1、W 3404583 0080782 372 = , Released: 1 July 1993 GSM 08.60 Version: 4.1 .O Date: 25 June, 1993 Koy words: Work Item No: European digital cellular telecommunication system (phase 2); Inband Control of Remote Transcoders and Rate Adaptors ETSI European Telecommunications Standards institute ETSI Secret
2、ariat: Route des Lucioles, F-06921 Sophia Antipoiis Cedex . France TP. + 33 92 94 42 00 TF. + 33 93 65 47 16 Tx. 47 00 40 F This is an unpublished work the copyright in which vests in the European Telecommunications Standards institute. Ali rights reserved. The information contained herein is the pr
3、operty of ETSI and no part may be reproduced or used except as authorised by contract or other written permission. The copyright and the foregoing restriction on reproduction and use extend to ali media in which the information may be embodied. Page 3 GSM 08.60 . version 4.1.0 : June 1993 CONTENTS 1
4、 . Scope 5 2 . General Approach 5 3 Frame Structure 7 3.1. Speech Frames 7 3.2. O . 1 l- II I BTS l AA II II 3 Frame Structure 3.1. Speech Frames. Octet no O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Page 7 GSM 08.60 - version 4.1.0 :
5、 June 1993 Bit number 3 4 5 6 7 8 1 2 O O O O O O O n O 1 C8 1 D8 1 D23 1 D38 1 D53 1 D68 1 D83 1 D98 1 D113 1 D128 1 D143 1 D158 1 D173 1 D188 1 D203 1 D218 1 D233 1 D248 1 C18 O c1 c9 D1 D9 D16 D24 D3 1 D3 9 D46 D54 D61 D69 D76 D84 D91 D99 DlO6 D114 D121 D129 D136 D144 D151 D159 D166 D174 D181 D18
6、9 D196 D204 D211 D219 D226 0234 D241 D249 D256 c19 O c2 c10 D2 D10 D17 D25 D32 D40 D47 D55 D62 D70 D77 D85 D92 D100 D107 D115 D122 D130 D137 D145 D152 D160 D167 Dl75 D182 D190 D197 D205 D212 D220 D227 D235 D242 D250 13257 c20 O c3 c11 D3 D11 D18 D26 D33 D41 D48 D56 D63 D71 D78 D86 D93 D101 D108 D116
7、 D123 D131 D138 D146 D153 D161 D168 D176 D183 D191 D198 D206 D213 D221 D228 D236 D243 D251 D258 c21 O c4 c12 D4 D12 D19 DS7 D34 D42 D49 D57 D64 D72 D79 D87 D94 D102 D109 D117 D124 D132 D139 D147 D154 Dl62 D169 D177 D184 D192 D199 D207 D214 D222 D229 D237 D244 D252 D259 T1 o c5 C13 D5 D13 D20 DS8 D35
8、 D43 D50 D58 D65 D73 D80 D88 D95 D103 D110 D118 D125 D133 Dl40 D148 D155 D163 D170 Dl78 D185 D193 D200 D208 D215 D223 D230 D238 D245 D253 D260 T2 - O C6 C14 D6 D14 D21 D29 D3 6 D44 051 D59 D66 D74 D81 D89 D96 D104 D111 D119 D126 D134 D141 D149 Dl56 D164 D171 D179 D186 Dl94 D201 D209 D216 D224 D231 0
9、239 D246 0254 C16 T3 - 0 c7 C15 D7 D15 D22 D30 D37 D45 D52 D60 D67 D75 D82 D90 D97 D105 D112 D120 D127 D135 D142 D150 D157 D165 D172 D180 D187 D195 D202 D210 D217 D225 D232 D240 D247 D255 C17 T4 m 3404583 0080788 800 m P.90 8 GSM 08.60 - verslon 4.1.0: June 1993 3.2. O DTXd = 1 : downlink DTX is app
10、lied. Though this parameter is linked with the resource allocation in the BTS at call setup, its value may vary during the connection. In the downlink frames the SP (Speech) indicator is set as output from the TX DTX handler (see TS GSM 06.31). If downlink DTX is not used, the SP indicator should be
11、 coded binary “1. 4.7. Procedures for Data Frames. When rate adaption to 64 Kbit/s is performed at the BTS (sub-64 kbit/s traffic channels are not used), the rate adaption between the format used on the radio interface and the 64 Kbitis format is made by the RAl/FIAl and the RA2 function as describe
12、d in TS GSM. 08.20. This is illustrated in figure 4.2. Fig. TS GSM 08.60/4.2. Rate adaption when performed at the BTS. When sub-64 kbitis traffic channels are used, up to four data frames are transferred in each TRAU frame. In order to convert between the TRAU frame format and the CCITT 80 bits fram
13、e format an additional intermediate rate adaption function, RAA, is applied. This is illustrated in figure 4.3. Fig. TS GSM 08.60i4.3. Rate adaption when sub-64 kbitls traffic channels are used. P8gO 20 QSM 08.60 - varsion 4.1.0: Jun. 1993 4.7.1. Tho RAA Function. Rie RAA function is used to convert
14、 between the CCiT V110 80 bits frame format and the TRAU frame format. When going from the V.110 format to the TRAU frame format the first octet (all bits coded binary 0“) in the CCm V110 80 bits frame is stripped off. Up to four such frames are then transferred in each TRAU frame as shown in sectio
15、n 3.3. When going from the TRAU frame format to the V.110 format the data frames are separated and the synchronization octet (all bits coded binary “0) is again included. The 80 bits V110 frame is illustrated in fig. 4.4, and the modified 72 bits frame is illustrated in fig. 4.5. Bit number Octet no
16、. .I 1 2 3 4 5 6 7 8 O 1 2 3 4 5 6 7 8 9 O 1 1 1 1 1 1 1 1 1 O D1 X X X X X X X X O X X X X X X X X X O X X X X X X X X X O X X X X X X X X X O X X X X X X X X X O X X X X X X X X X O X X X X X X X X X Figure TS GSM 08.60f4.4. CCRT V110 80 bits frame Bit number 2 3 4 5 6 7 8 I Octet no.11 D1 X X X X
17、 X X X X Figure TS GSM 08.6W4.5. Modified CClll V110 72 bits frame transferred in a TRAU data frame position. Page 21 GSM 08.60 - version 4.1.0 : June 1993 4.7.2. Tho RAl/RAl Function This function is described in TS GSM 04.21. 4.7.3. Tho RA2 Function. This function is described in TS GSM 04.21. 4.7
18、.4. Procoduror for 8 kbit/s intermediate rate adaption rate For 8 kbis intermediate rate adaption rate up to two data frames are transferred in each TRAU frame. The first data frame is transferred in TRAU data frame position 1 and the subsequent data frame is transferred in TRAU data frame position
19、3 (see section 3.3). In TRAU data frame position 2 and 4 all bits are coded binary “1“. If the data transfer terminates before the TRAU frame has been completed, the remaining data bit positions in the TRAU frame should be coded binary “1“. 4.7.5. Procodurei for 16 kblt/c intermediate rate adaption
20、rate For 16 kbit/s intermediate rate adaption rate, up to four data frames are transferred in each TRAU frame. The first data frame is transferred in TRAU data frame position 1, the next in data frame position 2 etc. If the data transfer terminates before the TRAU frame has been completed, the remai
21、ning data bit positions in the TRAU frame should be coded binary “1“. 4.7.6. Support of Non-Transparent Bearer Appllcationr. In GSM Rec. 08.20 the procedures for transfer of non-transparent bearer applications are specified. The 240 bit RLP frame is converted to four modified V110 80 bit frames. The
22、 same conversion is applied when transferred in a TRAU frame. The frames are coded as specified in section 4.7.4 and 4.7.5. 4.8. Fr8mo Synchronization. 4.8.1. So8rch for Framo Synchronization. The frame synchronization is obtained by means of the first two octets in each frame, with all bits coded b
23、inary “O“. and the first bit in octet no. 2, 4, 6, 8, . 38 coded binary “1. The following 35 bit alignment pattern is used to achieve frame synchronization: = 3404583 0080802 TOO H Page 22 GSM 08.60 - version 4.1.0: June 1993 4.8.2. Frame Synchronization After Performing Downlink Tlmlng Adjustments.
24、 If the timing of the downlink speech frames is adjusted, the adjustment is indicated in bits C6 - C11 as described in section 4.6.1.1 and 4.6.1.2. The frame synchronization unit shall change its frame synchronization window accordingly. 4.8.3. Frame Synchronlzatlon Monitoring and Recovery. The moni
25、toring of the frame synchronization shall be a continuous process using the same procedure as for initial detection. Loss of frame synchronization shall not be assumed unless at least three consecutive frames, each with at least one framing bit error, are detected. If the TRAU looses its frame synch
26、ronization it starts a timer Tsync = 1 second. If Tsync expires before frame synchronization is again obtained the TRAU initiates sending of the urgent alarm pattern described in section 4.10.2. The exception from this procedure is when “Resource Release“ is detected while Tsync is running (see sect
27、ion 4.3). In this case the procedure in section 4.3 shall be followed. If loss of frame synchronization is detected by the CCU it starts a timer Tsync. If Tsync expires before frame synchronization is again obtained the call shall be released and an indication given to O&M. Tsync is reset every time
28、 frame synchronization is again obtained. 4.9. Correction/detectlon of bit errors on the terrertrlal clrcults. 4.9.1. Error Detoctlon on the Control Bits. For the control bits, (C-bits), no error coding is made. However, in order to reduce the possibility of misinterpretation of control information
29、due to bit errors, the following procedure should be followed: 4.9.1.1. Goner81 Procedure If any undefined combination of the C-bits is received (see section 33, the frame should be reacted upon as received with errors. 4.9.1.2. Speech Frames. In addition to the general procedure described in the pr
30、evious section, the following procedure should be followed for the speech frames: Bits C6 - C11: Time Alignment. The full range of the time alignment adjustment should only be applied when the TRAU is in the Initial Time Alignment state (see section 4.6.1.1 and 4.6.1.2). If, in the Static Time Align
31、ment state, a time alignment order is received indicating an adjustment of more than 250 vS, the next downlink frame should be delayed only one 250 pS step. If an uplink frame is received with the “Time Alignment“ field set to an unused value (101000 . 11 11011, this value should be interpreted as “
32、no change“. 3404583 0080803 947 R Page 23 GSM 08.60 - version 4.1.0 : June 1993 4.9.2. Handllng of frames recelved with errors. If TRAU frame is received in the uplink or downlink with detectable errors in the control bits, then the control information shall be ignored. The speech or data bits shall
33、 be handled as if no error had been detected. If frame synchronisation has been lost (ref. section 4.8.3) in the uplink direction the TRAU shall - - for speech, mute the decoded speech as if it has received frames with errors (cf. TS GSM 06.1 1) for data, send idle frames as defined in TS GSM 08.20
34、to the MSC/interworking. If frame synchronisation has been lost in the downlink direction then the same procedure shall be followed as when frame synchronisation is lost on the PCM link. 4.10. Procoduros for Operation & Maintenance. The general procedures for Operation and Maintenance are described
35、in TS GSM 12.21, If the transcoders are positioned outside the BTS, some O&M functions will be required for the TRAU and the CCU. In par ticular this applies for transcoders positioned at the MSC site. The transcoders outside the BTS are considered a part of the BSC, and the O&M functions for the TR
36、AU should therefore be implemented in the BSC. The CCU is a part of the BTS and the O&M functions for this unit should therefore be implemented in the BTS. 4.10.1. Transfer of OM Information Between tho TRAU and the BSC. The transfer of O&M information between the BSC and the TRAU is possible to do
37、in two ways. Either it is handled directty between the BSC and the TRAU or a BTS is used as a message transfer point. The choice between the two methods is up to the manu facturer of the BSC: i) The transfer of O&M information between the BSC and the TRAU is handled internally by the BSC. The O&M si
38、gnalling between the TRAU and the BSC may either be handled by proprietary BSC solutions or the O&M TRAU frames defined in section 3.2 and 3.5.2 could be used. In the latter case the BSC has to act as a terminal for the O&M TRAU frames sent between the TRAU and the BSC. i) The O&M information betwee
39、n the TRAU and the BSC is transferred using 0&M TRAU frames between the TRAU and the CCU in a BTS. The BTS then acts as a relay function between the O&M TRAU franies and the associated O&M messages sent between the BTS and the BSC. 3404583 0080804 883 Page 24 GSM 08.60 - vorrlon 4.1.0: Jun. 1993 4.1
40、0.2. Procodures In the TRAU. In case of urgent fault conditions in the TRAU, e.g. loss of frame synchronization, non-ability of the transcoder to process data etc., this should if posible, be signalled to the BTS/BSC as an urgent alarm pattern. The urgent alarm pattern is a continuous stream of bina
41、ry “O“. If O&M TRAU frames information between the TRAU and the BSC is transferred using O&M frames between the CCU in a BTS and the TRAU, the TRAU sends O&M frames periodicalty until the identical 0&M TRAU frame is received for acknowledgement. The period is at least 6420ms (1,28 sec). In case of m
42、inor fault conditions, when no immediate action is required, the TRAU may send O&M frames indicating the fault instead of the urgent alarm pattern. 4.10.3. Procoduros In the BSC. The BSC should be able to detect a faulty TRAU, take it out of service and give an indication to O&M. A faulty TRAU could
43、 be detected e.g. by routine tests, alarms from the TRAU, release of call initiated by the BTS due to remote transcoder failure etc. How this is handled by the BSC is regarded as a BSC internal matter. 4.10.3.1. Uso of O&M Frames. The use and coding of O&M TRAU frames is left to the implementor of t
44、he BSCTTRAU. If O&M TRAU frames are used, they are always carrying 264 data bits. Any corresponding O&M message between the BSC and the BTS shall always carry all 264 O&M data bits. 4.10.4. Procodurer In tho ETS. If a CCU in a BTS receives O&M TRAU frames from the TRAU, the BTS shall - - send the id
45、entical frame to the TRAU for acknowledgement, and put the 264 data bits from the received frames into an appropriate O&M message and send it to the BSC If the CCU receives O&M frames during a call then “stolen frames“ shall be indicated to the MS and layer 2 frames of format A (see TS GSM 04.06) sh
46、all be transmitted. If the CCU receiives O&M frames during a data call, then the same procedure shall be used as when V.110 frame is lost. If receiving an O&M message from the BSC, carrying TRAU O&M information, the BTS puts the 264 data bits from the received message into an O&M TRAU frame and then
47、 the CCU allocated to the addressed connection sends the frame to the TRAU in one single O&M TRAU frame. Repetition is done according to TS GSM 12.21 In case of a faulty CCU, the O&M procedures are BTS internal. If the CCU receives the urgent alarm pattern, the BTS shall initiate release of the call as specified in TS GSM 08.58 with the cause field set to “Remote Transcoder Failure“.
