9 Medium Access Control (MAC) procedures on DBPSCH

3GPP44.160General Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocol Iu modeRelease 16TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

9.1 General

The MAC procedures defined in this sub-clause are applicable in MAC-Dedicated state and in MAC-DTM state on DBPSCH only. When a radio bearer is set-up on DBPSCH(s) (see 3GPP TS 44.118) the corresponding TBF is implicitly established, on this DBPSCH(s), on the logical channel (when FLO is not used) on which this TBF is mapped. This TBF shall use the TBF mode as specified in sub-clause 5.2.2.2 and according to the radio bearer attributes as may be indicated in the CMAC-CONFIG primitive received from RRC.

9.2 Transfer of RLC/MAC blocks

9.2.0 General

Tables 9.2.0.1 to 9.2.0.3 summarise the RLC/MAC control messages that may be sent on a DBPSCH.

Table 9.2.0.1: RLC/MAC control messages sent on PACCH or ADCH when mapped on DBPSCH

RLC messages:	Reference
Packet Downlink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.6
EGPRS Packet Downlink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.6a
Packet DBPSCH Downlink Ack/Nack Type 2	3GPP TS 44.060 sub-clause 11.2.6b
Packet Uplink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.28
Packet DBPSCH Uplink Ack/Nack Type 2	3GPP TS 44.060 sub-clause 11.2.28a
Miscellaneous messages:	Reference
Packet Control Acknowledgement	3GPP TS 44.060 sub-clause 11.2.2
Packet Downlink Dummy Control Block	3GPP TS 44.060 sub-clause 11.2.8
Packet Uplink Dummy Control Block	3GPP TS 44.060 sub-clause 11.2.8b
Packet Polling Request	3GPP TS 44.060 sub-clause 11.2.12
Packet Uplink Assignment	3GPP TS 44.060 sub-clause 11.2.29
Handover Access	3GPP TS 44.060 sub-clause 11.2.33
Physical Information	3GPP TS 44.060 sub-clause 11.2.34

Table 9.2.0.2: RLC/MAC control messages on SDCCH, SACCH,
FACCH (PT="01")

RLC messages:	Reference
Packet DBPSCH Downlink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.6b
Packet DBPSCH Uplink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.28a
Miscellaneous messages:	Reference
Packet Control Acknowledgement	3GPP TS 44.060 sub-clause 11.2.2
Packet Downlink Dummy Control Block	3GPP TS 44.060 sub-clause 11.2.8
Packet Uplink Dummy Control Block	3GPP TS 44.060 sub-clause 11.2.8b
Handover Access	3GPP TS 44.060 sub-clause 11.2.33
Physical Information (not on SACCH)	3GPP TS 44.060 sub-clause 11.2.34

Table 9.2.0.3: RLC/MAC control messages on FACCH (PT="10")

RLC messages:	Reference
Packet DBPSCH Downlink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.6b
Packet DBPSCH Uplink Ack/Nack	3GPP TS 44.060 sub-clause 11.2.28a
Miscellaneous messages:	Reference
Packet Control Acknowledgement	3GPP TS 44.060 sub-clause 11.2.2

9.2.1 Dedicated allocation

9.2.1.1 General

On DBPSCH, the transfer of RLC/MAC blocks is governed by the principles of the dedicated allocation. Dedicated allocation is applicable to GPRS TBF mode, EGPRS TBF mode, TCH TBF mode, DCCH TBF mode, UDCH TBF mode and CDCH TBF mode. No other medium access mode shall apply for TCH TBF mode, DCCH TBF mode, UDCH TBF mode and CDCH TBF mode.

A mobile station in dedicated allocation shall monitor the assigned DBPSCH(s). The mobile station shall attempt to decode every downlink RLC/MAC block on the assigned DBPSCH(s). Whenever the mobile station receives an RLC/MAC block containing an RLC/MAC control block, the mobile station shall attempt to interpret the message contained therein and act upon it.

Except for TCH TBF mode in T-RLC mode, PACKET UPLINK DUMMY CONTROL block(s) (respectively PACKET DOWNLINK DUMMY CONTROL block(s)) shall be sent in periods when no RLC/MAC block is scheduled for transmission in uplink direction (respectively downlink direction, following the scheduling requirements defined in 3GPP TS 45.008). For TCH TBF mode and UDCH TBF mode in T-RLC mode, DTX may apply.

9.2.1.2 Performance requirements for TCH and DCCH TBF modes

When the mobile station receives a DBPSCH assignment, the mobile station shall switch to the assigned DBPSCH(s) and be ready to transmit within the reaction time defined in 3GPP TS 45.010.

The network (NW) and the mobile station (MS) shall follow the performance requirements defined in the table below. These performance requirements are given on a logical channel and MAC state basis, and define the response time of the network and the mobile station upon receipt of a request from the remote peer entity, where:

– Trmin and Tresp denote respectively the minimum and maximum response times following the reception of a given request, expressed in TDMA frames, as follows:

– if a polling request is received whose last burst has been physically transmitted in the TDMA frame number FNcomm, then the first burst carrying a segment of the corresponding response shall be physically transmitted in the TDMA frame number FNresp where:

FNcomm + Trmin + 1 ≤ FNresp ≤ FNcomm + Tresp +1

– following the mapping of logical channels onto physical channels and the arithmetics on TDMA frame numbers specified in 3GPP TS 45.002.

Table 9.2.1.2.1: Response time

Request sent on

Response sent on

Trmin

Tresp (see note 1)

MAC-Dedicated state

MAC-DTM state

SDCCH

MS: 11

NW: TRMIN_SDCCH (32 or 83)

MS: 113

NW: TRESP_SDCCH (134 or 185, respectively)

Not applicable

SACCH

MS: 11

NW: 83

MS: 11

NW: 83

SACCH

(with a TCH or PDTCH)

SACCH

(with a TCH or PDTCH)

MS: 25

NW: TRMIN_SACCH (25 or 129)

MS: 129

NW: TRESP_SACCH (129 or 233, respectively)

MS: 25

NW: TRMIN_SACCH

FACCH/Full rate

MS: 9

NW: TRMIN

MS: 18 (max between 18 and 17)

NW: TRESP_MAC_Dedicated

MS: 14 (max between 13 and 14)

NW: TRESP_MAC_DTM

TCH/Full rate

FACCH/Full rate

MS: 9

NW: TRMIN

MS: 18 (max between 18 and 17)

NW: TRESP_MAC_Dedicated

MS: 14 (max between 13 and 14)

NW: TRESP_MAC_DTM

FACCH/Half rate

MS: 10

NW: TRMIN

MS: 28 (max between 28 and 27)

NW: TRESP_MAC_Dedicated

MS: 19 (max between 18 and 19)

NW: TRESP_MAC_DTM

NOTE 1: these values account for the maximum amount of Radio Bearers multiplexed on a given logical channel, and the priorities of associated RLC/MAC blocks. For FACCH, it also accounts for the RLC/MAC control signalling related to the traffic on the TCH.

NOTE 2: The combination TCH/H – FACCH/H is not supported.

NOTE 3: "max between n and m" is to account for the shift of the start of the FACCH block where the response is sent, that occurs depending on the end of the TCH/FACCH block where the request was sent. (due to a different number of idle/SACCH frames included in the counts).

9.2.1.3 Performance requirements for UDCH and CDCH TBF modes

On a DBPSCH where FLO is used, the network (NW) and the mobile station (MS) shall follow the performance requirements defined in the table below. These performance requirements are given on a transport channel and MAC state basis, and define the response time of the network and the mobile station upon receipt of a request from the remote peer entity, where:

– Trmin and Tresp denote respectively the minimum and maximum response times following the reception of a given request, expressed in TDMA frames, as follows:

FNcomm + Trmin + 1 ≤ FNresp ≤ FNcomm + Tresp +1

– following the mapping of transport channels onto physical channels and the arithmetics on TDMA frame numbers specified in 3GPP TS 45.002.

Table 9.2.1.3.1: Response time

Request sent on	Response sent on	Trmin	Tresp (see note 1)
			MAC-Dedicated state	MAC-DTM state
UDCH/Full rate	ADCH/Full rate	MS: 9 NW: TRMIN_DCH	MS: 31 (max between 31 and 30) NW: TRESP_DCH_MAC_Dedicated	MS: 27 (max between 27 and 26) NW: TRESP_DCH_MAC_DTM
CDCH/Full rate	ADCH/Full rate
ADCH/Full rate	ADCH/Full rate
UDCH/Half rate	ADCH/Half rate	MS: 10 NW: TRMIN_DCH	MS: 54 (max between 54 and 53) NW: TRESP_DCH_MAC_Dedicated	MS: 45 (max between 45 and 44) NW: TRESP_DCH_MAC_DTM
CDCH/Half rate	ADCH/Half rate
ADCH/Half rate	ADCH/Half rate
NOTE 1: these values account for the maximum amount of Radio Bearers multiplexed on DBPSCH, and the priorities of associated RLC/MAC blocks. For ADCH, it also accounts for the RLC/MAC control signalling related to TBFs in CDCH or UDCH TBF modes. NOTE 2: "max between n and m" is to account for the shift of the start of the FACCH block where the response is sent, that occurs depending on the end of the TCH/FACCH block where the request was sent. (due to a different number of idle/SACCH frames included in the counts). NOTE 3: these requirements are valid for both interleaving alternatives i.e. 20ms and 40ms.

9.2.2 Transfer of RLC/MAC blocks on TCH

One and only one TBF in TCH TBF mode may be mapped onto a TCH.

No RLC/MAC control blocks shall be sent on TCH. RLC/MAC control blocks belonging to a TBF in TCH TBF mode operating in NT-RLC mode shall be sent on FACCH with Payload Type (PT) = "10". No RLC/MAC control block shall be sent on FACCH if the corresponding TCH is occupied by a TBF operating in T-RLC mode unless this RLC/MAC control block belongs to a TBF in DCCH TBF mode mapped on this FACCH or carries a PHYSICAL INFORMATION message. The HANDOVER ACCESS message shall be sent on FACCH irrespective of the TBF mapped on TCH, following the rules defined in sub-clause 9.2.3.

An RLC/MAC control block carrying a PHYSICAL INFORMATION message on FACCH shall be sent with Payload Type (PT) = "01".

RLC/MAC blocks shall be transmitted with the following priority (highest priority first):

– RLC/MAC blocks on FACCH, except Packet Uplink/Downlink Dummy Control Blocks;

– RLC data blocks on TCH;

– RLC/MAC control blocks on FACCH containing Packet Uplink/Downlink Dummy Control Blocks.

9.2.3 Transfer of RLC/MAC blocks on FACCH, SACCH and SDCCH

A TBF associated with a URB may operate in DCCH TBF mode but shall not be mapped on SACCH.

On SACCH, MAC shall ensure the following as long as there is data to send for SRB1, and SRB3 and/or SRB4:

– every second RLC/MAC block sent on SACCH shall belong to SRB1, and the other to SRB3 or SRB4, and

– every second RLC/MAC block belonging to SRB1 shall be discarded, the other shall be sent on SACCH.

All RLC data blocks belonging to a TBF in DCCH TBF mode shall be encoded using CS-1.

The mobile station shall attempt to decode every downlink RLC/MAC block on FACCH, SACCH or SDCCH. Whenever the mobile station receives an RLC/MAC block containing an RLC/MAC control block, the mobile station shall attempt to interpret the message contained therein, and shall act on it.

Each RLC data block sent on FACCH, SACCH or SDCCH shall contain a Reduced Radio Bearer identity (RRBid) field corresponding to the radio bearer to which the RLC data block belongs.

On SDCCH, all the RLC data blocks of an uplink TBF shall each contain a G-RNTI field in the RLC data block header until contention resolution is completed on the mobile station side (see sub-clause 7.2.3.3.2.3). After the reaction time specified in 3GPP TS 45.010 no other RLC data blocks shall contain a G-RNTI field, except for those retransmitted RLC data blocks that originally contained a G-RNTI, which will be repeated including the same G-RNTI.

RLC/MAC blocks and HANDOVER ACCESS message shall be transmitted with the following priority (highest priority first):

– HANDOVER ACCESS message

– RLC/MAC control blocks with a Payload Type (PT) = "01" i.e. related to a TBF in DCCH TBF mode or carrying a PHYSICAL INFORMATION message, except Packet Uplink/Downlink Dummy Control blocks;

– RLC data blocks containing a piggy-backed acknowledgement;

– RLC/MAC control blocks with a Payload Type (PT) = "10" i.e. related to a TBF in TCH TBF mode, except Packet Uplink/Downlink Dummy Control blocks;

– RLC data blocks not containing a piggy-backed acknowledgement;

– RLC/MAC control blocks containing Packet Uplink/Downlink Dummy Control Blocks.

9.2.4 Transfer of RLC/MAC blocks on PDTCH and PACCH

9.2.4.1 General

9.2.4.1.1 Downlink transfer

9.2.4.1.1.1 General

RLC/MAC blocks shall be transmitted in the downlink with the following priority (highest priority first):

– RLC/MAC control blocks except Packet Downlink Dummy Control blocks;

– RLC data blocks;

– RLC/MAC control blocks containing Packet Downlink Dummy Control Blocks.

If the network has no other RLC/MAC block to transmit, but wishes to transmit on the downlink (e.g. to provide USF), the network shall transmit an RLC/MAC control block containing a Packet Downlink Dummy Control block.

9.2.4.1.1.2 Polling for Packet Downlink Ack/Nack

Whenever the mobile station receives an RLC data block addressed to (one of) its TBF(s) with a valid RRBP field in the RLC data block header (i.e. is polled), the mobile station may transmit a (EGPRS) Packet Downlink ACK/NACK message in the uplink radio block specified by the RRBP field whatever the BSN value of the received RLC data block, unless another RLC/MAC control message is waiting to be transmitted, in which case the other RLC/MAC control message shall be sent. The mobile station shall transmit an RLC/MAC control message other than a (EGPRS) PACKET DOWNLINK ACK/NACK message at most every second time it is polled for that TBF. Furthermore the mobile station shall not transmit an RLC/MAC control message on this TBF other than a (EGPRS) PACKET DOWNLINK ACK/NACK message if the (EGPRS) PACKET DOWNLINK ACK/NACK message contains a Final Ack Indicator set to ‘1’ and shall not start T3192. The mobile station shall not send a PACKET CONTROL ACKNOWLEDGEMENT message unless otherwise specified (see sub-clause 9.3).The mobile station shall not send the Iu mode channel request description field in the (EGPRS) PACKET DOWNLINK ACK/NACK message.

In EGPRS TBF mode the mobile station shall react on a poll inside an erroneously received RLC data block for which the header is correctly received.

Whenever the network receives a valid RLC/MAC control message from the TBF, it shall reset counter N3105. The network shall increment counter N3105 for each radio block allocated to that TBF with the RRBP field, for which no RLC/MAC control message is received. If N3105 = N3105max, the network shall start timer T3195. When T3195 expires, the network shall notify a link failure to the RRC layer.

The PACKET DOWNLINK ACK/NACK message contains a Channel Quality Report (see 3GPP TS 45.008). The optional I_LEVEL measurement results shall be included in at least every other PACKET DOWNLINK ACK/NACK message.

The EGPRS PACKET DOWNLINK ACK/NACK message may contain an EGPRS Channel Quality Report (see 3GPP TS 45.008).

In the case of simultaneous uplink and downlink TBFs, the transmission of the polling response takes precedence over the transmission of allocated uplink radio blocks.

A mobile station of multislot class 1 to 12 need not respond to the poll if it is not compliant with the mobile station’s multislot class (see 3GPP TS 45.002).

A mobile station of multislot class 13 to 18 shall always respond to the poll.

9.2.4.1.2 Uplink transfer

9.2.4.1.2.1 General

RLC/MAC blocks and HANDOVER ACCESS message shall be transmitted with the following priority (highest priority first):

– HANDOVER ACCESS message

– RLC/MAC control blocks except Packet Uplink Dummy Control blocks;

– RLC data blocks;

– RLC/MAC control blocks containing Packet Uplink Dummy Control Blocks.

Uplink TBFs are scheduled with USF. USF is assigned as described in sub-clause 9.2.4.1.2.2.

Whenever the mobile station detects an assigned USF value on an assigned DBPSCH, the mobile station shall transmit either a single RLC/MAC block or a sequence of four RLC/MAC blocks on the same DBPSCH and, in case there are more DBPSCHs assigned in uplink than in downlink, also on all higher numbered assigned DBPSCHs. The time relation between an uplink block, which the mobile station shall use for transmission, and the occurrence of the USF value is defined in 3GPP TS 45.002. The number of RLC/MAC blocks to transmit is controlled by the USF_GRANULARITY parameter characterising the uplink TBF.

When the mobile station transmits an RLC/MAC block to the network, it shall start timer T3180 for the uplink TBF on which the block was sent. When the mobile station detects an assigned USF value on an assigned DBPSCH for the TBF, the mobile station shall restart timer T3180. If timer T3180 expires, the mobile station shall notify a link failure to the RRC layer.

Whenever the network receives a valid RLC/MAC block from the TBF, it shall reset counter N3101. The network shall increment counter N3101 for each radio block, allocated to that TBF, for which no data is received. If N3101 = N3101max, the network shall stop the scheduling of RLC/MAC blocks from the TBF and start timer T3169. When T3169 expires, the network shall notify a link failure to the RRC layer.

The mobile station shall attempt to decode every downlink RLC/MAC block on all assigned DBPSCHs. Whenever the mobile station receives an RLC/MAC block containing an RLC/MAC control block, the mobile station shall attempt to interpret the message contained therein and act on the message.

Whenever the mobile station detects an assigned USF value on any assigned DBPSCH, the mobile station may transmit a PACCH block on the same DBPSCH in the next block period (see 3GPP TS 45.002). The mobile station shall not transmit an RLC data block in any uplink radio block allocated via the polling mechanism (see 3GPP TS 44.060 sub-clause 10.4.4).

In case there are more DBPSCHs assigned in uplink than in downlink, the network shall transmit all PACCH messages on the DBPSCH carried on the lowest numbered timeslot in the allocation.

9.2.4.1.2.2 On receipt of a Packet Uplink Assignment message

The USF of a TBF belonging to a URB is initially assigned by RRC using radio bearer control procedures (see 3GPP TS 44.118). The USF of a TBF belonging to a SRB is assigned by RLC/MAC.

The network may send a PACKET UPLINK ASSIGNMENT message to the mobile station on the PACCH on DBPSCH addressing a particular TBF on DBPSCH (identified in the Global_TFI field) in order to:

– assign a USF to this TBF only in case this TBF does not already have any assigned USF and/or to

– change one or more of the following parameters of this TBF: (EGPRS) channel coding command field, resegment bit, BEP_PERIOD2 field. All other parameters may only be changed through radio bearer control procedures (see 3GPP TS 44.118)

The network shall include a valid RRBP field in the RLC/MAC control block header and clear counter N3105.

In case the mobile station receives a PACKET UPLINK ASSIGNMENT message on PACCH (DBPSCH) addressing a particular uplink TBF on DBPSCH (identified in the Global_TFI field), the mobile station shall only act on the following fields:

– USF granularity and USF value per timeslot fields in the message (see 3GPP TS 44.060) if the mobile station does not already have a USF assigned to this TBF,

– starting time (if included),

– (EGPRS) Channel coding command,

– Resegment bit (if included), and

– BEP_PERIOD2 field (if included) and ignore other fields.

When the mobile station receives an uplink assignment that does not contain a TBF starting time, the mobile station shall begin to use the newly assigned parameters immediately for this TBF. If a TBF starting time information element is present the mobile station shall wait until the starting time before beginning to use these parameters for this TBF. If while waiting for the frame number indicated by the TBF starting time the mobile station receives another uplink assignment for the same TBF, the mobile station shall act upon the most recently received uplink assignment and shall ignore the previous uplink assignment.

When the mobile station receives the PACKET UPLINK ASSIGNMENT message, it shall transmit the PACKET CONTROL ACKNOWLEDGEMENT message in the radio block indicated by the RRBP field.

If the network does not receive the PACKET CONTROL ACKNOWLEDGEMENT message in the radio block indicated by the RRBP field, it shall increment counter N3105 and retransmit the PACKET UPLINK ASSIGNMENT message. If counter N3105 exceeds its limit, the network shall stop scheduling new uplink resources for the TBF, stop sending the PACKET UPLINK ASSIGNMENT message to the mobile station and start timer T3195.

When timer T3195 expires the network shall notify a link failure to the RRC layer.

9.2.4.1.2.3 Release of the USF

The network may initiate the release of the USF of a particular TBF by sending a PACKET UPLINK ACK/NACK message with the Final Ack Indicator set to ‘1’. The network shall include a valid RRBP field in the RLC/MAC control block header and clear counter N3103. The release of the USF, using this procedure, may be initiated at a point determined by the network.

If the mobile station receives a PACKET UPLINK ACK/NACK message with the Final Ack Indicator bit set to ‘1’, it shall transmit a PACKET CONTROL ACKNOWLEDGEMENT message in the radio block indicated by the RRBP field and release the USF.

When the network receives the PACKET CONTROL ACKNOWLEDGEMENT message in the radio block indicated by the RRBP field, it may reuse the USF resource.

If the network does not receive the PACKET CONTROL ACKNOWLEDGEMENT message in the radio block indicated by the RRBP field, it shall increment counter N3103 and retransmit the PACKET UPLINK ACK/NACK message. If counter N3103 exceeds its limit, the network shall stop scheduling new uplink resources for the TBF, stop sending the PACKET UPLINK ACK/NACK message to the mobile station and start timer T3169.

When timer T3169 expires the network shall notify a link failure to the RRC layer.

9.2.4.2 Scheduling an inactive TBF on a DBPSCH

When a previously inactive TBF (i.e. for which the latest transmitted CV was equal to 0 and for which no USF is assigned) has data to send, the mobile station shall send one RLC data block for this TBF the next time the network schedules any of the mobile station’s TBFs using the assigned USFs. This TBF shall be considered inactive until a USF is assigned to it. This RLC data block shall not be sent in a block that has been reserved for sending a RLC/MAC control message via the RRBP field. On sending a RLC data block on a radio block that has been stolen by this mechanism, the mobile station start timer T3194 for the associated radio bearer. The mobile station shall stop timer T3194 on receipt of the USF for this radio bearer (see sub-clause 9.2.4.1.2.2). The mobile station shall be able to steal further blocks from any of its scheduled TBFs, provided that no more than one block is stolen for a particular radio bearer during an interval defined by the duration of timer T3194. On expiry of timer T3194 the mobile station shall restart the timer unless it has expired four times, in which case the mobile station shall notify a link failure to the RRC layer.

9.2.4.3 Further USF handling

If the mobile station has more than one active TBF with data to send, the mobile station shall send data for the TBF corresponding to the received USF, with the exception given in sub-clause 9.2.4.2. If the mobile station has no data to send for the scheduled TBF (i.e. no RLC data block or no RLC/MAC control message other than PACKET UPLINK DUMMY CONTROL BLOCK message), and if the MS has data to send for one or more other TBFs mapped onto the same DBPSCH, the mobile station may send data from one of these other TBFs.

If the mobile station has only one TBF with data to send, the mobile station shall ignore the USF and shall transmit data for this TBF.

9.2.5 Transfer of RLC/MAC blocks on UDCH, CDCH and ADCH

9.2.5.1 General

On the DBPSCH(s) where FLO is used, the transfer of RLC/MAC blocks on transport channels shall follow the rules below:

– RLC/MAC blocks for data transfer belonging to a SRB shall only be sent on CDCH, with Payload Type = ’00’;

– RLC/MAC blocks for data transfer belonging to a URB operating in NT-RLC mode shall only be sent on UDCH, with Payload Type = ’01’;

– RLC/MAC blocks for data transfer belonging to a URB operating in T-RLC mode shall only be sent on UDCH. No RLC/MAC overhead is used (see sub-clauses 12.8b.1.3 and 12.8b.2.3);

– RLC/MAC blocks for control message transfer shall only be sent on ADCH, with Payload Type = ’10’.

RLC/MAC blocks shall be transmitted with the following priority (highest priority first):

– HANDOVER ACCESS message;

– RLC/MAC blocks for control message transfer on ADCH, except Packet Uplink/Downlink Dummy Control blocks;

– RLC/MAC blocks for SRB data transfer on CDCH containing a piggy-backed acknowledgement;

– RLC/MAC blocks for SRB data transfer on CDCH not containing a piggy-backed acknowledgement;

– RLC/MAC blocks for URB data transfer on UDCH;

– RLC/MAC blocks for control message transfer on ADCH containing Packet Uplink/Downlink Dummy Control blocks.

In addition, on DBPSCH/H where FLO is used, the transfer of RLC/MAC blocks on transport channels shall follow the rule below:

– Every RLC/MAC block for data transfer belonging to a SRB shall be sent twice in a row. The first and second transport blocks used for the RLC/MAC block shall be sent with the signalling TFC.

– Every RLC/MAC block for control message transfer shall be sent twice in a row. The first and second transport blocks used for the RLC/MAC block shall be sent with the signalling TFC. In case ciphering is used, the RLC/MAC block shall only be ciphered with the parameters used with the first transport block, in both transport blocks.

The mobile station shall attempt to decode every downlink RLC/MAC block on DBPSCH. Whenever the mobile station receives an RLC/MAC block containing an RLC/MAC control block, the mobile station shall attempt to interpret the message contained therein, and shall act on it.

9.2.5.2 Transport format combination (TFC) selection

9.2.5.2.1 General requirements

On each DBPSCH where FLO is used, the MAC layer shall select a TF for each TrCH within the TFS configured by RRC for each TrCH so that the resulting TFC belongs to the TFCS configured by RRC.

For RLC/MAC block for data transfer belonging to a TBF in CDCH TBF mode, the MAC layer shall always select the signalling TFC(s) specified in 3GPP TS 44.118.

For RLC/MAC block for data transfer belonging to a TBF in UDCH TBF mode, the MAC layer shall select a TF within the TFS of the TrCH on which the corresponding radio bearer is mapped. It shall not select a TF that does not belong to this TFS.

For RLC/MAC block for control message transfer, the MAC layer shall always select the signalling TFC specified in 3GPP TS 44.118.

9.2.5.2.2 Downlink

The selection of the TFC in the downlink is left up to network implementation. The network shall follow the requirements defined in sub-clause 9.2.5.2.1.

9.2.5.2.3 Uplink

The mobile station shall be notified of the highest allowed TFC in the TFCS, that may be used for uplink transmission. The mobile station shall not select any TFC of which the TFCI is higher than the TFCI of the highest allowed TFC. If no highest allowed TFC is notified to the mobile station, the highest allowed TFC shall be the highest TFC in the TFCS. All the TFCs up to and including the highest allowed TFC are valid TFCs. All other TFCs are invalid.

Every TTI, the mobile station shall select a valid TFC as follows:

– No other TFC shall allow the transmission of more highest priority data than the selected TFC

– No other TFC shall allow the transmission of more data from the next lower priority TBF. This shall be applied for each TBF for the remaining priority levels.

9.2.5.3 Polling for PACKET DBPSCH DOWNLINK ACK/NACK TYPE 2

Upon receipt by the mobile station of a polling request within an RLC/MAC block for data transfer, the mobile station shall send a PACKET DBPSCH DOWNLINK ACK/NACK TYPE 2 message within the next possible uplink occurrence on ADCH, following the requirements defined in sub-clause 9.2.1.3.

9.3 PACKET CONTROL ACKNOWLEDGEMENT

Upon receipt by the mobile station of a polling request (see sub-clauses 12.7.4 and 12.9.3) within an RLC/MAC control message sent on a given logical channel, the mobile station shall send a corresponding PACKET CONTROL ACKNOWLEDGEMENT message within the next possible uplink occurrence on the same logical channel or ADCH (FLO only). The PACKET CONTROL ACKNOWLEDGEMENT message shall be formatted using the normal burst format. The next possible uplink occurrence is defined following the rules below:

– If the RLC/MAC control message is received on PACCH with a valid RRBP field as part of this RLC/MAC control message, the mobile station shall transmit a PACKET CONTROL ACKNOWLEDGEMENT message in the uplink radio block specified (see 3GPP TS 44.060 sub-clause 10.4.5)

– Otherwise, the mobile station shall send the PACKET CONTROL ACKNOWLEDGEMENT message following the requirements defined in sub-clauses 9.2.1.2 and 9.2.1.3, considering the PACKET CONTROL ACKNOWLEDGEMENT message has higher priority than any other RLC/MAC control messages, and any RLC data block. Upon reception by the network of a PACKET CONTROL ACKNOWLEDGEMENT message that does not target a specific RLC entity, within the requirements defined in sub-clauses 9.2.1.2 and 9.2.1.3, the network shall reset counter N3105. If the network does not receive a PACKET CONTROL ACKNOWLEDGEMENT message before the response time specified in sub-clauses 9.2.1.2 and 9.2.1.3, it shall increment counter N3105. If counter N3105=N3105max, the network shall indicate a link failure to the RRC layer.

9.3a Handover Access and Physical Information

9.3a.1 Handover Access

During a handover, upon trigger from RRC through the HANDOVER-Req primitive, the mobile station shall send a HANDOVER ACCESS message containing the necessary handover reference value (see sub-clause 4.3.4) to the network on either FACCH, PACCH (on DBPSCH), ADCH (FLO only) or SDCCH. While the HANDOVER ACCESS message is being sent on FACCH, PACCH (on DBPSCH) , ADCH (FLO only) or SDCCH, the mobile station may send additional HANDOVER ACCESS messages on SACCH. In this case, the HANDOVER ACCESS message may be sent on any TDMA frame block (Bn) belonging to the allocated SACCH (see 3GPP TS 45.002). The mobile station shall not send any HANDOVER ACCESS message on SACCH if no HANDOVER ACCESS message is being sent on FACCH, PACCH, ADCH (FLO only) or SDCCH.

Upon reception of a HANDOVER ACCESS message by the network, the RRC shall be notified through the HANDOVER-Ind primitive (see sub-clause 4.3.4) and the network shall then proceed as specified in 3GPP TS 44.118.

In case of non-synchronized cells (see 3GPP TS 44.118), no other RLC/MAC block than those containing the HANDOVER ACCESS message shall be sent by the mobile station while the PHYSICAL INFORMATION message has not been received by this mobile station.

9.3a.2 Physical Information

During a handover, upon trigger from RRC layer through the PHYSICAL-INFO-Req primitive, the network shall send a PHYSICAL INFORMATION message containing the necessary timing advance value (see sub-clause 4.3.4) to the mobile station, on FACCH, PACCH (on DBPSCH) , ADCH (FLO only) or SDCCH. The PHYSICAL INFORMATION message shall be ciphered if applicable i.e. if ciphering is started (see 3GPP TS 44.118).

Upon reception of a PHYSICAL INFORMATION message, the RRC shall be notified through the PHYSICAL-INFO-Ind primitive and the mobile station shall then proceed as specified in 3GPP TS 44.118.

9.4 Abnormal cases

– If the mobile station receives an RLC/MAC control message on a logical channel where this RLC/MAC control message is not allowed (see sub-clause 9.2.0), the mobile station shall ignore the message.

– If the mobile station receives an acknowledgement message (PACKET UPLINK ACK/NACK, PACKET DBPSCH UPLINK ACK/NACK, PACKET DBPSCH UPLINK ACK/NACK TYPE 2) with missing mandatory fields, the mobile station shall notify the RRC layer, which shall in turn re-establish all RLC entities for the radio bearers currently established on the DBPSCH(s) and release the DBPSCH(s), as specified in 3GPP TS 44.118.

– If the mobile station receives an acknowledgement message (PACKET UPLINK ACK/NACK, PACKET DBPSCH UPLINK ACK/NACK, PACKET DBPSCH UPLINK ACK/NACK TYPE 2) for a radio bearer that is either not established on the DBPSCH(s) or for which no data has been sent in the direction of the acknowledgement on the DBPSCH(s), the mobile station shall notify the RRC layer, which shall in turn re-establish all RLC entities for the radio bearers currently established on the DBPSCH(s) and release the DBPSCH(s), as specified in 3GPP TS 44.118.