1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 - TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU-!).4%.!.#% G0G0).4%2.!4)/.!,G0G042!.3-)33)/.3934%-3G0 !.!,/5%G9.5-“%2).G0G0/&G0G0$)4!,G0G0“,/#+3G0G0).42!.3-)33)/.G0G03934%-3)45G134G0G0RecommendationG0G0- (Extract from the “LUEG0“OOK)NOTES1 ITU-T Recommend
2、ation M.410 was published in Fascicle IV.1 of the Blue Book. This file is an extract fromthe Blue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, thecontents of the file are identical to the Blue Book version and copyright conditions remain
3、 unchanged (see below).2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both atelecommunication administration and a recognized operating agency. ITU 1988, 1993All rights reserved. No part of this publication may be reproduced or utilized in any form or b
4、y any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the ITU.Fascicle IV.1 - Rec. M.410 1Recommendation M.410Fascicle IV.1 - Rec. M.410NUMBERING OF DIGITAL BLOCKS IN TRANSMISSION SYSTEMS1 GeneralThis Recommendation gives the numbering of trib
5、utaries in digital blocks and the numbering of blockswithin higher order blocks and digital line system. The Series G Recommendations referred to below can be foundin Volume III (Digital networks, transmission systems and multiplexing equipments).2 Primary multiplex equipment2.1 Primary PCM multiple
6、x equipment operating at 2048 kbit/s (Recommendation G.732)Channel time slots 1 to 15 and 17 to 31 are assigned to 30 telephone channels numbered from 1 to 30 asindicated in Figure 1/M.410.Channel time slots 0 1 2 15 16 17 18 .31Numbering of telephone channels 1 2 15 16 17 .30FIGURE 1/M.410Example o
7、f primary multiplex equipment assignments2.2 Primary PCM multiplex equipment operating at 1544 kbit/s (Recommendation G.733)Channel time slots 1 to 24 are assigned to 24 telephone channels numbered from 1 to 24.2.3 Synchronous digital multiplex equipment operating at 2048 kbit/s (Recommendation G.73
8、6)Channel time slots 1 to 31 are assigned to 31 channels at 64 kbit/s numbered from 1 to 31.2.4 Synchronous digital multiplex equipment operating at 1544 kbit/s (Recommendation G.734)Channel time slots 1 to 23 are assigned to 23 channels at 64 kbit/s numbered from 1 to 23.2.5 Primary PCM multiplex e
9、quipment at 2048 kbit/s and offering synchronous 64 kbit/s digital access options(Recommendation G.737)It should be possible to assign channel time slots 1 to 15 and 17 to 31 to thirty telephone channelsnumbered from 1 to 30 as indicated in Figure 1/M.410.Provision should also be made to provide 64
10、kbit/s digital access to at least two of these channel time slots,allocated in an order of priority given in Recommendation G.737.If there are n telephone channels and (30 n) 64 kbit/s digital accesses, the channels are numbered from 1to 30, with the digital access channels having DA (digital access
11、) appended to the channel number.2 Fascicle IV.1 - Rec. M.4103 Second order PCM multiplex equipments3.1 Second order PCM multiplex equipment operating at 8448 kbit/s (Recommendation G.744)3.1.1 Channel time slots assignement for the case of channel associated signallingChannel time slots 5 to 32, 34
12、 to 65, 71 to 98 and 100 to 131 are assigned to 120 telephone channelsnumbered from 1 to 120 as indicated in Figure 2/M.410.Channel time slotsNumbering of channels0123456 32 33 34 . 6512 28 29 . 60Channel time slotsNumbering of channels66 67 68 69 70 71 72 98 99 100 1316162 88 89 120FIGURE 2/M.410Ex
13、ample of second order PCM multiplexequipment assignments3.1.2 Channel time slot assignment for the case of common channel signallingThe telephone channels corresponding to channel time slots 2 to 32, 34 to 65, 67 to 98 and 100 to 131 arenumbered from 1 to 127.When there is a bilateral agreement betw
14、een the Administrations involved for using channel time slot 1 foranother telephone or service channel, this channel will be numbered 0.3.2 Second order digital multiplex equipment operating at 8448 kbit/s (Recommendations G.742 and G.745)The four tributaries operating at 2048 kbit/s are numbered fr
15、om 1 to 4 in the order of interleaving.3.3 Second order digital multiplex equipment operating at 6312 kbit/s (Recommendation G.743)The four tributaries operating at 1544 kbit/s are numbered from 1 to 4 in the order of interleaving.4 Higher order multiplex equipment4.1 Digital multiplex equipments op
16、erating at the third order bit rate of 34 368 kbit/s (Recommendation G.751and G.753)The four tributaries operating at 8448 kbit/s are numbered from 1 to 4 in the order of interleaving.4.2 Digital multiplex equipments operating at the fourth order bit rate of 139 264 kbit/s (RecommendationsG.751 and
17、G.754)4.2.1 Method using a 3rd order bit rate in the digital hierarchyThe four tributaries operating at 34 368 kbit/s are numbered from 1 to 4 in the order of interleaving.4.2.2 Method by directly multiplexing 16 digital signals at 8448 kbit/sThe 16 tributaries at 8448 kbit/s are numbered from 1 to
18、16: 1 to 4 in the order of interleaving for the firstintermediate tributary at 34 368 kbit/s, 5 to 8 for the second, 9 to 12 for the third and 13 to 16 for the fourth asindicated in Figure 3/M.410.Fascicle IV.1 - Rec. M.410 3Four intermediate tributaries at 34 368 kbit/sin the order of interleaving
19、1 2 3 4Tributaries at 8448 kbit/s in the order ofinterleaving 1 2345678910111213141516FIGURE 3/M.410Example of third order multiplexequipment assignments4.3 Digital multiplex equipment based on a second order bit rate of 6312 kbit/s (Recommendation G.752)4.3.1 Third order digital multiplex equipment
20、 operating at 32 064 kbit/sThe five tributaries operating at 6312 kbit/s are numbered from 1 to 5 in the order of interleaving.4.3.2 Third order digital multiplex equipment operating at 44 736 kbit/sThe seven tributaries operating at 6312 kbit/s are numbered from 1 to 7 in the order of interleaving.5 Digital line system at 564 992 kbit/s on coaxial pairs (Recommendation G.954)The four tributaries operating at 139 264 kbit/s are numbered from 1 to 4 in the order of interleaving.
