11.2.5 Packet Channel Request

04.603GPPGeneral Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocolRelease 1999TS

This message is sent in random mode on the PRACH using the PRACH uplink block format defined in 3GPP TS 04.04. The order of bit transmission is defined in 3GPP TS 04.04. The numbering, assembling and field mapping conventions defined for RLC/MAC control blocks in sub-clause 10.0b shall apply.

The message format is either 11-bit or 8-bit. The mobile station shall use the format indicated by the System Information parameter ACCESS_BURST_TYPE

The 11-bit format is coded as shown in Table 11.2.5.1.

The 8-bit format is coded as shown in Table 11.2.5.2.

Table 11.2.5.1: PACKET CHANNEL REQUEST 11 bit message content

< Packet channel request 11 bit message content > ::=

< One Phase Access Request : 0 < MultislotClass : bit (5) >

< Priority : bit (2) >

< RandomBits : bit (3) > >

| < Short Access Request : 100 < NumberOfBlocks : bit (3) >

< Priority : bit (2) >

< RandomBits : bit (3) > >

| < Two Phase Access Request : 110000 < Priority : bit (2) >

< RandomBits : bit (3) > >

| < Page Response : 110001 < RandomBits : bit (5) > >

| < Cell Update : 110010 < RandomBits : bit (5) > >

| < MM Procedure : 110011 < RandomBits : bit (5) > >

| < Single Block Without TBF Establishment : 110100 < RandomBits : bit (5) > > ;

Table 11.2.5.2: PACKET CHANNEL REQUEST 8 bit message content

< Packet channel request 8 bit message content > ::=

< One Phase Access Request : 1 < MultislotClass : bit (5) >

< RandomBits : bit (2) > >

| < Short Access Request : 00 < NumberOfBlocks : bit (3) >

< RandomBits : bit (3) > >

| < Two Phase Access Request : 01000 < RandomBits : bit (3) > >

| < Page Response : 01001 < RandomBits : bit (3) > >

| < Cell Update : 01010 < RandomBits : bit (3) > >

| < MM Procedure : 01011 < RandomBits : bit (3) > >

| < Single Block Without TBF Establishment : 01100 < RandomBits : bit (3) > > ;

Table 11.2.5.3: PACKET CHANNEL REQUEST details

MultislotClass (5 bit field)
This information field indicates the multislot class of the ME. The coding is defined in the following table. The semantics of this field is defined in 3GPP TS 05.02, Annex B.

bit
5 4 3 2 1
0 0 0 0 0 multislot class 1
0 0 0 0 1 multislot class 2
: : : :
1 1 1 0 0 multislot class 29
other reserved values

Priority (2 bit field)
This information field indicates the requested Radio Priority. This field is coded as shown in the following table. The 8 bit format has a default Radio Priority of 4.bit

bit
2 1
0 0 Radio Priority 1 (Highest priority)
0 1 Radio Priority 2
1 0 Radio Priority 3
1 1 Radio Priority 4 (Lower priority)

NumberOfBlocks (3 bit field)
This information field indicates the number of blocks requested during a mobile originated Temporary Block Flow. This field is coded as shown in the following table:

bit
3 2 1
0 0 0 1 RLC data block
0 0 1 2 RLC data blocks
. . . 1 1 1 8 RLC data blocks

RandomBits (2 bit field or 3 bit field or 5 bit field)
This is an unformatted field.