1、 INTERNATIONAL TELECOMMUNICATION UNION CCITT Series GTHE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE Supplement 14(11/1988) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Methods for measuring regularity return loss Reedition of CCITT G-series Recommendation
2、Supplement 14 published in the Blue Book, Fascicle III.3 (1989) NOTES 1 CCITT G-series Recommendation Supplement 14 was published in Fascicle III.3 of the Blue Book. This file is an extract from the Blue Book. While the presentation and layout of the text might be slightly different from the Blue Bo
3、ok version, the contents 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 a telecommunication administration and a recognized operating agency.
4、ITU 1988, 2007 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Fascicle III.3 Supplement 14 1 Supplement No. 14 METHODS FOR MEASURING REGULARITY RETURN LOSS (referred to in Recommendation G.623; this Supplement
5、 is to be found on page 669 of Fascicle III.3 of Orange Book, Geneva, 1977) ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS For further details, please refer to ITU-T List of Recommendations. INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS General definit
6、ions G.100G.109 General Recommendations on the transmission quality for an entire international telephone connection G.110G.119 General characteristics of national systems forming part of international connections G.120G.129 General characteristics of the 4-wire chain formed by the international cir
7、cuits and national extension circuits G.130G.139 General characteristics of the 4-wire chain of international circuits; international transit G.140G.149 General characteristics of international telephone circuits and national extension circuits G.150G.159 Apparatus associated with long-distance tele
8、phone circuits G.160G.169 Transmission plan aspects of special circuits and connections using the international telephone connection network G.170G.179 Protection and restoration of transmission systems G.180G.189 Software tools for transmission systems G.190G.199 INTERNATIONAL ANALOGUE CARRIER SYST
9、EM GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS Definitions and general considerations G.210G.219 General Recommendations G.220G.229 Translating equipment used on various carrier-transmission systems G.230G.239 Utilization of groups, supergroups, etc. G.240G.299 INDIVI
10、DUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES Carrier telephone systems on unloaded symmetric cable pairs, providing groups or supergroups G.320G.329 Carrier systems on 2.6/9.5 mm coaxial cable pairs G.330G.339 Carrier systems on 1.2/4.4 mm coaxial cable pairs G.3
11、40G.349 Additional Recommendations on cable systems G.350G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES General Recommendations G.400G.419 Interconnection of radio-relay links with carrier systems on
12、metallic lines G.420G.429 Hypothetical reference circuits G.430G.439 Circuit noise G.440G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY Radiotelephone circuits G.450G.469 Links with mobile stations G.470G.499 TESTING EQUIPMENTS TRANSMISSION MEDIA CHARACTERISTICS General G.600G.609 Symmetric
13、cable pairs G.610G.619 Land coaxial cable pairs G.620G.629 Submarine cables G.630G.649 Optical fibre cables G.650G.659 Characteristics of optical components and subsystems G.660G.699 Printed in Switzerland Geneva, 2007 ITU-T RECOMMENDATIONS SERIES Series A Organization of the work of the ITU-T Serie
14、s B Means of expression: definitions, symbols, classification Series C General telecommunication statistics Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmi
15、ssion systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installatio
16、n and protection of cables and other elements of outside plant Series M TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Series N Maintenance: international sound programme and television transmission circuits Series O Spe
17、cifications of measuring equipment Series P Telephone transmission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks and open system communications Series Y Global information infrastructure and Internet protocol aspects Series Z Languages and general software aspects for telecommunication systems
