6 Paging procedures

3GPP44.060General Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocolRelease 17TS

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

For a mobile station in packet idle mode, the network may use the paging procedures to initiate the establishment of an RR connection, to trigger a cell update from the mobile station prior to a downlink packet transfer, or to send MBMS notification. A number of mobile stations can be paged for either downlink packet transfer or RR connection establishment in the same paging message. Mobile terminated RR connection establishment for GSM services (see 3GPP TS 23.060 [19] shall not be used in packet idle mode when a mobile station has enabled PEO.

For a mobile station in packet transfer mode, the network may use the paging procedures to initiate the establishment of an RR connection. A number of mobile stations can be paged for RR connection establishment in the same paging message. After sending the mobile station a PS HANDOVER COMMAND message the network shall not use paging procedures to initiate the establishment of an RR connection for that mobile station until the PS handover procedure has been completed (see sub-clause 8.10). Mobile terminated RR connection establishment for GSM services (see 3GPP TS 23.060 [19]) shall not be used in packet transfer mode when a mobile station has enabled PEO.

Paging procedures for RR connection establishment are described in sub-clause 6.1. Paging procedures for downlink packet transfer are described in sub-clause 6.2.

6.1 Paging procedure for RR connection establishment

The network may initiate the establishment of an RR connection by the paging procedure for RR connection establishment.

The network initiates the paging procedure for RR connection establishment by sending a paging request message on the appropriate paging subchannel on CCCH or PCCCH, addressing the mobile station and indicating RR connection establishment.

The paging subchannels on CCCH and PCCCH are specified in 3GPP TS 45.002 and 3GPP TS 43.013. The paging request message for RR connection establishment is sent on the PCCCH if the mobile station is GPRS attached, PCCCH is present in the cell and the network operates in network mode of operation I (see 3GPP TS 23.060). Otherwise, the paging request message is sent on CCCH.

The network may also page the mobile station for RR connection establishment by sending a paging request message on PACCH if the mobile station is in packet transfer mode.

A mobile station in packet transfer mode is not required to decode the paging subchannels, on neither CCCH nor PCCCH, in the following two cases:

– the mobile station is not capable to handle an RR connection and a TBF simultaneously (GPRS class B mode of operation); or

– the mobile station requires that the BSS co-ordinates the allocation of radio resources for an RR connection and one or more simultaneous TBFs (GPRS class A mode of operation by means of DTM).

6.1.1 Paging initiation using paging subchannel on CCCH

The paging initiation procedure and the paging request messages used on CCCH are specified in 3GPP TS 44.018.

6.1.2 Paging initiation using paging subchannel on PCCCH

The network initiates the paging procedure by sending a PACKET paging request message on an appropriate paging subchannel on PCCCH, considering the DRX parameters valid for each targeted mobile station.

For each mobile station, that is paged for RR connection establishment, a channel needed field is included in the PACKET PAGING REQUEST message, see sub-clause 11.2.10. The channel needed field defines how the mobile stations shall use the establishment cause field in the CHANNEL REQUEST message, as specified in 3GPP TS 44.018.

6.1.3 Paging initiation using PACCH

Paging initiation using PACCH applies when sending a paging request message to a mobile station that is GPRS attached, when the mobile station is in packet transfer mode or in broadcast/multicast receive mode, if so indicated for that mobile by the network, and the network is able to co-ordinate the paging request with the radio resources allocated for the mobile station (or MBMS session) on a PDCH.

This kind of paging co-ordination shall be provided in network mode of operation I (see 3GPP TS 23.060). A mobile station in packet transfer mode in a cell indicating support of network mode of operation I in the NMOrelated fields broadcast on BCCH or PBCCH shall expect the paging messages to be received on the PACCH.

This kind of paging co-ordination shall be provided for mobile stations capable of DTM if the network supports DTM. A mobile station capable of DTM in packet transfer mode in a cell indicating support of DTM procedures in the DTM_SUPPORT field broadcast on BCCH or PBCCH shall expect the paging messages to be received on the PACCH.

This kind of paging co-ordination may be provided also in network mode of operation II or III regardless of the DTM capability of the cell and of the mobile station and shall be indicated in that case by setting the BSS_PAGING_COORDINATION field to "The cell supports Circuit-Switched paging coordination" on BCCH or PBCCH. If such indication is received, a mobile station in packet transfer mode shall expect the paging messages to be received on the PACCH.

A mobile station in broadcast/multicast receive mode shall expect the paging messages to be received on the PACCH of an MBMS radio bearer if the network has indicated so with the MBMS In-band Signalling Indicator field in the MBMS ASSIGNMENT and/or MBMS NEIGHBOURING CELL INFORMATION messages, and if the mobile station has an MS_ID on that MBMS radio bearer.

The network shall not send paging messages on the PACCH to a mobile station whose MS_ID has been released because the mobile station has not responded when being polled (i.e. T3195 has started for that MS_ID).

If a mobile station is receiving multiple MBMS radio bearers and the mobile station has an MS_ID on at least one of the MBMS radio bearers where the network has indicated that system information for the serving cell and paging messages are sent on the PACCH/D then the mobile station shall not monitor its paging group on the (P)CCCH in parallel to the MBMS radio bearers. The network shall send the PACKET PAGING REQUEST message to the mobile station on the appropriate PACCH. The message includes the mobile station identification and the channel needed field which defines how the mobile station shall use the establishment cause field in the CHANNEL REQUEST message, as specified in 3GPP TS 44.018.

6.1.4 Paging response

Upon receipt of a Paging Request or Packet Paging Request message, for the purpose of triggering an RR connection establishment, a mobile station operating in GPRS class B mode of operation and in packet transfer mode shall either ignore or respond to the paging request according to 3GPP TS 22.060.

When the mobile station responds to a paging request for RR connection establishment, it shall follow the paging response procedures as specified in 3GPP TS 44.018. For that purpose, a mobile station in packet transfer mode or a mobile station that has initiated a packet access procedure may abort all ongoing TBFs or the packet access procedure in the following two cases:

– the mobile station is not capable to handle an RR connection and a TBF simultaneously (GPRS class B mode of operation or a mobile station in DLMC configuration); or

– the mobile station requires that the BSS co-ordinates the allocation of radio resources for an RR connection and one or more simultaneous TBFs (GPRS class A mode of operation by means of DTM).

6.2 Paging procedure for downlink packet transfer

The network may initiate the paging procedure for downlink packet transfer in order to obtain the mobile station cell location required for the downlink packet transfer. The procedure is triggered by a page request from the GMM sublayer on the network side, see 3GPP TS 24.007 and 3GPP TS 44.018. The procedure is initiated by sending a paging request message on the appropriate paging subchannel on CCCH, EC-CCCH or PCCCH. The paging subchannels on CCCH, EC-CCCH and PCCCH are specified in 3GPP TS 45.002 and 3GPP TS 43.013.

The paging request message is sent on PCCCH, if PCCCH is present in the cell. Otherwise, the paging request message is sent on CCCH. A paging request message to a mobile station that has enabled EC operation is sent on EC-CCCH.

A mobile station that indicates DTM support to the network is not required to decode the paging subchannels, on neither CCCH nor PCCCH, while it is in dedicated mode. If the cell location for a mobile station that has indicated DTM support is required while the mobile station is in dedicated mode, the network may use the packet notification procedure defined in 3GPP TS 44.018.

6.2.1 Paging procedure using paging subchannel on CCCH

The packet paging procedure and the paging request messages used on CCCH are specified in 3GPP TS 44.018.

6.2.2 Paging using paging subchannel on PCCCH

The network initiates the paging procedure by sending a PACKET paging request message on an appropriate paging subchannel on PPCH, considering the DRX parameters valid for each targeted mobile station.

6.2.3 Paging response

On receipt of a PACKET paging request message, the RR sublayer of addressed mobile station indicates the receipt the paging request to the GMM sublayer (see 3GPP TS 24.007 and 3GPP TS 44.018).

NOTE: The mobile station performs a pageresponse by sending an upper layer PDU to the network as defined in 3GPP TS 44.018 and 3GPP TS 44.064. The transfer of an upper layer PDU may serve as a cell update.

6.2.4 Paging procedure using paging subchannel on EC-CCCH

The packet paging procedure and the paging request messages used on EC-CCCH are specified in 3GPP TS 44.018.

6.3 Paging Procedures for MBMS Notification

6.3.1 Notification to mobile station in packet idle mode

6.3.1.1 General

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

The network initiates the paging procedure for MBMS notification on PCCCH (sub-clause 6.3.1.3) if PCCCH is present in the cell, otherwise on CCCH (sub-clause 6.3.1.2). The paging procedure for MBMS notification is also initiated on PACCH when the mobile station is in broadcast/multicast receive mode, if so indicated for that mobile station by the network (sub-clause 6.3.1.3a).

The 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 for any reason.

6.3.1.2 Paging procedure for MBMS notification using paging subchannel on CCCH

The paging procedure for MBMS notification and the paging request messages used on CCCH are specified in 3GPP TS 44.018.

6.3.1.3 Paging procedure for MBMS notification using paging subchannel on PCCCH

6.3.1.3.1 General

The network initiates the paging procedure for MBMS notification of an MBMS session by sending a PACKET paging request message including for that session either the MBMS pre-notification (see sub-clause 6.3.1.3.2) or MBMS notification (see sub-clause 6.3.1.3.3) on one or more paging subchannels on PCCCH. The PACKET PAGING REQUEST message may also contain other MBMS (pre)notification(s) and/or pages as described in sub-clauses 6.1.2 and 6.2.2. The following requirements apply:

– If in the PACKET PAGING REQUEST message the mobile station is at the same time (pre)notified (see sub-clauses 6.3.1.3.2 and 6.3.1.3.3) and paged, the mobile station shall discard all (pre)notification(s) in that message and proceed as described in sub-clause 6.1 or 6.2, whichever applies.

– If in the PACKET PAGING REQUEST message the mobile station is at the same time pre-notified (see sub-clause 6.3.1.3.2) and notified (see sub-clause 6.3.1.3.3), the mobile station shall discard all pre-notifications in that message and proceed as described in sub-clause 6.3.1.3.3.

6.3.1.3.2 MBMS pre-notification

In order to pre-notify an MBMS session, the network shall send a PACKET PAGING REQUEST message by including for that session only 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.

Upon reception of a PACKET PAGING REQUEST message including for an MBMS session only the TMGI and, if available, the MBMS Session Identity of that 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 described in sub-clause 6.3.1.3.3.

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 procedure on PCCCH 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 6.3.1.3.3.

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 described in sub-clause 6.3.1.3.3.

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.

6.3.1.3.3 MBMS notification

In order to notify an MBMS session, the network shall send a PACKET PAGING REQUEST message by including for that session:

– 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 PACKET PAGING REQUEST 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 described in sub-clause 6.3.1.4.

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 6.3.1.4), establishment of MBMS bearer upon receipt of MBMS ASSIGNMENT message (see sub-clause 7.7.2.2), MBMS packet access procedure (see sub-clause 7.7.1).

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

6.3.1.3a Paging procedure for MBMS notification using PACCH

Under the above circumstances, the network initiates the paging procedure for MBMS notification of an MBMS session not only on PCCCH (see sub-clause 6.3.1.3) if PCCCH is present in the cell, otherwise on CCCH (see sub-clause 6.3.1.2), but also by sending a PACKET paging request message including for that session either the MBMS pre-notification (see sub-clause 6.3.1.3.2) or MBMS notification (see sub-clause 6.3.1.3.3) on the appropriate PACCH. The PACKET PAGING REQUEST message may also contain other MBMS (pre-)notification(s) and/or pages as described in sub-clauses 6.1.2 and 6.2.2 (see sub-clause 6.3.1.3.1).

Upon reception of MBMS notification on PACCH, the mobile station in broadcast/multicast receive mode shall act according to sub-clause 8.1.5.2.

If the mobile station responds to the MBMS notification:

– it shall act as described in sub-clause 6.3.1.4 if PCCCH is present in the cell;

– otherwise it shall act as described in 3GPP TS 44.018 (sub-clause 3.5.1.3.4).

6.3.1.4 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. Upon expiry of timer T3214, a mobile station in packet idle mode or MAC-Idle state (respectively broadcast-multicast receive mode) shall enter DRX mode (respectively remain in broadcast-multicast receive mode) and discard the corresponding notification. Upon reception of an MBMS ASSIGNMENT message for that session, the mobile station shall stop timer T3214 and shall proceed as described in sub-clause 7.7.2.2.

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

– Any other procedure on PCCCH 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), establishment of MBMS bearer upon receipt of MBMS ASSIGNMENT (see sub-clause 7.7.2.2), MBMS packet access procedure (see sub-clause 7.7.1).

If the MBMS notification indicates that counting shall be performed the mobile station shall perform an MBMS packet access procedure, as described in sub-clause 7.7.1.

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) and shall use information received on the PBCCH to decode the channel descriptions contained in the assignment. If frequency hopping is applied, the mobile station shall use the last CA (Cell Allocation) received on PBCCH to decode the Mobile Allocation. Alternatively, the network may provide a Mobile Allocation in the assignment. If an MBMS Radio Bearer Starting Time is indicated, the mobile station shall monitor PCCCH until the point in time denoted by the MBMS Radio Bearer Starting Time. The mobile station shall then switch to the assigned PDCHs and start timer T3190. If the MBMS Radio Bearer Starting Time has already elapsed or is not present, the mobile station shall switch to the assigned PDCHs and start timer T3190. The timer T3190 is restarted when receiving the first valid RLC data block for that session. In EGPRS TBF mode T3190 is also restarted when receiving an erroneous RLC data block for which the header is correctly received and which addresses the mobile station. The mobile station is not allowed to send normal bursts on the uplink unless it has a valid timing advance, and is assigned an MS_ID for that session. If the mobile station receives more than one MBMS notification including an MBMS p-t-m channel description for that same session while it monitors PCCCH, it shall act upon the most recently received assignment for that session and shall ignore the previous assignment.

On expiry of timer 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.

6.3.2 Notification to mobile station in packet transfer mode or in dual transfer mode

6.3.2.1 General

MBMS notification initiation using PACCH applies when sending an MBMS notification to a mobile station or a group of mobile stations that is/are in packet transfer mode or in dual transfer mode.

6.3.2.2 MBMS Notification using the PACCH

The network may send the PACKET MBMS ANNOUNCEMENT message on any PDCH.

Upon receipt of a PACKET MBMS ANNOUNCEMENT message containing a TMGI and optionally an MBMS Session Identity corresponding to an MBMS session the mobile station is required to receive, the mobile station shall pass an indication including the TMGI, and when available the MBMS Session Identity, to the upper layers. If the Restriction Timer is included in the received PACKET MBMS ANNOUNCEMENT message, the mobile station shall set and start an instance of the T3222 to the value indicated in the Restriction Timer field, otherwise if the Estimated Session Duration is included in the received PACKET MBMS ANNOUNCEMENT message the mobile station shall set and start both an instance of the T3222 and the session duration timer for this MBMS session with a value equal to the Estimated Session Duration. The mobile station shall store the MBMS specific information contained in the PACKET MBMS ANNOUNCEMENT message.

If T3222 expires the mobile station shall discard the stored MBMS information associated with this instance of T3222.

6.3.2.3 Response to MBMS Notification received on PACCH

If the mobile station enters packet idle mode and completes the Transfer non-DRX mode period before the expiry of T3222 or where no instance of T3222 was set and the PACKET MBMS ANNOUNCEMENT message did not include the MBMS p-t-m channel description, the mobile station shall stop T3222, if started, and initiates the MBMS Packet Access Procedure on a PCCCH (sub-clause 7.7.1.2) or, if a packet control channel does not exist, on a CCCH (sub-clause 7.7.1.3) or, if the PACKET MBMS ANNOUNCEMENT message contained uplink resource description for an MPRACH, on that MPRACH (sub-clause 7.7.1.4).

Any MPRACH description or MBMS p-t-m channel description stored from a previously received PACKET MBMS ANNOUNCEMENT message shall be deleted after the mobile station completes cell reselection or after a handover procedure is completed.

If the mobile station enters packet idle mode before the expiry of T3222 and the PACKET MBMS ANNOUNCEMENT message included the MBMS p-t-m channel description, the mobile station shall stop T3222 and shall start listening to downlink RLC blocks identified by the assigned TFI on the defined PDCHs either at the point in time denoted by the MBMS Radio Bearer Starting Time, if present and not already elapsed, or immediately otherwise.

The mobile station shall follow the procedures described in sub-clause 6.3.1.4.

6.4 Paging Procedure for ETWS Primary Notification delivery

6.4.1 General

The network may initiate the paging procedure for delivery of an ETWS Primary Notification message (see 3GPP TS 23.041) on PCCCH (sub-clause 6.4.3) if PCCCH is present in the cell, otherwise on CCCH (sub-clause 6.4.2).

6.4.2 ETWS Primary Notification delivery using paging subchannel on CCCH

The paging procedure for ETWS Primary Notification delivery and the paging request messages used on CCCH are specified in 3GPP TS 44.018.

6.4.3 ETWS Primary Notification delivery using paging subchannel on PCCCH

The network initiates the paging procedure for delivery of an ETWS Primary Notification message (see 3GPP TS 23.041) by broadcasting the PACKET PAGING REQUEST message on all paging subchannels on PCCCH with the ETWS Primary Notification field present. These paging messages are sent continuously during the ETWS warning period.

Each paging message carries a segment of the actual ETWS Primary Notification message, i.e. segmentation is applicable if an ETWS Primary Notification message is too large to fit into a single PACKET PAGING REQUEST message. In order to allow a mobile station to receive the segments in any order, the size of a specific segment (retransmitted during the ETWS warning period) shall not be altered. Segments belonging to the same ETWS Primary Notification message shall be given the same Primary Notification Identifier (PNI) value.

6.4.4 Reception of ETWS Primary Notification message

Upon receipt of a PACKET PAGING REQUEST message carrying a segment of an ETWS Primary Notification message, the mobile station shall leave DRX mode, start timer T3232, start reading all paging groups corresponding to its PCCCH_GROUP and attempt to acquire all segments of the ETWS Primary Notification message, having the same Primary Notification Identifier (PNI) value, before delivering the assembled message to the upper layers.

While attempting to acquire the ETWS Primary Notification message a mobile station shall continue to follow packet idle mode and connection establishment procedures. Upon initiating cell reselection or connection establishment procedures (RR connection establishment or TBF establishment) while attempting to acquire an ETWS Primary Notification message, a mobile station shall discard any partially received ETWS Primary Notification message and stop timer T3232. The mobile station shall not attempt to acquire an ETWS Primary Notification message while performing a connection establishment procedure or while performing cell reselection.

If the mobile station detects a change in the PNI value prior to acquiring a complete ETWS Primary Notification message, it shall abort the current message, restart timer T3232 and attempt to acquire the new message.

When the mobile station successfully acquires a complete ETWS Primary Notification message it shall stop timer T3232 and enter DRX mode. If timer T3232 expires the mobile station shall abort the current message and enter DRX mode.