11.2.5a EGPRS 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 may be sent by an EGPRS capable mobile station in a cell supporting EGPRS and where the EGPRS_PACKET_CHANNEL_REQUEST parameter indicates that this message shall be used.

This message is sent in random mode on the PRACH or RACH (see 3GPP TS 04.18) 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 is coded in 11‑bit format.

The EGPRS capability is indicated using alternative training sequences (see 3GPP TS 05.02)

Table 11.2.5a.1: EGPRS PACKET CHANNEL REQUEST message content

Training sequence
(see 3GPP TS 05.02)

bits
11……1

Packet Channel Access

TS1

< EGPRS Packet channel request message content >

EGPRS with 8PSK capability in uplink

TS2

< EGPRS Packet channel request message content >

EGPRS without 8PSK capability in uplink

Table 11.2.5a.2: EGPRS PACKET CHANNEL REQUEST message content

< EGPRS Packet channel request 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) > >

| < Signalling : 110011 < RandomBits : bit (5) > > ;

Table 11.2.5a.3: EGPRS PACKET CHANNEL REQUEST details

MultislotClass (5 bit field)

Priority (2 bit field)

NumberOfBlocks (3 bit field)

RandomBits (3 bit field)
For the definition of these information fields see Packet Channel Request in sec. 11.2.5.