1、STD.1TI.l-R RECMN fl=dL9-2-ENGL 1997 4855232 0532176 44T = 74 Rec. ITU-R M.819-2 RECOMMENDATION ITU-R M.819-2 INTERNATIONAL MOBILE TELECOMMUNICATIONS-2000 (IMT-2000) FOR DEVELOPING COUNTRIES (Question ITU-R 77/8) (1992-1994-1997) Summary This Recommendation describes the objectives to be met by IMT-
2、2000 to meet the needs of developing countries. The potential of mobile radio technologies, including IMT-2000, to help developing countries “bridge the gap” between their communication capabilities and those in developed countries is given in Annex 1. The IT Radiocommunication Assembly, considering
3、 a) telecommunications infrastructure; that in developing countries there is an urgent need to provide an economical, reliable and high quality b) c) of great benefit to developing countries; d) and number of users; that there is a need to provide mobile and fixed services in urban, rural and remote
4、 regions; that the relative simplicity of installation and maintenance of radio based telecommunications systems could be that there is a need for a flexible, modular system which can be readily expanded in terms of types of service e) sources are limited or unavailable: that there is a need for rug
5、ged equipment to operate reliably in harsh environments and where electric power f) must be reliable and comparable to those of the fixed network; g) mobile or fixed radio links; that, giving due regard to propagation conditions and other factors, the telecommunications services provided that users
6、(fixed, mobile) should be able to communicate with any other user whether access is via satellite, h) j) early stage in the development of IMT-2000 so that those needs can ultimately be met; Recommendation ITU-R M.687 and the relevant ITU-T Recommendations and ongoing studies; that it is important t
7、o examine the application of IMT-2000 with regard to developing countries needs at an k) switching and that this is likely to continue for a number of years, that telecommunication networks in some developing countries are mainly analogue, often use mechanical recommends that the relevant aspect of
8、IMT-2000, as defined in Recommendation IT-R M.687, be specified as far as practicable in a manner which allows it to be used to meet the needs of developing countries with the following objectives: 1 that IMT-2000 provide, in both urban and rural areas, economical services of high quality and integr
9、ity comparable to those of the fixed network. The systems must be capable of serving a wide range of user densities and coverage areas as well as remote regions; 2 that IMT-2000 be capable of providing services to both mobile and fixed users, including voice, point-to-multipoint, short messages, pag
10、ing, facsimile, text and data services; COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling ServicesSTDmITU-R RECMN M.819-2-ENGL 1997 m 4855212 0532177 38b m Rec. ITU-R M.819-2 75 3 (easily expandable) permitting flexible growth in terms of number
11、 of users, coverage areas and types of services; that to allow a system to be introduced with minimum initiai investment, IMT-2000 design should be modular 4 conditions where there are only a few users and where severe propagation conditions are encountered; that MT-2000 take account of the need to
12、match, efficiently and economically, spectnim usage to local 5 that IMT-2OOO hardware be capable of being optimized for local conditions e.g. to take account of heavy usage, operation in a variety of environments including extremes of heat and cold, high humidity, dust, corrosive atmospheres and oth
13、er environmental hazards, recognizing the need to achieve long equipment lifetimes, high MTBF and low maintenance that permit a reasonable justification of the required investment; 6 that appropriate means such as repeaters, etc., be incorporated to provide service economically to more distant users
14、, beyond line-of-sight of a base station. Similarly, it should be possible to serve remote regions by suitable means such as satellites, etc.; 7 that iMT-2000 provide an open architecture which will permit the easy introduction of new technology and different applications and will allow choice of eq
15、uipment based on performance need including the ability to provide voice channels employing higher encoding rates such as 64 kbit/s and 32 kbit/s; 8 international; that IMT-2000 provide user friendly (simple and easy) operation to initiate and receive calls, both national and 9 from a range of power
16、 sources; that equipment is designed to take into account the need for low power consumption and the need to operate 10 that IMT-2000 have the capability of providing an effective alternative to wired local loops in urban areas; 11 at a single point. that regional iMT-2000 be connected to existing a
17、nalogue/digital networks at suitable points and in some cases NOTE 1 - Information on mobile radiocommunication technology for developing countnes is given in Annex 1, ANNEX 1 Mobile radiocommunication technology for developing countries 1 Introduction and summary Recognizing the disparity that exis
18、ts in the telecommunication infrastructures in the world, this Annex points out the potential of cellular technology (and its evolution into IMT-2000 technologies) to help developing countries bridge the gap. Report ITU-R M.1153 and Recommendation ITU-R M.687 include some of the relevant aspects wit
19、h the idea that future systems - IMT-2000 - can serve the needs of developing as well as developed countries. IMT-2000 have been conceived primarily for mobile telecommunications which of course is of interest to developing as well as developed countries. The objective of this Annex is to emphasize
20、the needs and interests of developing countries by promoting the application of IMT-2000 for fixed services. It should furthermore be stressed that the use of IMT-2000 for such applications is also attractive to developed countries. COPYRIGHT International Telecommunications Union/ITU Radiocommunica
21、tionsLicensed by Information Handling ServicesSTD-ITU-R RECMN M=817-2-ENGL 1997 m g855212 0532178 212 m 76 Rec. ITU-R M.819-2 Key objectives for IMT-2000 that could benefit developing countries are: - Fixed service - - Standardization as a means of reducing costs Flexibility to start from a small, s
22、imple, configuration and grow as needed - Accommodation of special needs - - Commonality with remote areas of developed countries Large cells, repeaters, use of satellites Section reference 0 4.1 $ 4.2 2 The telecommunications gap* The role of telecommunications in the development process as a means
23、 to increase productivity and efficiency, as a substitute for, or complement to, transportation and to save energy, etc., is today more important than ever but the gap between developed and developing countries is wider than ever. This has been clearly indicated by the Independent Commission for Wor
24、ldwide Telecommunications Development set up by the IT in 1983. In addition the limited financial resources available to developing countries lead to the allotment to telecommunications of resources insufficient to close the “telecommunications gap” either as much or as quickly as required. 3 The po
25、tential and benefits of IMT-2000 technologies Present cellular technology and its evolution into the IMT-2000 technologies by the end of the century, offer great potential to help developing countries bridge the gap in a more effective way. IMT-2000 is a radio-based approach and so offers all the ad
26、vantages of wireless network access. Figure 1 provides an illustration of some of the possible uses of IMT-2000 radio interfaces for wireless network access in the fixed service. The actual definition of IMT-2000 radio interfaces is dealt with in the appropriate IMT-2000 Recommendation. With IMT-200
27、0 a scheme can be established which enables a simple start-up with the provision of basic telephone services that can evolve, as required, to higher user information rates in the local loop and to a full mobility service. This is particularly appropriate when development capital is scarce as it may
28、be the only way to keep modernization affordable. The global acceptance of IMT-2000 should enable mass production for the global market and multiple applications. This, together with global competition should lead to low cost products. Some of the aspects that make IMT-2000 an attractive alternative
29、 to traditional wireline systems for telecommunications services are: - - growth capacity and flexibility; - - capability for rapid provision of voice and non-voice services in new areas; cost reductions resulting from technology improvements, modular design and mass usage of IMT-2000; capability fo
30、r covering wide geographical areas. * Notepom the Director, Radiocommunication Bureau - The statements made in this section are based on the following ITU publications: - “Contributing Telecom to the earningslsavings of foreign exchange in developing countries”, April 1988. - “Benefits of Telecom to
31、 the transportation sector of developing countries”, March 1988. - “Telecom and the National Economy”, May 1988. - “The Missing Link”. Report of Independent Commission for Worldwide Telecommunications Development, ITU, 1984. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLic
32、ensed by Information Handling ServicesSTD-ITU-R RECMN M-837-2-ENGL 3997 4855232 0532379 359 U Rec. ITU-R M.819-2 77 FIGURE 1 Some possible uses of IMT-2000 radio interfaces for network wireless access in the fixed service al Urbanscenario b) Suburbadrural scenario c) Remote areas scenario Office blo
33、ck CB Houseismall business Localexchange Radio interface Radio interface Radio interface Satellite al3 Terminai (telephone/data) 0 Coverage area 3 Small rural exchange/PBX pJ Repeater Feeder link -.-.-.- 08 19-0 1 COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by In
34、formation Handling ServicesSTD-ITU-R RECMN M-819-2-ENGL 1997 m 4855212 0532180 970 m 78 Rec. ITU-R M.819-2 Additional attractive aspects of a wireless approach include: - economics: wireless access provides point-to-multipoint radio links (base stations to user terminals) which can offer an economic
35、al alternative and significant simplification when compared to wireline access (local subscriber loops); maintenance: wireless access has the potential to alleviate some of the maintenance problems associated with wires such as accidental cuts, weather conditions, theft, etc.; - - investment and amo
36、rtization: wireline access networks are usually installed with capacity to meet future demands over a period of 10-15 years due to the sheer inconvenience and the economics of piecemeal deployment. “Buried capital” cannot earn revenue until much later. Wireless access systems can be deployed and re-
37、provisioned at short intervals. Capital investment is only required on a step-by-step basis, and this can provide additional safeguards against uncertainties in the forecasting of service requirements. A number of developing countries are currently planning to use cellular technology to solve some o
38、f their problems such as lack of service in rural and remote areas or lack of capacity to satisfy demand promptly in urban areas. 4 Objectives and issues Objectives have been set in Recommendation IT-R M.687 for IMT-2000 which are related to quality, mobility, flexibility, efficiency, connectivity,
39、adaptability, security, identification, suggestions for charging (billing), etc. The relative importance that each objective has to a developing country depends, on the one hand, on its stage of development and national goals, and on the other, whether effective cost-savings will result from not imp
40、lementing a specific feature in a particular situation. Nevertheless, it is important to point out the features and characteristics that stand out as very important to developing countries and that deserve special notice. They are fixed service requirements, standardization and flexibility. 4.1 Fixe
41、d service A very important objective defined for IMT-2000, from the point of view of developing countries, is that they can be used for the provision of service to fixed users either in rural or urban areas. Two main factors that cause a radio solution to be considered are: - high installation and m
42、aintenance costs associated with rural wireline networks due to long distances, difficult terrain and climatic conditions; - the high and often difficult-to-foresee growth that limits the ability to plan the outside plant network properly in urban areas. It is therefore of great importance for situa
43、tions where wireline facilities are not available, that IMT-2000 can be used as a temporary or permanent substitute for the wireline network. This objective requires IMT-2000 to meet certain conditions and characteristics: - it should, to the maximum extent possible, support equipment and component
44、design that can withstand rural conditions typically fouqd in developing countries, such as rough roads, dusty environment, extreme temperatures and high humidity, while at the same time providing long equipment life-time with minimum maintenance. It is, however, not intended that the basic IMT-2000
45、 equipment satisfies all the needs of the fixed service, while at the same time catering to the IMT-2000. Rather, the basic IMT-2000 structure and technology should permit fixed service requirements to be met; - it should take into account the effect on reliability and availability of special propag
46、ation conditions such as, in mountainous terrains, areas of high rain precipitation or dense forests; - it should allow for large cell sizes. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services STD-ITU-R RECMN M.819-2-ENGL 1997 4855212 05
47、32181 807 Rec. ITU-R M.819-2 79 Since the service to be provided is an extension of the national and international network, it should be possible to integrate it into the network without any, or with only very minor, limitations. The objective that IMT-2000 should provide a service with quality, int
48、egrity and security comparable to that provided in the fixed network is therefore very important to developing countries. In some developing countries, the service provided by an IMT-2000 may well be the only telecommunications pathway, and is likely to act as a lifeline, particularly for the provis
49、ion of storm and flood warnings or similar public service activities. Service can also be provided to tourist areas, sports events and for other special needs. The possibility of accessing both terresuial and satellite systems, through the use of the same band or adjacent bands, could be important to countries with large, thinly populated rural areas. One possible application would be to link rural and remote base stations. The use of an open architecture is of considerable importance for IMT-2000 usage for fixed services as this would permit the administration in developing coun
