11.2.6e EGPRS Packet Downlink Ack/Nack Type 2

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 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 Type 2

Direction: mobile station to network

Table 11.2.6e.1 : EGPRS Packet Downlink Ack/Nack TYPE 2 information elements

< EGPRS Packet Downlink Ack/Nack Type 2 message content > ::=

< DOWNLINK_TFI : bit (5) >

< MS OUT OF MEMORY : bit(1)>

{ 0 | 1 < EGPRS Channel Quality Report Type 2 : < EGPRS Channel Quality Report Type 2 IE > >}

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

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

{ 0 | 1 < EPD A/N Type 2 Extension length : bit (8) >

< bit (val(EPD A/N Type 2 Extension length) + 1)

& { < EPD A/N Type 2 Extension Info > ! { bit** = <no string> }} > }

— Truncation of the EGPRS Ack/Nack Description is allowed if the mobile station is assigned a downlink

— dual carrier configuration and the available space in the message without EGPRS Ack/Nack Description IE

— does not allow for the inclusion of a valid EGPRS Ack/Nack Description IE, i.e. is less than 16 bits.

— In the same conditions, the receiver shall assume that no EGPRS Ack/Nack description IE is included.

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

{ — Rel-14 extension

{ 0 | 1 < MS Transmission Offset : bit (4) >

< MS Sync Accuracy : bit (4) > }

}

<padding bits > } ;

< EPD A/N Type 2 Extension Info > ::=

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

< EARLY_TBF_ESTABLISHMENT : bit (1) >

{ 0 | 1 < Secondary Dual Carrier Channel Report : < EGPRS Channel Quality Report Type 2 IE > }

< spare bit >** // ; — Truncation may occur between released versions of the protocol

— The receiver shall assume the value zero of any truncated bits

Table 11.2.6e.2: EGPRS Packet Downlink Ack/Nack TYPE 2 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. On DBPSCH, this field equals the radio bearer identity of the radio bearer to which this message applies.

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. If a PFI field is included in this message, it relates to the TBF request contained in the Channel Request Description IE. Neither this IE nor the PFI field shall be included if the Extended Channel Request Description IE is included.

Extended Channel Request Description
This information element is defined in sub-clause 12.7b. This IE contains a request for one or more additional uplink TBFs and shall only be included if the mobile station and the network support multiple TBF procedures. If this IE is included, the Channel Request Description IE and PFI field in the message shall be omitted.

EGPRS Channel Quality Report Type 2 IE
This information element is defined in sub-clause 12.5a.1. For a mobile station with a dual carrier downlink assignment, this IE shall contain measurements corresponding to the downlink carrier which is paired with the uplink carrier on which this message is being sent.

PFI (7 bit field)
This field contains the PFI parameter identifying a Packet Flow Context relating to the resource request specified in the Channel Request Description IE. The PFI parameter is encoded as the contents of the PFI information element as defined in 3GPP TS 44.018. 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. If this field is included but the Channel Request Description IE is omitted, this field shall be ignored.

EARLY_TBF_ESTABLISHMENT (1 bit field)

This field indicates whether or not the channel request is meant to request pre-allocation of an uplink TBF:

0 The channel request is not meant to pre-allocate an uplink TBF.
1 The channel request is meant to pre-allocate an uplink TBF.

Secondary Dual Carrier Channel Report

This information element is described in sub-clause 12.5a.1. For a mobile station with a dual carrier downlink assignment, this IE shall contain measurements corresponding to the downlink carrier which is not paired with the uplink carrier on which this message is being sent. This IE shall not be included by an MS with a single carrier downlink assignment.

MS Transmission Offset (4 bit field)

If a downlink TBF is established using a downlink assignment message indicating “MS Transmission Offset” and “MS Sync Accuracy” parameters are needed then this field is included (8.1.2.2). It is coded as described in sub-clause 10.4.33.

MS Sync Accuracy (4 bit field)

If a downlink TBF is established using a downlink assignment message indicating “MS Transmission Offset” and “MS Sync Accuracy” parameters are needed then this field is included (8.1.2.2). It is coded as described in sub-clause 10.4.32.