1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.55 (1 2/1999) SERIES Q: SWITCHING AND SIGNALLING International automatic and semi-automatic working - Signalling for circuit multiplication equipment Signalling between signal processing network equipments
2、(SPNE) and international switching centres (ISC) ITU-T Recommendation Q.55 (Formerly CCITT Recommendation) STD.1TU-T RECflN Q.55-ENGL 1779 48b259L Ob89061 173 ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE INTERNATIONAL AUTOMATIC AND SEMI-AUTOM
3、ATIC WORKING Basic Recommendations Numbering plan and dialling procedures in the international service Routing plan for international service General Recommendations relative to signalling and switching systems (national or international) Tones for use in national signalling systems General characte
4、ristics for international telephone connections and circuits 4.14.3 4.4-4.59 Q.lO-Q.11 4.20-4.34 4.3.54.39 4.404.47 4.4-4.9 Q.12-4.19 Signalling for satellite systems 0.48-0.49 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN 4.60-4.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS SPECIFICATI
5、ONS OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM R1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES INTERWORKING OF SIGNALLING SYSTEMS SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1
6、PUBLIC LAND MOBILE NETWORK INTERWORKING WITH SATELLITE MOBILE SYSTEMS INTELLIGENT NETWORK BROADBAND ISDN SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.100-4.119 Q. 120-4.249 4.250-4.309 4.3 10-Q.399 4.400-4.499 QSOO-Q.599 Q.60O-Q.699 4.700-4.849 Q.8.50-Q.999 Q.1000-Q. 1099 Q. 1 10O-Q. 1 199 Q
7、. 1200-4.1699 Q.1700-4.1799 Q.20004.2999 For further details. please refer to the list of ITU-T Recommendations. STD-ITU-T RECMN Q-55-ENGL 3997 4862573 Ob890bS 005 ITU-T Recommendation Q.55 Signalling between signal processing network equipments (SPNE) and international switching centres (ISC) Summa
8、ry This ITU-T Recommendation describes a signalling interface, procedures, and protocol required between an International Switching Centre (ISC) and Signal Processing Network Equipment (SPNE). This signalling interface provides for the call by call control of an SPNE in real time to ensure an approp
9、riate signal enhancement capability such as echo control. The framework of this signalling interface allows for growth for the control of potential further SPNE types. Source ITU-T Recommendation Q.55 was prepared by ITU-T Study Group 11 (1997-2000) and approved under the WTSC Resolution 1 procedure
10、 on 3 December 1999. STD-ITU-T RECMN Q.55-ENGL 1777 U 48b257L Ob870b3 T41 FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T
11、is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for stud
12、y by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSC Resolution 1. In some areas of information technology which fall within -Ts purview, the necessary standards are prepared on a coll
13、aborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or imple
14、mentation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process
15、. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly u
16、rged to consult the TSB patent database. o ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 1 2 3 4 5 5.1 5.2 6 6.1 6.2 6.3
17、7 7.1 7.2 Annex A . SPNE over TS16 (CAS): Lower layer protocol Annex B . Protocol for MAS in the DL channel in 1544 kbit/s networks Annex C . Lower layer protocol for MAS within timeslot O in 2048 kbit/s networks . Annex D . Lower layer protocol for MAS in timeslot “n“ with 2048 kbit/s networks . An
18、nex E . Lower layer protocol for local area network signalling link . Annex F . SPNE Over SS7: Lower layer protocol . Scope References Definitions Abbreviations . Architecture Network oriented architecture Protocol oriented architecture . 5.2.1 Upper layer protocol architecture 5.2.2 Lower layer pro
19、tocol architecture . Signalling procedures . Nonnal procedures . 6.1.1 ISC procedures 6.1.2 SPNE procedures . Abnomal procedures . 6.2.1 Abnormal ISC procedures (for further study) . 6.2.2 Abnormal SPNE procedures . Maintenance procedures . 6.3.1 Connectivity test (optional) . Detailed protocol desc
20、ription . Lower layer protocol description Upper layer protocol description 7.2.1 Channel associated signalling for 2048 kbit/s networks . 7.2.2 Message associated signalling in 1544 kbit/s networks 7.2.3 Message associated signalling in timeslot O of 2048 kbit/s networks . 7.2.4 7.2.5 Local Area Ne
21、twork (LAN) 7.2.6 SS7 based protocol Message associated signalling in timeslot “n“ of 2048 kbit/s networks Page 1 1 2 4 4 4 9 10 11 12 12 12 13 14 14 14 14 14 15 15 16 16 17 19 19 20 22 22 23 25 27 29 31 STD-ITU-T RECMN Q-55-ENGL 1999 m 4862591 Ob870b5 L4 E Annex G . Specification and Description La
22、nguage (SDL) diagrams G.l SDLs for Facility Related Channel Associated Signalling (CAS) . G.2 SDLs for Facility Related Message Associated Signalling (MAS) G.3 SDLs for LAN signalling . G.4 SDLs for SS7 Annex H . SPNE Protocol Data Units H . 1 Echo cancellation H.2 Noise reduction . H.3 Automatic Le
23、vel Control (ALC) H.4 Frequency Equalization (FE) H.5 A-law/p-law conversion . Appendix I - Channel monitor (for further study) Appendix II - Discussion of signalling protocols used on the DL 1544 kbit/s networks . II . 1 Standards for the use of the data link channel 1544 kbit/s networks . 11.2 Ret
24、ransmission of control data . 11.3 Synchronization Appendix III - Call control capacity of the DL signalling channel . Page 33 33 37 47 52 55 55 56 56 56 56 57 57 57 57 58 58 sTD.1TU-T RECMN Q-55-ENGL bqqy 486257L 0687066 750 Introduction There is a need in networks for signal processing equipment,
25、including echo cancellers, automatic level controllers, frequency equalizers, noise reducers, A-Law to p-Law converters, etc. This equipment needs to be controlled on a call by call basis, to ensure the highest possible transmission quality. This ITU-T Recommendation describes signalling interface p
26、rocedures and protocols required between an International Switching Centre (ISC) and Signal Processing Network Equipment (SPNE). This signalling interface enables an SPNE to be controlled in real time, on a call by call basis, to ensure that the appropriate signal enhancement capability and paramete
27、rs are provided for the call. This is referred to as Per-Call-Control (PCC). The framework of this signalling interface allows for growth for the control of potential further SPNE types. This signalling interface can be used to facilitate the efficient support of existing and further signal processi
28、ng equipment at the international interface, such as echo cancellation, automatic level control, noise reduction, fiequency equalization, A-Law to p-Law converters and other capabilities. It can be used to ensure that the appropriate capabilities are enabled or disabled on a call by cai1 basis. The
29、method by which a switch determines whether a Signal Processing Function (SPF) should be enabled or disabled is not covered by this ITU-T Recommendation. This ITU-T Recornmendation includes both the upper layer protocol and references to lower layers of the signalling interface. Lower layers include
30、 Data Link for 1544 kbith facilities, timeslot O or 1 - “n“ for 2048 kbit/s facilities, a local area network interface, and a Signalling System No. 7 interface with simplified MTP. STDmITU-T RECMN Q-55-ENGL 1999 YB62591 UbB9Ub7 677 ITU-T Recommendation Q.55 Signalling between signal processing netwo
31、rk equipments (SPNE) and international switching centres (ISC) (Geneva, 1999) 1 Scope This ITU-T Recommendation describes a signalling interface between an International Switching Centre (ISC) and Signal Processing Network Equipment, referred to as an SPNE. This ITU-T Recommendation covers the follo
32、wing SPFs: echo control devices, noise reduction devices, automatic level control devices, A-law/p-law converters and frequency equalization devices. Left for further study are additional SPF types, such as PCM offset converters, etc. This interface can be supported in a facility-related manner usin
33、g the Data Link (DL) of 1544 kbit/s facilities or any timeslot including timeslot O of 2048 kbit/s facilities. The interface can also be supported using a Local Area Network (LAN) or Signalling System No. 7 (SS7). This ITU-T Recommendation is specifically concerned with the transfer of signalling in
34、formation on a per-call-control basis between the ISC and the SPNE, and for controlling various functions contained in the SPNE. This ITU-T Recommendation defines several signalling protocol architectures; however, it is not necessary that an ISC or SPNE support all of them. The signalling interface
35、 defined in this ITU-T Recommendation assumes a fixed relationship between the circuits of the ISC and the SPNE. While this ITU-T Recommendation is intended for use on international networks, the information defined here may be used within national networks. 2 References The following ITU-T Recommen
36、dations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are t
37、herefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - - - - ITU-T Recommendation G.165 (1 993), Echo cancellers. ITU-T Recommendati
38、on G.168 (1 997), Digital network echo cancellers. ITU-T Recommendation G.169 (1999), Automatic level control devices. CCITT Recommendation G.703 (1 99 i), Physical/electrical characteristics of hierarchical digital interfaces. ITU-T Recommendation G.704 (1998), Synchronous frame structures used at
39、1544, 6312, 2048, 8448 and 44 736 kbit/s hierarchical levels. CCITT Recommendation G.711 (1988), Pulse code modulation (PCM) of voice frequencies. ITU-T Recommendation Q.50 (1 993), Signalling between circuit multiplication equipments (CME) and international switching centres. ITU-T Recommendation Q
40、. 1 15 (1997), Logic for the control of echo control devices. - - - - STDnITU-T RECMN Q*55-ENGl- 1797 48b2591 Ob89068 523 = - - CCITT Recommendation 4.422 (1 988), Clausesfor exchange line signaIIing equipment. ITU-T Recommendation 4.701 (1 993), Functional description of the message transfer part (
41、MTP) of Signalling System No. 7. ITU-T Recommendation 4.704 (1 993), Signalling System No. 7 - Signalling network functions and messages. CCITT Recommendation 4.710 (1988), SimpZiJied MTP versionfor small systems. ITU-T Recommendation 4.921 (1997), ISDN user-network interface - Data link layer speci
42、fication. - CCITT Recommendation 4.940 (1 988), ISDN user-network interface protocol for management - General aspects. IEEE Std 802 (1990), Local and Metropolitan Area Networks: IEEE Standards: Overview and Architecture. - - - - 3 Definitions This ITU-T Recommendation defines the following terms: 3.
43、1 A-law - p-law converter (AMC): An A-Law - p-Law converter is a device that converts a received PCM signal sample from A-Law to p-Law in one direction, and p-Law to A-Law in the other. 3.2 automatic level controller (ALC): An automatic level controller is defined as an SPF located in the digital tr
44、ansmission path that automatically adjusts the level of a signal towards a predetermined value. Devices that modify the frequency response or spectral content of the signal are also covered by this definition. The telecommunications carrier and the ALC manufacturer will typically agree upon features
45、 to be included. See ITU-T Recommendation G. 169. 3.3 channel: Used herein to refer to a 64 kbits digital circuit occupying a specific position in a fiame. 3.4 channel associated signalling (CAS): CAS refers to the channel associated signalling referred to in G.704. 3.5 data link (DL): A 4 kbits cha
46、nnel derived from the multi-f-ame alignment signal in the 1544 kbits multiplexed digital signal defined in ITU-T Recommendation G.704. 3.6 El facility: A transmission link operating at 2048 kbit/s, supporting 30 or 31 64 kbits channels. 3.7 echo canceller device WCD): An echo canceller device is an
47、SPF that is able to remove some or all of the returned echo signal from a voice circuit. It operates by monitoring the speech signal sent to a voice circuit, and by comparing this signal with the signal received from the circuit, is able to determine what components of the returned signal are caused
48、 by an echo path in the circuit. It then is able to remove some or all of the returned echo, providing a voice circuit that is free or nearly free from the echo signal. ITU-T Recommendations G.165 and G.168 describe echo canceller performance. 3.8 facility related (FR): A signalling channel carried
49、within the bit stream of a 1544 kbits or 2048 kbits facility, carrying information related to the speech channels integral to this facility. 3.9 frequency equalizer (FE): A frequency equalizer is a device capable of amplifymg or attenuating certain frequencies of a speech channel. It is a subset of an automatic level controller (see above). STD-ITU-T RECMN Q.55-ENGL 1999 W 4862591 Ob89069 4bT W 3.10 functional entity (In telecommunications service provision applications): A grouping of service providing functions in a single location and a subset of the total set of
