1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 1 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU%.%2!,G0G02%#/-%.$!4)/.3G0G0/.G0G04%,%0(/.%37)4#().G0G0!.$G0G03).!,).#,!53%3G0G0!00,)#!“,%G0G04/G0G0)45G134G0G034!.$!2$3934%-3%.%2!,G0G0!30%#43G0G0/&G0G04(%G0G054),):!4)/./&G0G034!.$!2$):%$G0G0#)44G0G03).!,).
2、3934%-3G0G0/.G0G00#-G0G0,).+3)45G134G0G0RecommendationG0G01 (Extract from the “LUEG0“OOK)NOTES1 ITU-T Recommendation Q.110 was published in Fascicle VI.1 of the Blue Book. This file is an extract fromthe Blue Book. While the presentation and layout of the text might be slightly different from the Bl
3、ue Book version, thecontents of the file are identical to the Blue Book version and copyright conditions remain unchanged (see below).2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both atelecommunication administration and a recognized operating agency
4、. ITU 1988, 1993All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the ITU.Fascicle VI.1 - Rec. Q.110 1Recommendation Q.110Fascicle VI.1 - Rec. Q
5、.1102.0 GENERAL ASPECTS OF THE UTILIZATION OF STANDARDIZEDCCITT SIGNALLING SYSTEMS ON PCM LINKS2.0.1 Signalling Systems No. 4 and No. 5Signalling Systems No. 4 and No. 5 are in-band signalling systems. It is not planned to specify modifiedversions of these systems for application to PCM transmission
6、 systems.Should it be required to use one of these signalling systems on circuits routed partly or wholly via PCMtransmission systems it is recommended that the standard in-band signalling arrangements for both line andinterregister signals be used. The circuits should be connected on a 4-wire basis
7、 to appropriate analogue inputs andoutputs of the PCM transmission system.When used at analogue exchanges the circuits should be connected on a 4-wire basis to appropriate analogueinputs and outputs of a PCM transmission system conforming to Recommendations G.732 1 or G.733 2.At digital exchanges, c
8、ircuits should be connected to PCM interfaces conforming to Recommendation Q.503.2.0.2 Signalling System No. 6For the transmission of signalling information over digital systems a digital version of Signalling System No.6 has been developed and is specified in Recommendations Q.251 and Q.295.Alterna
9、tively, the analogue version of System No. 6, as also specified in Recommendations Q.251 to Q.295may be used without modifications by replacing the analogue voice-frequency channel of the signalling data link byPCM voice-frequency channels. In this case, the connection of the modem to the PCM transm
10、ission channel should bemade on a 4-wire basis to the analogue input and the analogue output.2.0.3 Signalling System No. 7Signalling System No. 7 has been developed for the use in integrated digital networks. It is optimized for64 kbit/s PCM transmission channels.In addition, it can be used on analo
11、gue transmission channels with lower bit rates.2.0.4 Signalling System R1Signalling System R1, as specified in Part I of Fascicle VI.4, may be used without modification on PCMvoice-frequency channels by direct connection of the circuits to appropriate analogue inputs and outputs of the PCMtransmissi
12、on system.An alternative method of transmitting the line signals via a PCM system as specified in RecommendationG.733 has been developed as the digital version of System R1. Details are given in Recommendations Q.314 to Q.316.The multifrequency interregister signals are applied in-band via the analo
13、gue input of the speech circuit.At digital exchanges, circuits should be connected to PCM interfaces conforming to Recommendation Q.503.2 Fascicle VI.1 - Rec. Q.1102.0.5 Signalling System R2The analogue version of System R2 line signalling cannot be transmitted via an analogue input of a PCMsystem s
14、ince these line signals are sent out-band using a 3825 Hz signalling channel. The digital version of System R2line signalling specified in Recommendations Q.421-Q.424 has been developed for use with PCM systems specified inRecommendation G.732 1. The multi-frequency inter-register signals are applie
15、d in-band via the input of the speechcircuit. At digital exchanges, circuits should be connected to PCM interfaces conforming to Recommendation Q.503.References1 CCITT Recommendation Characteristics of primary PCM multiplex equipment operating at 2048 kbit/s,Vol. III, Fascicle III.3, Rec. G.732.2 CCITT Recommendation Characteristics of primary PCM multiplex equipment operating at 1544 kbit/s,Vol. III, Fascicle III.3, Rec. G.733.
