11.2.6a EGPRS Packet Downlink 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 from the mobile station to the network to indicate the status of downlink RLC data blocks received and to report the channel quality of the downlink. The mobile station may optionally initiate an uplink TBF or request a temporary suspension of the downlink TBF.

Message type: EGPRS Packet Downlink Ack/Nack

Direction: mobile station to network

Table 11.2.6a.1 : EGPRS Packet Downlink Ack/Nack information elements

< EGPRS Packet Downlink Ack/Nack message content > ::=

< DOWNLINK_TFI : bit (5) >

< MS OUT OF MEMORY : bit(1)>

{ 0 | 1 < EGPRS Channel Quality Report : < EGPRS Channel Quality Report IE > >}

{ 0 | 1 < Channel Request Description : >Channel Request Description IE > >}

{ 0 | 1 < PFI : bit(7) > }

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

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

<padding bits > ;

Table 11.2.6a.2: EGPRS Packet Downlink Ack/Nack information element details

DOWNLINK_TFI (5 bit field)
This field contains the TFI of the mobile station’s downlink TBF. This field is defined in sub-clause 12.15.

EGPRS Ack/Nack Description IE (L bit field)
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 channel quality reports and channel requests. L shall be set so that the entire EGPRS Packet Downlink Ack/Nack message evenly fits into an RLC/MAC control block. If a lower L covers the entire receive window, that L shall be used.

MS OUT OF MEMORY (1 bit field)
This field indicates that the MS has no more enough memory to perform Incremental Redundancy.

0 The MS has enough memory
1 The MS is running out of memory

Channel Request Description IE
This information element is defined in sub-clause 12.7.

EGPRS Channel Quality Report IE
This information element is defined in sub-clause 12.5.1.

PFI (7 bit field)
This field contains the PFI parameter identifying a Packet Flow Context. The PFI parameter is encoded as the contents of the PFI information element as defined in 3GPP TS 24.008. This field may be included if the network supports packet flow context procedures and if a Channel Request Description IE is included in the message.