ITU-T R 106-1995 Muldex Unit for Telegraph and Low Speed Data Transmission Using TDM Bit Interleaving with an Aggregate Bit Rate Higher Than 4800 bit s - Telegraphy (Study Group 14.pdf

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1、_ - ITU-T RECMN*R=LOb 95 m 4862591 0606395 227 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TELEGRAPHY R.106 (08/95) MULDEX UNIT FOR TELEGRAPH AND LOW SPEED DATA TRANSMISSION USING TDM BIT INTERLEAVING WITH AN AGGREGATE BIT RATE HIGHER THAN 4800 bits IT

2、U-T Recommendation R.106 (Previously “CCITT Recommendation”) FOREWORD The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (IT). The IT-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dati

3、ons on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The

4、 approval of Recommendations by the Members of the I?ZT-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). ITU-T Recommendation R.106 was prepared by -T Study Group 14 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 29th of Au

5、gust 1995. NOTES 1. telecommunication administration and a recognized operating agency. 2. follows: In this Recommendation, the expression “Administration” is used for conciseness to indicate both a The status of annexes and appendices attached to the Series R Recommendations should be interpreted a

6、s - - an annex to a Recommendation forms an integral part of the Recommendation; an appendix to a Recommendation does not form part of the Recommendation and only provides some complementary explanation or information specific to that Recommendation. O ITU 1995 All rights reserved. No part of this p

7、ublication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. ITU-T RECMN*R-LOb 95 Y862591 O606397 OTT CONTENTS Introduction . .: . Scope References Definitions Abbreviations . Basic p

8、arameters .; Clock synchronization Synchronization Interfaces Page 1 1 1 2 10 Loops 3 i 1 Implementation . 3 12 Application . 3 . 4 Annex A Recommendation R.106 (08/95) 1 ITU-T RECMN*R.LOb 95 48b259L 0606378 T3b SUMMARY This Recommendation defines the general principles and parameters of the muldex

9、that is used to send telegraph signals and low-speed data using TDM bit-interleaving with an aggregate bit rate higher than 4800 bith on an analogue telephone-type circuit or a higher order TDM system. In this Recommendation telegraph TDM systems are used for framing, and therefore there is no need

10、to standardize a special frame structure for the aggregate bit rates higher than 4800 bi/s. 11 Recommendation R.106 (OW95) - ITU-T RECMN*R.ZOb 95 4862593 0606399 972 M Recommendation R.106 MULDEX UNIT FOR TELEGRAPH AND LOW SPEED DATA TRANSMISSION USING TDM BIT INTERLEAVING WITH AN AGGREGATE BIT RATE

11、 HIGHER THAN 4800bils Geneva, 1995) . 1 Introduction Telegraph Time Division Multiplex (TDM) systems with an aggregate bit rate of 600 (Recommendation R.103), 2400 (Recommendations R.lO1, R.105, R.112) and 4800 bigs (Recommendation R.102) are widely used on telegraph networks. The TDM systems listed

12、 above provide the setting up of both code- and speed-dependent and code- and speed- independent telegraph channels for signal transmission using modulation rates of 50 to 300 bauds. In certain cases, for instance, on international paths of satellite circuits it becomes necessary to be able to use t

13、he bearer circuit capacity more effectively, i.e. to use an aggregate bit rate higher than 4800 bit/s. It is more preferable to design telegraph TDM systems operating at aggregate bit rates higher than 4800 bids on the basis of existing TDM systems complying with Recommendations R.lO1, R.102, R.105

14、and R.112. The modem to be used in telegraph TDM systems with an aggregate bit rate higher than 4800 bids over leased telephone-type circuits is also subjected to standardization in the R-Series Recommendations. It should be noted that the systems, mentioned above, with modems providing the mode of

15、aggregate bit streams 2400 and 4800 bids multiplexing (for instance, V.29 modem), cannot be used on a combined bearer circuit consisting of a telephone channel and a 9600 bit/s digital circuit, because in this case an aggregate 9 600 bids signai cannot be properly split into streams of 2400 or 4800

16、biih for each muldex. When designing a telegraph TDM system with an aggregate bit rate higher than 4800 bitk it is not desirable to allow additional losses of link capacity due to frame alignment between 2400 or 4800 bit/s streams belonging to different muldexes. 2 Scope This Recommendation defines

17、the general principles and parameters of the muldex that is used to send telegraph signals and low-speed data using TDM bit-interleaving with an aggregate bit rate higher than 4800 bids on an analogue telephone-type circuit or a higher order TDM system. In this Recommendation, telegraph TDM systems

18、complying with the existing R. 100-Series Recommendations are used for framing, and therefore there is no need to standardize a special frame structure for the aggregate bit rates higher than 4800 bids. 3 References The following Recommendations and other references contain provisions which, through

19、 reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying

20、 the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - ITU-T Recommendation R.lO1 (19931, Code and speed dependent TDM system for anisochronous telegraph and data transmission using bit interlea

21、ving. Recommendation R.106 (08195) 1 ITU-T RECMN*R*LOb 95 48b2591 ObOb400 414 Aggregate signalling rate (bit/s) 9600 9600 - ITU-T Recommendation R.102 (1993), 4800 bizis code and speed dependent and hybrid TDM systems for anisochronous telegraph and data transmission using bit interleaving. ITU-T Re

22、commendation R.103 (1988), Code and speed - dependent TDM 600 bids system for use in point-to-point or branch-line muldex configurations. ITU-T Recommendation R.105 (1993), Duplex muldex concentrator, connecting a group of gentex and telex subscribers to a telegraph exchange by assigning vrtual chan

23、nels to time slots of a bit-interleaved TDM system. ITU-T Recommendation R.112 (1993), TDM hybrid system for anisochronous telegraph and data transmission using bit interleaving. - - - TDM systems Four R.lO1, R.105 or R.112 systems Two R. 102 systems 4 Definitions 4800 This Recommendation makes use

24、of the terms defined in Recommendation R.140. Two R.lO1, R.105 or R.112 systems 5 Abbreviations For the purposes of this Recommendation, the following abbreviations are used: ES Erasing Sequence FSR Frame Synchronization word Receiver G Generator Mx add Additional Muldex Mx main Main Muldex TDM Time

25、 Division Multiplex UM Unit Muldex 6 Basic parameters 6.1 common aggregate signal at the transmitting side and demultiplexing them at the receiving side as shown in Table 1. The muldex unit shall be capable of multiplexing aggregate signals of telegraph TDM systems into the TABLE 1m.106 2 Recommenda

26、tion R.106 (08/95) ITU-T RECNN*R=LOb 95 W 48b2591 Ob06401 350 W 6.2 The muldex unit shall provide for maintaining the frame alignment signal on one TDM system that is called main and make “erasing” of the frame alignment signal in an aggregate signal of other TDM systems that are called subordinate.

27、 6.3 “modulo 2” with an “erasing” sequence at the sending end and make reverse conversion at the receiving end. The muldex unit shall “erase” an aggregate signal of a subordinate TDM system by means of a signal addition 6.4 The “erasing” sequence is defined as a signal of type . 0001 110001 1 l., wh

28、ere the length of each “zero” or “one” is 19.5802 ms (the length of the TDM R.lO1 system aggregate signal subframe) in the case of the basic 2400 bit/s aggregate signal and 9.7901 ms (the length of the TDM R.102 system aggregate signal subframe length) in the case of the basic 4800 bit/s aggregate s

29、ignal. 7 Synchronization 7.1 The “erasing” sequence shall be synchronized with the beginning of the main TDM system frame. 7.2 of the main 2400 bit/s aggregate signal and clause 6R.102 for the case of the main 4800 bit/s aggregate signal. The conditions and time of log idiog out muldex unit frame al

30、ignment shall comply with 6.4R.101 in the case 8 Clock synchronization 8.1 The muldex unit shall operate with a built-in generator that is synchronized by means of the modem. 8.2 synchronization. The muldex unit shall have outputs on 2400 or 4800 Hz for the main and subordinate TDM systems 8.3 The c

31、onnection capability and methods for synchronization of the remote TDM systems are for further study. 9 Interfaces 9.1 V-Series Recommendations. The nomenclature of the required interchange circuits is left for further study. The electrical characteristics of the interface between the muldex unit an

32、d the modem shall conform to the 9.2 The interface between the muldex unit and the local telegraph TDM systems shall be provided by the digital signal without the use of modems. The electrical characteristics of the interface shall comply with the V-Series Recommendations. 10 Loops Maintenance loops

33、, their location and names are left for further study. 11 Implementation The block diagram of the muldex unit is shown in Figure A. 1. 12 Application An application scheme in the network for the equipment in question is shown in Figure A.2. Recommendation R.106 (08/95) 3 ITU-T RECMNUR.3Ob 95 M 48625

34、93 0606402 297 Annex A Mx main Mx add FSR c G ES - mod 2 UM Main muldex Additional muldex Frame Synchronization word Receiver Time surnrnator Generator of the erasing sequence and synchronizing pulse Erasing Sequence Clock sychronization “modulo Wsummator Muldex Unit FIGURE A.lR.106 Block diagram of the muldex unit 4 Recommendation R.106 (08/95) ITU-T RECMN*R-LOb 95 +Ab2591 Ob06403 123 FIGURE A.2R.106 Application scheme on the network Recommendation R.106 (08/95) 5