency bands covering essential requirements under article 3.2 of the R&TTE Directive". [3] ETSI EN 300 673 (V1.2.1): "Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for Very Small Aperture Terminal (VSAT), Satellite News Gathering (SNG), Satellite Interactive Terminals (SIT) and Satellite User Terminals (SUT) Earth Stations operated in the frequency ranges between 4 GHz and 30 GHz in the Fixed Satellite Service (FSS)". [4] ETSI EN 301 360 (V1.1.3): "Satellite Earth Stations and Systems (SES); Harmonized EN for Satellite Interactive Terminals (SIT) and Satellite User Terminals (SUT) transmitting towards geostationary satellites in the 27,5 GHz to 29,5 GHz frequency bands covering essential requirements under article 3.2 of the R&TTE Directive". [5] ETSI EN 301 489-1 (V1.3.1): "Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements". ETSI ETSI TR 101 309 V1.1.1 (2002-04) 6 [6] ETSI EN 301 489-12 (V1.1.1): "Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 12: Specific conditions for Very Small Aperture Terminal, Satellite Interactive Earth Stations operated in the frequency ranges between 4 GHz and 30 GHz in the Fixed Satellite Service (FSS)". [7] ETSI EN 301 430 (V1.1.1): "Satellite Earth Stations and Systems (SES);Harmonized EN for Satellite News Gathering Transportable Earth Stations (SNG TES) operating in the 11-12/13-14 GHz frequency bands covering essential requirements under article 3.2 of the R&TTE directive". |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 3 Definitions and abbreviations | |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 3.1 Definitions | For the purposes of the present document, the following terms and definitions apply: Channel layer: layer in charge of multiplexing and demultiplexing data, including signalling, into and from data containers Inbound channel: channel carrying data and transmitted from a ST to a GW or to another ST Inbound Gateway: gateway receiving the Inbound Traffic Channel Inbound Traffic Channel: channel carrying traffic data and transmitted from a ST to a GW or to another ST Initialization Centre: centre in charge of the STs logins Initialization Signalling Channel: channel carrying signalling between the Initialization Centre and the STs Management Centre: centre in charge of the system management Management Signalling Channel: channel carrying signalling between the Management Centre and the STs Outbound channel: channel carrying data and received by STs from a GW or another ST Outbound Gateway: gateway transmitting the Outbound Traffic Channel Outbound Traffic Channel: channel carrying traffic data and received by STs from a GW or another ST Physical layer: layer in charge of the physical transmission of all the bits transmitted through a channel Processing layer: layer in charge of processing the data received via the satellite and the terrestrial interfaces (e.g. routing, signalling, etc.) |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 3.2 Abbreviations | For the purposes of the present document, the following abbreviations apply: AP Access Provider ASSC Autonomous Satellite Signalling Channel CDMA Code Division Multiple Access Chl Channel Ctr Centre Ctrlr Controller DAMA Demand Assignment Multiple Access EIRP Equivalent Isotropically Radiated Power EN European Standard ES Earth Station FDMA Frequency Division Multiple Access FEC Forward Error Correcting code FSS Fixed Satellite Service ETSI ETSI TR 101 309 V1.1.1 (2002-04) 7 GPS Global Positioning System GW Gateway IB-GW InBound GateWay IOB-GW Inbound and OutBound GateWay LAN Local Area Network ISP Internet Service Provider NAP Network Access Provider OB On board OB-GW Outbound Gateway PABX Private Automatic Branch eXchange PC Personal Computer PSPDN Public Switched Packed Data Network PSTN Public Switched Telephone Network R&TTE Radio and Telecommunication Terminal Equipment (directive) SIT Satellite Interactive Terminals SNG TES Satellite News Gathering Transportable Earth Stations SP Service Provider ST Satellite Terminal SUT Satellite User Terminals TDMA Time Division Multiple Access TR Technical Report TS Technical Specifications VSAT Very Small Aperture Terminal ETSI ETSI TR 101 309 V1.1.1 (2002-04) 8 |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4 Section I - General characteristics | |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.1 System Architecture | A satellite system with ASSC may consist of one or more satellite networks with ASSC which may use common parts (e.g. channels, stations, functional centre). Two types of networks are considered: star networks and meshed networks, as presented in figure 1 (Channels of a ST in a star network) and figure 2 (Channels of a ST in a mesh network). Outbound Gateway Management Centre Initialization Signalling Channel Outbound Traffic Channel Inbound Traffic Channel ASSC Inbound Gateway Management Signalling Channel Satellite Terminal for End User Initialization Centre Telecom Operators and Service Providers Figure 1: Channels of a ST in a star network ETSI ETSI TR 101 309 V1.1.1 (2002-04) 9 Gateway Control Centre Initialization Signalling Channel Outboud Traffic Channel Inbound Traffic Channel ASSC Management Signalling Channel Satellite Terminal for End User Initialization Centre Telecom Operators and Service Providers Satellite Terminal for End User Figure 2: Channels of a ST in a mesh network |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.1.1 Network elements | A satellite network with ASSC consists of the following elements: • Satellite Terminals (STs), • a unique Initialization Centre which manages each ST entering the network, • one or more Control Centre which dynamically assigns satellite capacity, • one or more Outbound Gateways which transmits traffic data to the STs, • one or more Inbound Gateways which receives traffic data from the STs. NOTE: These last four elements may be in separated or collocated earth stations. |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.1.2 Channels | The STs transmit and receive the following satellite channels: • Outbound Traffic Channels: channels received by STs from Outbound Gateways or from other STs. • Inbound Traffic Channels: channels transmitted by STs to Inbound Gateways or to other STs. • Management Signalling Channels: bi-directional channels between the Control Centres and STs. • Initialization Signalling Channel: bi-directional channel between a ST and the Initialization Centre. ETSI ETSI TR 101 309 V1.1.1 (2002-04) 10 |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.1.3 System general characteristics | The inbound and signalling channels are transmitted through the same satellite in order to provide easy ST synchronization, whatever is the access technique used (FDMA, TDMA, CDMA). The outbound channel or channels may be transmitted via the same or other satellites. A ST is under the control of only one Control Centre, at a time, either permanently or dynamically assigned. A ST may have to receive one or several outbound signals, at a time, i.e. modulated carriers carrying data or signalling. The outbound signals to be received by a ST are either dynamically assigned by the Control Centre or permanently assigned. A ST may have to transmit one or several inbound signals, at a time. The inbound signals to be transmitted by a ST are either dynamically assigned by the Control Centre or permanently assigned. The Inbound and Outbound Gateways (GWs) may be connected either to a public environment (e.g. a PSTN, PSPDN, data platforms, ISP, etc), or a private environment (e.g. PABX, LAN, leased lines through another network). The Satellite Terminals may be locally connected either to private environments (PABX or LAN, or leased lines through another network), or to consumer environments (phone, fax, PC connection) or, in some locations, used for an extension of a public network (e.g. a PSTN). The present document does not contain any requirement on the type of service which could be provided with such systems with ASSC. |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.1.4 ST satellite links | For a ST, the following satellite single hop links should be used: • between the ST and the Initialization Centre, both ways, for signalling, • from the ST to the assigned Inbound Gateway, for traffic data, • between the ST and the assigned Control Centre, both ways for signalling, • between the ST and other STs in a mesh network for traffic data. |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.1.5 Other system links | For the management of the system elements other than the STs, there may be additional signalling links either terrestrial or via satellite such as: • between the Initialization Centre and the Control Centre(s) (e.g. for network configuration, capacity allocation, etc.), • between the Initialization Centre and the Inbound Gateway(s) (e.g. for monitoring and control information), • between the Initialization Centre and the Outbound Gateway(s) (e.g. for monitoring and control information), • between the Control Centre(s) and the Inbound Gateway(s) (e.g. for the capacity management and monitoring and control), • between the Control Centre(s) and the Outbound Gateway(s). (e.g. for the capacity management and monitoring and control). ETSI ETSI TR 101 309 V1.1.1 (2002-04) 11 |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.2 Services | |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.2.1 Duplex circuit mode | Duplex circuits could be established between Satellite Terminals and Gateways or between Satellite Terminals, for data, telephone or facsimile. |
5d9ab0dd1cab224de9f24fdf2ca99b26 | 101 309 | 4.2.2 Data transfer | Data transfer could be possible in a symmetric or dissymmetric mode, or in a Packet mode. |
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