11.2.5a EGPRS Packet Channel Request

3GPP44.060General Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocolRelease 17TS

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 using the PRACH uplink block format or on the RACH (see 3GPP TS 44.018) using the RACH uplink / Uplink access burst block format defined in 3GPP TS 44.004. The order of bit transmission is defined in 3GPP TS 44.004. 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 45.002).

Table 11.2.5a.1: EGPRS PACKET CHANNEL REQUEST messages (non-PEO access)

Training sequence
(see 3GPP TS 45.002)

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 (non-PEO access)

< EGPRS Packet channel request message content > ::=

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

< Priority : bit (2) >

< RandomBits : bit (3) > >

       | < Short Access Request :       100         — The value 100 was allocated in an earlier version of the protocol and shall not be used

                                                                                                                           < NumberOfBlocks : bit (3) >

                                                                                                                           < Priority : bit (2) >

                                                                                                                              < RandomBits : bit (3) > >

| < One Phase Access Request by Reduced Latency MS : 101 < MultislotClassGroup : bit (3) >

< Priority : bit (2) >

< RandomBits : bit (3) > >

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

< RandomBits : bit (3) > >

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

| < One phase Access Request in RLC unack mode : 110101 < RandomBits : bit (5) > >

| < Dedicated Channel Request : 110110 < RandomBits : bit (5) > >

| < Emergency call : 110111 < RandomBits : bit (5) > >

| < Two Phase Access Request by IPA capable MS 111000 < Priority : bit (2) >

< RandomBits : bit (3) > >

| < Signalling by IPA capable MS : 111001 < RandomBits : bit (5) > >;

Table 11.2.5a.3: EGPRS PACKET CHANNEL REQUEST messages (PEO access)

Training sequence
(see 3GPP TS 45.002)

bits
11……1

Packet Channel Access

TS4

< EGPRS PACKET CHANNEL REQUEST message content >

Access from a MS that has enabled PEO and is performing the Packet Access procedure.

TS4

< EGPRS MULTILATERATION REQUEST message content >

Access from a MS that has enabled PEO and is performing the radio access part of the MTA procedure using the RLC Data Block method or sending a Page Response for a positioning event (see Table 11.2.5a.4).

Table 11.2.5a.4: EGPRS PACKET CHANNEL REQUEST message and EGPRS MULTILATERATION REQUEST message content (PEO access)

TS

Bit 11

Bit 10

Bit 9

Bit 8

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

4

0

0

0

< EGPRS PACKET CHANNEL REQUEST message content for ‘PEO One Phase Access Request’ > ::=

< Access Cause : bit (2) >

< PEO Priority : bit (1) >

< Random Bits : bit (3) >

< EGPRS Capability : bit (1) >

< Spare : bit (1) > ;

4

0

0

1

< EGPRS MULTILATERATION REQUEST message content (RLC Data Block method or Page Response for Positioning Event) > :: =

< RandomBits : bit (3) >

< Access Discriminator : bit (1) >

< Final MTA Access : bit (1) >

< Spare : bit (3) > ;

4

0

1

0

< EGPRS MULTILATERATION REQUEST message content (Access Burst method) > :: =

< Short ID : bit (8) > ;

4

0

1

1

< EGPRS MULTILATERATION REQUEST message content (Extended Access Burst Method – part 1) > :: =

< Random ID Low : bit (4) >

< MS Transmission Offset : bit (4) >;

4 (Note 1)

1

0

0

< EGPRS MULTILATERATION REQUEST message content (Extended Access Burst Method – part 2) > :: =

< Random ID Low : bit (4) >

< MS Sync Accuracy : bit (4) >;

4

1

0

1

Spare (8)

4

1

1

Spare (9)

Note 1: See Table 11.2.5a.4.1 for 19 remaining bits of EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’.

NOTE: A mobile station that has enabled PEO (i.e. eDRX or PSM – see 3GPP TS 23.060 [19]) while in a cell that supports PEO, shall always send an EGPRS PACKET CHANNEL REQUEST message using TS4 (see Table 11.2.5a.3) and access type ‘PEO One Phase Access Request’ (see Table 11.2.5a.4) on the RACH when performing the Packet Access procedure. A mobile station that has enabled PEO while in a cell that supports PEO shall send an EGPRS MULTILATERATION REQUEST message on the RACH when performing the radio access part of the MTA procedure or when sending a Page Response due to receiving a page with a ‘pending positioning event’ indication (see 3GPP TS 44.018 [11] and 3GPP TS 44.031). The MTA method indicated by the EGPRS MULTILATERATION REQUEST message (i.e. one of the RLC Data Block method, Access Burst method or Extended Access Burst method) shall be supported by both the mobile station and the cell.

Table 11.2.5a.4.1: EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’ (Bit 12 to Bit 30)

TS

Bits 12 to Bit 30

4 (CC1)

< Random ID High : bit (12) >

< Short BSS ID : bit (3) >

< Final MTA Access : bit (1) >

< spare : bit (3) >;

Table 11.2.5a.5: EGPRS PACKET CHANNEL REQUEST details

MultislotClass (5 bit field)

This information field indicates the EGPRS multislot class of the MS. The multislot class indicated by this field shall be the same as the EGPRS multislot class indicated in the MS Radio Access Capability IE (see 3GPP TS 24.008). The coding is defined in the following table.

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
1 1 1 0 1 multislot class with Tx=1 by IPA capable MS, the network shall assume the MS is multislot class 1

1 1 1 1 0 multislot class with Tx=2 by IPA capable MS, the network shall assume the MS is multislot class 5

1 1 1 1 1 multislot class with Tx=4 by IPA capable MS, the network shall assume the MS is multislot class 12

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
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)

Access Cause (2 bit field)

This field indicates the type of payload a mobile station has to send as follows:

bit

2 1

0 0 signalling (e.g. page response, cell update, MM signalling, etc)

0 1 single block transfer

1 0 User data transfer – requested RLC mode = acknowledged

1 1 reserved

PEO Priority (1 bit field)

This field indicates the priority of the uplink data transfer being requested by the mobile station as follows:

0 low priority packet transfer

1 high priority packet transfer

EGPRS capability (1 bit field)

This field indicates whether the MS supports GMSK only (EGPRS without 8PSK) or GMSK and 8PSK (EGPRS with 8PSK on uplink and downlink)

0 EGPRS without 8PSK

1 EGPRS with 8PSK (uplink and downlink)

RandomBits (3 bit field or 5 bit field)
For the definition of these three last information fields see Packet Channel Request in sec. 11.2.5.

MultislotClassGroup (3 bit field)

This information field indicates the set of the EGPRS multislot classes to which the mobile station belongs. The network shall assume the longest transition times (Tta, Ttb, Tra, Trb) and the minimum number of RX, TX and SUM slots common to multislot classes in each set for the assignments (see Annex L).

bit multislot classes
3 2 1
0 0 0 5-7
0 0 1 9-11
0 1 0 31, 36, 41
0 1 1 12, 32, 37, 42
1 0 0 33, 34, 43
1 0 1 38, 39
1 1 0 44, 45
1 1 1 reserved

Access Discriminator (1 bit field)

This field indicates whether the MS sending an EGPRS MULTILATERATION REQUEST message for performing the radio access part of the MTA procedure using the RLC Data Block method or for sending a Page Response for a positioning event:

bit

0 MTA procedure using the RLC Data Block method

1 Page Response for a positioning event

Short ID (8 bit field)

This field identifies a 8 bit Short ID value used by a MS performing the radio access part of the MTA procedure using the Access Burst method (see 3GPP TS 44.018 [11]). The Short ID value used by a MS in a given cell is pre-determined (selected by the SMLC and included as part of the assistance information included in a RRLP message sent to a MS to trigger the Multilateration Timing Advance procedure – see 3GPP TS 44.031). It allows the BSS managing a cell in which it receives an EGPRS MULTILATERATION REQUEST message indicating ‘Access burst method’ to identify the applicable SCCP connection between the BSS and the serving SMLC (see 3GPP TS 49.031 and 3GPP TS 44.031).

Random ID Low (4 bit field)

This field is sent as part of an EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 1’ or ‘Extended Access Burst Method – part 2’. It consists of the 4 least significant bits of the Random ID parameter provided to the MS in the RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031).

MS Transmission Offset (4 bit field)

This field is sent as part of an EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 1’ or included in a RLC Data Block following the transmission of an EGPRS MULTILATERATION REQUEST message indicating ‘RLC Data Block method’ or ‘Page Response for Positioning Event’. It is coded as described in sub-clause 10.4.33

MS Sync Accuracy (4 bit field)

This field is sent as part of an EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’ or included in a RLC Data Block following the transmission of an EGPRS MULTILATERATION REQUEST message indicating ‘RLC Data Block method’ or ‘Page Response for Positioning Event’. It is coded as described in sub-clause 10.4.32

Random ID High (12 bit field)

This field is sent as part of an EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’. It consists of the 12 most significant bits of the Random ID parameter provided to the MS in the RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031).

The value of the Random ID resulting from combining the Random ID Low and Random ID High fields sent by the MS is is selected from the set of the Random ID values provided by the RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031). Each Random ID value provided by the RRLP Multilateration Timing Advance Request message can only be used in one cell used during the MTA procedure.

Short DSS ID (3 bit field)

This field is sent as part of an EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’. It consists of the Short BSS ID parameter provided to the MS in the RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031).

Final MTA Access (1 bit field)

This field indicates whether or not the current access request is the final access request the MS will make when performing the radio access part of the MTA procedure. It is ignored by the BSS if the Access Discriminator field indicates ‘Page Response for a positioning event’.

bit

0 One or more additional access requests pending for MTA procedure

1 Final access request for MTA procedure