[置顶] GSM Channel Mode Modify和Channel Mode Modify Acknowledge信令

最近研究了下如何通过GSM Channel Mode Modify和Channel Mode Modify Acknowledge信令，获知GSM终端支持的data Rate

 

思路与原理：

• I n   an RR connected state, acknowledges a CHANNEL MODE MODIFY message by sending a CHANNEL MODE MODIFY ACKNOWLEDGEMENT message specifying and switching to the correct mode.

• -  the new mode if that mode is supported.

• -  the old mode if the new mode is not supported .

相关信令：

Step	Direction	Message
1	SS->MS	PAGING REQUEST TYPE 1
2	MS->SS	CHANNEL REQUEST
3	SS->MS	IMMEDIATE ASSIGNMENT
4	MS->SS	PAGING RESPONSE
5	SS->MS	CHANNEL MODE MODIFY
6	MS->SS	CHANNEL MODE MODIFY ACKNOWLEDGE
7	SS->MS	CHANNEL MODE MODIFY
8	MS->SS	CHANNEL MODE MODIFY ACKNOWLEDGE
9	SS->MS	CHANNEL MODE MODIFY
10	MS->SS	CHANNEL MODE MODIFY ACKNOWLEDGE
11	SS->MS	CHANNEL MODE MODIFY
12	MS->SS	CHANNEL MODE MODIFY ACKNOWLEDGE
13	SS->MS	CHANNEL MODE MODIFY
14	MS->SS	CHANNEL MODE MODIFY ACKNOWLEDGE
15	SS->MS	CHANNEL RELEASE

注意：在Channel Mode Modify中使用Time slot需要和Immediate Assignment中分配的Time slot一致，否则可能因此无法获取到Channel Mode Modify Acknowledge
 

在PDU Manager中的channel mode decode如下：

0 - Signalling Only (0x0)

1 - Speech Full Rate or Half Rate Version 1 (0x1)

33 - Speech Full Rate or Half Rate Version 2 (0x21)

65 - Speech Full Rate or Half Rate Version 3 (0x41)

129 - Speech Full Rate or Half Rate Version 4 (0x81)

130 - Speech Full Rate or Half Rate Version 5 (0x82)

131 - Speech Full Rate or Half Rate Version 6 (0x83)

3 - Data, 12.0 Kbit/s Radio Interface Rate (0x3)      9600 bps

11 - Data, 6.0 Kbit/s Radio Interface Rate (0xB)      4800 bps

19 - Data, 3.6 Kbit/s Radio Interface Rate (0x13)      2400 bps

 

相关PICS

1. GSM FR (TSPC_AddInfo_Full_rate_version_1)
2. GSM FR (TSPC_AddInfo_Full_rate_version_2)
3. GSM FR (TSPC_AddInfo_Full_rate_version_3)
4. GSM FR (TSPC_AddInfo_Full_rate_version_4)
5. GSM FR (TSPC_AddInfo_Full_rate_version_5)
6. GSM FR (TSPC_AddInfo_Full_rate_version_6)
7. 9.6 k full rate data mode (TSPC_AddInfo_96Data)  
            data 12 Kb/s 
8. 4.8 k full rate data mode (TSPC_AddInfo_48DataF)         
   data 6 Kb/s
9. 2.4 k full rate data mode (TSPC_AddInfo_24DataF)         
   data 4.8 Kb/s  

The mode field is encoded as follows: (octet 2) Bits 8 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0    signalling only 0 0 0 0 0 0 0 1    speech full rate or half rate version 1 1 1 0 0 0 0 0 1    speech full rate or half rate version 1 in VAMOS mode (Note 3) 0 0 1 0 0 0 0 1    speech full rate or half rate version 2 1 1 0 0 0 0 1 0    speech full rate or half rate version 2 in VAMOS mode (Note 3) 0 1 0 0 0 0 0 1    speech full rate or half rate version 3 1 1 0 0 0 0 1 1    speech full rate or half rate version 3 in VAMOS mode (Note 3) 1 0 0 0 0 0 0 1    speech full rate or half rate version 4 1 0 0 0 0 0 1 0    speech full rate or half rate version 5 1 1 0 0 0 1 0 1    speech full rate or half rate version 5 in VAMOS mode (Note 3) 1 0 0 0 0 0 1 1    speech full rate or half rate version 6 0 1 1 0 0 0 0 1    data, 43.5 kbit/s (downlink)+14.5 kbps (uplink) 0 1 1 0 0 0 1 0    data, 29.0 kbit/s (downlink)+14.5 kbps (uplink) 0 1 1 0 0 1 0 0    data, 43.5 kbit/s (downlink)+29.0 kbps (uplink) 0 1 1 0 0 1 1 1    data, 14.5 kbit/s (downlink)+43.5 kbps (uplink) 0 1 1 0 0 1 0 1    data, 14.5 kbit/s (downlink)+29.0 kbps (uplink) 0 1 1 0 0 1 1 0    data, 29.0 kbit/s (downlink)+43.5 kbps (uplink) 0 0 1 0 0 1 1 1    data, 43.5 kbit/s radio interface rate 0 1 1 0 0 0 1 1    data, 32.0 kbit/s radio interface rate 0 1 0 0 0 0 1 1    data, 29.0 kbit/s radio interface rate 0 0 0 0 1 1 1 1    data, 14.5 kbit/s radio interface rate 0 0 0 0 0 0 1 1    data, 12.0 kbit/s radio interface rate 0 0 0 0 1 0 1 1    data, 6.0 kbit/s radio interface rate 0 0 0 1 0 0 1 1    data, 3.6 kbit/s radio interface rate 0 0 0 1 0 0 0 0    data, 64.0 kbit/s Transparent Data Bearer (Note 2)   Other values are reserved for future use.   Note 1: The speech versions are also referred as follows (see 3GPP TS 26.103):   full rate or half rate version 1: GSM FR or GSM HR full rate or half rate version 2: GSM EFR (half rate version 2 not defined in this version of the protocol) full rate or half rate version 3: FR AMR or HR AMR full rate or half rate version 4: OFR AMR-WB or OHR AMR-WB full rate or half rate version 5: FR AMR-WB (half rate version 5 not defined in this version of the protocol) full rate or half rate version 6: OHR AMR (full rate version 6 not defined in this version of the protocol) Note 2: This code point is only used for channel assignments made in GAN mode. Note 3: This code point is only used for a mobile station that indicates support for VAMOS-II (see 3GPP TS 24.008).