11.2.28 Packet Uplink Ack/Nack

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 on the PACCH by the network to the mobile station indicate the status of the received RLC data blocks. This message may also update the timing advance and power control parameters. A fixed allocation mobile station may also be assigned uplink resources.

Message type: PACKET UPLINK ACK/NACK

Direction: network to mobile station

Classification: non-distribution message

Table 11.2.28.1: Packet UPlink Ack/Nack information elements

< Packet Uplink Ack/Nack message content > ::=

< PAGE MODE : bit (2) >

{ 00 < UPLINK_TFI : bit (5) >

{ 0 — Message escape

{ < CHANNEL_CODING_COMMAND : bit (2) >

< Ack/Nack Description : < Ack/Nack Description IE > >

{ 0 | 1 < CONTENTION_RESOLUTION_TLLI : bit (32) > }

{ 0 | 1 < Packet Timing Advance : < Packet Timing Advance IE > > }

{ 0 | 1 < Power Control Parameters : < Power Control Parameters IE > > }

{ 0 | 1 < Extension Bits : Extension Bits IE > } — sub-clause 12.26

{ 0 | 1 < Fixed Allocation Parameters : < Fixed Allocation struct > > }

{ null | 0 bit** = < no string > — Receiver backward compatible with earlier version

| 1 — Additions for R99

{ 0 | 1 <Packet Extended Timing Advance : bit (2)>}

<TBF_EST : bit (1)>

< padding bits > }

! < Non-distribution part error : bit (*) = < no string > > }

| 1 — Message escape bit used to define EGPRS message contents

{ 00 { < EGPRS Channel Coding Command : < EGPRS Modulation and Coding IE >>

< RESEGMENT : bit (1) >

< PRE_EMPTIVE_TRANSMISSION : bit (1) >

< PRR RETRANSMISSION REQUEST : bit (1) >

< ARAC RETRANSMISSION REQUEST : bit (1) >

{ 0 | 1 < CONTENTION_RESOLUTION_TLLI : bit (32) > }

<TBF_EST : bit (1)>

{ 0 | 1 < Packet Timing Advance : < Packet Timing Advance IE > > }

{ 0 | 1 <Packet Extended Timing Advance : bit (2)> }

{ 0 | 1 < Power Control Parameters : < Power Control Parameters IE > > }

{ 0 | 1 < Extension Bits : Extension Bits IE > } — sub-clause 12.26

{ < EGPRS Ack/Nack Description : < EGPRS Ack/Nack Description IE > >

{ 0 | 1 < Fixed Allocation Parameters : < Fixed Allocation struct > > } } //

< padding bits >

! < Non-distribution part error : bit (*) = < no string > > }

! < Message escape : {01| 10 | 11} bit (*) = <no string> > } } — Extended for future changes

! < Address information part error : bit (*) = < no string > > }

! < Distribution part error : bit (*) = < no string > > ;

< Fixed Allocation struct > ::=

< FINAL_ALLOCATION : bit (1) >

{ 0 — Repeat Allocation

< TS_OVERRIDE : bit (8) >

| 1 — Allocation with Allocation bitmap

< TBF Starting Time : < Starting Frame Number Description IE > >

{ 0 | 1 <TIMESLOT_ALLOCATION : bit (8) > }

{ 0 { 0 — with length of Allocation Bitmap

< BLOCKS_OR_BLOCK_PERIODS : bit (1) >

< ALLOCATION_BITMAP_LENGTH : bit (7) >

< ALLOCATION_BITMAP : bit (val(ALLOCATION_BITMAP_LENGTH)) >

| 1 — without length of Allocation Bitmap (fills remainder of the message)

< ALLOCATION_BITMAP : bit ** > }

! < Message escape : 1 bit (*) = <no string> > };

Table 11.2.28.1: Packet UPlink Ack/Nack information element details

PAGE_MODE (2 bit field)
This field is defined in sub-clause 12.20.

UPLINK_TFI (5 bit field)
This field identifies the uplink TBF to which this message applies. This field is coded the same as the TFI field defined in sub-clause 12.15.

CHANNEL_CODING_COMMAND (2 bit field)
The Channel Coding Indicator field indicates the channel coding scheme that the mobile station shall use when transmitting on the uplink.

bits
2 1 value
0 0 CS-1
0 1 CS-2
1 0 CS-3
1 1 CS-4

Ack/Nack Description
This information element is defined in sub-clause 12.3.

EGPRS Modulation and Coding Scheme
The EGPRS Modulation and Coding Scheme information element is defined in sub-clause 12.10d.

RESEGMENT (1 bit field)
This field is defined in sub-clause 12.10e.

PRE_EMPTIVE_TRANSMISSION (1 bit field)
This bit informs the mobile station if it may or may not transmit the oldest RLC data block whose corresponding element in V(B) has the value PENDING_ACK (and repeating the process, refer to sub-clause 9.1.3.2) when the protocol is stalled or has no more RLC data blocks to transmit.

0 The mobile station shall not use pre-emptive transmission.
1 The mobile station shall use pre-emptive transmission.

PRR RETRANSMISSION REQUEST (1 bit field)

0 indicates that retransmission of a PACKET RESOURCE REQUEST message is not requested

1 indicates that retransmission of a PACKET RESOURCE REQUEST message is requested

ARAC RETRANSMISSION REQUEST (1 bit field)

0 indicates that retransmission of an ADDITIONAL MS RADIO ACCESS CAPABILITIES message is not requested

1 indicates that retransmission of an ADDITIONAL MS RADIO ACCESS CAPABILITIES message is requested

EGPRS Ack/Nack Description
This information element is defined in sub-clause 12.3.1. The number of bits (L) available for Ack/Nack Description information element depends on the inclusion of other information elements. L may be set so that the entire EGPRS PACKET UPLINK ACK/NACK message evenly fits into an RLC/MAC control block. If a lower L covers the entire receive window, that L may be used.

CONTENTION_RESOLUTION_TLLI (32 bit field)
The CONTENTION_RESOLUTION_TLLI field is present only if the network has decoded one of the uplink RLC data blocks containing the TLLI. The mobile station shall perform the contention resolution function if the TLLI information element is present. This field contains a TLLI, which is defined in sub-clause 12.16.

Packet Timing Advance
This information element is defined in sub-clause 12.12.

TIMESLOT_ALLOCATION (8 bit field)
This field is defined in sub-clause 12.18.

Power Control Parameters
This information element, if present, contains power control command for the mobile station. If this information element is not present for certain previously allocated timeslots, the MS shall continue to use the previous power on these timeslots. This information element is defined in sub-clause 12.13.

Extension Bits
This information element, if present, shall be skipped over. Any information content shall be ignored by the mobile station. This information element is defined in sub-clause 12.26.

FINAL_ALLOCATION (1 bit field)
This field indicates whether this allocation is the last allocation of the TBF.

0 this allocation is not the last allocation of the TBF
1 this allocation is the last allocation of the TBF

Repeat Allocation
If present, the mobile station shall repeat the current allocation after the current allocation ends.

TS_OVERRIDE (8 bit field)
This is defined in sub-clause 12.19.

Allocation with Allocation bitmap
If present, the mobile station shall use the included Allocation bitmap and associated parameters. The mobile station shall not repeat the current allocation after the current allocation ends.

BLOCKS_OR_BLOCK_PERIODS (1 bit field)
This indicates if the ALLOCATION_BITMAP is to be interpreted as blocks or block periods.

0 the ALLOCATION_BITMAP is to be interpreted as blocks
1 the ALLOCATION_BITMAP is to be interpreted as block periods

ALLOCATION_BITMAP_LENGTH (7 bit field)
This field specifies the number of bits in the ALLOCATION_BITMAP.
Range 0 to 127

TBF Starting Time
The TBF Starting Time field contains a starting time that indicates the earliest frame number during which the assigned TBF may start.

In case of dynamic allocation, the MS shall continue to use the parameters of the existing TBF until the TDMA frame number occurs. When the indicated TDMA frame number occurs, the mobile station shall immediately begin to monitor the USF field and use the new assigned uplink TBF parameters when its USF has occurred.

In case of fixed allocation, the MS shall continue to use the parameters of the existing TBF until the TDMA frame number occurs. When the TDMA frame number occurs, the MS shall then use the assigned uplink resources from the indicated TDMA frame number forward, according to the parameters in the fixed allocation struct.

This information element is defined in sub-clause 12.21.

ALLOCATION_BITMAP (variable length field)
The ALLOCATION_BITMAP field is variable length. If the ALLOCATION_BITMAP_LENGTH field is not present, the ALLOCATION_BITMAP fills the remainder of the message. If the BLOCKS_OR_BLOCK_PERIODS field is not present, then the ALLOCATION_BITMAP should be interpreted as blocks. This field is defined in sub-clause 12.4.

Packet Extended Timing Advance (2 bit field)
This field is defined in sub-clause 12.12b.

TBF_EST (1 bit field)
If included, this field indicates that the mobile station is allowed to request the establishment of new TBF on PACCH.

0 the mobile station is not allowed to request the establishment of new TBF

1 the mobile station is allowed to request the establishment of new TBF