1、 ITU-R RECMN*M 1167 95 4855232 052Y775 985 1 2 3 4 5 6 7 8 9 Rec . ITU-R M.1167 1 RECOMMENDATION ITU-R M.1167 FRAMEWORK FOR THE SATELLITE COMPONENT OF FUTURE PUBLIC LAND MOBILE TELECOMMUNICATION SYSTEMS (FPLMTS) (Question ITU-R 3918) (1995) CONTENTS introduction Scope 2.1 Purpose . Structure of the
2、Recommendation Related documents . Abbreviations . Distinct features of the satellite component of FPLMTS . Key features of the satellite component of FPLMTS . 6.1 6.2 Coverage and handover 6.3 Satellite system configuration . 6.4 Mobile location . Authorized use of location information 6.5 Security
3、 aspects Integrated satellite and terrestrial components . 7.1 Network integration 7.2 Service integration 7.3 Radio interface integration 7.4 Roaming between the terrestrial and satellite components . 6.4.1 Standardizationkommonality of interfaces associated with the satellite component of FPLMTS 8
4、.1 Radio interfaces 8.1.1 General considerations 8.1.2 Satellite-PES/MES/SP (Interface A) . 8.2 Network interfaces Services supported by the satellite component of FFLMTS 9.1 General FPLMTS considerations 9.2 Satellite component considerations . Page 2 2 2 2 3 3 3 3 4 5 5 5 5 5 5 6 6 6 6 8 8 9 10 10
5、 10 10 COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services ITU-R RECflN*fl. LLb7 95 4855232 0524776 813 2 Rec. ITU-R M.1167 1 Introduction Future Public Land Mobile Telecommunications Systems (FPLMTS) are third generation mobile systems w
6、hich are scheduled to start service around the year 2000 subject to market considerations. They will provide access, by means of one or more radio links, to a wide range of telecommunication services supported by the fixed telecommunication networks (e.g. PSTNDSDN), and to other services which are s
7、pecific to mobile users. A range of mobile terminal types is encompassed, linking to terrestrial or satellite based networks, and the terminals may be designed for mobile or fixed use. Key features of FPLMTS are: - - - high quality; - high degree of commonality of design worldwide; compatibility of
8、services within FPLMTS and with the fixed networks; use of a small pocket-terminal with worldwide roaming capability. FPLMTS are defined by a set of interdependent ITU Recommendations of which this one is a member. The integrated terrestrial and satellite components of FPLMTS are complementary in te
9、rms of service provision. Together they cover the wide range of user densities, service types, and available service sets which comprise FPLMTS. Each component has particular advantages and constraints. The terrestrial component provides, economically, high quality telecommunication services typical
10、ly to areas of high to very high user densities. The satellite component provides users with quality telecommunication services primarily on a virtually global coverage basis, and is most economic outside those areas covered by the terrestrial component. Additionally to providing this global coverag
11、e, the satellite component may, in more densely populated areas, precede and encourage later coverage by the terrestrial component. 2 Scope Recommendation ITU-R M.8 18 sets the overall requirements of the satellite component of FPLMTS. Recommen- dation ITU-R M.1035 describes the framework of the rad
12、io interfaces of FPLMTS taking particular account of the terrestrial component. This Recommendation together with Recommendation IT-R M. 1035 describes the technical and operational capabilities and features of the satellite component, particularly where they are distinct from those of the terrestri
13、al component. It forms the framework for further development of the satellite component of the integrated overall systems of FPLMTS. In particular, the Recommendation comments on the aspects of integration with the terrestrial component, operational considerations, network interfaces and radio inter
14、faces. 2.1 Purpose This Recommendation builds upon Recommendation ITU-R M.8 18 in particular, to provide input material firstly to the derived Recommendations on radio interface selection procedures for satellite system and subsequently to the key choices and specifications of FPLMTS satellite compo
15、nent, as well as the guidelines for satellite system design. 3 Structure of the Recommendation This framework Recommendation sets out a number of considerations in the form of outline discussions which are grouped together into sections on: distinct features of the satellite component (8 6); integra
16、ted satellite and terrestrial components (0 7); standardizationcommonality of interfaces associated with the satellite component (0 8); and services supported by the satellite component of FPLMTS (0 9). The considerations form a part of the overall Recommendation and the specific Recommendations, sh
17、own in bold and italics, follow the discussions within the relevant section. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling ServicesITU-R RECMNtM. 1167 95 W 4855232 0524777 758 Rec. ITU-R M.1167 4 Related documents Recommendations ITU-R M.818
18、, ITU-R M.819, ITU-R M.1035, ITU-R M.1036 and ITU-R M.1078 5 Abbreviations CDMA: code division multiple access DTMF: dual tone multi frequency e.i.r.p.: equivalent isotropic radiated power FDMA: frequency division multiple access FSS: fixed-satellite service GSO: geostationary orbit HEO: highly incl
19、ined elliptical orbit IN: intelligent network ISL: inter-satellite link LEO: low-Earth orbit LES: land earth station MEO: medium Earth orbit MES: MS: MSS: mobile-satellite service PES: PS: SP: satellite pager TDMA: time division multiple access WT: universal personal telecommunication mobile earth s
20、tation (See Note i) mobile station (See Note 1) personal earth station (See Note 1) personal station (See Note 1) 3 NOTE 1 - It should be noted that in this Recommendon the expressions (mobile) station and (mc-ile) terminal are equivalent. 6 Distinct features of the satellite component of FPLMTS 6.1
21、 Key features of the satellite component of FPLMTS The geographical coverage of any one satellite is likely to be much larger than that of any cluster of terrestrial base stations. Coverage is likely to be by means of a number of spot beams from any one satellite - each spot beam is likely to be lar
22、ger than any terrestrial cell. Coverage by satellite can be regional, multiregional or global. Potential orbit constellations will fall into a number of categories, such as GSO, LEO, WO, HEO; each with its own particular properties (e.g. propagation delay, Doppler shift etc.) and FPLMTS design impli
23、cations. Technical and/or economic considerations may constrain the distribution and the number LES (forming gateways to the fixed networks) which can be accommodated in a satellite system. The Radio Regulations provision No. 746A identifies frequencies on a worldwide basis for FPLMTS of which some
24、frequencies are additionally identified for the satellite part of the system. It should be noted that it may be desirable to dedicate the use of this band to the satellite component rather than share with the terrestrial component. The terrestrial and satellite components of FPLMTS should be optimiz
25、ed taking the existence of the other component into account. The LESS will connect to the satellites using feeder links which operate in frequency bands outside those identified for mobile satellite and FPLMTS operation. The feeder link frequencies may be used by other satellite systems and terrestr
26、ial systems, and appropriate sharing criteria need to be observed. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services ITU-R RECMN*M* 1167 95 W 4855212 0524778 694 W 4 Rec. ITU-R M.1167 - - ISLs if used, will operate outside the FPLMTS ba
27、nd. When using the satellite component in indoor locations, it may be necessary to enhance performance by suitable orientation and location of the antenna. - It is assumed that there will be more than one satellite system possibly utilizing different satellite constellations in operation and that th
28、ey will be in competition. However, even with only one satellite system in operation, multiple service providers can provide competition in service provision to users. 6.2 Coverage and handover For the terrestrial component of FPLMTS, geographical coverage is provided from base stations which commun
29、icate over relatively limited ranges giving service to users within that range; the coverage area thus formed is termed a cell. To achieve continuity of coverage a number of contiguous cells are provided and, for users in motion, the system automatically transfers calls in progress from one cell to
30、another. This transfer involves functionality in both the mobile and in the base station together with its infrastructure. The transfer process is termed handover. In the satellite component, continuity of coverage is provided by the contiguous footprints of (spot) beams from one or more satellites
31、in a constellation. For non-geostationary satellites, these footprints will be in motion, and continuity of calls in progress, whether for mobile or stationary users, is achieved by handover between beams; again involving functionality in the mobile and in the satellite component. The importance of
32、handover depends upon the expected rate of handover occurrence. In a terrestrial network the rate of handover is mainly influenced by the rate at which a terminal crosses cell boundaries. However, handover due to user movement rarely happens in a satellite network since the size of a satellite cell
33、(beam) is usually very wide compared with the moving range of a terminal during a call. In a non-geostationary satellite constellation, the satellite beams, or cells, will be in motion, necessitating a handover mechanism between beams and between satellites in order to achieve call continuity. There
34、fore, handover requirements may depend upon the choice of satellite constellation as well as satellite cell sizes. Handover involving the satellite component of FPLMTS may be initiated based on prediction of the satellite movements, estimates of signal strength or quality of service parameters (bit
35、error ratio, delay, etc.), traffic conditions or user requests. This needs to be taken into account when designing the handover mechanisms and protocols for FPLMTS. It should be noted that such handovers in the satellite component due to satellite movement may be performed locally between the termin
36、al and the LES through appropriate air interface protocols, and using dedicated connections between LESS (or ISL connections between satellites), if required. Thus such handovers can be performed solely within the mobility management of the FPLMTS satellite networks. Six scenarios for handover invol
37、ving the satellite component have been identified as indicated below: a) on the same satellite, maintain the same feeder link, handover the service link; b) on the same satellite, handover the feeder link, maintain the same service link; c) on the same satellite, handover the feeder link, and handov
38、er the service link (combination of cases a) and b); d) e) handover from satellite to satellite, handover feeder link, handover service link (satellite handover-trunk handover); handover from the satellite component to terrestrial component (intercomponent handover); f) handover from the terrestrial
39、 component to the satellite component (intercomponent handover). For users of equipment which is able to access both the terrestrial and satellite components, there may be a perceived need to maintain continuity of calls in progress as the user crosses the boundary between the components (i.e. inter
40、component handover). Such handovers are expected to be relatively rare and the actual implementation will be for the network operators to determine. Nonetheless, technical capability of the process involved should be further considered. Spectrum availability or the economics of the satellite compone
41、nt may limit the number of FPLMTS satellite systems. If each FPLMTS satellite network provides virtually global coverage, there is no technical reason to provide handover between FPLMTS satellite networks. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Informatio
42、n Handling Services ITU-R RECflN*:M. 11b7 95 Y855212 0524779 520 m Rec. ITU-R M.1167 5 6.3 Satellite system configuration There may be more than one type of satellite system within FPLMTS each having a different internal configuration and different ownership. Each system will comprise of: a number o
43、f satellites with defined spacings and orbital parameters forming a constellation; radio (service) links from the satellites to the mobiles; radio (feeder) links from the satellite to theLESs (not in the FPLMTS frequency bands); a number of LESS; a satellite operators control, routing, and monitorin
44、g system; and interfaces to other networks (fixed and mobile). LES antennas and associated controllers may be grouped together, electrically or geographically. The LES, or LES grouping, interfaces to other networks through a gateway or switching entity, and the mobility management functions associat
45、ed with the satellite system may be either within the gateway or shared between the satellite infrasmcture and the interfacing network. In the first case the satellite component can be considered as a self contained mobile system capable of interfacing to any network regardless of the degree of inte
46、lligence in that network. In the second case the satellite component may couple with other intelligent networks (e.g. mobile or FPLMTS terrestrial component networks). Since the satellite component of FPLMTS wiU have a limited number of LESs, then operation of the network will inherently involve int
47、ernational (terrestrial) connections, and access to the satellite component may also involve an international connection. 6.4 Mobile location The satellite component can provide information on mobile terminal position at least equivalent to the cell or spot beam in which the terminal is operating. I
48、nformation regarding the position of a mobile may be regarded as confidential to the system operator, although derived information for use by associated bodies (e.g. for billing purposes) will be made available as necessary. 6.4.1 Authorized use of location information When there is a desire to use
49、this information by a body authorized by the relevant regulator (e.g. for aiding the emergency services) then it should be recognized that the location area: may be very large and not well defined; may extend over several countries; and may be time dependent and system traffic dependent. In addition i# should be noted that, in the satellite case, the physical landing point (ie. the location of the LES involved) for any call, including those to the emergency services, may be far removed from the location of the mobile, and quite possibly in a different country. 6.5 Security aspect
