1、 Rec. ITU-R M.1079-2 1 RECOMMENDATION ITU-R M.1079-2 Performance and quality of service requirements for International Mobile Telecommunications-2000 (IMT-2000) access networks (Question ITU-R 229/8) (1994-2000-2003) Summary This Recommendation defines the speech/data quality and performance require
2、ments for IMT-2000 access networks taking into consideration the end-to-end requirements. It also defines the connection/session performance, concerning issues such as call set-up time, delay characteristics and handover probability, to be achieved in the IMT-2000 access network that the user will e
3、xpect in a network of comparable performance to the fixed network. 1 Introduction IMT-2000 are third generation mobile systems which provide access to a wide range of telecommunication services, supported by the fixed telecommunication networks (e.g. public switched telephone network (PSTN)/ISDN/Int
4、ernet Protocol (IP), and to other services that are specific to mobile users. Key features of IMT-2000 are: high degree of commonality of design worldwide; compatibility of services within IMT-2000 and with the fixed networks; high quality; small terminal suitable for worldwide use; worldwide roamin
5、g capability; capability for multimedia applications, and a wide range of services and terminals. The capabilities of IMT-2000 systems are being continuously enhanced in line with market and technology trends. This Recommendation on performance and QoS requirements defines the requirements for speec
6、h quality, data quality, connection/session performance and the radio interface performance to be achieved in IMT-2000. Annex 1 contains information on planning tools to address end-to-end voice transmission quality. 2 Scope This Recommendation defines the speech/data quality and performance require
7、ments for IMT-2000 access networks, taking into consideration the end-to-end requirements. 2 Rec. ITU-R M.1079-2 This Recommendation lists the basic Recommendations essential for: achieving speech quality comparable to the fixed network by specifying natural speech, free, for example from excessive
8、delay and echoes, that will enable users to converse easily using the IMT-2000 network, taking account of the full range of impairments like transcoding and environmental noise that are to be expected; and acceptable data quality and performance requirements. This Recommendation also defines the con
9、nection/session performance, concerning issues like call set-up time, delay characteristics and handover probability, to be achieved in the IMT-2000 access network that the user will expect in a network of comparable performance to the fixed network. The scope of the Recommendation includes both the
10、 terrestrial and the satellite radio interfaces, as defined in Recommendation ITU-R M.1457. 3 Structure of the Recommendation This Recommendation contains recommendations dealing with speech/data quality, connection/ session performance, data, the requirements for other services and the radio perfor
11、mance requirements. In particular, QoS requirements are given in this Recommendation to meet end-to-end quality for services in wireless mobile networks. 4 Related documents The following are the applicable related documents: Recommendation ITU-R M.816: Framework for services supported on Internatio
12、nal Mobile Telecommunications-2000 (IMT-2000) Recommendation ITU-R M.818: Satellite operation within International Mobile Telecommunications-2000 (IMT-2000) Recommendation ITU-R M.819: International Mobile Telecommunications-2000 (IMT-2000) for developing countries Recommendation ITU-R M.1034: Requi
13、rements for the radio interface(s) for International Mobile Telecommunications-2000 (IMT-2000) Recommendation ITU-R M.1224: Vocabulary of terms for International Mobile Telecommunications-2000 (IMT-2000) Recommendation ITU-R M.1225: Guidelines for evaluation of radio transmission technologies for IM
14、T-2000 Recommendation ITU-R M.1311: Framework for modularity and radio commonality within IMT-2000 Rec. ITU-R M.1079-2 3 Recommendation ITU-R M.1457: Detailed specifications of the radio interfaces of International Mobile Telecommunications-2000 (IMT-2000) ITU-T Recommendation E.770: Land mobile and
15、 fixed network interconnection traffic grade of service concept ITU-T Recommendation E.771: Network grade of service parameters and target values for circuit-switched land mobile services ITU-T Recommendation E.800: Terms and definitions related to quality of service and network performance includin
16、g dependability ITU-T Recommendation F.116: Service features and operational provisions in IMT-2000 ITU-T Recommendation G.107: The E-model, a computational model for use in transmission planning ITU-T Recommendation G.114: One-way transmission time ITU-T Recommendation G.131: Control of talker echo
17、 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 terminals to access the PSTN ITU-T Recommendation G.726: 40,
18、 32, 24, 16 kbit/s adaptive differential pulse code modulation (ADPCM) ITU-T Recommendation G.728: Coding of speech at 16 kbit/s using low-delay code excited linear prediction ITU-T Recommendation G.729: Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear-prediction
19、(CS-ACELP) ITU-T Recommendation G.1010: End-user multimedia QoS categories ITU-T Recommendation P.79: Calculation of loudness ratings for telephone sets ITU-T Recommendation P.313: Transmission characteristics for cordless and mobile digital terminals ITU-T Recommendation P.800: Methods for subjecti
20、ve determination of transmission quality ITU-T Recommendation P.830: Subjective performance assessment of telephone-band and wideband digital codecs ITU-T Recommendation P.831: Subjective performance evaluation of network echo cancellers 4 Rec. ITU-R M.1079-2 ITU-T Recommendation P.862: Perceptual e
21、valuation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs ITU-T Recommendation Q.1701: Framework of IMT-2000 networks ITU-T Recommendation Q.1711: Network functional model for IMT-2000 ITU-T Recommendation Y.1
22、540: Internet protocol data communication service IP packet transfer and availability performance parameters ITU-T Recommendation Y.1541: Network performance objectives for IP-based services 5 Abbreviations and acronyms (see Note 1) ADPCM adaptive differential pulse code modulation BER bit error rat
23、io CN core network CRC cyclic redundancy code DCME digital circuit multiplex equipment FTP file transfer protocol GoB good or better GoS grade of service IP Internet protocol ISP Internet service provider MOS mean opinion score MT mobile terminal PDP packet data protocol PDU protocol data unit PLR p
24、acket loss ratio PoW poor or worst QoS quality of service RAN radio access network RANI radio access network interface Rec. ITU-R M.1079-2 5 RLP radio link protocol RRM radio resource management SDU service data unit SMS short message service VoIP voice over IP NOTE 1 Additional abbreviations are pr
25、ovided in Recommendation ITU-R M.1224. 6 Definitions 6.1 QoS The collective effect of service performances which determine the degree of satisfaction of a user of a service. It is characterized by the combined aspects of performance factors applicable to all services, such as: service operability pe
26、rformance service accessibility performance service retainability performance service integrity performance other factors specific to each service. 6.2 Speech quality The speech quality expresses the degree of customer satisfaction with conversational speech transmission. Speech quality depends on t
27、he quality of the whole speech path from the talker at one end of the connection to the listener at the other, and can be categorized into two types of quality: quality which is mainly dependent on handset acoustics and quality which is mainly dependent on the transmission medium. Telecommunications
28、 services where special attention needs to be paid to speech quality, such as audio teleconferencing and voice mail, should also be considered. 6.3 Connection performance Connection performance is expressed in ITU-T Recommendation E.770 as Grade of Service (GoS). GoS parameters consist of the signal
29、ling delay for call set-up and call release, and the probability of end-to-end blocking, as well as the probability of unsuccessful handover, etc. 6.4 Service retainability performance Service retainability performance is defined in ITU-T Recommendation E.800 as the probability that a service, once
30、obtained, will continue to be provided for a communication under given conditions, for example conditions of fading, shadowing and co-channel interference. 6 Rec. ITU-R M.1079-2 6.5 Reliability performance Reliability performance is defined in ITU-T Recommendation E.800 as the probability that an it
31、em can perform a required function under stated conditions for a given time interval. Faults in the telephone network can be classified as two types. One type is where the user encounters a small scale fault in the network segment other than the users own segment, in which case service can be re-est
32、ablished if the user calls again at once. The other type is where the fault occurs in the users segment or a large-scale fault occurs in the network segment, in which case, no service can be provided even if the user calls many times. A measure of reliability performance of the users segment is the
33、failure rate, and a measure of the network segment is unavailability. 6.6 Guidelines of design To realize telecommunication services which achieve the criteria specified in quality of service, guidelines for the design of the network are needed. The quality of systems which are designed in accordanc
34、e with these guidelines will be expected to meet the recommendations made below (see Fig. 1). 1079-01FIGURE 1An example of the functional structure of quality for telecommunication serviceQoSGuidelines of designService retainability performanceSpeech/data qualityGuidelines of maintenanceConnection/s
35、ession performanceReliability performanceService operability performanceElements addressed by this Recommendation6.7 Guidelines of management Guidelines to maintain and operate the facilities are needed. These guidelines are the basis on which a service provider or a network operator maintains the s
36、ervice, judges the quality in order to improve the service, and takes remedial action. Rec. ITU-R M.1079-2 7 7 Considerations In developing this Recommendation it was considered: a) that ITU-R has been studying IMT-2000 and has issued Recommendations ITU-R M.687, ITU-R M.816, ITU-R M.817, ITU-R M.81
37、8, ITU-R M.819, ITU-R M.1034, ITU-R M.1035, ITU-R M.1036, ITU-R M.1078, ITU-R M.1224, ITU-R M.1311, and ITU-R M.1457 which relate to these systems; b) that the ITU-R studies are continuing; c) that IMT-2000 encompasses a number of different systems; d) that users will expect the speech/data quality,
38、 information transmission quality, reliability of connection, and degree of blocking to be comparable to those for the same services provided by the fixed networks, recognizing the limitations imposed by the radio environment; e) that service availability will be dependent on a number of factors whi
39、ch could include: mobile terminal type, speed of motion, and geographic factors; for example hand portable sized/vehicle mounted terminals, indoor/outdoor, residential or business areas, urban/suburban/rural areas, etc.; f) the relevant ITU-T Recommendations and on-going studies; g) that there is a
40、need for mobile terminals to roam between public land mobile telecommunication networks in different countries and between networks in the same country; h) that IMT-2000 will offer voice and data services which interconnect with the PSTN/ISDN/B-ISDN/Internet and other public fixed and mobile network
41、s; j) that voiceband data applications will be an important early part of IMT-2000 and of the application of IMT-2000 to developing countries; k) that the choice of speech codec and the speech quality achieved in the mobile network will have a major impact on the penetration of the telephone market
42、place. If the quality is poor and the delay in the speech path is too great, the adoption of IMT-2000 by the general public may not reach the expected level; data quality achieved in the mobile network will have major impact also for introduction of high-speed multimedia and Internet services; l) th
43、at this issue has not been exposed fully in first and second generation systems because these are used to serve people to whom mobility is imperative. In a mass market, with many users in a static or semi-mobile environment, mobility may not be sufficient to justify poor quality and excessive delay,
44、 in competition with a fixed network offering high quality; m) that with a competitive mass market a significant number of calls will be mobile to mobile, or make use of cascaded connections, and that in such circumstances quality must be adequately maintained; n) users will expect the speech qualit
45、y to be maintained in connections through the PSTN/Internet involving transcoding to 64 kbit/s PCM, DCME, ADPCM and analogue circuits; o) that Internet and IP-based services such as Web browsing are growing at rapid speed. 8 Rec. ITU-R M.1079-2 8 Recommendations The ITU Radiocommunication Assembly r
46、ecommends the following requirements to determine QoS performance for the various services: 8.1 Overview of different levels of QoS Network services are considered end-to-end, this means from a TE to another TE. An end-to-end service may have a certain QoS which is provided for the user of a network
47、 service. It is the user that decides whether he is satisfied with the provided QoS or not. To realize a certain network QoS a bearer service with clearly defined characteristics and functionality is to be set up from the source to the destination of a service. A bearer service includes all aspects
48、to enable the provision of a contracted QoS. These aspects are among others the control signalling, user plane transport and QoS management functionality. An IMT-2000 bearer service layered architecture is depicted in Fig. 2, each bearer service on a specific layer offers its individual services usi
49、ng services provided by the layers below. In this Figure additional functional groupings that support the external bearer service between the “CN gateway” and the “TE” on the right side have been omitted for simplicity. 8.1.1 The end-to-end service and IMT-2000 bearer service On its way from the TE to another TE the traffic has to pass different bearer services of the network(s). A TE is connected to the IMT-2000 network by use of an MT. The end-to-end service on the application level uses the bearer services of the underlying network(s). As the end-to-end ser
