1、 Rep. ITU-R F.2058 1 REPORT ITU-R F.2058 Design techniques applicable to broadband fixed wireless access systems conveying Internet protocol packets or asynchronous transfer mode cells (2006) TABLE OF CONTENTS Page 1 Introduction 2 2 Types of FWA systems conveying IP packets or ATM cells in terms of
2、 radio channel utilization 2 3 Scope 3 4 References 3 5 Abbreviations . 5 6 Technical characteristics addressed 8 6.1 Modulation and multiple access method 8 6.2 CoS and QoS. 9 6.3 Transfer delay characteristics . 9 6.4 VoIP technique . 10 6.5 Efficient spectrum utilization technique. 10 6.6 Error c
3、orrection techniques in an ATM-based FWA system . 10 ANNEX 1 Mechanism to ensure QoS or CoS in the broadband FWA systems 11 ANNEX 2 Example calculations of average access protocol delay and delay variation of CSMA/CA-based FWA 29 ANNEX 3 Example calculations of additional waiting time in multiple Vo
4、IP flow situations for TDMA-based FWA 34 ANNEX 4 Example calculations of QoS class 0 network delay 39 ANNEX 5 Technical characteristics of broadband FWA systems to support VoIP technique. 43 ANNEX 6 Techniques to improve spectrum utilization efficiency 50 ANNEX 7 Error correction techniques in an AT
5、M-based FWA system 53 2 Rep. ITU-R F.2058 1 Introduction There is an urgent need for broadband services in the telecommunication market. Users needs are not uniform but diversified in terms of bit rate and service quality. Internet protocol (IP) and asynchronous transfer mode (ATM) are becoming basi
6、c signal transfer methods in recent wired networks in order to cope with such multimedia service demands. This trend also affects the fixed wireless systems used in the access networks. It is generally understood that IP-based and ATM-based fixed wireless access (FWA) systems should desirably have s
7、imilar quality of service (QoS) or class of service (CoS) control capability to that of wired systems. Both QoS and CoS are defined as classified categories prescribed by transmission performance parameters. QoS is used for classes of the transmission performance which satisfy users quality requirem
8、ents. On the other hand, CoS is generally used for the classes of similar performance which are presented to users as a guideline by a network administrator. Furthermore, FWA systems are required to achieve objectives of IP or ATM performance parameters in the wired network adopted in ITU-T Recommen
9、dations I.356 and Y.1541. For this purpose, PHY layer parameters of FWA systems must be designed to meet these objectives of IP or ATM performance parameters. Relations between PHY layer parameters and IP layer performance parameters, such as IPTD are given in ITU-T Recommendations Y.1540 and Y.1541
10、. Relations between PHY layer parameters and ATM layer performance parameters, such as the cell loss ratio (CLR) or cell error ratio (CER) are given in ITU-T Recommendation I.356. ATM-based FWA systems should also satisfy the (SESR) objective specified in Recommendation ITU-R F.1668 (performance and
11、 availability requirements and objectives for FWA systems connected to PSTN are described in Recommendation ITU-R F.1400). Both IP and ATM are packet or cell-based technologies operating at a high clock frequency where IP packet or ATM cell transmission may affect the system design and utilization e
12、fficiency of the radio-frequency spectrum. Such requirements will lead to design approaches which differ from existing voice-based FWA. Also necessary technologies for IP packets or ATM cells in FWA applications are, in many respects, common to those used in radio local area networks (RLANs). The pu
13、rpose of this Report is to provide example design techniques and methods addressing various aspects of FWA systems carrying IP or ATM data. 2 Types of FWA systems conveying IP packets or ATM cells in terms of radio channel utilization Types of FWA systems conveying IP packets or ATM cells in terms o
14、f radio channel utilization can be categorized as follows. The first type is to allocate an exclusive radio channel to each subscriber permanently or during a call retains. The typical system is point-to-point (P-P) or point-to-multipoint (P-MP) broadband wireless access systems generally using freq
15、uency bands above 20 GHz. This type of system is usually used for the leased line access services. The second type is to allocate a radio resource when a call attempt occurs. The typical system is an FWA system providing PSTN services for mass users. Some of the systems use the technologies of mobil
16、e wireless access systems in order to reduce the cost of equipment. The third type is to allocate a radio channel only when traffic such as IP packets or ATM cells occurs. This type achieves more efficient frequency usage compared with the first types especially for P-MP topology, provided that over
17、head bits are not too numerous. MP-MP topology is also suitable in this type of FWA. Rep. ITU-R F.2058 3 The typical systems for the second type include those based on RLANs. FWA systems based on RLAN technologies may also have an advantage of reduce equipment costs. A feature of the third type may
18、be explained as follows in case of ATM cell transmission. There are two cases for FWA systems conveying ATM cells: a) FWA transmits ATM cells transparently without identifying any information contained in a cell; b) FWA identifies information contained in the header portion of an ATM cell and thus c
19、ontrols the treatment of each cell within the radio section. In case a), the system design method of FWA should basically be identical to systems intended for SDH signal transmission. This corresponds to the first type of FWA systems described above. On the other hand, in case b), there can be a dif
20、ferent approach in transmitting ATM cells over the radio section in order to efficiently utilize radio-frequency spectrum. Several RLANs, used mostly for nomadic wireless access (NWA) purposes, or other types of wireless access systems using IP packet or ATM cell over the radio are realized as comme
21、rcial products or examined in standardization bodies of forums. Standards for wireless access systems, both fixed and nomadic, are given in Recommendation ITU-R F.757 and Recommendation ITU-R M.1450. 3 Scope This Report provides various design techniques applicable to FWA systems based on RLAN or NW
22、A system technologies, which provide IP packets or ATM cell transport with a rate of more than several Mbit/s targeted for ubiquitous penetration. The design solutions presented in the Annexes to this Report are suggested as one means towards satisfying the particular MAC layer standards set forth i
23、n ITU-T Recommendations concerning IP and ATM transmission. It should also be noted that the material presented in Annex 6 is not applicable to IP traffic since the idle cell notion is very specific to ATM. The FWA discussed in this Report is focused primarily on P-MP applications wherein the capaci
24、ty of one radio carrier provided by a base station will be shared by several or more terminal stations, although some of the techniques described in the Annexes to this Report are applicable also to P-P and MP-MP applications. 4 References ITU-R Recommendations Recommendation ITU-R F.757 Basic syste
25、m requirements and performance objectives for fixed wireless access using mobile-derived technologies offering telephony and data communication services. Recommendation ITU-R M.1450 Characteristics of broadband radio local area networks. Recommendation ITU-R F.1668 Error performance objectives for r
26、eal digital fixed wireless links used in 27 500 km hypothetical reference paths and connections. Recommendation ITU-R F.1704 Characteristics of multipoint-to-multipoint fixed wireless systems with mesh network topology operating in frequency bands above about 17 GHz, 2004. 4 Rep. ITU-R F.2058 Recomm
27、endation ITU-R F.1763 Radio interface standards for broadband wireless access systems in the fixed service operating below 66 GHz. ITU-T Recommendations ITU-T Recommendation Y.1540 Internet protocol communication service IP packet transfer and availability performance parameters. ITU-T Recommendatio
28、n Y.1541 Network performance objectives for IP-based services. ITU-T Recommendation P.800 Methods for subjective determination of transmission quality. ITU-T Recommendation P.862 Mapping function for transforming P.862 raw result scores to MOS-LQO. ITU-T Recommendation I.356 B-ISDN ATM layer cell tr
29、ansfer performance. ITU-T Recommendation G.107 The E-model, a computational model for use in transmission planning. ITU-T Recommendation G.113 Transmission impairments due to speech processing. ITU-T Recommendation G.114 One-way transmission time. ITU-T Recommendation G.711 Pulse code modulation (PC
30、M) of voice frequencies. ITU-T Recommendation G.723.1 Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s. ITU-T Recommendation G.729 Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP). Others ETSI TS 101 761
31、-1 v1.3.1 Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Data Link Control (DLC) Layer; Part 1: Basic Data Transport Functions. ETSI TS 101 856 v1.1.1 Broadband Radio Access Networks (BRAN); Functional Requirements for Fixed Wireless Access systems bellow 11 GHz: HIPERMAN. ETSI TS 101 999
32、v1.1.1 Broadband Radio Access Networks (BRAN); HIPERACCESS; PHY protocol specification. IEEE standard for local and metropolitan area networks Specific requirements Part 11: Wireless LAN medium access control (MAC) and physical layer (PHY) specifications Amendment 1: High-speed physical layer in the
33、 5 GHz band. IEEE standard for local and metropolitan area network Specific requirements Part 11: Wireless LAN medium access control (MAC) and physical layer (PHY) specifications. IEEE standard for local and metropolitan area networks Specific requirements Part 11: Wireless LAN medium access control
34、 (MAC) and physical layer (PHY) specifications Amendment 4: Further higher-speed physical layer extension in the 2.4 GHz band. IEEE standard for local and metropolitan area networks Part 16: Air interface for fixed broadband wireless access systems. ARIB STD-T70 v1.0 Low power data communication sys
35、tems/broadband mobile access communication system (HiSWANa). Rep. ITU-R F.2058 5 Design and considerations for traffic class expediting and dynamic multicast filtering, IEEE Std 802.1D Annex H, IEEE, 1998. http:/www.ietf.org/html.charters/mpls-charters.html http:/www.ietf.org/html.charters/diffserv-
36、charter.html http:/www.ietf.org/html.charters/rsvp-charter.html Wireless medium access control (MAC) and physical layer (PHY) specifications: Medium access control (MAC) enhancements for quality of service (QoS), IEEE std 802.11e/D1, March 2001. INOUE, Y., SAITOH, S., IIZUKA, M. and MORIKURA, M. Dec
37、ember 2000 A fair data transfer method by using a CoS control mechanism for fixed wireless access systems, The 2000 International Conference on broadband wireless access systems, p. 19-25. KAGAMI, O., OTHA, A. and HOJO, H. November 2002 Development of compact wireless access equipment for an AWA sys
38、tem based on HiSWANa standard, NTT Rev., p. 49-53, Vol. 14, No. 6. TTC Standard JJ-201.01 2003 A method for speech quality assessment of IP telephony. ETSI TR 101 329-7 End-to-end quality of service in TIPHON systems; Design guide for elements of TIPHON connection from an end-to-end speech transmiss
39、ion point of view. MASUDA, M. and ORI, K. November 2001 Network performance metrics in estimating the speech quality of VoIP, IEICE APSITT2001, p. 333-337. ICHIKAWA, T., et. al., Approximation of characteristics of CSMA/CA based on IEEE 802.11 standard, B-5-186, Proceedings of the 2003 IEICE Society
40、 Conference. 5 Abbreviations This Report uses the following abbreviations: ACK Acknowledge AIFS Arbitration inter-frame space ARQ Automatic repeat request ATM Asynchronous transfer mode BC Broadcast channel BCC Block convolutional code BE Best effort BEB Binary exponential backoff BER Bit error rati
41、o BS Base station BWA Broadband wireless access CBR Constant bit rate CBQ Class based queuing CDV Cell delay variation CER Cell error ratio CLR Cell loss ratio 6 Rep. ITU-R F.2058 CMR Cell misinsertion ratio CoS Class of service CSMA/CA Carrier sensing multiple access with collision avoidance CTD Ce
42、ll transfer delay CW Contention window CWmin Contention window minimum DAMA Demand assign multiple access DiffServ Differentiated service DIFS Distributed coordination function inter frame space DL Data link DS Differentiated service DSA Dynamic slot assignment EDCF Enhanced distributed coordination
43、 function FCS Frame check sequence FDD Frequency division duplex FSDD Frequency switched division duplexing FEC Forward error correction FIFO First in first out FTP File transfer protocol FWA Fixed wireless access GBN Go-Back-N method GBR Guaranteed bit rate HCF Hybrid coordination function HEC Head
44、er error control HIPERACCESS High performance radio ACCESS network HIPERMAN High performance radio metropolitan area network HRP Hypothetical reference path IEEE Institute of Electrical and Electronics Engineering IETF Internet engineering task force IP Internet protocol IPDV IP packet delay variati
45、on IPER IP packet error ratio IPLR IP packet loss ratio IPTD IP packet transfer delay ITU-R International Telecommunication Union Radiocommunication Sector Rep. ITU-R F.2058 7 ITU-T International Telecommunication Union Telecommunication Standardization Sector LCO Loss cell outcome LDP Label distrib
46、ution protocol LSR Label switching router MAC Media access control layer MC Multicast MP Measurement point MP-MP Multipoint-to-multipoint MPLS Multi-protocol label switching MOS Mean opinion score NAK Negative Acknowledge nrtPS Non-real-time polling service OFDM Orthogonal frequency division multipl
47、exing PCR Peak cell rate PDU Protocol data units PHSI Payload header suppression identifier PLC Packet loss concealment PS Physical slot PplPacket loss probability PplNPacket loss probability in network PplBPacket loss probability in jitter absorption buffer PHB Per-hop behaviour PHY Physical layer
48、P-P Point-to-point P-MP Point-to-multipoint PESQ Perceptual evaluation of speech quality PSTN Public switched telephone network QoS Quality of service R Rating factor RSVP Resource reservation protocol rtPS Real-time polling service RTS/CTS Request to send/clear to send SLA Service level agreement S
49、C Single carrier SDH Synchronous digital hierarchy 8 Rep. ITU-R F.2058 SDMA Space division multiple access SIFS Short inter frame space SR Selective repeat TC Traffic category TCI Tag control information TDD Time division duplex TDM Time division multiplex TDMA Time division multiple access ToS Type of service TTC Telecommunication Technology Committee UBR Unspecified bit rate UGS Unsolicited grant service UNI User network interface VoIP Voice over Internet protocol WAN Wide area network WFQ Weighted fair queuing WRR Weighted round robin 6
