1、 Rec. ITU-R F.1490-1 1 RECOMMENDATION ITU-R F.1490-1*Generic requirements for fixed wireless access systems (Questions ITU-R 125/9 and ITU-R 215/8) (2000-2007) Introduction Today many technologies have been considered for fixed wireless access (FWA) applications, in particular, technologies from cel
2、lular platforms and specialized systems. The application of FWA will benefit both developing and developed countries. Many countries are planning to deploy FWA systems for the primary delivery of telecommunication services. In this Recommendation, two different FWA platforms are considered one based
3、 on a public mobile network and the other based on a PSTN network. Scope This Recommendation summarizes generic requirements needed to ensure that radio technologies can be applied to FWA applications and intended for the use by administrations and operators considering deployment of FWA systems. Ab
4、breviations AMSC Anchor mobile switching centre BS Base station DTMF Dual tone multi-frequency FMC Fixed mobile convergence FS Fixed station LAN Local area network MAN Metropolitan area networks MPEG Moving Picture Expert Group MSC Mobile services switching centre PABX Private automatic branch excha
5、nge PCS Personal communications systems PSTN Public switched telephone networks P-MP Point-to-multipoint P-P Point-to-point RNC Radio network controller SDH Synchronous digital hierarchy *This Recommendation should be brought to the attention of Radiocommunication Study Group 8 (Working Party 8A). 2
6、 Rec. ITU-R F.1490-1 SN Service node TDMA Time division multiplexing access TE Terminal equipment References ITU-R Recommendations Recommendation ITU-R F.757: Basic system requirements and performance objectives for fixed wireless access using mobile-derived technologies offering basic telephony ser
7、vices. Recommendation ITU-R M.819: International Mobile Telecommunications-2000 (IMT-2000) for developing countries. Recommendation ITU-R F.1400: Performance and availability requirements and objectives for fixed wireless access to public switched telephone network. Recommendation ITU-R F.1399: Voca
8、bulary of terms for wireless access. ITU-T Recommendations ITU-T Recommendation G.173: Transmission planning aspects of the speech service in digital public land mobile networks. ITU-T Recommendation G.174: Transmission performance objectives for terrestrial digital wireless systems using portable t
9、erminals to access the PSTN. ITU-T Recommendation G.175: Transmission planning for private/public network interconnection of voice traffic. ITU-T Recommendation G.711: Pulse code modulation (PCM) of voice frequencies. ITU-T Recommendation G.726: 40, 32, 24, 16 kbit/s adaptive differential pulse code
10、 modulation (ADPCM). ITU-T Recommendation G.728: Coding of speech at 16 kbit/s using low delay-code excited linear prediction. ITU-T Recommendation I.430: Basic user-network interface Layer 1 specification. ITU-T Recommendation G.965: V-interfaces at the digital local exchange (LE) V5.2 interface (b
11、ased on 2 048 kbit/s) for the support of access network (AN). Recommendations The ITU Radiocommunication Assembly recommends that the following requirements for FWA systems should be met. 1 Service requirements Identified telephony-based requirements for FWA: FWA subscribers can have wireline (i.e.
12、PSTN-like) numbers. FWA subscribers can have local area dialling capability (dial tone, etc.) similar to that of fixed PSTN subscribers. FWA subscribers tariffing structure can be selected by the operator. Wireline-like (PSTN-like) tariffing scheme can be used if required. Rec. ITU-R F.1490-1 3 In o
13、rder to achieve faster call set-up times, transparent mode is needed as an alternative option in FWA based on mobile network solution (see 4). Fixed station (FS) terminal remote management (see 5). Payphone support (see 6). Group 3 facsimile support (see 6). Charging capabilities (see 6). Performanc
14、e monitoring (see 5). Power and lightning protection. Optional display for FWA terminal (in order to get use of supplementary services). Performance and availability objectives and requirements must meet those established in Recommendation ITU-R F.1400. 1.1 Applications of FWA Likely applications or
15、 services for data rates higher than 64 kbit/s (based on report of survey responses for FWA), for those systems that are able to support these data rates: Internet access. Multimedia and interactive applications such as telemedicine and tele-education. Intranet. Videoconference. Videophone for banki
16、ng, tourist agencies, etc. ISDN. File transfer. Leased lines. Banking. Tourist agencies. Remote host access. MPEG video. Ethernet. Wireless local area network (LAN). Broadband service delivery to homes and business. Wireless broadband for trunk configurations for mobile telecommunications systems (e
17、.g. PCS and GSM) in backhaul links, metropolitan area networks (MANs), and synchronous digital hierarchy (SDH) rings. Private automatic branch exchange (PABX) (virtual, e.g. wireless Centrex). 1.2 Minimum bit rate for data services Some requirements have indicated a minimum bit rate of 9.6 kbit/s. H
18、owever, other requirements for data services will be equivalent to those for IMT-2000 in the mobile environment (144 kbit/s and above). 1.3 ISDN compatibility Required in most cases (see Annexes 1 and 2 for more information). 4 Rec. ITU-R F.1490-1 2 FWA system capabilities FWA applications could hav
19、e the following capabilities: a) to rapidly deploy a fixed wireless technology to provide voice services in large segments of the market that do not have any telecommunication service; b) to meet a pent-up demand for high-end, broadband services, both in the business and residential markets; c) as a
20、 rural type, to achieve one of major goals in a country for the improvement of telephone density in rural areas; d) to provide the availability of desired added features besides local telephone service features for the customers; e) to provide the fixed wireless capabilities for service providers, f
21、or example; in order to deploy a wireless competitive local exchange carrier in competition with the incumbent local exchange carrier; f) to provide a second or third telephone for customers due to increased uses of fax machines, modems, and Internet access; g) to provide wireless Centrex and privat
22、e branch exchange for business customers having a traffic requirement at the primary rate and above and searching for low cost alternatives; h) as an urban type, to provide as multimedia-compatible wireless access network in place of wired networks in the development of new commercial, industrial an
23、d residential areas on spot basis in urban area. 3 Types of FWA systems FWA systems may be broadly categorized as three types, each addressing a different market: Wireline equivalent/replacement system applies where wireline services and equipment must be supported to the full extent: either due to
24、the type of equipment to be supported or due to the expectations of the user. Capable of delivering toll quality speech and performance equivalent to wired access service. Fixed mobile convergence (FMC) system applies where the prime requirement is reduced cost and ease of installation, and the requ
25、irements for equipment support or customer service expectation are different than full wireline support. Broadband system applies where greater traffic throughput is required, such as business and interactive applications. Rec. ITU-R F.1490-1 5 Because of these different target markets, FWA systems
26、will have different service requirements. These three markets can be distinguished by some of their basic services as follows: 3.1 Wireline equivalent/replacement system a) Minimum capability to support fax and modem service with support for higher data rates desired. b) Optional support for ISDN. c
27、) No mobility between the network and the subscriber premises network interface device. d) End user terminals may be mobile (e.g. cordless phone). 3.2 FMC system a) Capable of supporting wireline like service. b) Capable of delivering performance equivalent to cellular voice quality. c) Capable of d
28、elivering fallback rate support for modem and fax service. d) Optional limited mobility support. e) Extension of existing cellular standards which may provide a higher level of wireline transparency. 3.3 Broadband system a) Capable of supporting greater speeds than wireline equivalent/replacement sy
29、stem. b) Fixed network and users supported. 4 FWA system configurations Due to the different needs in different environments two separate FWA network level solutions are needed. Those two systems are named here as FWA supported from a mobile network and FWA supported from a PSTN access network. It i
30、s believed that both network level solutions are needed in order to satisfy the needs of different operators and end-users. 4.1 FWA supported from a mobile network The FWA supported from a mobile network could be based on the standard mobile network and mobile services switching centre (MSC). This s
31、olution basically comprises of the following network elements: MSC, radio network controller (RNC), base station (BS), fixed cellular subscriber units, known as FWA terminals and terminal equipment (TE). In this application handover between cells is not supported. From the system point of view, inte
32、rfaces to the end-user terminals (e.g. telephone, facsimile machine, personal computer, etc.) and network management system are included. In this system solution, the MSC operates as a service node (SN). Figure 1 shows a reference model for this solution. As can be seen from Fig. 1, the FWA system i
33、ncludes a possibility to provide services to both fixed and mobile users. This is an important requirement as already pointed out in Recommendation ITU-R M.819. 6 Rec. ITU-R F.1490-1 Rec. ITU-R F.1490-1 7 Open standard interfaces are used in both network interface and the customer interfaces. This e
34、nables, on one hand, switch vendors easily to build independent switching and radio networks and on the other hand, end-users to use standard equipment like telephone sets, fax machines, personal computers etc. This solution meets, especially, the needs of mobile operators seeking for FWA subscriber
35、s and also to greenfield operators who start their operations with FWA and later seek to enhance their service offerings to mobile users. The following additions may need to be made to an ordinary mobile system in order to create FWA supported from a mobile network. These additions are: FWA subscrib
36、ers should have wireline (i.e. PSTN-like) numbers. FWA subscribers should have local area dialling capability (dial tone, etc.) similar to that of a fixed PSTN subscriber. FWA subscribers typically have some form of mobility restriction. The operator can define the mobility (service area) for each s
37、ubscriber individually. These subscribers can then only get telephone service inside his/her FWA service area. FWA subscribers tariffing structure can be selected by the operator. Wireline-like (PSTN-like) tariffing scheme can be used if required. In order to achieve faster call set-up times, transp
38、arent mode may be needed as an alternative option in FWA based on mobile system solution. FS terminal remote management. 4.2 FWA supported from a PSTN access network The FWA supported from a PSTN access network comprises of the FWA access node, the standard BS, FWA stations and standard TE. From the
39、 system point of view, the interfaces towards the SN, TE (e.g. telephone, facsimile machine, personal computer, etc.) and network management system are offered. Figure 2 shows a reference model for FWA supported from a PSTN access network solution. As can be seen from Fig. 2, the FWA system includes
40、 a possibility to provide services to both fixed and mobile users. This is an important requirement as already pointed out in Recommendation ITU-R M.819. Open and standard interfaces are used in both network interface and the customer interfaces. This enables, on one hand, switch vendors easily to b
41、uild independent access networks and on the other hand, end-users to use standard equipment like telephone sets, fax machines, personal computers, etc. This solution is offered to those operators who need to connect the FWA system directly to the service node (i.e. local exchange). The specific sign
42、alling schemes vary from country to country and are standardized by respective PTTs or government regulatory bodies. Thus the signalling in FWA supported from a PSTN access network has to be adapted according to the national fixed public network protocol mapping specifications. 8 Rec. ITU-R F.1490-1
43、 Rec. ITU-R F.1490-1 9 5 Mobility of FWA terminals In order to fulfil different operators needs, a possibility to use different FWA terminals (fixed and mobile) may offer the option of limited mobility. In addition to this different degrees of mobility for terminals are needed. Each operator can cho
44、ose the best suitable terminal configuration (no mobility, restricted mobility, etc.) for operators FWA system. 5.1 FWA supported from a mobile network Optimized for residential use (for example one per household); operator should be able to allow limited portability according to operators license a
45、greement; operator should be able to restrict portability with the accuracy which is available in the mobile system. 5.2 FWA supported from a PSTN access network Optimized for residential use inside access network area; operator should be able to allow limited portability according to operators lice
46、nse agreement; operator should be able to restrict portability with the accuracy which is available in the mobile system. 6 FWA call set-up procedures In order to satisfy the needs of different customers (operators and end-users) there needs to be two different call set-up procedure modes for both F
47、WA systems: the transparent mode and the non-transparent mode. Transparent mode offers shorter call set-up delays and ensures the user that the speech path is already connected before dialling. Because dial tone comes from a service node (MSC or SN), it takes longer time to get dial tone. Non-transp
48、arent call set-up mode has longer call set-up times and a drawback that it is not ensured that the speech path is already connected before dialling. However, in non-transparent mode it is faster to get dial tone because it comes from the FWA terminal. 6.1 FWA supported from a mobile network 6.1.1 Tr
49、ansparent mode In the transparent mode the transmission path is established between the FS and MSC by off-hook ensuring the user that the speech path is already connected before dialling. Figure 3 shows basic principles for transparent mode in FWA supported from a mobile network. 10 Rec. ITU-R F.1490-1 Rec. ITU-R F.1490-1 11 6.1.2 Non-transparent mode Figure 4 shows basic principles for non-transparent mode in FWA supported from a mobile network. 6.1.3 Mixed mode A mixed mode can al
