1、- ETSI GSM*O3.50 b = 3400855 0138907 263 -1 L Ar GSM 03.50 September 1996 Version 5.0.0 Source: ETSI TC-SMG _ Reference: TS/SMG-O20350Q ICs: 33.060.50 Key words: Digital cellular telecommunications system, Global System for Mobile communications (GSM) GLOBAL SYSTEM FOR MOBILE COMMUNICATIONS Digital
2、cellular telecommunications system (Phase 2+); Transmission planning aspects of the speech service in the GSM Public Land Mobile Network (PLMN) system (GSM 03.50) ETSI European Telecommunications Standards Institute ETSI Secretariat Postai address: F-O6921 Sophia Antipolis CEDEX - FRANCE Off ice add
3、ress: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariatetsi.fr Tel.: +33 4 92 94 42 O0 - Fax: +33 4 93 65 47 16 _ _ Copyright Notification: No part may be reproduced except as authorized by written permission. The copyri
4、ght and the foregoing restriction extend to reproduction in all media. 0 European Telecommunications Standards Institute 1996. All rights reserved. ETSI GSM*03-50 96 = 3400855 CIL38908 LTT Page 2 GSM 03.50 Version 5.0.0: September 1996 Whilst every care has been taken in the preparation and publicat
5、ion of this document, errors in content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to “ETSI Editing and Committee Support Dept.“ at the address shown on the title page. ETSI . 9b 3400855 OL3B909 O36 Page 3 GSM 03.50 Version 5.0.0: September 199
6、6 Contents Foreword . 7 1 Scope 9 1.1 Normative references 9 1.2 Definitions and abbreviations . 11 1.3 Introduction 12 2 Network configurations 12 2.1 General 12 2.2 Model of the PLMN 12 2.3 Interfaces . 12 2.4 Configurations of Connections . 13 2.4.1 General Configurations of Connections 13 2.4.2
7、Reference configurations to illustrate delay and echo control issues 13 4-wire circuits in the PLMN 14 2.5 3 Transmission performance . 14 3.1 Overall LosdLoudness ratings 15 3.1.1 Connections with handset MSs . 15 3.1.2 Connections with handsfree MSs 16 3.1.3 Connections with headset MSs . 16 Ctabi
8、litv Loss 16 3.2 3.3 Delay 17 3.3.1 General 17 3.3.2 Sources of delay 17 3.3.2.1 Elements of the PLMN that cause delay 17 3.3.2.2 Elements of the PSTN that cause delay 17 Effects of delay 17 Allocation of delay to the PLMN 18 3.3.4.1 Allocation of delay to the PLMN when using a full rate system . 18
9、 3.3.4.2 Allocation of delay to the PLMN when using a half rate system . 18 Delay of various network configurations 18 3.3.5.1 National and international connections with no echo control in the PSTN (reference configurations A) 18 3.3.5.2 National and intemational connections with echo control in th
10、e PSTN (reference configurations 8) 18 3.3.5.3 Connections where re-routeing leads to a significant increase in transmission path length (reference configurations C) . 19 Delay related requirements on the MS 19 3.3.6.1 Full rate MS . 19 3.3.6.2 Half rate MS . 19 3.3.6.3 Handsfree MS 19 3.4 Echo . 19
11、 3.4.1 General 19 3.4.2 Electrical echo control in the PLMN (Reference configurations A) . 20 3.4.3 Acoustic echo control in the PLMN . 20 3.4.3.1 Acoustic echo control in a handsfree MS 20 3.4.3.2 Acoustic echo control in a handset MS . 20 3.4.3.3 Acoustic echo control in a headset MS . 20 Interact
12、ion between tandem echo control devices (reference configurations B Abbreviations and acronyms“. GSM 03.04 (ETS 300 524): “Digital cellular telecommunication system (Phase 2); Signalling requirements relating to routeing of calls to mobile subscribers“. GSM 06.01 (ETS 300 580-1): “Digital cellular t
13、elecommunication system; Full rate speech processing functions“. GSM 06.1 O (ETS 300 580-2): “Digital cellular telecommunication system; Full rate speech transcoding“. GSM 06.1 1 (ETS 300 580-3): “Digital cellular telecommunication system; Substitution and muting of lost frames for full rate speech
14、channels“. GSM 06.1 2 (ETS 300 580-4): “Digital cellular telecommunication system; Comfort noise aspect for full rate speech traffic channels“. GSM 06.31 (ETS 300 580-5): “Digital cellular telecommunication system; Discontinuous Transmission (DTX) for full rate speech traffic channel“. GSM 06.32 (ET
15、S 300 580-6): “Digital cellular telecommunication system; Voice Activity Detection (VAD)“. GSM 06.02 (ETS 300 581 -1): “Digital cellular telecommunication system; Half rate speech processing functions“. GSM 06.20 (ETS 300 581 -2): “Digital cellular telecommunication system; Half rate speech transcod
16、ing“. GSM 06.21 (ETS 300 581 -3): “Digital cellular telecommunication system; Substitution and muting of lost frames for half rate speech traffic channels“. GSM 06.22 (ETS 300 581 -4): “Digital cellular telecommunication system; Comfort noise aspects for half rate speech traffic channels“. GSM 06.41
17、 (ETS 300 581 -5): “Digital cellular telecommunication system; Discontinuous Transmission (DTX) for half rate speech traffic channels“. GSM 06.42 (ETS 300 581 -6): “Digital cellular telecommunication system; Voice Activity Detection (VAD) for half rate speech traffic channels“. - ETSI GSM*O3.50 Yb m
18、 3400855 OL387Lb 27b Page 10 GSM 03.50 Version 5.0.0: September 1996 11 51 I-ETC 300 245-2: “Integrated Services Digital Network (ISDN): Technical characteristics of telephony terminals: Part 2: PCM A-Law handset telephony“. 11 61 ITU-T Recommendation G.103 (1 998): “Hypothetical reference connectio
19、ns“ 11 71 ITU-T Recommendation G.111 (1993): “Loudness ratings (LRs) in an international connections“. i81 ITU-T Recommendation G.113 (1 993): “Transmission impairments“. 11 91 ITU-T Recommendation G.114 (1 993): “Mean one-way propagation time“. ITU-T Recommendation G.121 (1 993): “Loudness ratings
20、(LRs) of national systems“. ITU-T Recommendation G.122 (1 993): “Influence of national systems on stability, talker echo, and listener echo in intemational connections“. 1221 ITU-T Recommendation G. 131 (1 988): “Stability and echo“. i231 ITU-T Recommendation G.165 (1 993): “Echo cancellers“. 1241 I
21、TU-T Recommendation G.223 (1 988): “Assumptions for the calculation of noise on hypothetical reference circuits for telephony“. 1251 ITU-T Recommendation G.703 (1 991): “Physical/electricaI characteristics of hierarchical digital interfaces“. ITU-T Recommendation G.711 (1988): “Pulse code modulation
22、 (PCM) of voice frequencies“. ITU-T Recommendation G.712 (1 992): “Transmission performance characteristics of pulse code modulation“. 281 ITU-T Recommendation G.167 (1 993): “Acoustic Echo Controllers“ ITU-T Recommendation M.1020 (1 993): “Characteristics of special quality intemational leased circ
23、uits with special bandwidth conditions“. ITU-T Recommendation M.1025 (1 993): “Characteristics of special quality international leased circuits with basic bandwidth conditioning“. i31 1 ITU-T Recommendation M.1030 (1 988): “Characteristics of ordinary quality international leased circuits forming pa
24、rt of private switched telephone networks“. 1321 ITU-T Recommendations M.1040 (1 988): “Characteristics of ordinary quality international leased circuits“. ITU-T Recommendation 0.1 32 (1 988), “Specification for a quantizing distortion measuring apparatus using a sinusoidal test signal“. i341 ITU-T
25、Recommendation P.11 (1 993): “Effect of transmission impairments“. ITU-T Recommendation P.34 (I 993): “Transmission characteristics of hands-free telephones“. ITU-T Recommendation P.38 (1 993): “Transmission characteristics of operator telephone systems (OTS)“. 1371 ITU-T Recommendation P.50 (1 993)
26、: “Artificial voices“. i411 421 i431 i481 ETSI GSN*03-50 96 m 3400855 0138917 102 m Page 11 GSM 03.50 Version 5.0.0: September 1996 ITU-T Recommendation P.51 (1 993), “Artificial mouths“. ITU-T Recommendation P.64 (1 993), “Determination of sensitivityfrequency characteristics of local telephone“. I
27、TU-T Recommendation P.76 (1 988), “Determination of loudness ratings; fundamental principles“. ITU-T Recommendation P.79 (1 993), “Calculation of loudness ratings“. ITU-T Recommendation Q.35 (1 988): “Technical characteristics of tones for the telephone service“. ITU-T Recommendation (2.551 (1 994):
28、 “Transmission characteristics of digital exchanges*. ITU-T Blue Book (1 988), Volume V, Supplement 13: “Noise spectra“. IS0 3 - 1973: “Preferred numbers - series of preferred numbers“. ITU-1 Recommendation P.57 (1 993): “Artificial Ears“. ITU-T Recommendation P.58 (1993): “Head and Torso Simulator
29、for Telephonometty“. LETS 300 245-3: “Integrated Services Digital Network (ISDN): Technical characteristics of telephony terminal: Part 3: PCM A-law loudspeaking and handsfree telephony“. 1.2 Definitions and abbreviations In addition to those below the definitions and abbreviations used in this spec
30、ification are listed in GSM 01.04. ADC ADPCM AEC BSC BTS DAC DMR DSI EEC EL ERP FDM ISC LE LSTR MRP OLR PCM POI RLR SLR STMR UPCMI Analogue to Digital Converter Adaptive Differential Pulse Code Modulation Acoustic Echo Control Base Station Controller (excluding transmission systems Base Transceiver
31、Station (excluding transmission systems) Digital to Analogue Converter Digital Mobile Radio Digital Speech Interpolation Electric Echo Control Echo Loss Ear Reference Point Frequency Division Multiplex Intemational Switching Local Exchange Listener Sidetone Rating Mouth Reference Point Overall Loudn
32、ess Rating Pulse Code Modulation Point of Interconnection (with PSTN) Receiver Loudness Rating Send Loudness Rating Sidetone Masking Rating 13-bit Uniform PCM Interface ETSI GSN*03.50 b 3400855 0138718 049 Page 12 GSM 03.50 Version 5.0.0: September 1996 1.3 Introduction Since the transmission qualit
33、y and the conversational quality of the PLMN will in general be lower than the quality of the PSTN connection due to coding distortion, delay, etc., only some transmission aspects can be brought in line with ITU-T Recommendations. It is therefore necessary to improve the overall quality as much as p
34、ossible by implementing proper routeing and network configurations. It should be recognized that the transmission plan for the pan-European PLMN cannot lead to major changes in the PSTN. However, it is important to use the improvements in the evolving PSTN (e.g. digitalization, introduction of echo
35、cancellers) in an effective way. The transmission requirements are in the first place based on international connections. When the quality is sufficient for international connections, it can be assumed that the national connections will have the same or better qualiy. In order to obtain a sufficient
36、 quality in the connection, it is preferable to have digital connectivity between the Base Station System (BSS) and the international exchange. The PLMN requirements are based on this assumption. When this situation cannot be provided, a lower quality must temporarily be accepted. This Recommendatio
37、n consists of two parts: one will deal with network configurations, the other with transmission performance. The part about network configurations gives information about the reference connections, on which the transmission plan is based. Furthermore, some guidelines are presented for improvement of
38、 the transmission quality in the evolving (digital) PSTN. The part about transmission performance gives mainly characteristics of the transmission between MS acoustic interface (MRP/ERP) and the interface between the PLMN and the PSTN (POI). For transmission aspects where it is impossible to give ov
39、erall characteristics, it is in some cases necessary to make recommendations for individual parts of the equipment. Annex A considers the effects of the type of acoustic interfaces of the MS. 2 Network configurations 2.1 General The basic configuration for the interworking with the PSTN is shown in
40、figure 1. 2.2 Model of the PLMN A more detailed model of the PLMN used for the consideration of transmission planning issues for speech is shown in figure 2. This model represents the main functions required and does not necessarily imply any particular physical realization. Routeing of calls is giv
41、en in Recommendation GSM 03.04. Any acoustic echo control is not specifically shown as it will be provided by analogue processing of digital processing or a combination of both techniques. 2.3 Interfaces The main interfaces identified within the GSM Recommendations are shown in figure 1. For the pur
42、poses of this Recommendation, the Air Interface and the Point of Interconnect (POI) are identified along with two other interfaces, Interface 2 and a 19bit Uniform PCM Interface (UPCMI). These interfaces are needed to define the PLMN transmission characteristics and the overall system requirements.
43、The Air Interface is specified by GSM 05 series Recommendations and is required to achieve MS transportability. Analogue measurements can be made at this point by using the appropriate radio terminal equipment and speech transcoder. The losses and gains introduced by the test speech transcoder will
44、need to be specified. The POI with the PSTN will generally be at the 2048 kbits/s level at an interface, in accordance with ITU-T Recommendation G.703. At the point, which is considered to have a relative level of O dBr, the analogue - Page 13 GCM 03.50 Version 5.0.0: September 1996 signals will be
45、represented by 8-bit A-law, according to ITU-T Recommendation G.711. Analogue measurements may be made at this point using a standard send and receive side, as defined in ITU-T Recommendations. ETSI GSM*03-50 96 3400855 OL389Lq T45 interface Z might be used in the case of direct MSC to MSC connectio
46、ns. Interface 2 is of the same nature as the POI. The UPCMI is introduced for design purposes in order to separate the speech transcoder impairments from the basic audio impairments of the MS. 2.4 Configurations of Connections 2.4.1 General Configurations of Connections Figure 3 shows a variety of c
47、onfigurations of connections. There are a number of PSTN features which should be avoided from such connections. These include: - echo control devices in the international network. If present, and not disabled, these devices will be in tandem with PLMN echo cancellers and may introduce degradation;
48、- satellite routeings. The delay inherent in the connections when added to the PLMN delay, may result in conversational difficulties. Double satellite links are likely to cause severe diff iculties and special precautions should be taken to avoid this situation under call forwarding arrangements; -
49、digital speech interpolation systems (DSI). There is likely to be an adverse interaction between DSI and DTX; - ADPCM. The distortion introduced by ADPCM on routes where PSTN echo control is not provided is likely to reduce the echo cancellation provided by the PLMN electric echo canceller; - significant differences in clock rates on non-synchronized digital network components. The resulting phase roll and slips are likely to degrade the performance of the PLMN echo canceller; - those analogue FDM routeings which exhibit phase r
