1、ITU-T RECMN*R.333 93 m 4Bh2.593 0593263 536 m INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TELEGRAPHY TELEGRAPH TRANSMISSION R.113 (03/93) COMBINED MULDEX FOR TELEGRAPHY AND SYNCHRONOUS DATA TRANSMISSION ITU-T Recommendation R.113 (Previously “CCITT Rec
2、ommendation”) - ITU-T RECMN*R.LL3 73 = Y862591 0573262 472 FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendation
3、s on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T
4、 Recommendation R.113 was prepared by the ITU-T Study Group IX (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, t
5、he ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFW3 have been replaced by the Radiocommunication Sector. In order not to delay publication of this Recommendation, no change has been made in the text to refer
6、ences containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. 2 telecommunication administration and a recognized operating agen
7、cy. In this Recommendation. the expression “Administration” is used for conciseness to indicate both a O ITU 1994 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 permis
8、sion in writing from the ITU. ITU-T RECMN*RmLL3 93 4b259L 0573263 309 CONTENTS 1 Aggregate bearer channels . . . . . . _. _._. . . . . . 1.3 Frame structure . . . . . , . . . . . . . . , . * . . . . * . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . .
9、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Digital circuits established by muldex . 2.2 Circuits for synchronous transmission 2.3 Channels for anisochronous transmission . System capability and channel parameters Branch-line transparent submuldex . .- , . . . 2 3 4 5 Channel
10、numbering Annex A - The diagram of combined muldex Recommendation R.113 (03193) Page 1 1 1 2 2 3 4 4 4 1 Recommendation R.113 COMBINED MULDEX FOR TELEGRAPHY AND SYNCHRONOUS DATA TRANSMISSION (Helsinki, 1993) The CCITT, considering (4 transmission by using a channel of the digital communication syste
11、m without modems; that the widespread introduction of digital transmission systems gives an advantage to telegraphy and data (b) circuit of digital communication system may be desirable for economical and flexible application of digital circuits; that the simultaneous transmission of synchronous dat
12、a and anisochronous telegraph signals- over a single (c) that 64 and 56 kbit/s digital circuits are available; (d) X.51, X.55 and X.56; that basic parameters of multiplexing in synchronous data networks are specified in Recommendations X.50, (e) specified in Recommendation R. i 1 1 ; that the code a
13、nd speed independent TDM system for anisochronous telegraph and data transmission is (0 that TDM systems described in Recommendation R.lOO also exist; (g) use branch-line multiplexing systems; that telegraph subscribers are often geographically situated in small groups and in this case it is appropr
14、iate to (h) that circuits established by means of muldex may be used both in switched and in leased circuits, unanimously declares the view that the equipment for synchronous data and anisochronous telegraph signals transmission over the digital network circuits at a rate of 64 or 56 kbit/s shall be
15、 manufactured to comply with the following standards: 1 Aggregate bearer channels 1.1 Aggregate rates of 56 or 64 kbit/s shall be used. 1.2 Mechanical and electrical characteristics of interchange circuits shall be as specified in Recom- mendations G.703 and V.36. 1.3 Frame structure 1.3.1 Recommend
16、ation X.50 or X.5 1. For applications of the aggregate bearer rate of 64 kbit/s, the frame structure should be as specified in 1.3.2 Recommendation X.55 or X.56. For applications of the aggregate bearer rate of 56 kbit/s, the frame structure should be as specified in 2 Digital circuits established b
17、y muldex 2.1 Digital circuits established by muldex may be used in terminal and transit modes of operation. Recommendation R. 1 13 (03/93) 1 ITU-T RECMN*R.LL3 93 W 4862573 0593265 181 2.2 Circuits for synchronous transmission 2.2.1 2.2.2 2.2.3 Recommendation X.21 or X.21 bis. The data rate should be
18、 0.6, 1.2.2.4.4.8 or 9.6 kbits. The principles of multiplexing shall be in accordance with Recommendations X.50, X.51, X.55 or X.56. Channel interface for synchronous transmission in terminal mode of operation should be in accordance with 2.2.4 The principles of circuit connection in transit mode of
19、 operation is a national option. 2.3 Channels for anisochronous transmission 2.3.1 The nominal modulation rate shall be 50, 100,200,300 and 600 bauds. 2.3.2 23.2.1 synchronous transmission at a rate of 2.4 kbit/s. 2.3.2.2 a rate of 300 envelopes per second and eight information bits in each envelope
20、 shall be used. 2.3.2.3 a rate of 400 envelopes per second and six information bits in each envelope shall be used. 2.3.2.4 The following principles of multiplexing shall be used: For anisochronous transmission, channels should be established by groups replacing any channel for In the case where fra
21、me structure complying with Recommendations X.5 1 and X.56 is applied, the sequence at In the case where frame structure complying with Recommendations X.50 and X.55 is applied, the sequence at In a case of eight information bit envelope the bit assignment is as follows: - For 50-baud channel - One
22、information bit from each envelope. - For 100-baud channel -Two information bits from an envelope being four positions apart. - For 200 and 300-baud channel - Four information bits from an envelope being two positions apart. - For 600-baud channel - All eight information bits from an envelope. In a
23、case of six information bit envelope the bit assignment is as follows: - - - - Transition coding process of telegraph signals shall be made in accordance with Annex NR. 1 1 1. Telegraph interface should correspond to national requirements. If in a TDM combined muldex the loss of frame alignment is i
24、ndicated, the output of channel should be 2.3.2.5 For 100-baud channel - One information bit from each envelope. For 200-baud channel - Two information bits being three positions apart. For 300-baud channel - Three information bits being two positions apart. For 600-baud channel - All information bi
25、ts from the envelope. 2.3.2.6 2.3.3 2.4 controlled as follows: 2.4.1 Recommendation X.21 or X.21 bis for the case of “Da not ready” condition. 2.4.2 outgoing envelopes to all ones. 2.4.3 Channels for anisochronous transmission: Channels used for synchronous transmission in a terminal mode of operati
26、on are controlled in accordance with Channels used for synchronous transmission in a transit mode of operation are controlled by setting the a) Leased circuit service There are two optional methods on per-channel basis: - continuous condition A; - continuous condition Z. b) Circuit-switched service
27、- continuous condition A. 2 Recommendation R.113 (03/93) ITU-T RECMN*RmLL3 93 = 4862593 0593266 OL8 = Nominal modulation rate (bauds) 50 100 200 300 600 3 System capability and channel parameters 3.1 configurations is shown in Table 1. The capacity of the system having channels for synchronous trans
28、mission in case of homogeneous Data signalling rate on the per-channel (%I Th eo r e t i c a I maximum (bauds) Distortion Maximum bearer due to sampling number of (bitls) Number of bits in an envelope using the channel channels modulation rate 1 300 4.25 i 60 100 2 600 4.25 80 200 4 1200 4.25 40 400
29、 4 1 200 6.25 40 400 8 2400 6.25 20 800 TABLE 1R.113 The capacity of the system having channels for synchronous transmission Nominal modulation rate (bauds) 50 100 200 300 600 Nominal modulation rate (bauds) Data signalling rate on the bearer per-channel (%o) (bis) Theoretical due to sampling number
30、 of maximum Distortion Maximum Number of bits in an envelope using the channel channels modulation rate (bauds) 1 400 3.12 1 20 133.3 1 400 6.25 1 20 133.3 2 800 6.25 60 266.7 3 1 200 6.25 40 400 6 2400 6.25 20 800 I Maximum number of channels I 600 1200 2400 4800 9600 80 40 20 10 5 3.2 Channel para
31、meters for anisochronous transmission and system capacity for homogeneous configuration are shown in Table 2 when eight information bit envelope is employed, and in Table 3 when six information bit envelope is employed. TABLE 3R. 113 Channel parameters for anisochronous transmission and system capac
32、ity using the six information bit envelope structure (6 + 2) Recommendation R.113 (03/93) 3 ITU-T RECMN*R-LLl 93 E YBb257L 0593267 T54 = Nominal modulation rate (bauds) 50 100 Maximum number of channels when using: - 8 information bits 8 4 - 6 information bits 6 6 4 Branch-line transparent submuldex
33、 200 300 2 2 3 2 4.1 structure and corresponding to channel for synchronous transmission at a rate of 2.4 kbit/s. For anisochronous , transmission the branch-line submuldex shall use bearer channel having an envelope The aggregate bit rate of branch-line submuldex line signai is 3 kbit/s when eight
34、information bit envelope structure is used and 3.2 kbit/s when six information bit envelope structure is used. 4.2 The transmission of anisochronous telegraph signals should be made using information bits of envelope in accordance with 2.2. Framing bits of envelope A are used for frame (envelope) al
35、ignment of branch-line submuldexes, status bit being used for service purposes (e.g. maintenance loop control). 4.3 The nominal modulation rates are 50, 100,200 and 300 bauds. 4.4 are as shown in Tables 2 and 3. The branch-line submuldex capacity for homogeneous configuration is given in Table 4. Ch
36、annel parameters TABLE 4/R. 1 13 5 Channel numbering 5.1 Numbering of channels at the rates of 600-9600 bit/s should comply with Recommendation X.53. 5.2 6R.114. Numbering of telegraph channels at the rate of 50-600 bauds should be as shown in Tables 5R.114 and Annex A The diagram of combined muldex
37、 (This Annex forms an integral part of this Recommendation) The diagram of muldex and branch-line submuldex is shown in Figure A. 1. In a main muldex its multiplex (including clock, frame alignment scheme, distributor, etc.) is common for channels both for synchronous and anisochronous transmission.
38、 Channel interfaces for synchronous transmission are directly connected to multiplex. Chatmel interfaces for anisochronous transmission are connected through coding/decoding unit operating in accordance with Annex AR11 1. This unit can be either aggregate or individual. Submuldex aggregate signal ha
39、ving an envelope structure and a rate of 3 or 3.2 kbit/s is sent from submuldex to the main muldex over the line just as for the remote user of the synchronous channel at a rate of 2.4 kbit/s. 4 Recommendation R.113 (03193) ITU-T RECMN*R.113 93 I 4862571 0593268 990 m W3.2 bis Anisochronous transmission - 5G600 bauds I I I I TO900480-90/d01 Li / EAS Envelope alignment scheme MB Basebandmodems FIGURE A. UR. 1 13 Recommendation R.113 (03/93) 5 ITU-T RECMN*R-LL3 93 W 4862571 0573269 827 W Printed in Switzerland Geneva, 1994
