1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T V.92TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 1(07/2003) SERIES V: DATA COMMUNICATION OVER THE TELEPHONE NETWORK Simultaneous transmission of data and other signals Enhancements to Recommendation V.90 Corrigendum 1 ITU-T Recommendation V
2、.92 (2000) Corrigendum 1 ITU-T V-SERIES RECOMMENDATIONS DATA COMMUNICATION OVER THE TELEPHONE NETWORK General V.1V.9 Interfaces and voiceband modems V.10V.34 Wideband modems V.35V.39 Error control V.40V.49 Transmission quality and maintenance V.50V.59 Simultaneous transmission of data and other sign
3、als V.60V.99 Interworking with other networks V.100V.199 Interface layer specifications for data communication V.200V.249 Control procedures V.250V.299 Modems on digital circuits V.300V.399 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. V.92 (2000)/Cor.1 (07/2003)
4、 i ITU-T Recommendation V.92 Enhancements to Recommendation V.90 Corrigendum 1 Summary This corrigendum improves the description of certain aspects of the Modem-on-Hold functions. Source Corrigendum 1 to ITU-T Recommendation V.92 (2000) was prepared by ITU-T Study Group 16 (2001-2004) and approved u
5、nder the ITU-T Recommendation A.8 procedure on 14 July 2003. ii ITU-T Rec. V.92 (2000)/Cor.1 (07/2003) 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 p
6、ermanent organ of ITU. 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, esta
7、blishes the topics for study 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 WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary st
8、andards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the R
9、ecommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents
10、 are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed
11、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. As of the date of approval of this Recommendation, ITU had recei
12、ved 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 urged to consult the TSB patent database. ITU 2003 All rights reserved.
13、 No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. V.92 (2000)/Cor.1 (07/2003) iii CONTENTS Page 1) Clause 9.7.1.2 . 1 2) Clause 9.10.1 1 3) Clause 9.10.2.1 . 1 4) Figure 20/V.92 Modem-on-hold request acknowledged. 2 ITU-T
14、 Rec. V.92 (2000)/Cor.1 (07/2003) 1 ITU-T Recommendation V.92 Enhancements to Recommendation V.90 Corrigendum 1 Introduction The following amendments are to be added to V.92 in order to clarify certain aspects of the Modem-on-Hold functions. 1) Clause 9.7.1.2 Replace the text of clause 9.7.1.2 with
15、the following: 9.7.1.2 Responding to retrain After detecting Tone A for more than 50 ms, the digital modem shall turn OFF circuit 106, clamp circuit 104 to binary one and transmit silence for 70 5 ms. The digital modem shall then transmit Tone B, condition its receiver to detect a Tone A phase rever
16、sal, and proceed in accordance with the full Phase 2 start-up procedure. NOTE A receiver should be aware of MH signals and not interpret them incorrectly as a retrain indication signal phase reversal. 2) Clause 9.10.1 Replace 9.10.1 with the following: This text supersedes the version contained in A
17、mendment 1 to V.92. 9.10.1 Transmission of MH sequences If Tone RT is transmitted before an MH sequence its duration shall be at least 20 ms if the tone was preceded by another MH sequence, or at least 50 ms otherwise. The transition from data mode to an initiating MH sequence shall be performed by
18、transmitting 70 5 ms of silence followed by Tone RT. If the initiating modem has detected the responding modems Tone RT signal before the end of the silence period, then the initiating modem may optionally skip Tone RT and proceed directly to transmitting the MH sequence. MH sequences shall be trans
19、mitted repeatedly, with the first 4 fill bits immediately following the last 4 fill bits of the preceding sequence. Each transmitted sequence shall be completed before transmitting other signals. 3) Clause 9.10.2.1 Add this new paragraph following the third paragraph of clause 9.10.2.1: The reversal
20、 of roles does not affect or imply any change to the link layer protocols (e.g. V.42) and the modem should continue in its previous negotiated state for these layers. 2 ITU-T Rec. V.92 (2000)/Cor.1 (07/2003) 4) Figure 20/V.92 Modem-on-hold request acknowledged Replace Figure 20 with the following ve
21、rsion: This figure supersedes the version contained in Amendment 1 to V.92. V.92COR.1_F20DATA RT70 5 ms 50 msMHreqDATA RT MHack ANSam80 msFigure 20/V.92 Modem-on-hold request acknowledged Printed in Switzerland Geneva, 2003 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T S
22、eries 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 Tra
23、nsmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Co
24、nstruction, installation 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 transmissio
25、n circuits Series O Specifications 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
