1、ITU-T RECMN*R-LOO 73 W 48b257L 0593204 870 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TELEGRAPHY TELEGRAPH TRANSMISSION R.l O0 (03/93) TRANSMISSION CHARACTERISTICS OF INTERNATIONAL TDM LINKS ITU-T Recommendation R.l O0 (Previously “CCITT Recommendatio
2、n”) ITU-T RECMN*R.LOO 93 II 4862.593 0593205 ?O? W 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 Recommendations on the
3、m 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 Recomme
4、ndation R.lOO was revised 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, the ITU Te
5、lecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector.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 references con
6、taining 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 agency. In th
7、is 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 permission in w
8、riting from the ITU. Recommendation R.100 TDM system type and aggregate rate R.lO1 2400 bit/s Alternative A (Note 2) R.lO1 2400 bit/s Alternative B R. 102 4800 bit/s R.103 600 bit/s R.105 2400 bit/s (Note 3) R.111 2400 bitis (Note 4) R.111 4800 bit/s (Note 4) R.1 i2 2400 bit/s (Note 5) NOTES TRANSMI
9、SSION CHARACTERISTICS OF INTERNATIONAL TDM LINKS (Geneva, 1980, modified at Melbourne, 1988 and at Helsinki, 1993) Quality of channels provided by homogeneous system Code-dependent channels (bauds) Code-independent channels (Note i) (bauds) 50 75 100 150 - - 46 22 46 30 22 15 92 46 46 30 - - - 8 128
10、 or 256 - - - - - - - - - - - 46 30 22 15 NOTE - The application of TDM systems providing code- and speed-independent channels in addition to code- and speed- dependent channels is a subject for further study. 1 Analogue path links 1.1 Standard telephone carrier systems with 4 kHz and 3 kHz spaced c
11、hannels permit homogeneous time division multiplex (TDM) telegraph systems, operated in association with 600-, 2400- and 4800-biUs data modems, to provide the capacities of telegraph channels shown in Table 1. TABLE 1R.100 Channel capacities of homogeneous TDM systems Recommendation R.100 (03/93) 1
12、ITU-T RECNN*R-LOO 93 II 4Bb259L 0593207 5BT = NOTES I Standard telephone carrier systems with 3 kHz spaced channels provide operation of telegraph TDM systems in association with 600- and 24O-bitls modems. 2 The provision of telegraph TDM systems operated at aggregate rates above 4800 bit/s is the s
13、ubject of further study. 1.2 the 600-, 2400- and 48O-bis duplex aggregate signais of an international TDM system. A 4-wire link is required in association with the data modem employed to provide satisfactory transmission for 1.3 The data modem employed should preferably comply with the appropriate a
14、spects of the Series-V Recommendations. The use of modem for telegraph TDM systems operated at aggregate rate above 4800 bids requires further study. 1.4 Recommendation H.22 i. The requirements of the actual V-Series modem employed should also be respected. The conditions of use of intemational TDM
15、links are generally similar to those for VFT links, described in 1.5 PCM (pulse code modulation) telephone channels complying with Recommendation G.712 2 are also generally suitable as bearers for TDM telegraph systems associated with modems complying with the Series-V Recommendations. However, poss
16、ible transmission arrangements involving tandem connection of a number of PCM telephone channels require further study. 1.6 Subclause 1.2.1R. 1 1 1 provides for the use of modems complying with the Recommendation cited in 3. 1.7 dation R. 1 1 1 should have aggregate bearers bit-synchronized to one a
17、nother Whenever possible, tandem connected code-independant TDM telegraph systems according to Recommen- 2 Digital path links 2.1 64 kbit/s international digital transmission circuits are realized by PCM time slots or via TDMA satellite systems. SCPC (single channel per carrier) satellite systems pr
18、ovide 56 kbit/s channels. Primary groups (60-108 kHz) in conjunction with V.36 3 modems may also be used. 2.2 64 kbih TDM link 2.2.1 Clause 1/R. 1 1 1 defines the telegraph TDM systems at 64 kbit/s. 2.2.2 Recommendations X.50 4 and X.51 5 set out the parameters of envelope interleaving TDM systems a
19、t 64 kbit/s, which provide 0.6, 2.4, 4.8 and 9.6 kbit/s tributary data channels. These data channels can be used to transfer the aggregate signals of TDM systems at 0.6 kbit/s (see Recommendation R. 103), 2.4 kbit/s (see Recommendations R.lO1, R.105, R.112 and clause 2R.11 I), 4.8 kbit/s (see Recomm
20、endation R.102 and clause 2m.11 I) and 9.6 kbit/s (see clause 2R. 11 1). 2.3 Recommendations X.55 6 and X.56 7. These systems provide the same tributary channels as in 2.2.2. 56 kbitls TDM links are realized using envelope interleaving TDM systems which are defined in 2.4 Figure 1 shows a typical mu
21、ltiplex hierarchy. 2.5 The capacities of 50-baud channels of 64- and 56-kbitls TDM systems are shown in Table 2. 2.6 and V.36 3. The characteristics of 64- and 56-kbiVs digital circuit interfaces are described in Recommendations G.703 8 2 Recommendation R.100 (03193) ITU-T RECMN*R.JOO 93 = 4862593 0
22、593208 4Lb O 64 mt/s 4 R.111 240 channels at 50 bauds transparent rG WsdJhnels / non-transparent / 92 charnels 30 channels at5obauds or at5Obauds non-transparent transparent transparent 32 channels at 50 bauds transparent 2.4 kbiffs 8 channels at 50 bauds transparent R.112 15 channels at 50 bauds tr
23、ansparent cf 46 channels at 50 bauds nomtransparent R.111 x.50-series 56/64 kbitk R.l O1 46 charnels at5obauds non-transparent *. . at5obauds nomtransparent R.103 I 600 biVs remote link R.lCBa 8 channels at 50 bauds non-transparent a The R.103 remote multiplexer may be connected toan R.lO1, R.112 or
24、 an R.102 multiplexer. In thisexample, the eight remote link channels are included in the 46 channels of the R 101 multiplexer. FIGURE l/R.l Typical mltiplex hierarchy Recommendation R.lOO (03/93) 3 ITU-T RECMN*R.LOO 93 4862593 0573209 352 Transparent TABLE uR.100 Non-transparent 50-baud channel cap
25、acities of homogeneous TDM systems 20 x R.lO1 (2.4 kbitls) 240 - - 920 X.50 (64 kbis) X.51 (64 kbitls) X.55 (56 kbitls) 20 x R.112 (2.4 kbitls) 10 x R.102 (4.8 kbitls) 300 920 300 920 20 x R. 1 1 I, clause 2 (2.4 kbitls) 10 x R. 1 1 1, clause 2 (4.8 kbitls) 160 - 160 - 5 x R. 1 1 1, clause 2 (9.6 kb
26、itls) I 160 I - 20 x R.105 (2.4 kbitls) 80 x R.103 (0.6 kbitls) - 5120 (Note) - 640 NOTE - Virtual channels. I References 4 CCITT Recommendation Transmission requirements of international voice-frequency telegraph links (at 50, 100 and 200 bauds), Rec. H.22. CCITT Recommendation Performance characte
27、ristics of PCM channels between 4-wire interfaces at audio frequencies, Rec. G.712. CCITT Recommendation Modems for synchronous data transmission using 60-1 O8 kHz group band circuits, Rec. V.36. CCITT Recommendation Fundamental parameters of a multiplexing scheme for the international interface bet
28、ween synchronous data networks, Rec. X.50. CCITT Recommendation Fundamental parameters of a multiplexing scheme for the international interface between synchronous data networks using IO-bit envelope structure, Rec. X.5 1. CCITT Recommendation Interface between synchronous data networks using a 6 +
29、2 envelope structure and single channel per carrier (SCPC) satellite channels, Rec. X.55. CCITT Recommendation Interface between synchronous data networks using an 8 + 2 envelope structure and single channel per carrier (SCPC) satellite channels, Rec. X.56. CCITT Recommendation PhysicaWelectricul characteristics of hierarchical digital interfaces, Rec. G.703 Recommendation R.lOO (03/93) ITU-T RECMN*R-LOO 93 4862573 0593230 07Y Printed in Switzerland Geneva, 1994
