1、INTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU V.80 Amendment 1 (07/2001) SERIES V: DATA COMMUNICATION OVER THE TELEPHONE NETWORK Simultaneous transmission of data and other signals In-band DCE control and synchronous data modes for asynchronous DTE Amen
2、dment I TU-T Recommendation V.80 - Amendment 1 (Formerly CCITT Recommendation) ITU-T V-SERIES RECOMMENDATIONS DATA COMMUNICATION OVER THE TELEPHONE NETWORK General Interfaces and voiceband modems Wideband modems Error control Transmission quality and maintenance Simultaneous transmission of data and
3、 other signals Intenvorking with other networks Interface layer specifications for data communication Control procedures Modems on digital circuits V.l-V.9 V. 1 0-V .34 v.35-v.39 V .40-V .49 v.50-v.59 V.60-V.99 V. 100-V. 199 V .200-V .249 V.250-V.299 v.300-v.399 For further details, please refer to
4、the list of ITU-T Recommendations. ITU-T Recommendation V.80 In-band DCE control and synchronous data modes for asynchronous DTE AMENDMENT 1 Summary This amendment amends the 1996 edition of ITU-T V.80 and is intended to be read in conjunction with this Recommendation. Source Amendment 1 to ITU-T Re
5、commendation V.80 was prepared by ITU-T Study Group 16 (2001-2004) and approved under the WTSA Resolution 1 procedure on 29 July 2001. ITU-T V.80/Amd.l (07/2001) i FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. Th
6、e ITU Telecommunication Standardization Sector (ITU-T) is a permanent 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 Standa
7、rdization Assembly (WTSA), which meets every four years, establishes 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
8、technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative 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. INT
9、ELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation 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,
10、whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are ca
11、utioned that this may not represent the latest information and are 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
12、microfilm, without permission in writing from ITU. 11 ITU-T V.801Amd.l (0712001) ITU-T Recommendation V.80 In-band DCE control and synchronous data modes for asynchronous DTE Symbol AMENDMENT 1 Hex code 1 Table 10 Replace Table 10 with the new table below. This change adds additional data signalling
13、 rate codes to Table 10 in support of cellular systems. Table 10N.80 - Synchronous Access Mode Commandhndication Bit Rate Values (values for parameters , , , ) 20h 21h 22h 23h 24h 25h 26h 27h 28h 29h 2Ah 2Bh 2Ch 2Dh 2Eh 2Fh 30h 31h Duplex or primary channel data signalling rate 1 200 bit/s 2 400 bis 4 800 biis 7 200 bis 9 600 biis 12 O00 bis 14 400 biis 16 800 biis 19 200 bids 21 600 bis 24 O00 bis 26 400 bis 28 800 bit/s 31 200 bitis 33 600 biis 32 O00 bifs 56 O00 biis 64 O00 bis ITU-T V.80/Amd.l (07/2001) 1
