9.1.65 EC Packet Channel Request

3GPP44.018GSM/EDGE Radio Resource Control (RRC) protocolMobile radio interface Layer 3 specificationRelease 17TS

This message may be sent by an EC capable mobile station attempting system access using the EC-RACH (see sub-clause 3.5.2.1.2a) in which the message format is as shown in Tables 9.1.65.1 and 9.1.65.2. This message can also be sent using the RACH (see sub-clause 3.5.2.1.2) in which the message format is as shown in Tables 9.1.65.3 and 9.1.65.4.

The uplink access burst block format is defined in 3GPP TS 44.004. The order of bit transmission is defined in 3GPP TS 44.004. The message is coded in 11‑bit format.

The EC capability is implied when a MS attempts system access using the EC-RACH or by the use of TS3 when a MS attempts system access using the RACH.

Table 9.1.65.1: EC PACKET CHANNEL REQUEST messages and EC MULTILATERATION REQUEST messages (EC-RACH)

Training sequence
(see 3GPP TS 45.002)

bits
11……1

Packet Channel Access

TS3

< EC PACKET CHANNEL REQUEST message content >

Uplink CC1 MS

TS4

< EC MULTILATERATION REQUEST message content > (Note 1)

Uplink CC1 MS

TS5

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 1, Note 2, Note 4)

Uplink CC2 MS or CC5 MS

TS6

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 1, Note 2, Note 4)

Uplink CC3 MS or CC5 MS

TS7

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 1, Note 2, Note 4)

Uplink CC4 MS or CC5 MS

TS8

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 1,Note 3, Note 4)

Uplink CC5 MS

Note 1: See sub-clauses 3.5.2.1.2a and 3.11 for which type of EC MULTILATERATION REQUEST message described in Table 9.1.65.2 is sent by a MS when performing the radio access part of the MTA procedure or when sending a Page Response for a positioning event.

Note 2: For CC5 MS, EDAB (see 3GPP TS 45.002 [32]) is supported with TS5 or TS6 or TS7 when sending an EC PACKET CHANNEL REQUEST message if EC SI 2 message indicates CC5 access is supported (i.e. CC4_Range_UL parameter is included) and if EC SI 2 parameter CC5_EC-RACH_FORMAT_IND is set to EDAB.

Note 3: For CC5 MS, ESAB (see 3GPP TS 45.002 [32]) is supported when sending an EC PACKET CHANNEL REQUEST message if EC SI 2 message indicates CC5 access is supported (i.e. CC4_Range_UL parameter is included) and if EC SI 2 parameter CC5_EC-RACH_FORMAT_IND is set to ESAB.

Note 4: For CC5 an EC MULTILATERATION REQUEST message can be sent if EC SI 2 message indicates CC5 access is supported (i.e. CC4_Range_UL parameter is included).

Table 9.1.65.2: EC PACKET CHANNEL REQUEST message and EC MULTILATERATION REQUEST message content (EC-RACH)

TS

Bit 11

Bit 10

Bit 9

Bit 8

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

3 (CC1)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

EGPRS Capability

4 (CC1)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Final MTA Access : bit (1) > ;

EGPRS Capability

4 (CC1)

0

1

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

< Short ID : bit (8) > ;

Spare

4 (CC1)

1

0

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

< Random ID Low : bit (4) >

< MS Transmission Offset : bit (4) >;

0

4 (CC1)

Note 1

1

0

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

< Random ID Low : bit (4) >

< MS Sync Accuracy : bit (4) >;

1

4 (CC1)

1

1

Spare (9)

5 (CC2)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

0

5 (CC2)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Final MTA Access : bit (1) > ;

1

5 (CC2)

0

1

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

< Short ID : bit (8) > ;

1

5 (CC2)

1

Spare (9)

1

6 (CC3)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

0

6 (CC3)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Final MTA Access : bit (1) > ;

1

6 (CC3)

0

1

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

< Short ID : bit (8) > ;

1

6 (CC3)

1

Spare (9)

1

7 (CC4) or 8 (CC5)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

0

7 (CC4) or 8 (CC5)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Final MTA Access : bit (1) > ;

1

7 (CC4) or 8 (CC5)

0

1

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

< Short ID : bit (8) > ;

1

7 (CC4) or 8 (CC5)

1

Spare (9)

1

Note 1: See Table 9.1.65.2.1 for 19 remaining bits of EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’.

Table 9.1.65.2.1: EC 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 9.1.65.3: EC PACKET CHANNEL REQUEST message and EC MULTILATERATION REQUEST message (RACH)

Training sequence
(see 3GPP TS 45.002)

bits
11……1

Packet Channel Access

TS3

< EC PACKET CHANNEL REQUEST message content > (Note 1)

Uplink CC1 MS

TS5

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 2, Note 3, Note 4, Note 6)

Uplink CC2 MS or CC5 MS

TS6

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 2, Note 3, Note 4, Note 6)

Uplink CC3 MS or CC5 MS

TS7

< EC PACKET CHANNEL REQUEST message content > or < EC MULTILATERATION REQUEST message content > (Note 2, Note 3, Note 4, Note 6)

Uplink CC4 MS or CC5 MS

TS8

< EC PACKET CHANNEL REQUEST message content > (Note 1, Note 5, Note 6)

Uplink CC5 MS

Note 1: Only sent on RACH when RACH Access Control is enabled (see sub-clause 9.1.30c)

Note 2: Only sent on RACH when 2TS EC-RACH is enabled (see sub-clause 9.1.43q)

Note 3: See sub-clauses 3.5.2.1.2a and 3.11 for which type of EC MULTILATERATION REQUEST message described in Table 9.1.65.4 is sent by a MS when performing the radio access part of the MTA procedure or when sending a Page Response for a positioning event.

Note 4: For CC5 MS, EDAB (see 3GPP TS 45.002 [32]) is supported with TS5 or TS6 or TS7 when sending an EC PACKET CHANNEL REQUEST message if EC SI 2 message indicates CC5 access is supported (i.e. CC4_Range_UL parameter is included) and if EC SI 2 parameter CC5_EC-RACH_FORMAT_IND is set to EDAB.

Note 5: For CC5 MS, ESAB (see 3GPP TS 45.002 [32]) is supported when sending an EC PACKET CHANNEL REQUEST message if EC SI 2 message indicates CC5 access is supported (i.e. CC4_Range_UL parameter is included) and if EC SI 2 parameter CC5_EC-RACH_FORMAT_IND is set to ESAB.

Note 6: For CC5 an EC MULTILATERATION REQUEST message can be sent if EC SI 2 message indicates CC5 access is supported (i.e. CC4_Range_UL parameter is included).

Table 9.1.65.4: EC PACKET CHANNEL REQUEST message content (RACH)

TS

Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

Bit 8

Bit 9

Bit 10

Bit 11

3 (CC1)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Signal Strength : bit (3) > ;

EGPRS Capability

5 (CC2)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

0

5 (CC2)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Spare : bit (1) > ;

1

5 (CC2)

0

1

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

< Short ID : bit (8) > ;

1

5 (CC2)

1

Spare (9)

1

6 (CC3)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

0

6 (CC3)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Spare : bit (1) > ;

1

6 (CC3)

0

1

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

< Short ID : bit (8) > ;

1

6 (CC3)

1

Spare (9)

1

7 (CC4) or 8 (CC5)

< EC PACKET CHANNEL REQUEST message content > :: =

< EC-NumberOfBlocks : bit (3)  >

< EC Priority : bit (1) >

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) > ;

0

7 (CC4) or 8 (CC5)

0

0

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

< RandomBits : bit (3) >

< Selected DL Coverage Class : bit (3) >

< Access Discriminator : bit (1) >

< Spare : bit (1) > ;

1

7 (CC4) or 8 (CC5)

0

1

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

< Short ID : bit (8) > ;

1

7 (CC4) or 8 (CC5)

1

Spare (9)

1

Table 9.1.65.5: EC PACKET CHANNEL REQUEST details

EC-NumberOfBlocks (3 bit field)

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

bit

3 2 1

0 0 0 page response

0 0 1 RLC/MAC control message

0 1 0 cell update or uplink data transfer requiring 1 MCS-1 coded RLC data block

0 1 1 uplink data transfer – 2 MCS-1 coded RLC data blocks required

1 0 0 uplink data transfer – 3 MCS-1 coded RLC data blocks required

.

.

.

1 1 1 uplink data transfer – 6or more MCS-1 coded RLC data blocks required

EC Priority (1 bit field)

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

0 normal priority (normal report)

1 high priority (exception report)

Selected DL Coverage Class (3 bit field)

This field indicates the Downlink Coverage Class that the mobile station has determined to be applicable at the point of sending an EC PACKET CHANNEL REQUEST and, when CC1 applies to the downlink, the extent to which the C-value exceeds the value indicated by the BT_Threshold_DL parameter sent in EC SI2 (see sub-clause 9.1.43q):

Case 1: EC SYSTEM INFORMATION indicates 4 of 4 possible coverage classes are supported:

bit

3 2 1

0 0 0 DL CC4

0 0 1 DL CC3

0 1 0 DL CC2

0 1 1 DL CC1; BT_Threshold_DL ≤ C_VALUE < BT_Threshold_DL + X dB

1 0 0 DL CC1; BT_Threshold_DL + X ≤ C_VALUE < BT_Threshold_DL + 2X dB

1 0 1 DL CC1; BT_Threshold_DL + 2X ≤ C_VALUE < BT_Threshold_DL + 3X dB

1 1 0 DL CC1; BT_Threshold_DL + 3X ≤ C_VALUE < BT_Threshold_DL + 4X dB

1 1 1 DL CC1; C_VALUE ≥ BT_Threshold_DL + 4X dB

Case 2: EC SYSTEM INFORMATION indicates 3 of 4 possible coverage classes are supported:

bit

3 2 1

0 0 0 DL CC4

0 0 1 DL CC2 or CC3

0 1 0 DL CC1; BT_Threshold_DL ≤ C_VALUE < BT_Threshold_DL + X dB

0 1 1 DL CC1; BT_Threshold_DL + X ≤ C_VALUE < BT_Threshold_DL + 2X dB

1 0 0 DL CC1; BT_Threshold_DL + 2X ≤ C_VALUE < BT_Threshold_DL + 3X dB

1 0 1 DL CC1; BT_Threshold_DL + 3X ≤ C_VALUE < BT_Threshold_DL + 4X dB

1 1 0 DL CC1; BT_Threshold_DL + 4X ≤ C_VALUE < BT_Threshold_DL + 5X dB

1 1 1 DL CC1; C_VALUE ≥ BT_Threshold_DL + 5X dB

Case 3: EC SYSTEM INFORMATION indicates coverage classes 1 and 4 are supported:

bit

3 2 1

0 0 0 DL CC4

0 0 1 DL CC1; BT_Threshold_DL ≤ C_VALUE < BT_Threshold_DL + X dB

0 1 0 DL CC1; BT_Threshold_DL + X ≤ C_VALUE < BT_Threshold_DL + 2X dB

0 1 1 DL CC1; BT_Threshold_DL + 2X ≤ C_VALUE < BT_Threshold_DL + 3X dB

1 0 0 DL CC1; BT_Threshold_DL + 3X ≤ C_VALUE < BT_Threshold_DL + 4X dB

1 0 1 DL CC1; BT_Threshold_DL + 4X ≤ C_VALUE < BT_Threshold_DL + 5X dB

1 1 0 DL CC1; BT_Threshold_DL + 5X ≤ C_VALUE < BT_Threshold_DL + 6X dB

1 1 1 DL CC1; C_VALUE ≥ BT_Threshold_DL + 6X dB

X is defined by the DL_Signal_Strength_Step_Size field (see sub-clause 9.1.43q). When determining the value of this field the received signal level based measurements (RLA_EC) or SINR based measurements (SLA) are used to determine the C-value, see 3GPP TS 45.008 [34].

Access Discriminator (1 bit field)

This field indicates whether the MS sending an access request 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 Radio access part of MTA procedure using the RLC Data Block method

1 Page Response for a positioning event

Signal Strength (3 bit field)

This field indicates the extent to which the received power exceeds the CC1 threshold:

bit

3 2 1

0 0 0 DL CC1; BT_Threshold_DL ≤ C_VALUE < BT_Threshold_DL + X dB

0 0 1 DL CC1; BT_Threshold_DL + X ≤ C_VALUE < BT_Threshold_DL + 2X dB

0 1 0 DL CC1; BT_Threshold_DL + 2X ≤ C_VALUE < BT_Threshold_DL + 3X dB

0 1 1 DL CC1; BT_Threshold_DL + 3X ≤ C_VALUE < BT_Threshold_DL + 4X dB

1 0 0 DL CC1; BT_Threshold_DL + 4X ≤ C_VALUE < BT_Threshold_DL + 5X dB

1 0 1 DL CC1; BT_Threshold_DL + 5X ≤ C_VALUE < BT_Threshold_DL + 6X dB

1 1 0 DL CC1; BT_Threshold_DL + 6X ≤ C_VALUE < BT_Threshold_DL + 7X dB

1 1 1 DL CC1; C_VALUE ≥ BT_Threshold_DL + 7X dB

X is defined by the DL_Signal_Strength_Step_Size field (see sub-clause 9.1.43q). When determining the value of this field the received signal level based measurements (RLA_EC) or SINR based measurements (SLA) are used to determine the C-value, see 3GPP TS 45.008 [34].

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)
For the definition of these three last information fields see 3GPP TS 44.060.

Short ID (8 bit field)

This field identifies the cell specific Short ID value used by a MS performing the radio access part of the MTA procedure using the Access Burst method (see sub-clause 3.11). The Short ID value used by a MS in a given cell is pre-determined (selected by the SMLC and is included in the RRLP Multilateration Timing Advance message sent to a MS to trigger the Multilateration Timing Advance procedure – see 3GPP TS 44.031). It allows the BSS 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 EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 1’ or ‘Extended Access Burst Method – part 2’. It is coded as described in 3GPP TS 44.060 [76]).

It consists of the 4 least significant bits of a Random ID parameter provided in the RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031).

Random ID High (12 bit field)

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

Short BSS ID (3 bit field)

This field is sent as part of an EC 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).

MS Transmission Offset (4 bit field)

This field is sent as part of an EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 1’. It is coded as described in 3GPP TS 44.060 [76]).

MS Sync Accuracy (4 bit field)

This field is sent as part of an EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst Method – part 2’. It is coded per the value part of the "MS Synchronization Accuracy" IE defined in 3GPP TS 49.031.

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 for 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 the radio access part of the MTA procedure

1 Final access request for MTA procedure