1、 Rec. ITU-R M.687-2 1 RECOMMENDATION ITU-R M.687-2 INTERNATIONAL MOBILE TELECOMMUNICATIONS-2000 (IMT-2000)*(Question ITU-R 39/8) (1990-1992-1997) Rec. ITU-R M.687-2 Summary This Recommendation defines the objectives to be met by IMT-2000 and provides the overall IMT-2000 concepts with particular con
2、sideration to achieving worldwide roaming and compatibility. This Recommendation provides a high level statement on the topics of: services, architecture, network aspects, implementation, sharing and operational characteristics. Guidance is provided, for a limited number of possible scenarios, on sp
3、ectrum bandwidth and band of operation based on critical technical parameters and traffic estimates. It forms a foundation for the subject of IMT-2000 and for the subsequent work activities and Recommendations. The ITU Radiocommunication Assembly, considering a) Resolution 212 (Rev.WRC-95); b) that
4、the frequency bands 1 885-2 025 MHz and 2 110-2 200 MHz are intended for use, on a worldwide basis, by administrations wishing to implement the International Mobile Telecommunications-2000 (IMT-2000); c) that the cost of radio and very large scale integration (VLSI) technology is continually decreas
5、ing, thus making competitive, in a number of cases, the alternative option of a radio approach for accessing voice and non-voice telecommunication services; d) that different future systems are under study; e) that system compatibility is necessary for international operation, and that commonality i
6、s desirable in any event to ensure that the overall system cost per mobile user is significantly less than it is with present systems; f) the need for a flexible system structure able to match network investment to revenue growth, to adapt readily to environmental factors and to respond to new devel
7、opments without restricting innovation; g) the possible need for common channels or frequency bands to allow regional and/or worldwide operation, particularly with the increasing use of personal (hand-held, portable) terminals; h) that the use of internationally agreed frequency bands also facilitat
8、es the planning of national networks and reduces the risk of harmful interference with other radio services; j) the increasing importance of the various types of non-voice telecommunication services; k) the relevant ITU-T Recommendations and on-going studies; l) that mobile terminals of the IMT-2000
9、 may be used to access mobile satellite systems for use on land, ships and aircraft; m) that there is a need for mobile terminals to roam between public land mobile telecommunication networks in different countries; _ *IMT-2000 was previously known as Future Public Land Mobile Telecommunications Sys
10、tems (FPLMTS). 2 Rec. ITU-R M.687-2 n) that a standardized radio interface would facilitate the roaming of mobile units between networks; o) that users may want to be able to use the same terminals and procedures as in the fixed networks (public switched telephone network (PSTN), public data network
11、 (PDN) and integrated services digital network (ISDN) to access similar telecommunication services in IMT-2000; p) that the application of cellular type mobile radiocommunication systems for use as fixed systems and their adaptation to the needs of developing countries is under study; q) that the de
12、scription of IMT-2000 will comprise a number of Recommendations for which this one is the key; r) that IMT-2000 are expected to be used by a large proportion of the general public, recommends that IMT-2000 intended for regional and/or worldwide use should conform to the following objectives and char
13、acteristics. 1 Objectives 1.1 General objectives IMT-2000 aim to achieve the following primary general objectives: 1.1.1 to make available to users who are on the move or whose location may change (mobile users), irrespective of their location (i.e. national and international roaming), a wide range
14、of telecommunication services (voice and non-voice), allowing communication between mobile users and other mobile users, users of the fixed public networks (PSTN, PDNs and ISDN) or other telecommunication networks as appropriate; 1.1.2 to provide these services over a wide range of user densities an
15、d geographic coverage areas; 1.1.3 to make efficient and economical use of the radio spectrum consistent with providing service at an acceptable cost; 1.1.4 to provide, as far as practical, services with a quality of service comparable to the fixed networks; 1.1.5 to provide for the continuing flexi
16、ble extension of service provision, subject to the constraints of radio transmission, spectrum efficiency and system economics; 1.1.6 to adopt a phased approach for the definition of IMT-2000. The first phase (Phase 1) includes those services supported by user bit rates up to approximately 2 Mbit/s.
17、 Phase 2 is envisaged as augmenting Phase 1 with new services, some of which may require higher bit rates; 1.1.7 to permit the use of the IMT-2000 for the purpose of providing its services to fixed users, under conditions approved by the appropriate national or regional authority, either permanently
18、 or temporarily, either in rural or urban areas; 1.1.8 to accommodate a variety of mobile terminals ranging from those which are small enough to be easily carried on the person (the personal pocket radio) to those which are mounted in a vehicle; 1.1.9 to admit the provision of service by more than o
19、ne network in any area of coverage; 1.1.10 to provide an open architecture which will permit the easy introduction of technology advancements, as well as different applications; 1.1.11 to allow the coexistence with, and interconnection with, mobile systems which use direct satellite links taking int
20、o consideration ITU-T Recommendation E.171; 1.1.12 to provide a modular structure which will allow the system to start from as small and simple configuration as possible and grow as needed, both in size and complexity within practical limits. Rec. ITU-R M.687-2 3 1.2 Technical objectives IMT-2000 ai
21、m to achieve the following primary technical objectives: 1.2.1 to support integrated communication and signalling; 1.2.2 to establish signalling interface standards, taking into account the principles established by ITU-T Recommen-dation X.200, and based on the relevant ITU-T signalling Recommendati
22、ons. IMT-2000 aim to achieve the following secondary technical objectives: 1.2.3 to provide for additional levels of security (for voice and data services) compared to that contained in 1.1.4. In addition, to allow for the provision of end-to-end encryption for voice and data services; 1.2.4 to prov
23、ide service flexibility which permits the optional integration of services such as mobile telephone, dispatch, paging and data communication, or any combination thereof; 1.2.5 to support terminal equipment interfaces (and procedures) defined for the fixed public networks which allow the alternative
24、use of terminal equipment in the fixed public networks; 1.2.6 to support equipment and component design that can withstand typical rural conditions (rough roads, dusty environment, extreme temperatures and humidity, etc.); 1.2.7 to accommodate the use of repeaters for covering long distances between
25、 terminals and base stations, providing this does not constrain the specification of the radio interfaces; 1.2.8 to allow the connection of PABXs or small rural exchanges to mobile stations; 1.2.9 procedures used in IMT-2000 should be based on the unique identification of the entities (e.g. service
26、providers, network operators, etc.) involved. 1.3 Operational objectives IMT-2000 aim to achieve the following primary operational objectives: 1.3.1 to provide for the required user authentication and billing functions; 1.3.2 to provide for unique user identification and numbering in accordance with
27、 appropriate ITU-T Recommen-dations; 1.3.3 to provide for a unique equipment identification scheme; 1.3.4 to enable each mobile user to request particular services, and initiate and receive calls, as desired. These calls for a given mobile user, incoming or outgoing at the same mobile termination, m
28、ay be simultaneously multiple and associated to different services (i.e., advanced voice and data services including multimedia); 1.3.5 to ensure that the opportunity for fraud in IMT-2000 is minimized, e.g. by restricting services such as multiple call forwarding which are prone to fraud; 1.3.6 to
29、ensure that the theft of IMT-2000 mobile stations is minimized, e.g. by maintaining a list of stolen mobile station identities and monitoring traffic for their use; 1.3.7 to minimize theft, fraud and also abuse of the emergency service by malicious calls, by having available relevant information for
30、 use by the appropriate authorities; 1.3.8 to aid the emergency services by providing additional emergency call information as far as possible, e.g. user identity, location information, and other information that may be required by national or local authorities. IMT-2000 aim to achieve the following
31、 secondary operational objectives: 1.3.9 to provide an indication to the paying party of eventual added call charges, e.g. due to roaming; 1.3.10 to allow the system to be configured for special conditions where mobility between cells, or even within a cell, is not required; or where a high traffic
32、per user is required; 1.3.11 to take account of the communications requirements for road traffic management and control systems; 1.3.12 to allow for extension of the cell size in rural or remote areas, providing this does not constrain the specification of the radio interfaces. 4 Rec. ITU-R M.687-2
33、2 Services 2.1 General 2.1.1 IMT-2000 should offer the services available in the fixed public networks (PSTN, ISDN and PDNs), as far as possible, bearing in mind the differences in the characteristics of the fixed networks and mobile radio environment. 2.1.2 IMT-2000 may also offer additional servic
34、es, taking into account the special nature of mobile communications. 2.1.3 IMT-2000 should be designed in such a way that the calling subscriber does not have to know the location of the mobile. 2.1.4 It should be possible for stations in IMT-2000 to be used in the maritime and aeronautical environm
35、ent, to the extent permitted by national or international regulatory authorities. 2.1.5 It should be possible for IMT-2000 to be used as a temporary or permanent substitute to fixed networks where fixed network facilities are limited or not available, or more generally where reasons of convenience o
36、r economics make this desirable. The system should then be capable of adaptation to these conditions (i.e. higher traffic per subscriber, no mobility between cells or even within a cell). 2.1.6 To support user mobility by registration on different terminals (e.g. by the use of a user identity module
37、 _UIM). 2.1.7 To support an open market place for the independent purchase of subscriptions and mobile terminals (e.g. by the use of a UIM). 2.1.8 IMT-2000 should be designed to allow international operation and automatic roaming of mobile subscribers and stations. (The degree to which the roaming f
38、acility between networks or countries shall be automatic is for further study). 2.1.9 IMT-2000 should be designed so that under favourable circumstances services requiring high information rates can be provided. 2.1.10 IMT-2000 should be capable of providing service to a variety of mobile terminals
39、ranging from those which are small enough to be easily carried on the person to those which are mounted in a vehicle. 2.1.11 Recommendation ITU-R M.816 contains the framework for the definition of the services to be supported in IMT-2000. 3 Frequency band considerations 3.1 General considerations Co
40、nsiderations on spectrum should take into account the estimated traffic, the available and foreseeable techniques, the propagation characteristics and time scale for meeting the users needs to the greatest possible extent. Considerations on frequency matters should take into account that the traffic
41、 generated by mobile systems, as well as the number and diversity of services, will continue to grow. 3.2 Traffic considerations Any estimation of the traffic should take into consideration that in the future, non-voice traffic will constitute an increasing proportion of the total traffic and that t
42、raffic will be generated outdoors as well as indoors by mobile and personal stations. Annex 1 contains an estimation for traffic in IMT-2000 which is based on the current understanding of the nature of personal telecommunications. Rec. ITU-R M.687-2 5 3.3 Spectrum requirements To comply with IMT-200
43、0 service requirements, namely the concept of regional and/or worldwide roaming, inclusion at least partly of worldwide common frequency should be considered as the first choice to enable universal access particularly for personal stations. 3.3.1 Worldwide compatibility The primary focus for worldwi
44、de compatibility, including common frequency band, is for the personal station where the benefits of worldwide compatibility have most impact. With respect to the mobile station, worldwide compatibility is desirable, but regional/international compatibility may be sufficient in a number of respects.
45、 While a complete common frequency band is preferred, this may not be immediately feasible. A degree of commonality can be obtained through regional/international compatibility with a common signalling band and sufficient overlap of the traffic bands to ensure compatibility for roaming. Common signa
46、lling and numbering standards are also essential. Multiple standards hamper implementation in smaller markets and developing countries, resulting in poor spectrum utilization and higher costs. 3.3.1.1 Roaming requirements Some users of IMT-2000 will require the ability for regional and/or internatio
47、nal roaming using their own terminals. In order to provide worldwide roaming capability, particularly for personal indoor and outdoor stations, it is preferred that full compatibility be maintained worldwide. One important requirement is that the band used for worldwide operation be within the frequ
48、ency agility of the personal stations. 3.3.2 Satellite communications IMT-2000 include a mobile-satellite component. Recommendation ITU-R M.818 describes this component. Figure 2 shows some configuration examples. The use of spectrum in accordance with Resolution 212 (Rev.WRC-95) could enable a sing
49、le equipment to use both terrestrial mobile and mobile satellite communications. The satellite components may also support: a satellite paging function which could reduce the amount of location registration data to be transferred; paging terrestrial mobile users beyond the range of the terrestrial system. The equipment required for this one-way function is simpler than that for two-way mobile satellite function; linking remote base stations or where temporary (e.g. emergency) system extension is needed. 3.3.3 Duplex techniques Frequency division duplex (FDD) and time di
