3.5 RR procedures on CCCH and EC-CCCH related to temporary block flow establishment

3GPP44.018GSM/EDGE Radio Resource Control (RRC) protocolMobile radio interface Layer 3 specificationRelease 17TS

3.5.0 General

The establishment of a temporary block flow (TBF) on a packet data physical channel is supported by procedures on CCCH when PCCCH is not provided in the cell or on EC-CCCH when the cell supports EC-GSM-IoT and the mobile station has enabled EC operation. The procedures for temporary block flow establishment using CCCH are only applicable to a mobile station supporting GPRS. The procedures are optional for the network.

These procedures constitute a complement to the corresponding procedures for temporary block flow establishment using PCCCH, defined in 3GPP TS 44.060, and include the procedures using:

– CCCH for packet paging for mobile stations that have not enabled EC operation (sub-clause 3.5.1),

– EC-CCCH for packet paging for mobile stations that have enabled EC operation (sub-clause 3.5.1a),

– CCCH for packet access for mobile stations that have not enabled EC operation, (sub-clause 3.5.2),

– EC-CCCH for packet access for mobile stations that have enabled EC operation (sub-clause 3.5.2a),

– CCCH for packet downlink assignment for mobile stations that have not enabled EC operation (sub-clause 3.5.3),

– EC-CCCH for packet downlink assignment for mobile stations that have enabled EC operation (sub-clause 3.5.5), and

– CCCH for MBMS packet access (sub-clause 3.5.4).

At any point in time a mobile station may enable one of PEO or EC operation. Support for GPRS services using GPRS TBFs or EGPRS TBFs is mandatory for a PEO capable mobile station and is optional for an EC capable mobile station.

3.5.1 Packet paging procedure using CCCH

The network can initiate the packet paging procedure in order to cause upper layers in the mobile station to respond, see clause 4. The packet paging procedure can only be initiated by the network.

3.5.1.1 Packet paging initiation by the network

The packet paging procedure is initiated by the RR entity of the network side. It is triggered by a page request from the MM sublayer, see 3GPP TS 24.007, or by an MBMS session start procedure or by an MBMS session update procedure in case of an MBMS notification, see 3GPP TS 48.018.

The network initiates the paging procedure by sending a paging request message on an appropriate paging subchannel on CCCH or PCCCH. Paging initiation using a paging subchannel on CCCH is used when sending paging information to a mobile station and PCCCH is not present in the cell.

NOTE 1: There are three types of paging request messages that are applicable:

– PAGING REQUEST TYPE 1;

– PAGING REQUEST TYPE 2; and

– PAGING REQUEST TYPE 3.

In a PAGING REQUEST message used for the packet paging procedure, the mobile station shall be identified by the P-TMSI (GPRS TMSI) or its IMSI. If the mobile station is identified by the P-TMSI, it shall proceed as specified in sub-clause 3.5.1.2.

In a paging request message used for MBMS notification, the MBMS session shall be identified by the TMGI and, if available, the MBMS Session Identity of that session, see sub-clause 3.5.1.3.

If the mobile station identified by its IMSI, it shall parse the message for a corresponding Packet Page Indication field:

– if the Packet Page Indication field indicates a paging procedure for RR connection establishment, or the field is not present in the message, the mobile station shall proceed as specified in sub-clause 3.3.2.2;

– if the Packet Page Indication field indicates a packet paging procedure, the mobile station shall proceed as specified in sub-clause 3.5.1.2.

A PAGING REQUEST message may include more than one mobile station identification.

The mobile station in packet idle mode is required to receive and analyse the paging messages and immediate assignment messages sent on the paging subchannels on CCCH corresponding to the paging groups determined for it in packet idle mode, as specified in 3GPP TS 45.002. These messages contain a page mode information element.

NOTE 2: The possible immediate assignment messages are: the IMMEDIATE ASSIGNMENT, the IMMEDIATE ASSIGNMENT EXTENDED, the IMMEDIATE PACKET ASSIGNMENT if supported and the IMMEDIATE ASSIGNMENT REJECT messages.

The treatment of page mode information, including the procedure when the mobile station selects a new PCH, and the procedure if a message in a paging subchannel is not received correctly are defined in sub-clause 3.3.2.1.1.

A PEO capable mobile station may negotiate the use of eDRX or PSM:

– If it successfully negotiates eDRX (enables eDRX) for paging based reachability it shall consider eDRX to be supported in all cells in the corresponding Routing Area (i.e. eDRX is negotiated at the Routing Area level).

– If it successfully negotiates PSM (with or without eDRX) it shall consider PSM to be supported in all cells in the corresponding Routing Area.

A PEO capable mobile station that has enabled eDRX wakes up to read a nominal paging group according to its negotiated eDRX as long as it remains in the same Routing Area it was in when it performed NAS signalling to enable eDRX regardless of whether or not PEO is enabled (see sub-clause 3.9.1).

An MS that has enabled PEO and is using eDRX shall ignore the "Paging reorganization" condition indicated by the page mode information element if received in any message (i.e. this condition targets mobile stations not using eDRX).

If PEO is enabled by a mobile station, after reading the message sent within its nominal paging group it shall use the RCC field in the message and the 6 bit BSIC field in the most recently read SCH to establish a BSIC (see 3GPP TS 45.008). If the BSIC does not match the BSIC value decoded upon first entering the serving cell (see 3GPP TS 45.008) or if the RCC and PEO_BCCH_CHANGE_MARK fields are not included in the message it shall consider PEO as disabled, abort the packet paging procedure and attempt cell re-selection.

3.5.1.2 On receipt of a packet paging request

On the receipt of a paging request message, the RR sublayer of addressed mobile station indicates the receipt of a paging request to the MM sublayer, see 3GPP TS 24.007.

An exception case is when a mobile station that has enabled PEO or EC operation and supports the MTA procedure or the MOTD procedure receives a paging request message that indicates a positioning event is pending (see sub-clauses 10.5.2.23, 10.5.2.24 and 10.5.2.25 for PEO and sub-clause 9.1.63 for EC operation). When this occurs the mobile station may perform a cell re-selection (see 3GPP TS 45.008 [34]) after which the RR sublayer of addressed mobile station indicates the receipt of a paging request to the MM sublayer, see 3GPP TS 24.007 [20].

Another exception case is when an EC-GSM-IoT capable mobile station, that has previously received an indication for restricted use of enhanced coverage (see 3GPP TS 24.008 [79]), receives a paging request message in (E)GPRS operation, while camping on a non-EC-GSM-IoT supporting cell, or in EC operation, while camping on an EC-GSM-IoT supporting cell, that indicates that the restricted use of enhanced coverage is removed. When this occurs, the mobile station may perform a cell re-selection (see 3GPP TS 45.008 [34]) after which the RR sublayer of addressed mobile station indicates the receipt of a paging request to the MM sublayer, see 3GPP TS 24.007 [20].

3.5.1.3 Packet Paging for MBMS notification on CCCH

3.5.1.3.1 General

The packet paging procedure for MBMS notification is initiated by the network upon receipt of an MBMS-SESSION-START-REQUEST PDU or of an MBMS-SESSION-UPDATE-REQUEST PDU from the SGSN, see 3GPP TS 48.018. The MBMS notification may be repeated during the session.

The packet paging procedure for MBMS notification consists of the following steps:

– optionally, the pre-notification of the MBMS session; and

– the notification of the MBMS session.

A mobile station in broadcast/multicast receive mode shall remain in broadcast/multicast receive mode if a paging procedure for a new MBMS session is not completed.

The network initiates the paging procedure for MBMS notification of an MBMS session by sending a paging message including either an MBMS pre-notification or an MBMS notification for that session on one or more paging subchannels on CCCH. The paging request message may be of type:

– PAGING REQUEST TYPE 1 message; or

– PAGING REQUEST TYPE 2 message.

The MBMS session shall be identified by the TMGI and, if available, the MBMS Session Identity of that session as contained in the MBMS-SESSION-START-REQUEST PDU or in the MBMS-SESSION-UPDATE-REQUEST PDU received from the SGSN.

The following requirements apply:

– If in the paging message the mobile station is at the same time (pre-)notified (see sub-clauses 3.5.1.3.2 and 3.5.1.3.3) and paged, the mobile station shall discard all (pre-)notification(s) in that message and proceed as described in sub-clause 3.3.2 or 3.5.1.1 and 3.5.1.2 accordingly.

– If in the paging message the mobile station is at the same time pre-notified (see sub-clause 3.5.1.3.2) and notified (see sub-clause 3.5.1.3.3), the mobile station shall discard all pre-notifications in that message and proceed as described in sub-clause 3.5.1.3.3.

3.5.1.3.2 MBMS pre-notification

In order to pre-notify an MBMS session on a CCCH, the network shall send a relevant paging request message (see sub-clause 3.5.1.3.1) including the TMGI and, if available, the MBMS Session Identity of that session. The network shall not include the MBMS Notification information.

Upon reception of a paging message including a pre-notifcation for an MBMS session, and if the mobile station requires reception of that session, the mobile station shall consider that session as being pre-notified (i.e. the mobile station is pre-notified). If the mobile station determines several pre-notified sessions in this message, the mobile station shall discard all pre-notifications but the pre-notification for the highest priority session. The mobile station in packet idle mode or MAC-Idle state shall then enter non-DRX mode, start timer T3220 and proceed as specified in sub-clause 3.5.1.3.3.

NOTE: In case all pre-notified sessions have the same priority, the selection of the highest priority session is implementation-dependent.

While timer T3220 is running, the mobile station shall stop timer T3220 and discard the pre-notification if:

– Any other RR procedure on CCCH not related to MBMS is triggered. The mobile station shall then proceed as per that procedure.

– A notification is received for a higher priority session. The mobile station shall then proceed as described in sub-clause 3.5.1.3.3.

If while timer T3220 is running the mobile station receives a pre-notification for a higher priority session, the mobile station shall discard the pre-notification for the lower priority session, remain in non-DRX mode, restart timer T3220 and proceed as specified in sub-clause 3.5.1.3.3.

Upon expiry of timer T3220, the mobile station in packet idle mode or MAC-Idle state shall return to DRX mode and discard the pre-notification. The mobile station in broadcast/multicast receive mode shall discard the pre-notification and remain in broadcast/multicast receive mode.

A mobile station in broadcast/multicast receive mode that is receiving an MBMS session shall ignore repeated pre-notifications of that session.

3.5.1.3.3 MBMS notification

In order to notify an MBMS session on CCCH, the network shall send a relevant paging request message (see sub-clause 3.5.1.3.1) including the following information:

– the TMGI and, if available, the MBMS Session Identity of that session;

– an indication whether counting shall be performed or not;

– optionally the MBMS p-t-m channel description allocated to that session and the estimated duration of the MBMS session or, if the MBMS session is ongoing, the estimated remaining duration of the MBMS session;

– optionally the MPRACH description.

NOTE 1: If the MBMS Session Repetition Number IE is included in the MBMS-SESSION-START-REQUEST PDU or in the MBMS-SESSION-UPDATE-REQUEST PDU (see 3GPP TS 48.018), the value part of this IE may be used by the network for e.g. deciding whether or not to perform the counting procedure or, in conjunction with the values of Allocation/Retention Priority IE (see 3GPP TS 48.018), whether or not to establish an MBMS radio bearer for the session.

Upon reception of a paging message including the notification of an MBMS session and if the mobile station requires reception of this session, the mobile station shall consider that session as being notified (i.e. the mobile station is notified). If the mobile station determines several notified sessions in this message, the mobile station shall act upon the notification for the highest priority session. The mobile station shall then stop timer T3220, if running, and proceed as specified in sub-clause 3.5.1.3.4.

NOTE 2: In case all notified sessions have the same priority, the selection of the highest priority session is implementation-dependent.

NOTE 3: Depending on its capabilities, the MS may act upon the notification for lower priority MBMS sessions provided it does not affect any of the following procedures for the highest priority MBMS session: response to MBMS notification (see sub-clause 3.5.1.3.4), MBMS packet access procedure on CCCH (see sub-clause 3.5.4).

A mobile station in broadcast/multicast receive mode that is receiving an MBMS session shall ignore repeated notifications of that session.

3.5.1.3.4 Response to MBMS notification

If the MBMS notification indicates that no counting shall be performed and contains no MBMS p-t-m channel description, the mobile station shall remain in or enter non-DRX mode and start timer T3214. The mobile station shall stop timer T3214 (specified in 3GPP TS 44.060) and proceed as specified in 3GPP TS 44.060 upon reception of an MBMS ASSIGNMENT message for that MBMS session. A mobile station in packet idle mode shall enter DRX mode upon expiry of T3214, and discard any corresponding notification. A mobile station in broadcast/multicast receive mode, i.e. engaged in one or more parallel MBMS session(s), shall remain in broadcast/multicast receive mode on expiry of T3214 and discard the corresponding notification.

While timer T3214 is running, the mobile station shall stop timer T3214 if:

– Any other RR procedure on CCCH not related to MBMS is triggered. The mobile station shall then proceed as per that procedure.

– A notification is received for a higher priority session. The mobile station shall then proceed as per that notification. Depending on its capabilities, the MS may act upon the notification for the lower priority MBMS session provided it does not affect any of the following procedures for the higher priority MBMS session: response to MBMS notification (see present sub-clause), MBMS packet access procedure on CCCH (see sub-clause 3.5.4).

If the MBMS notification indicates that counting shall be performed the mobile station shall perform an MBMS packet access procedure as specified in the sub-clause 3.5.4.

If the MBMS notification includes an MBMS p-t-m channel description, the mobile station shall set and start the session duration timer for this MBMS session with a value equal to the Estimated Session Duration (included in the MBMS Session Parameters List). If an MBMS Radio Bearer Starting Time parameter is not indicated or if the indicated starting time has elapsed, the mobile station shall switch to the assigned PDCH(s), start T3190 and listen for downlink RLC/MAC blocks for that session. If an MBMS Radio Bearer Starting Time parameter, that indicates a starting time that has not elapsed, is included, the mobile station shall wait until the point in time denoted by the MBMS Radio Bearer Starting Time parameter. It shall then switch to the assigned PDCHs, start timer T3190 and listen for downlink RLC/MAC blocks for that session. When receiving the first valid RLC/MAC block for that session, the mobile station shall restart timer T3190 and behave as described in 3GPP TS 44.060.

Upon expiry of T3190, the mobile station shall abort the procedure and return to packet idle mode or MAC-Idle state. The mobile station in broadcast/multicast receive mode shall abort the procedure and remain in broadcast/multicast receive mode.

3.5.1a Packet paging procedure using EC-CCCH

The network can initiate the packet paging procedure in order to cause upper layers in a mobile station to respond, see clause 4. The packet paging procedure can only be initiated by the network (see subclause 3.5.1a.1 and sub-clauses 3.10.1 and 3.10.3).

3.5.1a.1 Packet paging initiation by the network

The packet paging procedure is initiated by the RR entity of the network side. It is triggered by a page request from the MM sublayer, see 3GPP TS 24.007.

The network initiates the paging procedure by sending an EC PAGING REQUEST message on an appropriate paging subchannel on EC-CCCH. Paging initiation using a paging subchannel on EC-CCCH is used when sending paging information to a mobile station that has enabled EC operation.

The EC PAGING REQUEST message shall identify the mobile station by the P-TMSI (GPRS TMSI) or its IMSI and may include more than one mobile station identification.

The mobile station in packet idle mode is required to receive and analyse the paging messages and immediate assignment messages sent on the paging subchannels on EC-CCCH corresponding to the paging groups determined for it in packet idle mode, as specified in 3GPP TS 45.002. The messages sent on EC-CCCH may contain an EC Page Extension field. The DL coverage class included in the paging request message shall refer to the highest coverage class of all mobile stations being addressed in the paging request message.

NOTE 1: The possible immediate assignment messages sent on EC-CCCH are the EC IMMEDIATE ASSIGNMENT TYPE 2, EC IMMEDIATE ASSIGNMENT TYPE 4, EC IMMEDIATE ASSIGNMENT REJECT and EC DOWNLINK ASSIGNMENT or EC DOWNLINK ASSIGNMENT TYPE 2 messages.

A mobile station that has enabled EC operation and has successfully negotiated eDRXdeterminess its nominal paging group as defined for EC operation (see 3GPP TS 45.002) according to its negotiated eDRX cycle and selected downlink coverage class. A mobile station that has enabled EC operation but has not negotiated eDRX determines its nominal paging group as defined for EC operation according to the lowest eDRX cycle, its IMSI and its selected downlink CC (see 3GPP TS 45.002). If it receives a matching paging message therein it shall act on it as described in sub-clause 3.5.1.2. Otherwise, if it receives any other message on the EC-PCH and the EC Page Extension field is included therein it shall proceed as follows:

– If the EC Page Extension field indicates paging extension is enabled for its downlink coverage class last communicated to the network (see 3GPP TS 45.008) it shall attempt to read one additional paging message using a paging group determined according to the downlink coverage class last communicated and the value of the Used DL Coverage Class field within the message where the EC Page Extension field was read as shown in Table 3.5.1a.1.

– If it finds a matching paging message therein it shall act on that message as described in sub-clause 3.5.1.2.

– If paging extension is not enabled or it does not find a matching paging message when attempting to read one additional paging message it sets its eDRX cycle to either the negotiated eDRX cycle (if eDRX has been negotiated) or the lowest eDRX cycle (if eDRX has not been negotiated), remains in packet idle mode and waits for the next instance of its nominal paging group.

– A mobile station that has enabled EC operation and has successfully negotiated eDRX shall, upon re-selecting to a cell in the same Routing Area that does not support EC operation, determine its nominal paging group as defined for PEO (see 3GPP TS 45.002 [32]) using its negotiated eDRX cycle length.

Table 3.5.1a.1: Page Extension Using Fixed Offset

		Used DL Coverage Class Indicated by Message Received on EC-PCH
		CC1	CC2	CC3	CC4
Last Communicated DL CC of MS Receiving Message on EC-PCH	CC1	PG1 + 2	PG1 + 4	PG1 + 8	PG1 + 8
	CC2	–	PG1 + 4	PG1 + 4	PG1 + (2 or 6)2
	CC3	–	–	PG1 + 2	PG1 + (1 or 3)3
	CC4	–	–	–	PG1 + 2
Note 1: PG (Paging Group) represents the start of the coverage class specific EC-PCH block corresponding to the nominal paging group of an MS (see 3GPP TS 45.002 [32]). The start of the coverage class specific EC-PCH block used for page extension is expressed as an offset relative to PG (where the value of the offset indicates the number of coverage class specific EC-PCH blocks comprising the offset). Note 2: Page Extension is determined using PG + 2 when a CC2 MS reading its nominal paging group in TDMA frames 35 to 42 (CC2 B2) or in TDMA frames 43 to 50 (CC2 B3) in MF N/N+1 determines that a CC4 page is ongoing from TDMA frames 35 to 50 in MF N/N+1/N+2/N+3. Page Extension is determined using Paging Group PG + 6 when a CC2 MS reading its nominal paging group in TDMA frames 19 to 26 (CC2 B0) or in TDMA frames 27 to 34 (CC2 B1) in MF N/N+1 determines that a CC4 page is ongoing from TDMA frames 19 to 34 in MF N/N+1/N+2/N+3. Note 3: Page Extension is determined using Paging Group PG + 1 when a CC3 MS reading its nominal paging group in TDMA frames 35 to 50 (CC3 B1) in MF N/N+1 determines that a CC4 page is ongoing from TDMA frames 35 to 50 in MF N/N+1/N+2/N+3. Page Extension is determined using Paging Group PG + 3 when a CC3 MS reading its nominal paging group in TDMA frames 19 to 34 (CC3 B0) in MF N/N+1 determines that a CC4 page is ongoing from TDMA frames 19 to 34 in MF N/N+1/N+2/N+3.

A mobile station that has enabled EC operation where PSM is used wakes up to read its nominal paging group according to the lowest eDRX cycle (if PSM was negotiated without a corresponding eDRX value) or its negotiated eDRX cycle (if PSM was negotiated with a corresponding eDRX value) while the Active timer is running. It continues to monitor its nominal paging group while the Active timer is running and if it receives a matching paging message therein it shall act on it as described in sub-clause 3.5.1.2. Otherwise, when the Active timer expires it stops monitoring its nominal paging group and remains in packet idle mode until its next uplink data transmission.

The nominal paging group a mobile station monitors takes into account the selected downlink Coverage Class (see sub-clause 3.10.3, 3GPP TS 45.002 [32] and 3GPP TS 45.008 [34]) indicated during its most recent system access (e.g. transmission of an EC PACKET CHANNEL REQUEST message – see sub-clause 9.1.65) that resulted in the successful transmission of an uplink LLC PDU (e.g. a cell update). This downlink Coverage Class information is always provided to the BSS when it receives a PAGING-PS PDU from the SGSN.

An EC capable MS whose last uplink transmission was in a cell that does not support EC-GSM-IoT may choose to enable EC operation upon reselection to a cell that supports EC-GSM-IoT. In this case it shall perform an uplink transmission (e.g. a cell update) to update the network (i.e. addition of Coverage Class information) and therefore be reachable for pages on the EC-PCH.

If EC operation is enabled in the serving cell a MS that supports GPRS services using GPRS/EGPRS TBFs may choose to disable EC operation in which case it shall perform an uplink transmission (e.g. a cell update) to update the network (i.e. removal of Coverage Class information) and therefore be reachable for pages on the PCH. Similarly, if EC operation is enabled in the serving cell a MS that supports GPRS services using GPRS/EGPRS TBFs may reselect to a cell that supports both EC-GSM-IoT and GPRS/EGPRS TBFs and choose to disable EC operation, in which case it shall perform an uplink transmission (e.g. a cell update) to update the network (i.e. removal of Coverage Class information) and therefore be reachable for pages on the PCH.

If EC operation is enabled in the serving cell a MS that performs reselection to a cell that does not support EC-GSM-IoT is not required to perform an uplink transmission (e.g. a cell update) to update the network in the new cell (i.e. the network retains Coverage Class information). An EC capable MS whose last uplink transmission was in a cell that does not support EC-GSM-IoT may choose to not enable EC operation upon reselection to a cell that supports EC-GSM-IoT in which case it is not required to perform an uplink transmission (e.g. a cell update) to update the network in the new cell. For both of these cases the MS is reachable for pages on the PCH as follows:

– If it has not negotiated eDRX it shall listen to the PCH using DRX applicable to that cell (indicated by system information – see 3GPP TS 44.018).

– If it has negotiated eDRX it shall listen to the PCH using its negotiated eDRX cycle.

– If it has negotiated PSM it shall listen to the PCH when the Active timer is running using DRX applicable to that cell (if PSM was negotiated without eDRX) or using the negotiated eDRX (if PSM was negotiated with eDRX.)

– When the MS monitors the PCH using the negotiated eDRX cycle it shall determine its nominal paging group as described in sub-clause 3.5.1 for the case of a PEO capable mobile station that has enabled eDRX.

For the case where a mobile station is unable to read any message sent on EC-PCH or EC-AGCH when waking up according to its nominal paging group it returns to idle mode and waits for the next instance of its nominal paging group.

3.5.2 Packet access procedure using CCCH

The packet access procedure using CCCH may be used to establish a temporary block flow to support the transfer of LLC PDUs in the direction from the mobile station to the network. Establishment using one phase and two phase packet access, see 3GPP TS 44.060 [76], are supported. The two phase packet access is supported by means of the single block or multiple block packet access option in this procedure, allowing the transfer of a PACKET RESOURCE REQUEST and possibly an ADDITIONAL MS RADIO ACCESS CAPABILITIES message to the network.

The single block packet access option in this procedure may also be used by a mobile station in packet idle mode to transfer an RLC/MAC control message other than the PACKET RESOURCE REQUEST message to the network, see sub-clause 3.5.2.2.

The single block MBMS access option in this procedure shall be used by a mobile station in packet idle mode to transfer the RLC/MAC control message MBMS SERVICE REQUEST message network, see sub-clause 3.5.4.

A MS that has enabled PEO (i.e. eDRX or PSM – see 3GPP TS 23.060 [74]) while in a cell that supports PEO, shall send an EGPRS PACKET CHANNEL REQUEST message with access type ‘PEO One Phase Access Request’ (see Table 3.5.2.1.2.2 and 3GPP TS 44.060 [76]) when attempting to establish a PS connection. An exception case is when the MS is accessing the network to perform the Multilateration Timing Advance (MTA) procedure (see sub-clause 3.11 and 3GPP TS 44.031) in a cell that supports MTA (see the MTA_BITMAP field described in sub-clause 10.5.2.37b) in which case it sends an EGPRS MULTILATERATION REQUEST message specific to the MTA method it is using (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]). Another exception case is when the MS is accessing the network to send a Page Response due to receiving a page indicating ‘pending positioning event’ (see sub-clause 10.5.2.23, sub-clause 10.5.2.24 and sub-clause 10.5.2.25) in a cell that supports MTA in which case the MS sends an EGPRS MULTILATERATION REQUEST message indicating ‘Page Response for Positioning Event’ (see 3GPP TS 44.060 [76]).

3.5.2.1 Entering the packet transfer mode: packet access procedure

The establishment of an uplink temporary block flow may be initiated by the RR entity of the mobile station using the packet access procedure. The procedure is triggered by a request from upper layers to transfer a LLC PDU, see 3GPP TS 24.007. The request from upper layers specifies radio priority and an RLC mode associated with the packet transfer or it indicates that the packet to be transferred contains signalling.

Upon such a request,

– if access to the network is allowed (sub-clause 3.5.2.1.1), the RR entity of the mobile station initiates the packet access procedure as defined in sub-clause 3.5.2.1.2;

– otherwise, it rejects the request.

If the request from upper layers indicates signalling, the highest radio priority level shall be used at determination if access to the network is allowed, and the acknowledged RLC mode shall be requested.

3.5.2.1.1 Permission to access the network

A mobile station configured for EAB and has enabled EAB (i.e. it has received EAB Authorization Mask and EAB Subcategory information for its selected PLMN from SYSTEM INFORMATION TYPE 21) shall, prior to proceeding with a mobile originated access attempt, re-read SI21 if more than 30 seconds have expired since the last time it read SI21.

For a mobile originated access attempt, a mobile station configured for EAB and that has enabled EAB shall perform a preliminary access barring check (see sub-clause 3.3.1.4) unless it receives an indication from the upper layers to override EAB or it is attempting system access to perform the Multilateration Timing Advance (MTA) procedure (see sub-clause 3.11 and TS 3GPP 44.031) in which case access to the network is allowed. If the preliminary access barring check indicates network access is barred then access to the network is not allowed. Otherwise, the mobile station shall proceed according to the remainder of this sub-clause.

Access to the network is allowed:

– if the mobile station is a member of at least one authorized access class or special access class as defined in sub-clause 3.3.1.1.1; and

– if packet access is allowed in the cell for the radio priority level associated with the packet transfer, as indicated by the PRIORITY_ACCESS_THR parameter broadcast in SI 13 message;

– if the cell belongs to one of the allowed LSAs for the mobile station, as indicated on the SIM, in the case where the mobile station is a LSA only access subscriber.

3.5.2.1.2 Initiation of the packet access procedure: channel request

A mobile station accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" (see 3GPP TS 24.008 [79]), when accessing the network to perform the packet access procedure, shall, while ignoring MS identities included within PAGING REQUEST messages, start listening to the downlink CCCH until successfully decoding one of the RR messages listed in sub-clause 3.3.1.1.1a. A MS that has enabled PEO shall read the PEO_BCCH_CHANGE_MARK field and the RCC field within the successfully decoded RR message. It shall use the 6 bit BSIC from the most recently read SCH and the RCC field from the decoded RR message to establish a BSIC (see 3GPP TS 45.008). If the BSIC does not match the BSIC value decoded upon first entering the serving cell (see 3GPP TS 45.008) it shall abort the packet access procedure and attempt cell re-selection. If a change of PEO BCCH CHANGE MARK is detected it shall first read SI13 before proceeding with the packet access procedure. If the RR message indicates an implicit reject for the PS domain (see sub-clause 3.3.1.1.1a) the mobile station shall abort the packet access procedure and initiate the implicit reject procedure (see sub-clause 3.3.1.1.3.2a). An exception case is where the mobile station has enabled EC operation and is sending an EC PACKET CHANNEL REQUEST message using the RACH (the RACH Access Control field indicates that RACH usage on timeslot number 0 is allowed, see sub-clause 3.5.2a) in which case it proceeds with the packet access without first decoding one of the RR messages listed in sub-clause 3.3.1.1.1a and checking the status of the PEO_BCCH_CHANGE_MARK field and implicit reject information sent therein.

A MS that has enabled PEO accessing the network to perform packet access when the low priority indicator is set to "MS is not configured for NAS signalling low priority" shall also listen to the downlink CCCH until successfully decoding one of the RR messages listed in sub-clause 3.3.1.1.1a and read the PEO_BCCH_CHANGE_MARK field and RCC field therein. It shall use the 6 bit BSIC from the most recently read SCH and the RCC field from the decoded RR message to establish a BSIC. If the BSIC does not match the BSIC value decoded upon first entering the serving cell (see 3GPP TS 45.008) or if the RCC and PEO_BCCH_CHANGE_MARK fields are not included in the message it shall consider PEO as disabled, abort the packet access procedure and attempt cell re-selection. If a change of PEO_BCCH_CHANGE_MARK is detected then it shall first read SI13 prior to performing the packet access. If it determines that the PEO_DSC field is not included in the SI13 Rest Octets IE it shall consider PEO as disabled, abort the packet access procedure and attempt cell re-selection.

The network indicates the RCC value corresponding to the serving cell within an IMMEDIATE ASSIGNMENT message using the IA Rest Octets IE (see sub-clause 10.5.2.16) or within an IMMEDIATE ASSIGNMENT REJECT message using the IAR Rest Octets IE (see sub-clause 10.5.2.17) or within an IMMEDIATE ASSIGNMENT EXTENDED message using the IAX Rest Octets IE (see sub-clause 10.5.2.18) or within an IMMEDIATE PACKET ASSIGNMENT message using the IPA Rest Octets IE (see sub-clause 10.5.2.78) or within a PAGING REQUEST TYPE 1 message using the P1 Rest Octets IE (see sub-clause 10.5.2.23) or within a PAGING REQUEST TYPE 2 message using the P2 Rest Octets IE (see sub-clause 10.5.2.24) or within a PAGING REQUEST TYPE 3 message using the P3 Rest Octets IE (see sub-clause 10.5.2.25).

A mobile station that has enabled PEO shall, when attempting to establish a PS connection and while ignoring MS identities included within PAGING REQUEST messages, be able to successfully decode an RR message within 500ms of starting to listen to the downlink CCCH. Otherwise, the packet access procedure is aborted, a random access failure is indicated to upper layers and autonomous cell re-selection is performed according to 3GPP TS 43.022.

If a MS that has enabled PEO does not detect a change in thePEO_BCCH_CHANGE_MARK and the time elapsed since it last read SI13 exceeds 24 hours it should read SI13 before proceeding with the packet access procedure.

A mobile station initiates the packet access procedure by leaving idle mode and scheduling the sending of CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST messages on RACH as decribed in sub-clause 3.3.1.1.2 (i.e. only the portion of sub-clause 3.3.1.1.2 describing message scheduling is used when the packet access procedure is initiated as described in this sub-clause). The cause to be used in the CHANNEL REQUEST message for a non-EGPRS TBF mode capable MS or an EGPRS TBF mode capable MS in a non-EGPRS capable cell depends on the purpose of the packet access procedure as follows:

– If the purpose of the packet access procedure is to send user data and the requested RLC mode is unacknowledged mode, the mobile station shall request a single block packet access and attempt a two phase packet access.

– If the purpose of the packet access procedure is to send user data and the requested RLC mode is acknowledged mode, the mobile station shall request either a one phase packet access or a single block packet access.

– If the purpose of the packet access procedure is to send a Page Response, a Cell update (the mobile station was in GMM READY state before the cell reselection) or for any other GPRS Mobility Management or GPRS Session Management procedure, the mobile station shall request a one phase packet access. An exception case is when the purpose of the packet access procedure is to send a Page Response due to receiving a page indicating ‘pending positioning event’ (see sub-clause 10.5.2.23, sub-clause 10.5.2.24 and sub-clause 10.5.2.25), in which case the mobile station shall send an EGPRS MULTILATERATION REQUEST message indicating ‘Page Response for Positioning Event’ (see 3GPP TS 44.060 [76]).

– If the purpose of the packet access procedure is to send a Measurement Report, the mobile station shall request a single block packet access.

– If the purpose of the packet access procedure is to send a PACKET PAUSE message, the mobile station shall request a single block packet access. Upon sending the first CHANNEL REQUESTmessage the mobile station shall start timer T3204. If timer T3204 expires before an IMMEDIATE ASSIGNMENT message granting a single block period on an assigned packet uplink resource is received, the packet access procedure is aborted. If the mobile station receives an IMMEDIATE ASSIGNMENT message during the packet access procedure indicating a packet downlink assignment procedure, the mobile station shall ignore the message.

– If the purpose of the packet access procedure is to send an MBMS SERVICE REQUEST message to the network, the mobile station shall request a single block MBMS access.

– If the purpose of the packet access procedure is to send a signalling message and the mobile station is accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" it shall use the single block packet access option.

A mobile station that has enabled PEO starts the radio access part of the MTA procedure upon receiving a RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031) if both the MS and the serving cell support the MTA procedure method indicated therein (see the MTA_BITMAP field described in sub-clause 10.5.2.37b). In this case it starts the MPM timer and starts accessing the network using cells it has selected to perform the radio access part of the MTA procedure. For each selected cell it compares the BSIC of the CCCH to the BSIC. If the BSIC does not match it does not perform the radio access part of the MTA procedure using that cell. If the BSIC matches it does not check the status of the PEO_BCCH_CHANGE_MARK field and implicit reject information sent for that cell, sends an EGPRS MULTILATERATION REQUEST message (see 3GPP TS 44.060 [76]) and proceeds as follows:

– If the EGPRS MULTILATERATION REQUEST message indicates the RLC Data block method is used (see sub-clause 3.11 and 3GPP TS 44.060 [76]) it includes a random reference which is drawn randomly from a uniform probability distribution for every new transmission. After transmitting this message and receiving a matching IMMEDIATE ASSIGNMENT message message (see sub-clause 9.1.18) or IMMEDIATE PACKET ASSIGNMENT message (see sub-clause 9.1.18b) it transmits a RLC data block containing MTA related parameters (see 3GPP TS 44.060 [76]) therein. After receiving a corresponding acknowledgement on the PACCH (see 3GPP TS 44.060 [76]) the MS tunes to the next cell in the list of applicable cells and continues the procedure therein. After performing the radio access part of the MTA procedure in all applicable cells or when the MPM timer expires it returns to idle mode in the cell it was in when the radio access part of the MTA procedure was triggered.

– If the EGPRS MULTILATERATION REQUEST message indicates the Access Burst method is used (see sub-clause 3.11 and 3GPP TS 44.060 [76]) it includes a Short ID parameter. After transmitting this message and receiving a matching IMMEDIATE ASSIGNMENT message (see sub-clause 9.1.18) or IMMEDIATE PACKET ASSIGNMENT message (see sub-clause 9.1.18b) it tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein. After performing the radio access part of the MTA procedure in all applicable cells or when the MPM timer expires it returns to idle mode in the cell it was in when the radio access part of the MTA procedure was triggered.

– If the Extended Access Burst method is used (see sub-clause 3.11) it sends a first EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst – part 1’ and includes the "Random ID Low" and "MS Transmission Offset" parameters therein. After receiving a matching IMMEDIATE ASSIGNMENT message (see sub-clause 9.1.18) or IMMEDIATE PACKET ASSIGNMENT message (see sub-clause 9.1.18b) it sends a second EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst – part 2’ and includes the "Random ID Low", the "MS Sync Accuracy", the "Random ID High" and the "Short BSS ID" parameters therein. After receiving a matching IMMEDIATE ASSIGNMENT message or IMMEDIATE PACKET ASSIGNMENT message for the second EGPRS MULTILATERATION REQUEST message it tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein. After performing the radio access part of the MTA procedure in all applicable cells or when the MPM timer expires it returns to idle mode in the cell it was in when the radio access part of the MTA procedure was triggered.

– The MS shall not send an EGPRS PACKET CHANNEL REQUEST message with access type ‘PEO One Phase Access Request’ while performing the radio access part of the MTA procedure except for the case of a high priority transmission (i.e. ‘PEO Priority’ = 1, see 3GPP TS 44.060 [76]) in which case it shall stop the MPM timer and terminate the MTA procedure. When a BSS receives an uplink LLC PDU while the MPM timer is running for the corresponding MS it informs the SMLC that no additional timing advance information is pending for the corresponding MTA procedure (see 3GPP TS 49.031), stops the MPM timer and terminates the MTA procedure for that MS.

EGPRS TBF mode capable mobile stations shall monitor the GPRS Cell Options IE on the BCCH (SI13) for the cell’s EGPRS capability and, if the mobile station is also Reduced Latency capable, the cell’s Reduced Latency Access capability. In the GPRS Cell Options IE it is also indicated if the EGPRS PACKET CHANNEL REQUEST message is supported in the cell and if Reduced Latency Access is supported in the cell. An exception case is where a MS has enabled PEO and is attempting to establish a PS connection in which case the EGPRS PACKET CHANNEL REQUEST message is sent regardless of whether or not the GPRS Cell Options IE indicates the EGPRS PACKET CHANNEL REQUEST message is supported in that cell. If the mobile station supports the IMMEDIATE PACKET ASSIGNMENT message, the mobile station shall monitor cell’s capability for IMMEDIATE PACKET ASSIGNMENT message within paging messages received on its own paging sub-channel. Table 3.5.2.1.2.1 specifies which message and which establishment cause shall be used by an EGPRS mobile station when accessing an EGPRS capable cell depending on the purpose of the packet access procedure, and mobile station’s and cell’s capabilities for the case where the cell does not support PEO or EC operation; this table covers the case where PBCCH is not present in the cell (see 3GPP TS 44.060 for the case where PBCCH is present in the cell). Table 3.5.2.1.2.2 specifies which message and which establishment cause shall be used by a mobile station when PEO is enabled. Table 3.5.2.1.2.3 specifies which message and which establishment cause shall be used by a mobile station when EC operation is enabled and the RACH Access Control field (see sub-clause 9.1.30c) indicates the RACH is to be used by mobile stations that have selected coverage class 1 in both uplink and downlink. The network shall not indicate Reduced Latency Access is supported if the EGPRS PACKET CHANNEL REQUEST message is not indicated as supported. The network shall not indicate IMMEDIATE PACKET ASSIGNMENT message is supported if the EGPRS PACKET CHANNEL REQUEST message is not indicated as supported.

Table 3.5.2.1.2.1: EGPRS Packet Access Procedure (neither PEO nor EC operation enabled)

Purpose of the packet access procedure	EGPRS PACKET CHANNEL REQUEST supported in the cell	EGPRS PACKET CHANNEL REQUEST not supported in the cell
User data transfer – requested RLC mode = unacknowledged	EGPRS PACKET CHANNEL REQUEST with access type = ‘Two Phase Access Request’	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
User data transfer – requested RLC mode = acknowledged	EGPRS PACKET CHANNEL REQUEST with access type = ‘One Phase Access Request’ or ‘Two Phase Access Request’	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
User data transfer – requested RLC mode = acknowledged (Reduced Latency supported by MS)	EGPRS PACKET CHANNEL REQUEST with access type = ‘One Phase Access Request by Reduced Latency MS’ (NOTE 2)	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
User data transfer – requested RLC mode = acknowledged by an IPA capable mobile station	EGPRS PACKET CHANNEL REQUEST with access type = ‘One Phase Access Request’ or ‘Two Phase Access Request by IPA capable MS’ (NOTE 3)	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
Upper layer signalling transfer (e.g. page response, cell update, MM signalling, etc)	EGPRS PACKET CHANNEL REQUEST with access type = ‘Signalling’	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
Upper layer signalling transfer for a mobile station when the low priority indicator is set to "MS is configured to NAS signalling low priority" (e.g. page response, cell update, MM signalling, etc)	EGPRS PACKET CHANNEL REQUEST with access type = ‘Signalling’ (NOTE 5) or ‘Two Phase Access Request’ (NOTE 6)	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
Upper layer signalling transfer (e.g. page response, cell update, MM signalling, etc) by an IPA capable mobile station	EGPRS PACKET CHANNEL REQUEST with access type = ‘Signalling Request by IPA capable MS'(NOTE 4)	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ for initiation of a two-phase access
Sending of a measurement report or of a PACKET CELL CHANGE FAILURE	CHANNEL REQUEST with establishment cause = ‘Single block packet access’
Sending of a PACKET PAUSE message	CHANNEL REQUEST with establishment cause = ‘Single block packet access’ (NOTE 1)
Sending of an MBMS Service Request message	CHANNEL REQUEST with establishment cause = ‘Single block MBMS access’
NOTE 1: Upon sending the first CHANNEL REQUESTmessage the mobile station shall start timer T3204. If timer T3204 expires before an IMMEDIATE ASSIGNMENT message granting a single block period on an assigned packet uplink resource is received, the packet access procedure is aborted. If the mobile station receives an IMMEDIATE ASSIGNMENT message during the packet access procedure indicating a packet downlink assignment procedure, the mobile station shall ignore the message. NOTE 2: The One phase Access Request by Reduced Latency MS shall be used by the mobile station supporting reduced latency if Reduced Latency Access is supported by the network. The ‘One Phase Access Request by Reduced Latency MS’ or ‘Two Phase Access Request by IPA capable MS’ may be used instead if the mobile station is capable of both Reduced Latency and IMMEDIATE PACKET ASSIGNMENT and the network supports IMMEDIATE PACKET ASSIGNMENT message and Reduced Latency Access. NOTE 3: (This note does not apply if Note 2 is applicable) The ‘One Phase Access Request’ with IPA capability signalled by the MultislotClass field in the EGPRS PACKET CHANNEL REQUEST message or ‘Two Phase Access Request by IPA capable MS’ shall be used by the mobile station supporting IMMEDIATE PACKET ASSIGNMENT message if support of the IMMEDIATE PACKET ASSIGNMENT message is signalled by the network. NOTE 4: The ‘Signalling Request by IPA capable MS’ shall be used if both mobile station and network supports IMMEDIATE PACKET ASSIGNMENT. NOTE 5: The access type ‘Signalling’ shall be used unless the mobile station is accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" (see 3GPP TS 24.008). NOTE 6: The access type ‘Two Phase Access Request’ shall be used if the mobile station is accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" (see 3GPP TS 24.008).

Table 3.5.2.1.2.2: EGPRS Packet Access Procedure (PEO enabled)

Purpose of the packet access procedure	PEO Capable Cell
User data transfer (requested RLC mode = acknowledged) or Upper layer signalling transfer (e.g. page response, cell update, MM signalling, etc)	EGPRS PACKET CHANNEL REQUEST with access type = ‘PEO One Phase Access Request’ (see TS 44.060 [76]) (NOTE 1)
Transmission of a EGPRS MULTILATERATION REQUEST message indicating ‘RLC Data Block‘ method or ‘Page Response for Positioning Event’ or ‘Extended Access Burst’ method or ‘Access Burst method.	EGPRS MULTILATERATION REQUEST see TS 44.060 [76]) (NOTE 1)
NOTE 1: A PEO capable MS in a cell that does not support PEO shall operate according to Table 3.5.2.1.2.1.

Table 3.5.2.1.2.3: EGPRS Packet Access Procedure (EC operation enabled – RACH used)

Purpose of the packet access procedure	EC-GSM-IoT Capable Cell
User data transfer (requested RLC mode = acknowledged) or Upper layer signalling transfer (e.g. page response, cell update, MM signalling, etc)	EC PACKET CHANNEL REQUEST sent using TS3 – see sub-clause 9.1.65 (NOTE 1)
NOTE 1: An EC capable MS in a cell that does not support EC-GSM-IoT shall operate according to Table 3.5.2.1.2.1 if it supports GPRS services using GPRS TBFs or EGPRS TBFs.

Upon leaving idle mode the mobile station shall ignore PAGING REQUEST messages indicating a packet paging procedure.

A mobile station belonging to GPRS MS class A or B shall continue to monitor its paging subchannel on CCCH for PAGING REQUEST messages indicating an establishment of RR connection. A mobile station belonging to GPRS MS class B may abort the packet access procedure at the receipt of a PAGING REQUEST messages indicating an establishment of RR connection. An exception is the case of a MS that has enabled PEO or EC operation in which case the MS never monitors its paging subchannel on CCCH for PAGING REQUEST messages indicating an establishment of RR connection (see sub-clause 3.3.1).

The CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST messages are sent on RACH and contain the parameters:

– an establishment cause which indicates packet access, and as applicable, a request for one phase packet access, single block packet access or a single block MBMS access for a CHANNEL REQUEST (sub-clause 9.1.8), or a request for one phase access or two phase access or short access or sending of signalling data for an EGPRS PACKET CHANNEL REQUEST (see 3GPP TS 44.060);

– a random reference which is drawn randomly from an uniform probability distribution for every new transmission;

– a capability indication which indicates the support of IMMEDIATE PACKET ASSIGNMENT for an EGPRS PACKET CHANNEL REQUEST (see 3GPP TS 44.060).

The EGPRS MULTILATERATION REQUEST message is sent on RACH and indicates packet access by a mobile station that has enabled PEO operation and is accessing the network to send a ‘Page Response for Positioning Event’ or to a perform the radio access part of a MTA procedure using one of the following methods:

– If the RLC Data block method is used (see sub-clause 3.11) this message includes a random reference which is drawn randomly from a uniform probability distribution for every new transmission.

– If the Access Burst method is used (see sub-clause 3.11) this message includes a Short ID parameter (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]).

– If the Extended Access Burst method is used (see sub-clause 3.11) the first instance of this message includes the "Random ID Low" and "MS Transmission Offset" parameters and the second instance of this message includes the "Random ID Low", "MS Sync Accuracy", "Random ID High" and the "Short BSS ID" parameters (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]).

Prior to sending an EGPRS PACKET CHANNEL REQUEST or EGPRS MULTILATERATION REQUEST message on the RACH a MS shall determine the applicable CCCH_GROUP as follows:

– If eDRX is enabled or it is attempting to enable eDRX the MS shall determine its CCCH_GROUP as per idle mode when extended DRX cycles are used (see 3GPP TS 45.002 [32]).

– Otherwise, the MS shall determine its CCCH_GROUP as per idle mode when extended DRX cycles are not used (see 3GPP TS 45.002 [32]).

The EC PACKET CHANNEL REQUEST messages are sent on RACH and indicate packet access by a mobile station that has enabled EC operation where the included parameters are as described in sub-clause 9.1.65. Prior to sending an EC PACKET CHANNEL REQUEST message on the RACH the MS shall set CCCH_GROUP = 0 (see sub-clauses 3.5.2.1.2 and 9.1.30c).

After sending the first CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EGPRS MULTILATERATION REQUEST message, the mobile station shall start listening to the full downlink CCCH timeslot corresponding to its CCCH_GROUP. After sending the first EC PACKET CHANNEL REQUEST message a mobile station that has enabled EC operation shall listen to the downlink CCCH timeslot using CCCH_GROUP = 0 (see 3GPP TS 45.002). In addition, a mobile station that has sent a CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EGPRS MULTILATERATION REQUEST message shall start listening to the BCCH to perform signal strength measurements as they are defined for packet idle mode, see 3GPP TS 45.008. A mobile station that has sent an EC PACKET CHANNEL REQUEST message need not perform signal strength measurements.

A mobile station accessing the network to perform the radio access part of a MTA procedure (see TS 3GPP 44.031) or accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" (see 3GPP TS 24.008) that has sent one or more CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST or EGPRS MULTILATERATION REQUEST messages shall proceed as follows:

– If the mobile station receives an IMMEDIATE ASSIGNMENT, an IMMEDIATE ASSIGNMENT EXTENDED, an EC IMMEDIATE ASSIGNMENT TYPE 1 (if EC operation is enabled), an IMMEDIATE PACKET ASSIGNMENT (if supported) or an IMMEDIATE ASSIGNMENT REJECT message corresponding to one of its last 3 transmitted CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST or EGPRS MULTILATERATION REQUEST messages it shall act on that message as described in sub-clause 3.5.2.1.3.

– If the mobile station successfully decodes an RR message, which is not a response corresponding to one of its last 3 transmitted CHANNEL REQUEST or EGPRS CHANNEL REQUEST or EC PACKET CHANNEL REQUEST messages, that indicates an implicit reject for the PS domain (see sub-clause 3.3.1.1.1a) it shall start timer T3146 (if not already running) and initiate the implicit reject procedure as described in sub-clause 3.3.1.1.3.2a.

– If the mobile station has enabled PEO and has sent one or more EGPRS MULTILATERATION REQUEST messages in a cell that supports MTA then it shall ignore the implicit reject information when received in an RR message which is not a response corresponding to one of its last 3 transmitted EGPRS MULTILATERATION REQUEST messages.

– If a mobile station sends a EGPRS MULTILATERATION REQUEST message indicating ‘RLC Data Block method’ or ‘Page Response for Positioning Event’ (see 3GPP TS 44.060 [76]) a matching IMMEDIATE ASSIGNMENT message includes "Request Reference" information that matches the Random Bits and TDMA Frame information used by the MS when sending the EGPRS MULTILATERATION REQUEST message (see sub-clause 10.5.2.30). Simlialrly, a matching IMMEDIATE PACKET ASSIGNMENT message includes Random Reference information that matches the 11 bits of information included within the EGPRS MULTILATERATION REQUEST message.

– If a mobile station sends a EGPRS MULTILATERATION REQUEST message indicating ‘Access Burst method’ (see 3GPP TS 44.060 [76]) a matching IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message includes the same "Short ID" parameter value used by the MS when sending the EGPRS MULTILATERATION REQUEST message (see sub-clause 10.5.2.87).

– If a mobile station sends a EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst method – part 1’ (see 3GPP TS 44.060 [76]) a matching IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message includes the same "Random ID Low" parameter value used by the MS when sending the EGPRS MULTILATERATION REQUEST message (see sub-clause 10.5.2.87).

– If a mobile station sends a EGPRS MULTILATERATION REQUEST message indicating ‘Extended Access Burst method – part 2’ (see 3GPP TS 44.060 [76]) a matching IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message message includes the same "Random ID High" parameter value used by the MS when sending the EGPRS MULTILATERATION REQUEST message (see sub-clause 10.5.2.87).

Having sent the maximum number of CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST or EGPRS MULTILATERATION REQUEST messages, the mobile station starts timer T3146. At expiry of timer T3146, if the packet access procedure is ongoing then it is aborted, a random access failure is indicated to upper layers and autonomous cell re-selection is performed according to 3GPP TS 43.022. At expiry of timer T3146, if the radio access part of the MTA procedure is ongoing then it is aborted for the current cell and the mobile station MS tunes to the next cell in the list of applicable cells and continues the radio access part of the MTA procedure therein.

If the mobile station receives an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message (if supported) during the packet access procedure indicating a packet downlink assignment procedure, the mobile station shall abort the packet access procedure and respond to the IMMEDIATE ASSIGNMENT or the IMMEDIATE PACKET ASSIGNMENT message as specified in sub-clause 3.5.3.1.2 or sub-clause 3.5.3.2. If the Packet Downlink Assignment IE in IMMEDIATE ASSIGNMENT message or IPA Downlink Assignment struct in IMMEDIATE PACKET ASSIGNMENT message indicates a downlink TBF, the mobile station shall then attempt an establishment of uplink TBF, using the procedure specified in 3GPP TS 44.060 which is applicable in packet transfer mode. If the Packet Downlink Assignment IE in IMMEDIATE ASSIGNMENT message indicates a downlink single block then the mobile station shall wait for the allocated single block and react on the received message before reattempting the uplink TBF establishment.

3.5.2.1.2a EC Packet access procedure (EC-CCCH)

The RR entity of a mobile station initiates the packet access procedure by scheduling the sending of EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages (see Table 3.5.2.1.2a.1 and sub-clause 9.1.65) as follows:

– Using the 1TS EC-RACH Mapping method if CC1 has been selected on the uplink or if Access_Timeslots=0, sent in EC SYSTEM INFORMATION TYPE 2.

– Using the 2TS EC-RACH Mapping method if CC2, CC3, CC4 or CC5 has been selected on the uplink and Access_Timeslots=1, sent in EC SYSTEM INFORMATION TYPE 2has been selected on the uplink and Access_Timeslots=1, sent in EC SYSTEM INFORMATION TYPE 2.

– When the 2TS EC-RACH Mapping method for CC2, CC3 and CC4 is used the EC-RACH is mapped over two consecutive timeslots, and the EC PACKET CHANNEL REQUEST messages sent across the 2 timeslots shall be identical and shall use the same training sequence code (i.e one of TS5, TS6 or TS7 is used according to the uplink CC).

– When the 2TS EC-RACH Mapping method is used for CC5 and EC SI 2 parameter CC5_EC-RACH_FORMAT_IND (see sub-clause 9.1.43q) indicates usage of ESAB, then EC-RACH CC5 transmissions are performed using ESAB (see 3GPP TS 45.002 [32])).

– When the 2TS EC-RACH Mapping method is used for CC5 and EC SI 2 parameter CC5_EC-RACH_FORMAT_IND (see sub-clause 9.1.43q) indicates usage of EDAB, then EC-RACH CC5 transmissions are performed using EDAB (see 3GPP TS 45.002 [32])).

See 3GPP TS 45.002 for details regarding coverage class specific rules for multiplexing blind physical layer transmissions using the 2 TS EC-RACH.

Prior to sending an EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message on the EC-RACH a MS shall determine the applicable EC_CCCH_GROUP as per idle mode for EC-GSM-IoT (see 3GPP TS 45.002 [32]).

After scheduling the transmission of EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages it leaves idle mode (in particular, the mobile station shall ignore EC PAGING REQUEST messages).

Table 3.5.2.1.2a.1: EC Packet Access Procedure

Purpose of the packet access procedure	EC-GSM-IoT Capable Cell
User data transfer (requested RLC mode = acknowledged) or Upper layer signalling transfer (e.g. page response, cell update, MM signalling, etc)	EC PACKET CHANNEL REQUEST sent using either TS3, TS5, TS6, TS7 or TS8 – see sub-clause 9.1.65 (NOTE 1)
Transmission of an EC MULTILATERATION REQUEST message indicating ‘RLC Data Block‘ method or ‘Page Response for Positioning Event’ or ‘Extended Access Burst’ method or ‘Access Burst method.	EC MULTILATERATION REQUEST sent using either TS4, TS5, TS6, TS7 or TS8- see sub-clause 9.1.65 (NOTE 1)
NOTE 1: An EC capable MS in a cell that does not support EC-GSM-IoT shall operate according to Table 3.5.2.1.2.1 if it supports GPRS TBFs or EGPRS TBFs.

The mobile station then sends maximally M + 1 EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages where each message is repeated according to the number of blind physical layer transmissions corresponding to its uplink CC. The first EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message is sent using a transmission opportunity corresponding to its uplink coverage class randomly selected (with uniform probability distribution) from a set of Tcc 51-multiframes on the EC-RACH/RACH as shown in Table 3.5.2.1.2a.2. When sending a page response the set of Tcc 51-multiframes starts with the first 51-multiframe immediately following the last 51-multiframe used for receiving the corresponding paging request. For a mobile originated access attempt the set of Tcc 51-multiframes starts with the first 51-multiframe (following the 51-multiframe during which upper layers requested the transfer of a LLC PDU) that contains a transmission opportunity corresponding to its uplink coverage class.

Table 3.5.2.1.2a.2: Values of parameters Scc and Tcc

	Scc	Tcc
CC1	Sm	Tm
CC2	Sm	Tm
CC3	2*Sm	2*Tm
CC4	4*Sm	2*(Tm+1)
CC5	4*Sm	3*(Tm+2)

The value for Sm is sent in the EC SYSTEM INFORMATION TYPE 2 message and is used for determining the Scc value applicable for monitoring the EC-AGCH according to the selected downlink coverage class of the mobile station.

The value for Tm is sent in the EC SYSTEM INFORMATION TYPE 2 message and is used for determining the Tcc value applicable for randomly selecting an EC-RACH (and possibly RACH) transmission opportunity corresponding to the selected uplink coverage class of the mobile station.

M is the value of the parameter "EC_Max_Retrans" sent in the EC SYSTEM INFORMATION TYPE 2 message.

The EC PACKET CHANNEL REQUEST message (see sub-clause 9.1.65) contains the following parameters:

– a random reference field which is drawn randomly from a uniform probability distribution for every new transmission;

– a field indicating the downlink coverage class selected by the mobile station (only included when the message is sent on EC-RACH);

– a field indicating the signal strength measured by the MS (only included when the message is sent on RACH);

– a field indicating the purpose of the data transfer ("page response", "cell update", "RLC/MAC control message" or "uplink data transfer") and the number of uplink data blocks it has to send (assuming MCS-1 channel coding is used);

– a field indicating the priority of the packet access request.

A mobile station that has enabled EC operation starts the radio access part of the MTA procedure upon receiving a RRLP Multilateration Timing Advance Request message (see 3GPP TS 44.031) if both the MS and the serving cell support the MTA procedure method indicated therein (see the MTA_BITMAP field described in sub-clause 10.5.2.37b). In this case it starts the MPM timer and starts accessing the network using cells it has selected to perform the radio access part of a MTA procedure. For each selected cell it compares the BSIC of the EC-CCCH to the BSIC. If the BSIC does not match it does not perform the radio access part of the MTA procedure using that cell. If the BSIC matches it does not check the status of the EC-BCCH CHANGE MARK field and implicit reject status information sent for that cell, sends a EC MULTILATERATION REQUEST message (see sub-clause 9.1.65) and proceeds as follows:

– If the EC MULTILATERATION REQUEST message indicates the RLC Data block method is used (see sub-clause 3.11) it includes a random reference which is drawn randomly from a uniform probability distribution for every new transmission and a field indicating the downlink coverage class selected by the mobile station (see sub-clause 9.1.65). After transmitting this message and receiving a matching EC IMMEDIATE ASSIGNMENT TYPE 2 message it transmits a RLC data block containing MTA related parameters (see 3GPP TS 44.060 [76]) therein. After receiving a corresponding acknowledgement on the EC-PACCH (see 3GPP TS 44.060 [76]) the MS tunes to the next cell in the list of applicable cells and continues the procedure therein. After performing the radio access part of the MTA procedure in all applicable cells or when the MPM timer expires it returns to idle mode in the cell it was in when the radio access part of the MTA procedure was triggered.

– If the EC MULTILATERATION REQUEST message indicates the Access Burst method is used (see sub-clause 3.11) it includes a Short ID parameter (see sub-clause 9.1.65). After transmitting this message and receiving a matching EC IMMEDIATE ASSIGNMENT TYPE 3 message (see sub-clause 9.1.68) it tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein. After performing the radio access part of the MTA procedure in all applicable cells or when the MPM timer expires it returns to idle mode in the cell it was in when the radio access part of the MTA procedure was triggered.

– If the Extended Access Burst method is used (see sub-clause 3.11) it sends a first EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst method – part 1’ and includes the "Random ID Low" and "MS Transmission Offset" parameters therein (see sub-clause 9.1.65). After receiving a matching EC IMMEDIATE ASSIGNMENT TYPE 3 message (see sub-clause 9.1.68) it sends a second EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst method – part 2’ and includes the "Random ID Low", the "MS Sync Accuracy", the "Random ID High" and the "Short BSS ID" parameters therein. After receiving a matching EC IMMEDIATE ASSIGNMENT TYPE 3 message for the second EC MULTILATERATION REQUEST message it tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein. After performing the radio access part of the MTA procedure in all applicable cells or when the MPM timer expires it returns to idle mode in the cell it was in when the radio access part of the MTA procedure was triggered.

– The MS shall not send an EC PACKET CHANNEL REQUEST message while performing the radio access part of the MTA procedure except for the case of a high priority transmission (i.e. ‘EC Priority’ = 1, see sub-clause 9.1.65) in which case it shall stop the MPM timer and abort the MTA procedure. When a BSS receives an uplink LLC PDU while the MPM timer is running for the corresponding MS it informs the SMLC that no additional timing advance information is pending for the corresponding MTA procedure (see 3GPP TS 49.031), stops the MPM timer and terminates the MTA procedure for that MS.

After sending the first EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message or a subsequent retransmission, the mobile station shall start reading the EC-AGCH (according to the downlink coverage class indicated within the corresponding EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message) in an attempt to find a response matching its last transmission.

– For the case where the EC MULTILATERATION REQUEST message indicates ‘RLC Data Block method’ or ‘Page Response for Positioning Event’ (see sub-clause 9.1.65) a matching EC IMMEDIATE ASSIGNMENT TYPE 2 message (see sub-clause 9.1.60) includes "EC Request Reference" information that matches the Random Bits and TDMA Frame information used by the MS when sending the EC MULTILATERATION REQUEST message (see sub-clause 10.5.2.83).

– For the case where the EC MULTILATERATION REQUEST message indicates ‘Access Burst method’ (see sub-clause 9.1.65) a matching EC IMMEDIATE ASSIGNMENT TYPE 3 message (see sub-clause 9.1.68) indicates a downlink coverage class corresponding to the training sequence used by the MS and includes the same "Short ID" parameter value used by the MS when sending the EC MULTILATERATION REQUEST message.

– For the case where the EC MULTILATERATION REQUEST message indicates ‘Extended Access Burst method – part 1’ (see sub-clause 9.1.65) a matching EC IMMEDIATE ASSIGNMENT TYPE 3 message indicates downlink coverage class 1 and includes the same "Random ID Low" parameter value used by the MS when sending the EC MULTILATERATION REQUEST message.

– For the case where the EC MULTILATERATION REQUEST message indicates ‘Extended Access Burst method – part 2’ (see sub-clause 9.1.65) a matching EC IMMEDIATE ASSIGNMENT TYPE 3 message indicates downlink coverage class 1 and includes the same "Random ID High" parameter value used by the MS when sending the EC MULTILATERATION REQUEST message.

– A MS that has selected downlink CC1 shall begin looking for a matching response starting within downlink 51-multiframe N (i.e. N = TDMA FN div 51) if it used uplink 51-multiframe N to send the last blind physical layer transmission of the EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message and there is at least one remaining valid CC1 reception opportunity in downlink 51-multiframe N. If a matching response is not found or there are no remaining valid CC1 reception opportunities within downlink 51-multiframe N it shall start reading 51-multiframe N+1in an attempt to find a matching response. The total number of downlink 51-multiframes it reads (excluding downlink 51-multiframe N) in an attempt to find a matching response is determined by Scc (see Table 3.5.2.1.2a.2).

– A MS that has selected downlink CC2 shall begin looking for a matching response starting within downlink 51-multiframe N if it used uplink 51-multiframe N to send the last blind physical layer transmission of the EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message, N mod 2 = 0 and there is at least one remaining valid CC2 reception opportunity that starts in downlink 51-multiframe N. If a matching response is not found using downlink 51-multiframes N and N+1 or there are no remaining valid CC2 reception opportunities that start within downlink 51-multiframe N it shall start reading downlink 51-multiframe N+1 (respectively N+2) if N mod 2 = 1 (respectively N mod 2 = 0). The total number of downlink 51-multiframes it reads (excluding downlink 51-multiframe N) in an attempt to find a matching response is determined by Scc (see Table 3.5.2.1.2a.2).

– A MS that has selected downlink CC3 shall begin looking for a matching response starting with downlink 51-multiframe N+1 (respectively N+2) when it used uplink 51-multiframe N to send the last blind physical layer transmission of the EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message where N mod 2 = 1 (respectively N mod 2 = 0). The total number of downlink 51-multiframes it reads in an attempt to find a matching response is determined by Scc (see Table 3.5.2.1.2a.2).

– A MS that has selected downlink CC4 shall begin looking for a matching response starting with downlink 51-multiframe N+1 (respectively N+2, N+3, N+4) when it used uplink 51-multiframe N to send the last blind physical layer transmission of the EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message where N mod 4 = 3 (respectively N mod 4 = 2, 1, 0). The total number of downlink 51-multiframes it reads in an attempt to find a matching response is determined by Scc (see Table 3.5.2.1.2a.2).

A mobile station accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" (see 3GPP TS 24.008) that has sent one or more EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages shall proceed as follows:

– If, while reading the total number of downlink 51-multiframes determined by Scc, the mobile station receives an EC IMMEDIATE ASSIGNMENT TYPE 2, EC IMMEDIATE ASSIGNMENT TYPE 4 or an EC IMMEDIATE ASSIGNMENT REJECT or an EC IMMEDIATE ASSIGNMENT TYPE 3 message corresponding to its last transmitted EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message it shall act on that message as described in sub-clause 3.5.2.1.3a.

– If a matching response is not found and the mobile station is not sending an exception report (see sub-clause 9.1.65) it shall examine the Implicit Reject Status (IRS) field sent as part of the EC-SCH INFORMATION message (see sub-clause 9.1.30c). If the IRS field indicates the access attempt is rejected the mobile station shall abort the packet access procedure, start timer T3146 (if not already running) and initiate the EC Implicit Reject procedure (see sub-clause 3.5.2a.2). An exception case is where a mobile station is performing the radio access part of the MTA procedure in a cell that supports MTA (see the MTA_BITMAP field described in sub-clause 9.1.43q) in which case it shall not examine the IRS field.

– Otherwise, the MS schedules the sending of another EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message (if allowed according to "EC_Max_Retrans") using a transmission opportunity corresponding to its uplink coverage class randomly selected (with uniform probability distribution) from a set of Tcc 51-multiframes on the EC-RACH (determined using Tm as shown in Table 3.5.2.1.2a.2).

– The set of Tcc 51-multiframes starts with the first 51-multiframe (following the set of Scc downlink 51-multiframe read in attempt to find a matching response or following the last downlink 51-multiframe read to acquire the IRS field) that contains a transmission opportunity corresponding to its uplink coverage class.

– When scheduling another EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message the MS uses the "CC_Access_Adaptation" parameter (broadcast in EC SYSTEM INFORMATION TYPE 2 message) to determine if it is allowed to increment both its uplink CC and downlink CC to the next CC supported by the network (unless it is already using CC4).

– Upon incrementing its uplink/downlink CC the number of subsequent EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message transmission attempts that may occur before it is allowed to increment its uplink/downlink CC once again is the same as when sending the first EC PACKET CHANNEL REQUEST message (i.e. determined by the "CC_Access_Adaptation" parameter).

– When sending up to M + 1 EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages the MS may increment its uplink CC and downlink CC a maximum of 2 times if CC adaptations are allowed according to the "CC_Access_Adaptation" parameter.

Having sent M + 1 EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages, the RR entity of the mobile station starts timer T3146 at the start of the first of the set of downlink 51-multiframes (excluding downlink 51-multiframe N) it reads in an attempt to find a matching response as determined by Scc (see Table 3.5.2.1.2a.2). At expiry of timer T3146, if the packet access procedure is ongoing then it is aborted, a random access failure is indicated to upper layers and autonomous cell re-selection is performed according to 3GPP TS 43.022. At expiry of timer T3146, if the radio access part of the MTA procedure is ongoing then it is aborted for the current cell and the mobile station tunes to the next cell in the list of applicable cells and continues the radio access part of the MTA procedure therein.

3.5.2.1.3 Packet immediate assignment

3.5.2.1.3.1 On receipt of a CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST message or EGPRS MULTILATERATION REQUEST

On receipt of a CHANNEL REQUEST message indicating a packet access, the network may allocate a temporary flow identity and assign a packet uplink resource comprising one PDCH for an uplink temporary block flow in GPRS TBF mode. On receipt of an EGPRS PACKET CHANNEL REQUEST message, the network may allocate a temporary flow identity and assign a packet uplink resource comprising one PDCH for an uplink temporary block flow in EGPRS TBF mode or GPRS TBF mode.

On receipt of an EC PACKET CHANNEL REQUEST message on the RACH, the network may allocate a temporary flow identity and assign pre-allocated packet uplink resources comprising one or several PDCHs for an uplink temporary block flow in EC TBF mode.

On receipt of an EGPRS MULTILATERATION REQUEST message on the RACH (see 3GPP TS 44.060 [76]), the network proceeds according the Multilateration Timing Advance (MTA) method indicated therein (see sub-clause 3.5.2.1.2 and 3.11).

If the establishment cause in the CHANNEL REQUEST message indicates a request for a single block packet access, the network shall grant only the single block period on the assigned packet uplink resource if the network allocates resource for the mobile station. If the establishment cause in the EGPRS PACKET CHANNEL REQUEST message indicates a request for a two phase access, the network shall grant one or two radio blocks for the mobile station (within a Multi Block allocation) to send a PACKET RESOURCE REQUEST and possibly an ADDITIONAL MS RADIO ACCESS CAPABILITIES messages on the assigned packet uplink resource if the network allocates resource for the mobile station.

If the establishment cause in the CHANNEL REQUEST message indicates a request for one phase packet access, the network may grant either a one phase packet access or a single block packet access for the mobile station. If a single block packet access is granted, it forces the mobile station to perform a two phase packet access. If the establishment cause in the EGPRS PACKET CHANNEL REQUEST message indicates a request for one phase packet access or sending signalling data, the network may grant either a one phase packet access or a two phase access (within a Multi Block allocation). If a multiple block packet access is granted, it forces the mobile station to perform a two phase packet access. In the case of a MS that has enabled PEO the establishment cause always indicates a one phase access and the network shall prioritize the granting of a one phase packet access.

When EC operation is not enabled the packet uplink resource is assigned to the mobile station in an IMMEDIATE ASSIGNMENT or an IMMEDIATE PACKET ASSIGNMENT message (if supported) sent in unacknowledged mode on the same CCCH timeslot on which the network has received the CHANNEL REQUEST or the EGPRS PACKET CHANNEL REQUEST message. The network may assign packet resource to the mobile station in an IMMEDIATE PACKET ASSIGNMENT message if the received EGPRS PACKET CHANNEL REQUEST message indicates the support of this assignment message. There is no further restriction on what part of the downlink CCCH timeslot the IMMEDIATE ASSIGNMENT and IMMEDIATE PACKET ASSIGNMENT message can be sent. Timer T3141 is started on the network side.

When EC operation is enabled the packet uplink resource is assigned to the mobile station in an EC IMMEDIATE ASSIGNMENT TYPE 1 message sent in unacknowledged mode on the same CCCH timeslot on which the network received the EC PACKET CHANNEL REQUEST message (see Table 3.5.2.1.2.3). Timer T3141 is started on the network side.

The IMMEDIATE ASSIGNMENT and EC IMMEDIATE ASSIGNMENT TYPE 1 messages contain:

– the information field of the CHANNEL REQUEST, the EGPRS PACKET CHANNEL REQUEST or the EC PACKET CHANNEL REQUEST message and the frame number of the frame in which the CHANNEL REQUEST, the EGPRS PACKET CHANNEL REQUEST or the EC PACKET CHANNEL REQUEST message was received;

– the packet channel description;

– the initial timing advance;

– the packet uplink assignment or EGPRS packet uplink assignment construction (only applies to the IMMEDIATE ASSIGNMENT message).

– the packet resources used for the uplink EC TBF which includes the set of pre-allocated uplink resources described by the EC Fixed Uplink Allocation IE (only applies to the EC IMMEDIATE ASSIGNMENT TYPE 1 message).

The IMMEDIATE PACKET ASSIGNMENT message contains parameters relevant to the assignment of packet resources as specified in subclauses 3.5.2.1.3.2 and 3.5.2.1.3.3.

If frequency hopping is applied, the network may use the indirect encoding or the direct encoding of the frequency configuration in the Packet Channel Description information element in IMMEDIATE ASSIGNMENT message or in the IPA Uplink Assignment struct, IPA Downlink Assignment struct, or IPA Single Block Uplink Assignment struct in IMMEDIATE PACKET ASSIGNMENT message. If the indirect encoding is used, the mobile station uses information received in system information or stored from a previous assignment to determine the frequency parameters, see 3GPP TS 44.060. If the direct encoding is used, the mobile station uses the cell allocation defined for the cell to decode the mobile allocation.

If the indirect encoding is used, the IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message may contain a CHANGE_MARK_1 field. If that is present, the mobile station shall verify the validity of the SI13_CHANGE_MARK associated with the GPRS mobile allocation to which the message refers, see 3GPP TS 44.060. If the CHANGE_MARK_1 field and the SI13_CHANGE_MARK do not match, the message does not satisfactorily define a PDCH.

If EC operation is enabled the network indicates the frequency configuration in the EC Packet Channel Description Type 1 information element (see sub-clause10.5.2.84) in the EC IMMEDIATE ASSIGNMENT TYPE 1 message.

If the mobile station receives an IMMEDIATE ASSIGNMENT message and the Dedicated mode or TBF information element indicates that this is the first message in a two-message assignment, the mobile station shall continue to listen to the full CCCH. The network may send a second IMMEDIATE ASSIGNMENT message to the mobile station within two multiframe periods following the first IMMEDIATE ASSIGNMENT message, specifying the packet channel description and, if required, a mobile allocation for the assignment. The two IMMEDIATE ASSIGNMENT messages in a two-message assignment shall have the same contents of the Request Reference information elements.

If the mobile station does not receive the second IMMEDIATE ASSIGNMENT messages in a two-message assignment within two multiframe periods following the first message, the mobile station shall discard the first IMMEDIATE ASSIGNMENT message received.

On receipt of an IMMEDIATE ASSIGNMENT message or, in case of a two-message assignment, a matching pair of IMMEDIATE ASSIGNMENT messages corresponding to one of its 3 last CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST messages, the mobile station stops T3146 (if running), stops sending CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST messages, and switches to the assigned PDCH.

On receipt of an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message (see sub-clauses 9.1.18 and sub-clause 9.1.18b) corresponding to one of its 3 last EGPRS MULTILATERATION REQUEST messages (see 3GPP TS 44.060 [76]), the mobile station stops T3146 (if running), stops sending EGPRS MULTILATERATION REQUEST messages, and proceeds as follows:

– If the EGPRS MULTILATERATION REQUEST message indicated ‘Page Response for Positioning Event’ (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]) the mobile station switches to the assigned PDCH and transmits a RLC Data Block thereon. Upon receiving a corresponding Ack the mobile station returns to Idle mode.

– If the EGPRS MULTILATERATION REQUEST message indicated ‘RLC Data Block method’ (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]) the mobile station switches to the assigned PDCH and transmits a RLC Data Block thereon. Upon receiving a corresponding Ack the mobile station considers the radio access part of the MTA procedure as successfully completed in the current cell, tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein.

– If the EGPRS MULTILATERATION REQUEST message indicated ‘Access Burst method’ (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]) the mobile station considers the radio access part of the MTA procedure as successfully completed in the current cell, tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein.

– If the EGPRS MULTILATERATION REQUEST message indicated ‘Extended Access Burst method – part 1’ (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]) the mobile station starts sending EGPRS MULTILATERATION REQUEST messages indicating ‘Extended Access Burst method – part 2.

– If the EGPRS MULTILATERATION REQUEST message indicated ‘Extended Access Burst method – part 2’ (see sub-clause 3.5.2.1.2 and 3GPP TS 44.060 [76]) the mobile station considers the radio access part of the MTA procedure as successfully completed in the current cell, tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein.

On receipt of an EC IMMEDIATE ASSIGNMENT TYPE 1 message corresponding to one of its 3 last EC PACKET CHANNEL REQUEST messages on the RACH, the mobile station stops T3146 (if running), stops sending EGPRS PACKET CHANNEL REQUEST messages, and switches to the assigned PDCH(s).

The content of the packet uplink assignment construction (respectively EGPRS packet uplink assignment construction indicates which type of packet access is granted: one phase packet access or single (respectively multiple) block packet access.

3.5.2.1.3.2 One phase packet access

In the case the one phase packet access is granted, the packet uplink assignment construction contains:

– the temporary flow identity;

– the USF value

– the channel coding scheme for RLC data blocks;

– the power control parameters;

– the polling bit;

– optionally, the timing advance index (see 3GPP TS 45.010);

– optionally, the TBF starting time.

In addition, the EGPRS packet uplink assignment construction also contains:

– the EGPRS modulation and coding scheme;

– information whether retransmitted uplink data blocks shall be resegmented or not;

– the EGPRS window size to be used within the transmission; and

– optionally a request for the mobile station to send its radio access capability information.

In addition, if sent in response to a one phase access with access type indicating "One Phase Access Request by Reduced Latency MS" as defined in 3GPP TS 44.060, the EGPRS packet uplink assignment construction also allows:

– the possibility to assign an uplink EGPRS TBF on a maximum of two uplink PDCH pairs situated on consecutive or on non-consecutive timeslots for RTTI configuration;

– the inclusion of an indication if RTTI or BTTI USF mode is used;

– the inclusion of an indication of whether the SSN-based or Time-Based approach shall be used for PAN fields.

The medium access method is dynamic allocation and the RLC mode is acknowledged mode, see 3GPP TS 44.060.

If the timing advance index (TAI) is included in the packet uplink assignment construction, the mobile station shall use the continuous update timing advance mechanism, see 3GPP TS 45.010, using PTCCH in the same timeslot as the assigned PDCH. If a timing advance index (TAI) field is not included, the continuous update timing advance mechanism shall not be used.

In case the packet uplink assignment or EGPRS packet uplink assignment construction contains a TBF starting time and the mobile station receives the message before the TBF starting time has expired, it shall wait until the frame number indicated by the TBF starting time before accessing the channel. If the mobile station receives the message after the TBF starting time has expired, it shall ignore the TBF starting time and may immediately access the channel. If the medium access method is dynamic allocation, the mobile station shall start timer T3164. Regardless of which allocation mode is used, the mobile station shall proceed with the contention resolution at one phase access defined in 3GPP TS 44.060.

If the Polling bit is set to 1, MS shall send a PACKET CONTROL ACKNOWLEDGEMENT message (see 44.060) on the assigned PDCH, in the uplink block specified by the TBF Starting Time. In this case the TBF Starting Time is used both to indicate when the assigned PDCH becomes valid and to specify the uplink block. If the TBF Starting Time is not present or has expired, the MS shall ignore the polling request.

When the mobile station switches to the assigned PDCH, it shall take the power control parameters received in the IMMEDIATE ASSIGNMENT or the IMMEDIATE PACKET ASSIGNMENT message into account, perform signal strength measurements and apply output power control procedures as they are defined for packet transfer mode, see 3GPP TS 45.008.

In the case the one phase packet access is granted to MS supporting IMMEDIATE PACKET ASSIGNEMENT, the IPA Uplink Assignment struct sent in the IMMEDIATE PACKET ASSIGNMENT message may assign packet uplink resource for multiple mobile stations and contain following parameters specific to different mobile stations:

– the temporary flow identity;

– the USF value;

– the EGPRS channel coding command for RLC data block;

– the timing advance value;

– the Radio Access Capabilities Request bit.

In addition, the IPA Uplink Assignment struct contains the timeslot number which is common to all mobile stations addressed in this construction. Relevant default values shall be used for the RLC window size, Alpha, RESEGMENT and USF_GRANULARITY parameters as specified in subclause 10.5.2.78.

If the Radio Access Capability Request bit is set to 1, mobile stations addressed in the IPA Uplink Assignment struct in the IMMEDIATE PACKET ASSIGNMENT message shall send MS Radio Access Capability 2 IE in PACKET RESOURCE REQUEST message.

When assigning an EGPRS TBF, the network may request information about radio access capabilities of the mobile station on one or several frequency bands within the IMMEDIATE ASSIGNMENT or the IMMEDIATE PACKET ASSIGNMENT message; the list of frequency bands is ordered by the network starting with the most important and ending with the least important one. The mobile station shall provide the network with its radio access capabilities for the frequency bands it supports, in the same priority order as the one specified by the network, by sending a PACKET RESOURCE REQUEST message, and an ADDITIONAL MS RADIO ACCESS CAPABILITIES if all the requested informations do not fit in the PACKET RESOURCE REQUEST. If the mobile station does not support any frequency band requested by the network, it shall report its radio access capabilities for the BCCH frequency band. The mobile station shall indicate in the PACKET RESOURCE REQUEST if it will send more information about its radio access capabilities in the ADDITIONAL MS RADIO ACCESS CAPABILITIES message. The PACKET RESOURCE REQUEST and the ADDITIONAL MS RADIO ACCESS CAPABILITIES shall be sent within the one or two first radio blocks allocated for the mobile station on the assigned PDCH.

The network may request a retransmission of the PACKET RESOURCE REQUEST and the ADDITIONAL MS RADIO ACCESS CAPABILITIES messages. A request for retransmission of one or both of these messages shall be indicated in the PACKET UPLINK ACK/NACK message. The mobile station has to indicate within the PACKET RESOURCE REQUEST if the message is a retransmitted one.

In the case of an uplink EGPRS TBF assignment in RTTI configuration where an IMMEDIATE ASSIGNMENT message is sent in response to a one phase access with access type indicating "One Phase Access Request by Reduced Latency MS" as defined in 3GPP TS 44.060, the assigned timeslots of the uplink PDCH pair(s) and the corresponding downlink PDCH pair (as defined in 3GPP TS 44.060) associated with each assigned uplink PDCH pair are indicated by a combination of the TN given by the Packet Channel Description information element and information in the EGPRS Packet Uplink Assignment construction of the IA Rest Octets information element as described in sub-clause 10.5.2.16.

3.5.2.1.3.3 Single block packet access

In the case the single block packet access is granted, the packet uplink resource description contains:

– the power control parameter setting;

– the TBF starting time.

In the case the single block packet access is granted to a mobile station supporting IMMEDIATE PACKET ASSIGNMENT message, the IPA Single Block Uplink Assignment struct sent in the IMMEDIATE PACKET ASSIGNMENT message may assign one uplink block for multiple mobile stations and contains the following parameters specific to different mobile stations:

– the power control parameter setting;

– the timing advance value;

– the relative TBF starting time; and

– the frequency parameters.

In addition, the IPA Single Block Uplink Assignment struct contains the timeslot number which is common to all mobile stations addressed in this construction.

If the mobile station receives the IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message before the TBF starting time has expired, it shall wait until the block period indicated by the TBF starting time. The network shall use the TBF starting time to indicate the first frame number belonging to the single block period granted for packet access. The mobile station may either use the assigned block period to send a PACKET RESOURCE REQUEST message to initiate the two phase packet access procedure defined in 3GPP TS 44.060, or to send an RLC/MAC control message other than the PACKET RESOURCE REQUEST message to the network, see sub-clause 3.5.2.2.

If the mobile station receives the IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message after the TBF starting time has expired, a failure has occurred.

If a failure occurs and the packet access attempt was due to a request from upper layers to transfer a LLC PDU, a TBF establishment failure has occurred and the mobile station proceeds as specified in sub-clause 3.5.2.1.5. If a failure occurs and the packet access attempt was due to the sending of an RLC/MAC control message, the packet access is aborted, the mobile station returns to packet idle mode.

3.5.2.1.3.3a Multiblock packet access

In the case the multiblock packet access is granted, the EGPRS packet uplink assignment description contains:

– timeslot number of the allocation and the number of blocks allocated;

– the power control parameter setting;

– the TBF starting time.

When assigning a multiblock packet access, the network may request information about radio access capabilities of the mobile station on one or several frequency bands within the IMMEDIATE ASSIGNMENT message and allocate one or two radio blocks for uplink control messages accordingly ; the list of frequency bands is ordered by the network starting with the most important and ending with the least important one. The mobile station shall then provide the network with its radio access capabilities for the frequency bands it supports, in the same priority order as the one specified by the network, by sending a PACKET RESOURCE REQUEST message in the first radio block on the assigned PDCH, and an ADDITIONAL MS RADIO ACCESS CAPABILITIES immediately after the PACKET RESOURCE REQUEST message on the assigned PDCH if all the requested informations do not fit in the PACKET RESOURCE REQUEST and two radio blocks have been allocated by the network. If the mobile station does not support any frequency band requested by the network, it shall report its radio access capabilities for the BCCH frequency band in the PACKET RESOURCE REQUEST message. The mobile station shall indicate in the PACKET RESOURCE REQUEST if it will send more information about its radio access capabilities in the ADDITIONAL MS RADIO ACCESS CAPABILITIES message. If the mobile station has been allocated two radio blocks and all the requested informations fit in the PACKET RESOURCE REQUEST message, no ADDITIONAL MS RADIO ACCESS CAPABILITIES message shall be sent (see 3GPP TS 44.060). Instead, some uplink control block (e.g. packet measurement report, packet uplink dummy control block) may be sent by the mobile station.

The network may indicate in the next PACKET UPLINK ASSIGNMENT message a request for retransmission of the ADDITIONAL MS RADIO ACCESS CAPABILITIES message (see 3GPP TS 44.060).

If the mobile station receives the IMMEDIATE ASSIGNMENT message before the TBF starting time has expired, it shall wait until the block period indicated by the TBF starting time. The network shall use the TBF starting time to indicate the first frame number belonging to the multi block period granted for packet access. If the mobile station receives the IMMEDIATE ASSIGNMENT message after the TBF starting time has expired, a failure has occurred.

If a failure occurs and the packet access attempt was due to a request from upper layers to transfer a LLC PDU, a TBF establishment failure has occurred and the mobile station proceeds as specified in sub-clause 3.5.2.1.5. If a failure occurs and the packet access attempt was due to the sending of an RLC/MAC control message, the packet access is aborted, the mobile station returns to packet idle mode.

3.5.2.1.3.4 Packet access rejection

The network may send to the mobile station an IMMEDIATE ASSIGNMENT REJECT message in unacknowledged mode on the same CCCH timeslot on which the channel request message was received. There is no further restriction on what part of the downlink CCCH timeslot an IMMEDIATE ASSIGNMENT REJECT message can be sent. This message contains the request reference and a wait indication.

On receipt of an IMMEDIATE ASSIGNMENT REJECT message corresponding to one of its 3 last CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST messages or EC PACKET CHANNEL REQUEST messages, the mobile station stops sending CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST messages, starts timer T3142 with the indicated value, ("wait indication" information element), starts T3146 if it has not already been started, and listens to the downlink CCCH or EC-CCCH until T3146 expires. During this time, additional IMMEDIATE ASSIGNMENT REJECT messages are ignored, but any immediate assignment corresponding to any other of its 3 last CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST messages make the mobile station follow the procedure in sub-clause 3.5.2.1.3.1. If no such immediate assignment is received (i.e. T3146 expires), the mobile station shall abort the packet access procedure, return to packet idle mode and notify higher layers (TBF establishment failure).

If the purpose of the packet access procedure is to send a PACKET PAUSE message and an IMMEDIATE ASSIGNMENT REJECT message is received, the packet access procedure is aborted.

If the mobile station has not received responses from the network on all, or in case more than 3 were sent the last 3, of its CHANNEL REQUEST or EGPRS PACKET CHANNEL REQUEST or EC PACKET CHANNEL REQUEST messages, it shall abort the packet access procedure, immediately return to packet idle mode and notify higher layers.

The mobile station is not allowed to make a new attempt for packet access in the same cell until T3142 expires, but may attempt packet access in an other cell after successful cell reselection for radio conditions reasons (see 3GPP TS 45.008). The value of the wait indication (i.e. T3142) relates to the cell from which it was received.

The mobile station may initiate RR connection establishment in the same cell before T3142 has expired, see sub-clause 3.3.1.1.3.2 and subclause 3.3.1.

3.5.2.1.3a Packet immediate assignment (EC-CCCH)

3.5.2.1.3a.1 On receipt of an EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST message

On receipt of an EC PACKET CHANNEL REQUEST message on the EC-RACH (see Table 3.5.2.1.2a.1), the network may allocate a temporary flow identity and assign pre-allocated packet uplink resources comprising one or four PDCHs (determined by the uplink coverage class of the mobile station) for an uplink temporary block flow in EC TBF mode.

When an EC PACKET CHANNEL REQUEST message is transmitted on the EC-RACH it implicitly indicates a request for an uplink EC TBF. Packet uplink resources are assigned to the mobile station in an EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message sent on the same EC-CCCH timeslot on which the network has received the EC PACKET CHANNEL REQUEST message.

On receipt of an EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message corresponding to its last EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST (see sub-clause 9.1.65) message, the mobile station stops T3146 (if running), stops sending EC PACKET CHANNEL REQUEST or EC MULTILATERATION REQUEST messages, and switches to the assigned PDCH(s).

The EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message contains:

– The downlink coverage class used when transmitting the message;

– optionally, an indication of page extension information;

– the 3 random bits of the information field of the EC PACKET CHANNEL REQUEST message and the 10 least significant bits of the frame number of the frame in which the EC PACKET CHANNEL REQUEST message was received;

– the EC_MA_NUMBER;

– training sequence code (TSC) information;

– the temporary flow identity;

– the EGPRS modulation and coding scheme for RLC data blocks;

– the power control parameters;

– optionally, the initial timing advance;

– the packet resources used for the uplink TBF which includes the set of pre-allocated uplink resources described by the EC Fixed Uplink Allocation IE;

– an indication of the uplink and downlink coverage class the MS is to use on the assigned packet resources;

– an indication of the quarter hyperframe used to send the EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message.

The EC_MA_NUMBER field of the EC Packet Channel Description Type 2 IE (see sub-clause 10.5.2.85) indicates the mobile allocation set to be used for EC operation.

When the mobile station switches to the assigned PDCH(s), it shall take the power control parameters received in the EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message into account.

On receipt of an EC IMMEDIATE ASSIGNMENT TYPE 3 message (see sub-clause 9.1.68) corresponding to its last EC MULTILATERATION REQUEST message when the Access Burst method is used (see sub-clause 3.5.2.1.2a), the mobile station stops T3146 (if running), stops sending EC MULTILATERATION REQUEST messages, considers the radio access part of the MTA procedure as successfully completed in the current cell, tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein. In this case the EC IMMEDIATE ASSIGNMENT TYPE 3 message contains:

– The downlink coverage class set according to the uplink coverage class used when transmitting the corresponding EC MULTILATERATION REQUEST message;

– optionally, an indication of page extension information;

– the 8 bit Short ID field included within the corresponding EC MULTILATERATION REQUEST message.

On receipt of an EC IMMEDIATE ASSIGNMENT TYPE 3 message (see sub-clause 9.1.68) corresponding to its last EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst method – part 1’ (see sub-clause 3.5.2.1.2a), the mobile station stops T3146 (if running), stops sending EC MULTILATERATION REQUEST messages indicating ‘Extended Access Burst method – part 1’, restarts TT3146 and starts sending EC MULTILATERATION REQUEST messages indicating ‘Extended Access Burst method – part 2’. In this case the EC IMMEDIATE ASSIGNMENT TYPE 3 message contains:

– Downlink coverage class 1;

– optionally, an indication of page extension information;

– the "Random ID Low" parameter included in the corresponding EC MULTILATERATION REQUEST message;

– timing advance information.

On receipt of an EC IMMEDIATE ASSIGNMENT TYPE 3 message (see sub-clause 9.1.68) corresponding to its last EC MULTILATERATION REQUEST message indicating ‘Extended Access Burst method – part 2’ (see sub-clause 3.5.2.1.2a), the mobile station stops T3146 (if running), stops sending EC MULTILATERATION REQUEST messages indicating ‘Extended Access Burst method – part 2’, considers the radio access part of the MTA procedure as successfully completed in the current cell, tunes to the next cell in the list of applicable cells and performs the radio access part of the MTA procedure therein. In this case the EC IMMEDIATE ASSIGNMENT TYPE 3 message contains:

– Downlink coverage class 1;

– optionally, an indication of page extension information;

– the "Random ID" parameter (derived from the "Random ID Low" parameter included in the first EC MULTILATERATION REQUEST message and the "Random ID High" parameter included in the second EC MULTILATERATION REQUEST message).

3.5.2.1.3a.2 Packet access rejection

The network may send to the mobile station an EC IMMEDIATE ASSIGNMENT REJECT message in unacknowledged mode on the same EC-CCCH timeslot on which the EC PACKET CHANNEL REQUEST message was received. There is no further restriction on what part of the downlink EC-CCCH timeslot an EC IMMEDIATE ASSIGNMENT REJECT message can be sent. This message contains the EC Request Reference and EC Wait Timer information.

On receipt of an EC IMMEDIATE ASSIGNMENT REJECT message corresponding to its last EC PACKET CHANNEL REQUEST message, the mobile station stops sending EC PACKET CHANNEL REQUEST messages, starts timer T3142 with the indicated value, (determined by the corresponding "EC Wait Timer" field), starts T3146 if it has not already been started, and listens to the downlink EC-CCCH until T3146 expires. During this time, additional EC IMMEDIATE ASSIGNMENT REJECT messages are ignored, but upon reception of any immediate assignment corresponding to its last EC PACKET CHANNEL REQUEST message it switches to the assigned PDCH(s) as described in sub-clause 3.5.2.1.3a. If no such immediate assignment is received (i.e. T3146 expires), the mobile station aborts the packet access procedure, returns to packet idle mode and notifies higher layers (TBF establishment failure).

The mobile station is not allowed to make a new attempt for packet access in the same cell until T3142 expires, but may attempt packet access in another cell after successful cell reselection for radio conditions reasons (see 3GPP TS 45.008). The value of the EC Wait Timer field (i.e. T3142) relates to the cell from which it was received.

The mobile station may initiate RR connection establishment in the same cell before T3142 has expired, see sub-clause  3.3.1.

3.5.2.1.4 Packet access completion

The one phase packet access procedure is completed at a successful contention resolution. The mobile station has entered the packet transfer mode. Timer T3141 is stopped on the network side. Timer T3164 is stopped on the mobile station side.

3.5.2.1.4a Packet access completion (EC-CCCH)

The packet access procedure is completed at a successful contention resolution. The mobile station has entered the packet transfer mode. Timer T3141 is stopped on the network side. Timer T3164 is stopped on the mobile station side.

3.5.2.1.5 Abnormal cases

If a failure occurs on the mobile station side before a successful contention resolution procedure is completed, the allocated temporary block flow is released; the mobile station returns to packet idle mode, upper layers are notified (TBF establishment failure), transactions in progress are aborted:

– If a TLLI mismatch has occurred during the contention resolution procedure, and the repetition of the packet access has been repeated the maximum number of times as defined in 3GPP TS 44.060, a TBF establishment failure has occurred.

– If the information available in the mobile station, after the reception of an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT or the second IMMEDIATE ASSIGNMENT message of a two-message assignment, does not satisfactorily define a PDCH, a TBF establishment failure has occurred.

– If the information available in the mobile station, after the reception of an EC IMMEDIATE ASSIGNMENT TYPE 1 message indicates a starting uplink timeslot other than timeslot 0, 1, 2, 3 or 4 for a mobile station using CC2, CC3 or CC4 on the uplink, a TBF establishment failure has occurred.

– If the mobile allocation indexes frequencies in more than one frequency band then a TBF establishment failure has occurred.

– If an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT or EC IMMEDIATE ASSIGNMENT TYPE 1 message indicates a PDCH in a non-supported frequency band then a TBF establishment failure has occurred.

On the network side, if timer T3141 elapses before a successful contention resolution procedure is completed, the newly allocated temporary block flow is released as specified in 3GPP TS 44.060 and the packet access is forgotten.

3.5.2.1.5a Abnormal cases (EC-CCCH)

If a failure occurs on the mobile station side before a successful contention resolution procedure is completed, the allocated temporary block flow is released; the mobile station returns to packet idle mode, upper layers are notified (TBF establishment failure), and transactions in progress are aborted:

– If a TLLI mismatch has occurred during the contention resolution procedure, and the EC PACKET CHANNEL REQUEST message has been sent the maximum number of times as defined by the "EC_Max_Retrans" field broadcast in EC SYSTEM INFORMATION TYPE 2 message, a TBF establishment failure has occurred.

– If the information available in the mobile station, after the reception of an EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message indicates a starting uplink timeslot other than timeslot 0, 1, 2, 3 or 4 for a mobile station using CC2, CC3 or CC4 on the uplink, a TBF establishment failure has occurred.

– The EC_MA_NUMBER field of the EC Packet Channel Description Type 2 IE (see sub-clause 10.5.2.85) indicates an EC Mobile Allocation set for which resources are not defined (according to the EC SYSTEM INFORMATION TYPE 1 message) then a TBF establishment failure has occurred.

– If an EC IMMEDIATE ASSIGNMENT TYPE 2 or EC IMMEDIATE ASSIGNMENT TYPE 4 message indicates a PDCH in a non-supported frequency band then a TBF establishment failure has occurred.

On the network side, if timer T3141 elapses before a successful contention resolution procedure is completed, the newly allocated temporary block flow is released as specified in 3GPP TS 44.060 and the packet access is forgotten.

3.5.2.1.6 (void)

3.5.2.2 Sending an RLC/MAC control message: single block packet access procedure

The sending of an RLC/MAC control message other than the PACKET RESOURCE REQUEST message from a mobile station in packet idle mode to the network may be initiated by the RR entity on the mobile station side using the packet access procedure. If access to the network is allowed (sub-clause 3.5.2.1.1), the packet access is done according to the procedures defined in sub-clauses 3.5.2.1.2 and 3.5.2.1.3, using the single block packet access option defined in sub-clause 3.5.2.1.3.3.

Further action depends on the RLC/MAC control message sent by the mobile station, see 3GPP TS 44.060. Unless otherwise indicated by the RLC/MAC control message, the mobile station remains in packet idle mode.

3.5.2a Packet access procedure using EC-CCCH

The packet access procedure using EC-CCCH may be used to establish a temporary block flow to support the transfer of LLC PDUs in the direction from the mobile station to the network.

If EC operation is enabled a MS that supports GPRS services using GPRS/EGPRS TBFs may choose to disable EC operation in the serving cell in which case the MS shall perform packet access as described in sub-clause 3.5.2. Similarly, an EC capable mobile station that reselects from a cell that does not support EC-GSM-IoT to a cell that supports EC-GSM-IoT may choose to not enable EC operation in which case it shall perform packet access as described in sub-clause 3.5.2. If EC operation is enabled and a MS performs reselection to a cell that does not support EC-GSM-IoT then it shall perform packet access as described in sub-clause 3.5.2.

A mobile station in EC operation enables PLMN specific access barring upon reading EC_Access_Control_Class and Exception_Report_Status information corresponding to its selected PLMN within the EC SYSTEM INFORMATION TYPE 2 message or EC SYSTEM INFORMATION TYPE 4 message. The mobile station disables PLMN specific access barring upon reading an EC SYSTEM INFORMATION TYPE 2 message or EC SYSTEM INFORMATION TYPE 4 message for which EC_Access_Control_Class and Exception_Report_Status information is not included for its selected PLMN. While PLMN specific access barring is enabled for its selected PLMN the mobile station shall perform an EC-GSM-IoT preliminary access barring check before accessing the network (see sub-clause 3.5.2a.1) unless it is attempting system access to perform the Multilateration Timing Advance (MTA) procedure (see sub-clause 3.11 and 3GPP TS 44.031). If the preliminary access barring check is performed and indicates network access is barred then access to the network is not allowed. Otherwise, the mobile station proceeds as described in the remainder of this sub-clause.

A mobile station that is accessing the network when the low priority indicator is set to "MS is configured to NAS signalling low priority" (see 3GPP TS 24.008 [79]) and is not sending an exception report (see sub-clause 9.1.65) and is not accessing the network to perform the Multilateration Timing Advance (MTA) procedure (see sub-clause 3.11 and 3GPP TS 44.031), shall read the Implicit Reject Status (IRS) field, EC-BCCH CHANGE MARK field and RACH Access Control field sent in the EC-SCH INFORMATION message (see Figure 9.1.30c.1 and 3GPP TS 45.002) prior to accessing the network. If a change of EC-BCCH CHANGE MARK is detected it shall read one or more EC-SYSTEM INFORMATION messages as needed (see sub-clause3.10.4). The MS then proceeds as follows:

– If the IRS field indicates the access attempt is rejected the mobile station shall abort the packet access procedure and initiate the EC Implicit Reject procedure (see sub-clause 3.5.2a.2).

– If the IRS field indicates the access attempt is not rejected, the RACH Access Control field indicates that RACH usage on timeslot number 0 is not allowed it shall proceed with the packet access procedure as decribed in sub-clause 3.5.2.1.2a.

– If the IRS field indicates the access attempt is not rejected, the RACH Access Control field indicates that RACH usage on timeslot number 0 is allowed and the mobile station has selected CC1 in both uplink and downlink, see 3GPP TS 45.008 [34], it shall proceed with the packet access procedure as decribed in sub-clause 3.5.2.1.2.

– If the IRS field indicates the access attempt is not rejected and the mobile station has selected CC2, CC3 or CC4 in the uplink and/or downlink (see 3GPP TS 45.008 [34]) then it shall proceed with the packet access procedure as decribed in sub-clause 3.5.2.1.2a.

A mobile station that is accessing the network when the low priority indicator is set to "MS is not configured for NAS signalling low priority" or is sending an exception report when the low priority indicator is set to "MS is configured to NAS signalling low priority" and is configured for dual priority (see 3GPP TS 24.008[79]) or is accessing the network to perform the radio access part of a MTA procedure, shall examine the EC-BCCH CHANGE MARK field and RACH Access Control field sent in the EC-SCH INFORMATION message. If a change of EC-BCCH CHANGE MARK is detected it shall read one or more EC SYSTEM INFORMATION messages as needed (see clause 3.10.4) and then proceed as follows:

– If the RACH Access Control field indicates that RACH usage is allowed and the mobile station has selected CC1 in both the uplink and downlink it shall proceed with the packet access procedure using the RACH on timeslot 0 (see sub-clause 3.5.2.1.2).

– Otherwise, it shall proceed with the packet access procedure as described in sub-clause 3.5.2.1.2a.

3.5.2a.1 EC-GSM-IoT Preliminary Access Barring Check

The EC-GSM-IoT preliminary access barring check shall indicate network access is barred for a MS that has enabled EC operation if any of the following conditions are satisfied:

– A MS that is a member of an Access Class in the range 0-9 and is attempting to send a normal report (see sub-clause 9.1.65) shall read the corresponding AC0 to AC9 bit in the EC_Access_Control_Class field sent in the EC SYSTEM INFORMATION TYPE 2 message (for the common PLMN) or in the EC SYSTEM INFORMATION TYPE 4 message (for the corresponding Additional PLMN when network sharing is in use in the cell). The MS determines it is not authorized based on the current value of the AC0 to AC9 bit.

– A MS that is a member of an Access Class in the range 0-9 and is attempting to send an exception report (see sub-clause 9.1.65) shall read the corresponding Exception_Report_Status field sent in the EC SYSTEM INFORMATION TYPE 2 message (for the common PLMN) or in the EC SYSTEM INFORMATION TYPE 4 message (for the corresponding Additional PLMN when network sharing is in use in the cell). The MS determines it is not authorized based on the current value of the Exception_Report_Status bit.

– A MS that is a member of one or more of a special Access Class in the range 11-15 and is attempting to send a normal report or an exception report shall read the corresponding AC11 to AC15 bit in the EC_Access_Control_Class field corresponding to its special Access Class sent in the EC SYSTEM INFORMATION TYPE 2 message (for the common PLMN) or in the EC SYSTEM INFORMATION TYPE 4 message (for the corresponding Additional PLMN when network sharing is in use in the cell). The MS determines it is not authorized based on the current value of the AC11 to AC15 bit.

If none of the conditions above are fulfilled, the EC-GSM-IoT preliminary access barring check shall indicate network access is not barred.

3.5.2a.2 EC-GSM-IoT Implicit Reject procedure

A mobile station for which timer T3146 is running shall proceed as follows:

– While T3146 is running, the mobile station listens to the downlink EC-CCCH for a response from the network and is not allowed to make a new access attempt.

– If a response corresponding to its last transmitted EC PACKET CHANNEL REQUEST messages is received the mobile station shall stop T3146 and act on that message as decribed in sub-clause 3.5.2.1.3.

– If T3146 expires the mobile station proceeds according to the remainder of this sub-clause.

The mobile station initiates timer T3236, returns to idle mode and monitors the EC-CCCH. The mobile station is not allowed to make a mobile originated access attempt in the same cell until T3236 expires or is stopped unless it is accessing the network when the low priority indicator is set to "MS is not configured for NAS signalling low priority" or is sending an exception report when the low priority indicator is set to "MS is configured to NAS signalling low priority" and is configured for dual priority (see 3GPP TS 24.008[79]).

If the mobile station receives an EC PAGING REQUEST message while T3236 is running it shall stop T3236 and respond to the EC PAGING REQUEST message.

3.5.3 Packet downlink assignment procedure using CCCH

The packet downlink assignment procedure using CCCH may be used to establish a temporary block flow to support the transfer of LLC PDUs in the direction from the network to the mobile station.

This procedure may also be used to assign a single downlink block on a PDCH to support the transfer of an RLC/MAC control message from the network to a mobile station in packet idle mode, see sub-clause 3.5.3.2.

3.5.3.1 Entering the packet transfer mode: packet downlink assignment procedure

The establishment of a downlink temporary block flow may be initiated by the RR entity on the network side using the packet downlink assignment procedure. The procedure is triggered by a request from upper layers to transfer a LLC PDU, see 3GPP TS 24.007. The request from upper layers specifies an optional Priority level, a QoS profile including the requested RLC mode, optional DRX parameters, and optional IMSI and an optional MS Radio Access Capability associated with the packet transfer. The BSS may order its preferred RLC mode independently of the RLC mode signalled from upper layers. If the mobile station supports RLC non-persistent mode the network may allocate an EGPRS TBF that uses this RLC mode.

Upon such a request, the network shall determine whether the mobile station is in packet idle mode or packet transfer mode. The packet downlink assignment procedure using CCCH is applicable when the mobile station is in packet idle mode and when there is no PCCCH present in the cell.

The network may allocate a temporary flow identity and assign a packet downlink resource comprising one PDCH for a downlink temporary block flow.

3.5.3.1.2 Initiation of the packet downlink assignment procedure

The network initiates the packet downlink assignment procedure by sending an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message (if supported) in unacknowledged mode on the CCCH timeslot corresponding to CCCH group the mobile station belongs to. The appropriate CCCH group is calculated from the IMSI, see 3GPP TS 45.002. The behaviour of the network when the RR entity does not receive the IMSI from the upper layers is implementation dependent for the calculation of the CCCH group where the IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message has to be sent. If the mobile station is in non-DRX mode or if the RR entity does not receive the IMSI or the DRX parameters from the upper layers, there is no further restriction on what part of the downlink CCCH timeslot the IMMEDIATE ASSIGNMENT, or IMMEDIATE PACKET ASSIGNMENT message, or the first part of the IMMEDIATE ASSIGNMENT message (in the case of a two-message assignment), can be sent. If the mobile station applies DRX, the IMMEDIATE ASSIGNMENT, or IMMEDIATE PACKET ASSIGNMENT message, or the first part of the IMMEDIATE ASSIGNMENT message (in the case of a two-message assignment), shall be sent in a CCCH block corresponding to a paging group determined for the mobile station in packet idle mode, see 3GPP TS 45.002. If the mobile station has negotiated the use of eDRX, the IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message shall be sent in a CCCH block corresponding to a paging group determined for the mobile station in packet idle mode according to the lowest eDRX cycle, see 3GPP TS 45.002.

The IMMEDIATE ASSIGNMENT message contains:

– the packet channel description;

– the initial timing advance;

– the packet downlink assignment construction.

The contents of the packet downlink assignment construction determines the further action. At the establishment of a downlink temporary block flow, the packet downlink assignment construction shall contain:

– the TLLI;

– the temporary flow identity;

– the RLC mode;

– the power control parameters;

– the polling bit;

– the initial timing advance validity flag;

– optionally, EGPRS Window Size (see 3GPP TS 44.060) and Link Quality Measurement Mode (see 3GPP TS 44.060);

– optionally, the timing advance index (see 3GPP TS 45.010);

– optionally, the TBF starting time;

– optionally, the NPM Transfer Time (see 3GPP TS 44.060);

– optionally, the Event-Based FANR indication (see 3GPP TS 44.060);

– optionally, the TTI Configuration (see 3GPP TS 44.060).

At the establishment of a downlink temporary block flow for MS supporting IMMEDIATE PACKET ASSIGNMENT message, the IPA Downlink Assignment struct sent in IMMEDIATE PACKET ASSIGNMENT message may assign packet downlink resources for multiple mobile stations and contains the following parameters specific to different mobile stations:

– the TLLI;

– the temporary flow identity;

– the power control parameters;

– optionally, the timing advance value.

In addition, the IPA Downlink Assignment struct also contains the following parameters which are common to all mobile stations addressed in this structure:

– the timeslot number;

– optionally the link quality measurement mode;

– the RLC mode;

– the frequency parameters;

Relevant default values shall be used for the RLC window size and Alpha parameters as specified in in subclause 10.5.2.78.

If frequency hopping is applied, the network may use the indirect encoding or the direct encoding of the frequency configuration in the Packet Channel Description information element in IMMEDIATE ASSIGNMENT message or in IPA Downlink Assignment struct in IMMEDIATE PACKET ASSIGNMENT message. If the indirect encoding is used, the mobile station uses information received in system information or stored from a previous assignment to determine the frequency parameters, see 3GPP TS 44.060. If the direct encoding is used, the mobile station uses the cell allocation defined for the cell to decode the mobile allocation.

If the BSS receives a DL-UNITDATA PDU that includes eDRX information but excludes coverage class information (i.e. the corresponding mobile station has enabled PEO) and that indicates timing advance information is needed (see 3GPP TS 48.018) it sends an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message to the mobile station that indicates timing advance information is needed (see sub-clause 10.5.2.16 and sub-clause 10.5.2.78).

If the indirect encoding is used, the IMMEDIATE ASSIGNMENT or the IMMEDIATE PACKET ASSIGNMENT message may contain a CHANGE_MARK_1 field. If that is present, the mobile station shall verify the validity of the SI change mark associated with the GPRS mobile allocation to which the message refers, see 3GPP TS 44.060. If the CHANGE_MARK_1 field and the SI change mark do not match, the message does not satisfactorily define a PDCH.

If the mobile station receives an IMMEDIATE ASSIGNMENT message and the Dedicated mode or TBF information element indicates that this is the first message in a two-message assignment, the mobile station shall start listen to the full CCCH. The network may send a second IMMEDIATE ASSIGNMENT message to the mobile station within two multiframe periods following the first IMMEDIATE ASSIGNMENT message, specifying the packet channel description and, if required, a mobile allocation for the assignment. The two IMMEDIATE ASSIGNMENT messages in a two-message assignment shall have the same contents of the Request Reference information elements.

If the mobile station was operating in DRX mode when it received the first message of a two-message assignment, the network shall not send the second IMMEDIATE ASSIGNMENT message within the two block periods immediately following the first message.

If the mobile station does not receive the second IMMEDIATE ASSIGNMENT messages in a two-message assignment within two multiframe periods following the first message, the mobile station shall discard the first IMMEDIATE ASSIGNMENT message received. After the two multiframe periods following the first message, the mobile station may resume to DRX mode.

On receipt of an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message or, in case of a two-message assignment, a matching pair of IMMEDIATE ASSIGNMENT messages, the mobile station stops monitoring downlink CCCH and switches to the assigned PDCH and starts listening for downlink RLC/MAC blocks identified by the assigned TFI; it starts timer T3190.

The IMMEDIATE ASSIGNMENT message may indicate a TBF starting time. If the mobile station receives the message before the TBF starting time has expired, it shall wait until the frame number indicated by the TBF starting time, start timer T3190 and switch to the assigned PDCH. If the mobile station receives the message after the TBF starting time has expired, it shall ignore the indicated TBF starting time, immediately start timer T3190 and switch to the assigned PDCH.

When the mobile station switches to the assigned PDCH, it shall take the power control parameters received in the IMMEDIATE ASSIGNMENT or the IMMEDIATE PACKET ASSIGNMENT message into account, perform signal strength measurements and apply output power control procedures as they are defined for packet transfer mode, see 3GPP TS 45.008.

If the Polling bit is set to 1, MS shall send a PACKET CONTROL ACKNOWLEDGEMENT message (see 44.060) on the assigned PDCH, in the uplink block specified by the TBF Starting Time. In this case the TBF Starting Time is used both to indicate when the assigned PDCH becomes valid and to specify the uplink block. If the TBF Starting Time is not present or has expired, the MS shall ignore the polling request.

An IMMEDIATE ASSIGNMENT message may indicate a timing advance index (TAI) in the packet timing advance IE. The mobile station shall then use the continuous update timing advance mechanism, see 3GPP TS 45.010, using PTCCH in the same timeslot as the assigned PDCH. If there is no indication of a timing advance index, the continuous update timing advance mechanism shall not be used.

The TA_VALID flag indicates if the value of the Timing Advance IE is valid or not.

If the network does not have a valid timing advance value for the mobile station to include in the IMMEDIATE ASSIGNMENT or the IMMEDIATE PACKET ASSIGNMENT message, the network shall use the procedures defined in 3GPP TS 44.060 on the assigned TBF, or the polling mechanism defined in the above paragraph if the PACKET CONTROL ACKNOWLEDGEMENT format is set to four access bursts, to obtain a timing advance value and to update the initially assigned timing advance value before the mobile station is required to transmit other than access burst on the newly assigned channel.

The packet downlink construction may optionally contain the EGPRS Window Size (see 3GPP TS 44.060) and Link Quality Measurement Mode (see 3GPP TS 44.060). The presence of these fields indicates EGPRS TBF mode (see 3GPP TS 44.060). If these fields are not present, this indicates GPRS TBF mode.

3.5.3.1.3 Packet downlink assignment completion

After having sent the packet downlink assignment, the network starts sending downlink RLC/MAC blocks on the assigned packet downlink resource and the packet downlink assignment procedure is completed at the network side.

On the mobile station side, the procedure is completed when the mobile station receives an RLC/MAC block identified by the assigned temporary flow identity. The mobile station stops timer T3190. The mobile station has entered packet transfer mode.

3.5.3.1.4 Abnormal cases

If a failure occurs on the mobile station side before the packet downlink assignment procedure is completed (TBF establishment failure), the temporary block flow is released; the mobile station returns to packet idle mode:

– If the mobile station does not receive a RLC/MAC block on the assigned PDCHs before timer T3190 expires, then a TBF establishment failure has occurred.

– If the information available in the mobile station, after the reception of an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENT message or the second IMMEDIATE ASSIGNMENT message of a two-message assignment, does not satisfactorily define a PDCH, then a TBF establishment failure has occurred.

– If the mobile allocation in the frequency parameters indexes frequencies in more than one frequency band, then a TBF establishment failure has occurred.

If an IMMEDIATE ASSIGNMENT or IMMEDIATE PACKET ASSIGNMENTmessage indicates a PDCH in a non-supported frequency band, then a TBF establishment failure has occurred.

3.5.3.2 Sending an RLC/MAC control message: single block packet downlink assignment procedure

The sending of an RLC/MAC control message to a mobile station in packet idle mode may be initiated by the RR entity on network side using the packet downlink assignment procedure. The procedure is used to assign a single downlink block on a PDCH for the transfer of the RLC/MAC control message. Using this procedure, the network shall not apply segmentation of the RLC/MAC control message.

The single downlink block assignment is done according to the procedure defined in sub-clause 3.5.3.1.2, with the following exceptions:

The packet downlink assignment construction in the IMMEDIATE ASSIGNMENT message shall contain only:

– the TLLI; and

– the TBF starting time.

If the mobile station receives the IMMEDIATE ASSIGNMENT message before the TBF starting time has expired, it shall wait until the frame number indicated by the TBF starting time. The network shall use the TBF starting time to indicate the first frame number belonging to the single block period assigned to the mobile station. The mobile station shall switch to the assigned PDCH and attempt to decode an RLC/MAC control message in the assigned downlink block. Further action depends on the RLC/MAC control message sent by the network, see 3GPP TS 44.060. Unless otherwise indicated by the RLC/MAC control message, the mobile station remains in packet idle mode. If the mobile station remains in packet idle mode, it shall continue to monitor downlink CCCH once the block period indicated by the TBF starting time has passed.

If the mobile station fails to decode or does not receive an RLC/MAC control message in the assigned downlink block, it shall remain in packet idle mode and continue to monitor downlink CCCH once the block period indicated by the TBF starting time has passed.

If the mobile station receives the IMMEDIATE ASSIGNMENT message after the TBF starting time has expired, it shall ignore the assignment.

If a failure occurs on the mobile station side due to any other reason, the mobile station shall ignore the assignment.

3.5.3.2a Sending an RLC/MAC control message: multiple blocks packet downlink assignment procedure

The sending of an RLC/MAC control message to a mobile station in packet idle mode may be initiated by the RR entity on network side using the packet downlink assignment procedure. The procedure is used to assign multiple downlink blocks on a PDCH for the transfer of the RLC/MAC control message. Using this procedure, the network may apply segmentation of the RLC/MAC control message.

The multiple downlink blocks assignment is done according to the procedure defined in sub-clause 3.5.3.1.2, with the following exceptions:

The multiple blocks packet downlink assignment construction in the IMMEDIATE ASSIGNMENT message shall contain only:

– the TBF starting time;

– the number of allocated blocks;

– optionally, the TMGI;

– optionally, the MBMS session identity;

– optionally, the TLLI / G-RNTI;

– optionally, the MS_ID and packet timing advance parameters.

If the message contains the TLLI / G-RNTI not addressing the mobile station, the message shall be ignored.

If the mobile station receives the IMMEDIATE ASSIGNMENT message before the TBF starting time has expired, it shall wait until the frame number indicated by the TBF starting time. The network shall use the TBF starting time to indicate the first frame number belonging to the multiple block period assigned to the mobile station. The mobile station shall switch to the assigned PDCH and attempt to decode an RLC/MAC control message in the assigned downlink block(s). Further action depends on the RLC/MAC control message sent by the network, see 3GPP TS 44.060. Unless otherwise indicated by the RLC/MAC control message, the mobile station remains in packet idle mode. If the mobile station remains in packet idle mode, it shall continue to monitor downlink CCCH.

If the mobile station fails to decode or does not receive an RLC/MAC control message in the assigned downlink block(s), it shall remain in packet idle mode and continue to monitor downlink CCCH.

If the mobile station receives the IMMEDIATE ASSIGNMENT message after the TBF starting time has expired, it shall ignore the assignment.

If a failure occurs on the mobile station side due to any other reason, the mobile station shall ignore the assignment.

3.5.4 MBMS packet access procedure using CCCH

3.5.4.1 General

If access to the network is allowed (sub-clause 3.5.2.1.1), the MBMS packet access is done according to the procedures defined in sub-clauses 3.5.2.1.2 and 3.5.2.1.3, using the single block MBMS access option.

The initiation of the MBMS packet access procedure is defined in 3GPP TS 44.060.

A mobile station shall continue to monitor its paging subchannel on CCCH for PAGING REQUEST messages indicating an establishment of RR connection or a packet paging procedure during the MBMS packet access procedure. A mobile station shall abort the MBMS packet access procedure at the receipt of a PAGING REQUEST message indicating an establishment of RR connection or a packet paging procedure.

3.5.4.2 On receipt of a CHANNEL REQUEST message

On receipt of a CHANNEL REQUEST message with access type indicating "Single block MBMS access", the network shall grant only the single block period on the assigned packet uplink resource if the network allocates resource for the mobile station.

The packet uplink resource is assigned to the mobile station in an IMMEDIATE ASSIGNMENT message sent in unacknowledged mode on the same CCCH timeslot on which the network has received the CHANNEL REQUEST message. The packet uplink resource description shall contain:

– the power control parameter setting;

– the TBF starting time.

If uplink resources are not available, the network may reject the access request by sending a IMMEDIATE ASSIGNMENT REJECT message (see sub-clause 3.5.4.4).

3.5.4.3 On receipt of an IMMEDIATE ASSIGNMENT message

If the mobile station receives the IMMEDIATE ASSIGNMENT message or, in case of a two-message assignment, a matching pair of IMMEDIATE ASSIGNMENT messages corresponding to one of its 3 last CHANNEL REQUEST messages, before the TBF starting time has expired, the mobile station shall wait until the block period indicated by the TBF starting time. The network shall use the TBF starting time to indicate the first frame number belonging to the single block period granted for packet access. The mobile station may use the assigned block period to send an MBMS SERVICE REQUEST message, as defined in 3GPP TS 44.060.

If the mobile station receives the IMMEDIATE ASSIGNMENT message after the TBF starting time has expired, a failure has occurred and the mobile station proceeds as specified in sub-clause 3.5.4.6.

While timer T3214 is running the mobile shall accept reception of repeated IMMEDIATE ASSIGNMENT messages, on the same CCCH timeslot on which the mobile station has sent the CHANNEL REQUEST message, and re-send the MBMS SERVICE REQUEST message, as defined in 3GPP TS 44.060.

3.5.4.4 On receipt of an IMMEDIATE ASSIGNMENT REJECT message

The network may send an IMMEDIATE ASSIGNMENT REJECT message to the mobile station in response to the CHANNEL REQUEST message. The mobile station shall then react according to the description in sub-clause 3.3.1.1.3.2.

3.5.4.5 On receipt of an MBMS ASSIGNMENT message

The MBMS assignment procedure using CCCH may be used in order to assign the radio bearer resources for an MBMS session in the cell or to notify the mobile station(s) that a radio bearer for that MBMS session is not established in the cell.

The assignment for the MBMS session is done by using the multiple blocks packet downlink assignment procedure (non-distribution or distribution MBMS assignment) as specified in the sub-clause 3.5.3.2a.

When the mobile station receives an MBMS ASSIGNMENT message for an MBMS session, it shall stop any ongoing packet access procedure for that MBMS session and proceed as defined in 3GPP TS 44.060.

3.5.4.6 Abnormal cases

If the mobile station receives an IMMEDIATE ASSIGNMENT message that contains faulty parameters, the mobile station shall abort the MBMS access procedure.

3.5.5 Packet downlink assignment procedure using EC-CCCH

The packet downlink assignment procedure using EC-CCCH may be used to establish a temporary block flow to support the transfer of LLC PDUs in the direction from the network to the mobile station when the mobile station has enabled EC operation.

3.5.5.1 Entering the packet transfer mode: packet downlink assignment procedure

The establishment of a downlink temporary block flow may be initiated by the RR entity on the network side using the packet downlink assignment procedure. The procedure is triggered by a request from upper layers to transfer a LLC PDU, see 3GPP TS 24.007. The request from upper layers specifies an optional Priority level, eDRX cycle, a downlink coverage class, P-TMSI, IMSI and an optional MS Radio Access Capability associated with the packet transfer.

Upon such a request, the network shall determine whether the mobile station is in packet idle mode or packet transfer mode. The packet downlink assignment procedure using EC-CCCH is applicable when the mobile station is in packet idle mode and the corresponding Ready timer is running.

The network may allocate a temporary flow identity and assign a packet downlink resource comprising one PDCH (for a mobile station using CC1 on the downlink) or 4 PDCHs (for a mobile station using CC2, CC3 or CC4 on the downlink) for a downlink temporary block flow. The uplink EC-PACCH corresponding to the downlink temporary block flow is also assigned by the network, comprising one PDCH (when CC1 assigned on the uplink) or 4 PDCHs (when CC2, CC3 or CC4 assigned on the uplink).

3.5.5.2 Initiation of the packet downlink assignment procedure

When the Ready timer is running the network initiates the packet downlink assignment procedure by sending an EC DOWNLINK ASSIGNMENT message (see sub-clause 9.1.64) or EC DOWNLINK ASSIGNMENT TYPE 2 (see sub-clause 9.1.67) in unacknowledged mode using the paging group determined using IMSI, the lowest eDRX cycle and the downlink coverage class of the mobile station (see 3GPP TS 45.002). The downlink coverage class information last transmitted to the network for a given mobile station is provided to the BSS in a DL-UNITDATA PDU (see 3GPP TS 48.018 [107]) sent for that mobile station.

The EC DOWNLINK ASSIGNMENT message or EC DOWNLINK ASSIGNMENT TYPE 2 contains:

– the temporary flow identity;

– the EGPRS modulation and coding scheme for RLC data blocks;

– the power control parameters;

– optionally, the initial timing advance;

– the packet resources used for the downlink TBF;

– the downlink Coverage Class used to send the message;

– the EC_MA_NUMBER;

– an indication of the uplink and downlink coverage class the MS is to use on the assigned packet resources;

– an indication of the quarter hyperframe used to send the EC DOWNLINK ASSIGNMENT message.

The EC_MA_NUMBER field of the EC Packet Channel Description Type 2 IE (see sub-clause 10.5.2.85) indicates the mobile allocation to be used.

When a BSS receives a DL-UNITDATA PDU that includes both Coverage Class and eDRX information it sends an assignment message on the EC-AGCH (associated with the EC-PCH of its EC_CCCH_GROUP) using the indicated downlink Coverage Class and the lowest eDRX cycle (see 3GPP TS 45.002 [48]).

When a BSS receives a DL-UNITDATA PDU that does not include Coverage Class information but includes eDRX information it sends an assignment message on the AGCH (associated with the PCH of its CCCH_GROUP) using the lowest eDRX cycle (see 3GPP TS 45.002 [48]).

If the BSS receives a DL-UNITDATA PDU that includes coverage class information (i.e. the corresponding mobile station has enabled EC-GSM-IoT operation) and that indicates timing advance information is needed (see 3GPP TS 48.018) it sends an EC DOWNLINK ASSIGNMENT message to the mobile station that includes this indication (see sub-clause 9.1.64).

On receipt of an EC DOWNLINK ASSIGNMENT message (see sub-clause 9.1.64) or EC DOWNLINK ASSIGNMENT TYPE 2 message the mobile station stops monitoring downlink EC-CCCH, switches to the assigned PDCH(s), starts listening for downlink RLC/MAC blocks identified by the assigned TFI and starts timer T3190. See 3GPP TS 45.010 [35] for mobile station reaction time requirements applicable to receiving an assignment message.

When the mobile station switches to the assigned PDCH(s), it shall take the power control parameters received in the EC DOWNLINK ASSIGNMENT or EC DOWNLINK ASSIGNMENT TYPE 2 message into account, perform signal strength measurements and apply output power control procedures as they are defined for packet transfer mode, see 3GPP TS 45.008.

3.5.5.3 Packet downlink assignment completion

After having sent the packet downlink assignment, the network starts sending downlink RLC/MAC blocks on the assigned packet downlink resource and the packet downlink assignment procedure is completed at the network side.

On the mobile station side, the procedure is completed when the mobile station receives an RLC/MAC block identified by the assigned temporary flow identity. The mobile station stops timer T3190. The mobile station has entered packet transfer mode.

3.5.5.4 Abnormal cases

If a failure occurs on the mobile station side before the packet downlink assignment procedure is completed (TBF establishment failure), the temporary block flow is released; the mobile station returns to packet idle mode:

– If the mobile station does not receive a RLC/MAC block on the assigned PDCHs before timer T3190 expires, then a TBF establishment failure has occurred.

– If the information available in the mobile station, after the reception of an EC DOWNLINK ASSIGNMENT message or EC DOWNLINK ASSIGNMENT TYPE 2, does not satisfactorily define a PDCH, then a TBF establishment failure has occurred.