1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU G.828 Corrigendum I (07/2001) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital networks - Quality and availability targets Error perormance parameters and objectives for internat
2、ional, constant bit-rate synchronous digital paths Corrigendum I ITU-T Recommendation G.828 - Corrigendum 1 (Formerly CCIlT Recommendation) INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU G.828 Corrigendum 1 (07/200 1 ) SERIES G: TRANSMISSION SYSTEMS AND M
3、EDIA, DIGITAL SYSTEMS AND NETWORKS Digital networks - Quality and availability targets Error performance parameters and objectives for international, constant bit-rate synchronous digital paths Corrigendum 1 ITU-T Recommendation G.828 - Corrigendum 1 (Formerly CCIlT Recommendation) ITU-T G-SERIES RE
4、COMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS TRANSMISSION SYSTEMS GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER- INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES GENERAL CHA
5、RACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE METALLIC LINES COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY TESTING EQUIPMENTS TRANSMISSION MEDIA CHARACTERISTICS DIGITAL TERMINAL EQUIPMENTS DIGITAL NETWORKS SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH General aspects G.100
6、-G.199 G.200-G.299 G.300-G.399 G.400-G.449 G.450-G.499 G.500-G.599 G.600-G.699 G.700-G.799 G.800-G.899 G.800-G.809 G.810-G.819 Design objectives for digial networks Network capabilities and functions $lability targ SDH network characteristics Management of transport network SDH radio and satellite s
7、ystems integration Optical transport networks DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.840-G.849 G.850-G.859 G.860-G.869 G.870-G.879 G.900-G.999 LL Forfirther details, please refm to the list of ITU-T Recommendations. ITU-T Recommendation 6.828 Error performance parameters and objectives for inter
8、national, constant bit-rate synchronous digital paths CORRIGENDUM 1 Summary This corrigendum corrects a defect identified in ITU-T G.828 (2000). Clause 6.1 of ITU-T G.828 is modified to avoid text ambiguities. Source Corrigendum 1 to ITU-T Recommendation G.828 was prepared by ITU-T Study Group 13 (2
9、00 1-2004) and approved under the WTSA Resolution 1 procedure on 13 July 200 1. ITU-T G.828lCor.l (07/2001) 1 FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T)
10、 is a permanent organ of . ITU-T 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 Assembly (WTSA), which meets every four years,
11、establishes the topics for study by the ITU-T study groups which, in tum, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within -Ts purview, the necessary st
12、andards are prepared on a collaborative basis with IS0 and JEC. 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 possibil
13、ity that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. takes no position concerning the evidence, validity or applicability of claimed intellectual Property Rights, whether asserted by ITU members or others outside of the Recommen
14、dation development process. As of the date of approval of this Recommendation, 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 ar
15、e therefore strongly urged 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 ITU. 11 ITU-T G.828
16、/Cor.l (07/2001) ITU-T Recommendation G.828 Error performance parameters and objectives for international, constant bit-rate synchronous digital paths CORRIGENDUM 1 1) Introduction Clause 6.1 of ITU-T G.828 (2000) contains the following sentences: “Synchronous digital paths operating at bit rates co
17、vered by this Recommendation are carried by transmission systems (digital sections) operating at equal or higher bit rates. Such systems must meet their allocations of the end-to-end objectives for the highest bit-rate paths which are foreseen to be carried. Meeting the allocated objectives for this
18、 highest bit-rate path should be sufficient to ensure that all paths through the system are achieving their objective. For example, in SDH, an STM-1 section may carry a VC-4 path and therefore the STM-1 section should be designed such that it will ensure that the objectives as specified in this Reco
19、mmendation for the bit rate corresponding to a VC-4 path are met.“ If this requirement is observed, it would for instance mean that in case of STM- 1 , the ES objective is met if the ESR does not exceed the appropriate allocation of 0.04. If this STM-1 section carries - perhaps at a later stage - pa
20、ths operating at lower bit rates, the objectives for such low bit-rate paths may not be met - depending on the error distribution - because the objectives are getting tighter with lower bit rates. 2) Resolved defect Replace the second before last paragraph of clause 6.UG.828 with the following text:
21、 Digital paths operating at bit rates covered by this Recommendation are carried by transmission systems (digital sections) operating at equal or higher bit rates. Such systems must meet their allocations of the end-to-end objectives for the most demanding paths which are foreseen to be carried. For
22、 example, in SDH, an STM-1 section may carry a VC-11NC-12 path and therefore the STM-1 section should be designed such that it will ensure that the objectives as specified in this Recommendation for the bit rate corresponding to a VC-11NC-12 path are met. Under the assumption of random error distrib
23、ution, meeting the allocated objectives in Table UG.828 for the highest bit rate should be sufficient to ensure that all paths through the system are achieving their objectives. ITU-T G.828/Cor.l(07/2001) 1 SERIES OF ITU-T RECOMMENDATIONS Series A Series B Organization of the work of lTU-T Means of
24、expression: definitions, symbols, classification Series C Series D Series E Series F Series G Series H Series I Series J General telecommunication statistics General tariff principles Overall network operation, telephone service, service operation and human factors Non-telephone telecommunication se
25、rvices Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Series M Constructi
26、on, installation and protection of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and television transmission circuits Series N Series
27、 O Series P Series Q Series R Series S Series T Series U Series V Series X Series Y Series Z Specifications of measuring equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Termin
28、als for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communications Global information inf-astructure and Internet protocol aspects Languages and general software aspects for telecommunication systems Printed in Switzerland Geneva, 2001
