9.1.60 EC IMMEDIATE ASSIGNMENT TYPE 2

3GPP44.018GSM/EDGE Radio Resource Control (RRC) protocolMobile radio interface Layer 3 specificationRelease 16TS

This message is sent on the EC-CCCH by the network to assign uplink packet resources to a mobile station that has enabled EC operation and attempts system access using the 1TS EC-RACH Mapping method or the 2TS EC-RACH Mapping method (see sub-clause 3.5.2.1.2a). When sending this message the network assigns pre-allocated uplink resources to the mobile station (see sub-clause 3.5.2.1.3a).

Message type: EC IMMEDIATE ASSIGNMENT TYPE 2

Significance: dual

Direction: network to mobile station

Table 9.1.60.1: EC IMMEDIATE ASSIGNMENT TYPE 2 message content

< EC Immediate Assignment Type 2 message content > ::=

< Message Type : bit (4) >

< Used DL Coverage Class : bit (2) >

{ 0 | 1 < EC Page Extension : bit (4) > }

< EC Request Reference : bit (13) >

< EC Packet Channel Description Type 2 : bit (15) >

< EC Fixed Uplink Allocation : < EC Fixed Uplink Allocation struct >>

<spare padding> ;

< EC Fixed Uplink Allocation struct > ::=

< Enhanced Access Burst : bit (1) >

{ 0 | 1 < Timing Advance : bit (6) }

< STARTING_UL_TIMESLOT: bit (3) >

< Uplink_TFI_Assignment : bit (5) >

< STARTING_DL_TIMESLOT_OFFSET: bit (2) >

< OVERLAID_CDMA_CODE: bit (2) >

{ 0 – use MCS-1 for uplink packet transfer

| 1 < Assigned MCS : bit (4) > }

< GAMMA : bit (5) >

< ALPHA Enable : bit (1) >

{ 0 | 1 < P0 : bit (4) >

< PR_MODE : bit (1) > }

< Start_First_UL_Data_Block : bit (4) >

{ 1 { 0 < Start_FN_Next_Data_Block : bit (3) >

| 1 – no gap between last block and next block } } ** 0 ;

Table 9.1.60.2: EC IMMEDIATE ASSIGNMENT TYPE 2 message details

Message Type (4 bit field)

This field indicates the type of message sent on the EC-CCCH (see Table 10.4.4)

Used DL Coverage Class (2 bit field)

Control messages on the EC-AGCH or EC-PCH are sent using blind physical layer transmissions, depending on the assigned downlink coverage class for the mobile station that the message is being sent to. The Used DL Coverage Class field is included in order to inform other mobile stations about the downlink coverage class, and thus the number of blind physical layer transmissions, that have been used to transmit the current control message. Mobile stations that have selected a lower downlink coverage class than what is indicated by this field can, upon successfully reading the control message, can avoid monitoring any remaining blind physical layer transmissions used to send the control message. This field is coded as follows:

bit

2 1

0 0 DL CC 1

0 1 DL CC 2

1 0 DL CC 3

1 1 DL CC 4

EC Page Extension (4 bit field)

This field indicates whether an EC capable mobile station of a specific coverage class should attempt one additional instance of page reading on the EC-PCH (see sub-clause 3.5.1a) when it successfully reads a message when waking up according to its nominal paging group but does not receive a matching page. This field is coded as follows:

bit

4 3 2 1

1 X X X mobile stations using downlink CC1shall attempt one additional page reading

X 1 X X mobile stations using downlink CC2 shall attempt one additional page reading

X X 1 X mobile stations using downlink CC3 shall attempt one additional page reading

X X X 1 mobile stations using downlink CC4 shall attempt one additional page reading

EC Request Reference (13 bit field)

This field is coded as described in sub-clause 10.5.2.83

EC Packet Channel Description Type 2 (15 bit field)

This information element is coded as described in sub-clause 10.5.2.85

Enhanced Access Burst (1 bit field)

This field indicates whether or not the mobile station shall use the Enhanced Access Burst procedure for contention resolution (see 3GPP TS 44.060) on the assigned EC TBF. This field is coded as follows:

Bit

0 The Enhanced Access Burst procedure shall not be used

1 The Enhanced Access Burst procedure shall be used

Timing Advance (6 bit field)

This field provides the timing advance value and is coded as per the value part of the Timing Advance IE described in sub-clause 10.5.2.40, with the value range limited to 0 to 63. If this field is not included the mobile station shall use a default value of 0 (i.e. no timing advance).

STARTING_UL_TIMESLOT (3 bit field)

This field indicates the first assigned timeslot within the set of assigned uplink timeslots.:

Bit

3 2 1

0 0 0 Timeslot 0 is the first assigned uplink timeslot

0 0 1 Timeslot 1 is the first assigned uplink timeslot

0 1 0 Timeslot 2 is the first assigned uplink timeslot

0 1 1 Timeslot 3 is the first assigned uplink timeslot

1 0 0 Timeslot 4 is the first assigned uplink timeslot

1 0 1 Timeslot 5 is the first assigned uplink timeslot

1 1 0 Timeslot 6 is the first assigned uplink timeslot

1 1 1 Timeslot 7 is the first assigned uplink timeslot

If the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q): a mobile station assigned CC2, CC3 or CC4 on the uplink is always assigned the use of 4 consecutive timeslots and therefore only timeslot 0, 1, 2, 3 or 4 shall be indicated as the first assigned uplink timeslot.

If the field EC_Reduced_PDCH_Allocation is set to 1 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q): A mobile station assigned CC2, CC3 or CC4 on the uplink is always assigned the use of 2 consecutive timeslots and therefore only timeslot 0, 1, 2, 3, 4, 5 or 6 shall be indicated as the first assigned uplink timeslot.

Uplink_TFI_Assignment (5 bit field)

This field is the binary representation of the Temporary Flow Identity, see 3GPP TS 44.060. Range: 0 to 31.

STARTING_DL_TIMESLOT_OFFSET (2 bit field)

This field defines the timeslot number of the lowest timeslot included in the assignment that is used for transfer of downlink RLC/MAC control messages on the EC-PACCH during the UL EC TBF. The number of additional timeslots that are included in the downlink assignment depends on the assigned DL Coverage Class. The assigned timeslots are contiguous, starting with the timeslot number indicated in the STARTING_DL_TIMESLOT_OFFSET field. The STARTING_DL_TIMESLOT_OFFSET field is encoded as an offset to the timeslot assigned with the STARTING_UL_TIMESLOT field. The encoding of the field is dependent of the value of the UL_COVERAGE_CLASS and DL_COVERAGE_CLASS fields in the same message.

If both UL_COVERAGE_CLASS and DL_COVERAGE_CLASS > CC1, the same timeslots are assigned in both the uplink and the downlink directions. The STARTING_DL_TIMESLOT_OFFSET field can then be considered as not valid by the mobile station.

If UL_COVERAGE_CLASS = CC1 and DL_COVERAGE_CLASS > CC1, the STARTING_DL_TIMESLOT_OFFSET field is encoded according to the following code points if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). If the field EC_Reduced_PDCH_Allocation is set to 1 only the first two code points of the following shall be used:

bit

2 1

0 0       Same timeslot as indicated by STARTING_UL_TIMESLOT

0 1       STARTING_UL_TIMESLOT – 1

1 0       STARTING_UL_TIMESLOT – 2

1 1       STARTING_UL_TIMESLOT – 3

If UL_COVERAGE_CLASS > CC1 and DL_COVERAGE_CLASS = CC1, the STARTING_DL_TIMESLOT_OFFSET field is encoded according to the following code points if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). If the field EC_Reduced_PDCH_Allocation is set to 1 only the first two code points of the following shall be used:

bit

2 1

0 0       Same timeslot as indicated by STARTING_UL_TIMESLOT

0 1       STARTING_UL_TIMESLOT + 1

1 0       STARTING_UL_TIMESLOT + 2

1 1       STARTING_UL_TIMESLOT + 3

If both UL_COVERAGE_CLASS and DL_COVERAGE_CLASS = CC1, the downlink is assigned to the timeslot indicated by the STARTING_UL_TIMESLOT field. If timer T3248 (sent in EC SI) is used, the STARTING_DL_TIMESLOT_OFFSET field defines the lowest assigned timeslot for EC-PACCH transfers using CC2 while timer T3248 is running (see 3GPP TS 44.060). The STARTING_DL_TIMESLOT_OFFSET field is then encoded according to the following code points if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). If the field EC_Reduced_PDCH_Allocation is set to 1 only the first two code points of the following shall be used:

bit

2 1

0 0       Same timeslot as indicated by STARTING_UL_TIMESLOT

0 1       STARTING_UL_TIMESLOT – 1

1 0       STARTING_UL_TIMESLOT – 2

1 1       No valid CC2 mapping applies while T3248 is running, CC1 to be used

If the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q), a mobile station using CC2, CC3 or CC4 on the downlink is always assigned the use of 4 consecutive timeslots. If the field EC_Reduced_PDCH_Allocation is set to 1 in the EC SYSTEM INFORMATION TYPE 2 message (sub-clause 9.1.43q), a mobile station using CC2, CC3 or CC4 on the downlink is always assigned the use of 2 consecutive timeslots.

OVERLAID_CDMA_CODE (2 bit field)

This field indicates the type overload CDMA code to be used for an uplink TBF (see 3GPP TS 45.002 [32]). This field is coded according to the following code points if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). If the field EC_Reduced_PDCH_Allocation is set to 1 only the first two code points of the following shall be used:

bit

2 1

0 0       Overlaid CDMA Code 0

0 1       Overlaid CDMA Code 1

1 0       Overlaid CDMA Code 2

1 1       Overlaid CDMA Code 3 

Note: Overlaid CDMA Code 0 corresponds to that the bursts are transmitted as if no code was applied.

Assigned MCS (4 bit field)

This field is coded as per EGPRS Modulation and Coding Scheme IE decribed in 3GPP TS 44.060.

GAMMA (5 bit field)

This field is the binary representation of the parameter CH for MS output power control in units of 2 dB, see 3GPP TS 45.008.

ALPHA Enable (1 bit field)

This field indicates whether or not the mobile station shall use the ALPHA parameter (if sent as part of EC SI) for uplink power control (see 3GPP TS 45.008 [34]). This field is coded as follows:

0 Do not use the ALPHA parameter

1 Use the ALPHA parameter

P0 (4 bit field)

For description and encoding, see the Packet Uplink Assignment message in 3GPP TS 44.060.

PR_MODE (1 bit field)

For description and encoding, see the Packet Uplink Assignment message in 3GPP TS 44.060.

Start_First_UL_Data_Block (4 bit field)

This field identifies the uplink transmission opportunity corresponding to the assigned uplink coverage class (see the EC Packet Channel Description Type 2 IE described in sub-clause 10.5.2.85) that the mobile station is to use to start sending its first uplink RLC data block on the set of assigned uplink timeslots. The 1st transmission opportunity occurs no earlier than in TDMA frame N+10 where TDMA frame N is the last TDMA frame used for transmission of the EC IMMEDIATE ASSIGNMENT TYPE 1 or EC IMMEDIATE ASSIGNMENT TYPE 2 message. See 3GPP TS 45.010 [35] for mobile station reaction time requirements applicable to receiving an assignment message. This field is coded as follows:

Bit

4 3 2 1

0 0 0 0 Use the 1st transmission opportunity

0 0 0 1 Use the 2nd transmission opportunity

0 0 1 0 Use the 3rd transmission opportunity

.

.

.

1 1 1 1 Use the 16th transmission opportunity

For CC1 the Kth transmission opportunity = the Kth BTTI radio block on the assigned timeslot occurring after TDMA frame N+9. The Kth BTTI radio block occurs in one of {B0, B1, …B11} (see 3GPP TS 45.002 [32]), whichever occurs first after TDMA frame N+9.

For CC2 the Kth transmission opportunity = the Kth set of 4 BTTI radio blocks on the assigned timeslots occurring after TDMA frame N+9. The Kth set of 4 BTTI radio blocks occurs in one of {B0, B1, …B11}, if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q), whichever occurs first after TDMA frame N+9. The Kth set of 4 BTTI radio blocks occurs in one of {B0, B1, …B5} (see 3GPP TS 45.003[86]), if the field EC_Reduced_PDCH_Allocation is set to 1, whichever occurs first after TDMA frame N+9.

For CC3 the Kth transmission opportunity = the Kth set of 8 BTTI radio blocks on the assigned timeslots occurring after TDMA frame N+9. The Kth set of 8 BTTI radio blocks occurs in one of {[B0, B1], [B2, B3], …[B10, B11]}, if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q), whichever occurs first after TDMA frame N+9. The Kth set of 8 BTTI radio blocks occurs in one of {B0, B1, B2} see 3GPP TS 45.003[86]), if the field EC_Reduced_PDCH_Allocation is set to 1, whichever occurs first after TDMA frame N+9.

For CC4 the Kth transmission opportunity = the Kth set of 16 BTTI radio blocks on the assigned timeslots occurring after TDMA frame N+9. The Kth set of 16 BTTI radio blocks occurs in one of {[B0, B1, B2, B3], [B4, B5, B6, B7], [B8, B9, B10, B11]}, if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q), whichever occurs first after TDMA frame N+9. The Kth set of 16 BTTI radio blocks occurs in one of {B0, B1, B2} see 3GPP TS 45.003[86]), if the field EC_Reduced_PDCH_Allocation is set to 1, whichever occurs first after TDMA frame N+9.

Start_FN_Next_Data_Block (3 bit field)

This field identifies the gap (in coverage class specific transmission opportunities) between the last pre-allocated uplink radio block transmitted on assigned uplink timeslots and the next pre-allocated uplink radio block to be used for the uplink transmission. This field is coded as follows:

Bit

3 2 1

0 0 0 a gap of 1 transmission opportunity

0 0 1 a gap of 2 transmission opportunities

0 1 0 a gap of 3 transmission opportunities

.

.

.

1 1 1 a gap of 8 transmission opportunities

For CC1 a gap of K transmission opportunities = K BTTI radio blocks on the assigned timeslot occurring immediately after the last BTTI radio block used for the uplink transmission. Any BTTI radio block in the set of {B0, B1, …B11} counts as a gap of one CC1 transmission opportunity (see 3GPP TS 45.002 [32]).

For CC2 a gap of K transmission opportunities = K sets of 4 BTTI radio blocks on the assigned timeslots occurring immediately after the last set of 4 BTTI radio blocks used for the uplink transmission. Each set of 4 BTTI radio blocks occurring in one of {B0, B1, …B11} counts as a gap of one CC2 transmission opportunity, if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). Else if the field EC_Reduced_PDCH_Allocation is set to 1, each set of 4 BTTI radio blocks occurring in one of {B0, B1, …B5} (see 3GPP TS 45.003[86]) counts as a gap of one CC2 transmission opportunity.

For CC3 a gap of K transmission opportunities = K sets of 8 BTTI radio blocks on the assigned timeslots occurring immediately after the last set of 8 BTTI radio blocks used for the uplink transmission. Each set of 8 BTTI radio blocks occurring in one of {[B0, B1], [B2, B3],…[B10, B11]} counts as a gap of one CC3 transmission opportunity, if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). Else if the field EC_Reduced_PDCH_Allocation is set to 1, each set of 8 BTTI radio blocks occurring in one of {B0, B1, B2} (see 3GPP TS 45.003[86]) counts as a gap of one CC3 transmission opportunity.

For CC4 a gap of K transmission opportunities = K sets of 16 BTTI radio blocks on the assigned timeslots occurring immediately after the last set of 16 BTTI radio blocks used for the uplink transmission. Each set of 16 BTTI radio blocks occurring in one of {[B0, B1, B2, B3], [B4, B5, B6, B7], [B8, B9, B10, B11]} counts as a gap of one CC4 transmission opportunity, if the field EC_Reduced_PDCH_Allocation is set to 0 in the EC SYSTEM INFORMATION TYPE 2 message (see sub-clause 9.1.43q). Else if the field EC_Reduced_PDCH_Allocation is set to 1, each set of 16 BTTI radio blocks occurring in one of {B0, B1, B2} (see 3GPP TS 45.003[86]) counts as a gap of one CC4 transmission opportunity.