4.7.13 Service Request procedure (Iu mode only)

24.0083GPPCore network protocolsMobile radio interface Layer 3 specificationRelease 18Stage 3TS

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

The purpose of this procedure is to transfer the PMM mode from PMM-IDLE to PMM-CONNECTED mode, and/or to assign radio access bearer in case of PDP contexts are activated without radio access bearer assigned. In latter case, the PMM mode may be PMM-IDLE mode or may alternatively be the PMM-CONNECTED mode if the MS requires radio access bearer re-establishment. This procedure is used for;

– the initiation of CM layer service (e.g. SM or SMS) procedure from the MS in PMM-IDLE mode,

– the network to transfer down link signalling,

– uplink (in PMM-IDLE or PMM CONNECTED) and downlink (only in PMM-IDLE) user data,

– counting the number of mobile stations in a cell which are interested in a specific MBMS service.

– requesting the establishment of a point-to-point Radio Bearer for receiving a MBMS service.

For downlink transfer of signalling or user data in PMM-IDLE mode, the trigger is given from the network by the paging request procedure, which is out of scope of the present document.

For pending downlink user data in PMM-CONNECTED mode, the re-establishment of radio access bearers for all active PDP contexts is done without paging.

For counting the number of mobile stations in PMM-IDLE mode interested in a specific MBMS service, the trigger is given from the network by the MBMS notification procedure (see 3GPP TS 25.331 [23c]).

For establishing a point-to-point radio bearer to allow MBMS service, the trigger is given from the RRC determining this need from the MBMS control parameters broadcasted by the network (see 3GPP TS 25.331 [23c]).

Service type can take either of the following values; "signalling", "data", "paging response", "MBMS multicast service reception" or "MBMS broadcast service reception". Each of the values shall be selected according to the criteria to initiate the Service request procedure.

If the MS is triggered to send a Service Request message for both MBMS multicast service and MBMS broadcast service simultaneously, the MS shall include a Service Type indicating "MBMS multicast service reception".

The criteria to invoke the Service request procedure are when:

a) the MS has any signalling messages except GMM messages (e.g. for SM or SMS) to be sent to the network in PMM-IDLE mode (i.e., no secure PS signalling connection has been established). In this case, the service type shall be set to "signalling".

b) the MS, either in PMM-IDLE or PMM-CONNECTED mode, has pending user data to be sent, no radio access bearer is established for the corresponding PDP context, and timer T3319 (see subclause 4.7.13.3) is not running or, optionally, if timer T3319 is running and the flag in the Uplink data status IE for this PDP context has not been set in the last Service Request. The procedure is initiated by an indication from the lower layers (see 3GPP TS 24.007 [20]). In this case, the service type shall be set to "data".

c) the MS receives a paging request using P-TMSI for PS domain from the network in PMM-IDLE mode. In this case, the service type shall be set to "paging response".

d) the MS is in PMM-IDLE mode or PMM-CONNECTED, receives an MBMS notification for an MBMS multicast service for which the MS has activated an MBMS context or for an MBMS broadcast service which has been selected for reception locally by upper layers in the MS, and is prompted by the contents of the notification to establish a PS signalling connection (see 3GPP TS 25.346 [110]). In this case, the service type shall be set to "MBMS multicast service reception" or "MBMS broadcast service reception", respectively.

e) the MS in PMM-IDLE mode or PMM-CONNECTED, determines from the broadcast MBMS control parameters that there is a need to establish a point-to-point Radio Bearer to enable MBMS reception (see 3GPP TS 25.346 [110]). In this case, the service type shall be set to "MBMS multicast service reception" or "MBMS broadcast service reception", respectively.

If one of the above criteria to invoke the Service request procedure is fulfilled, then the Service request procedure may only be initiated by the MS when the following conditions are fulfilled:

– its GPRS update status is GU1 UPDATED and the stored RAI is equal to the RAI of the current serving cell; and

– no GMM specific procedure is ongoing (see subclause 4.1.1.1).

If a GMM specific procedure is ongoing at the time a request from CM sublayer, the RRC or the RABM (see 3GPP TS 24.007 [20]) is received and the ATTACH REQUEST or ROUTING AREA UPDATE REQUEST message has been sent, then, depending on implementation, the MS shall abort the received request or delay it until the GMM specific procedure is completed. If the ATTACH REQUEST or ROUTING AREA UPDATE REQUEST message has not been sent, the MS may indicate "follow-on request pending" in the message (i.e. the MS wishes to prolong the established PS signalling connection after the GMM specific procedure). Then, the MS shall delay the Service request procedure until the GMM specific procedure is completed.

If the network indicates "follow-on proceed" in the ATTACH ACCEPT or ROUTING AREA UPDATE ACCEPT message and the MS has a service request pending, the MS shall react depending on the service type. If the service type is:

– "signalling": the MS shall abort the Service request procedure and send the pending signalling messages immediately;

– "data": the MS shall immediately perform the pending Service request procedure using the current PS signalling connection;

– "paging response": the MS shall abort the Service request procedure. No further specific action is required from the MS.

If the network indicates "follow-on proceed" and the MS has no service request pending, then no specific action is required from the MS. As an implementation option, the MS may start timer T3340 as described in subclause 4.7.1.9 if no user plane radio access bearers are set up.

If the network indicates "no follow-on proceed" in the ATTACH ACCEPT or ROUTING AREA UPDATE ACCEPT message, the MS shall not initiate the pending Service request procedure until the current PS signalling connection is released.

NOTE: The "follow-on proceed" indication was not defined in earlier versions of the protocol. A network that is compliant with the earlier versions of the protocol will always encode the respective bit as zero, i.e. as "follow-on proceed", even if it does not prolong the PS signalling connection.

After completion of a Service request procedure but before re-establishment of radio access bearer, if the PDP and MBMS context status information elements are included, then the network shall deactivate all those PDP and MBMS contexts locally (without peer to peer signalling between the MS and the network), which are not in SM state PDP-INACTIVE on network side but are indicated by the MS as being in state PDP-INACTIVE.

After completion of a Service request procedure, the pending service is resumed and uses then the connection established by the procedure. If the service type is indicating "data", then the radio access bearers for all activated PDP contexts are re-established by the network, except for those activated PDP contexts having maximum bit rate value set to 0 kbit/s for both uplink and downlink and as an option those which have no pending user data. The re-establishment of radio access bearers for those PDP contexts is specified in subclause 6.1.3.3.

A service request attempt counter is used to limit the number of service request attempts and no response from the network. The service request attempt counter shall be incremented as specified in subclause 4.7.13.5.

The service request attempt counter shall be reset when:

– an attach or combined attach procedure is successfully completed;

– a normal or periodic routing area updating or a combined routing area updating procedure is successfully completed;

– a service request procedure is successfully completed ; or

– the UE moves to GMM-DEREGISTERED state.

4.7.13.1 Service Request procedure initiation

The MS initiates the Service request procedure by sending a SERVICE REQUEST message. The timer T3317 shall be started after the SERVICE REQUEST message has been sent and state GMM-SERVICE-REQUEST-INITIATED is entered. The message SERVICE REQUEST shall contain the P-TMSI and the Service type shall indicate either "data", "signalling", "paging response", "MBMS multicast service reception" or "MBMS broadcast service reception". The MS shall not issue another Service request when the MS is in state GMM-SERVICE-REQUEST-INITIATED

If the PDP context status information element is included in the SERVICE REQUEST message, then the network shall deactivate all those PDP contexts locally (without peer to peer signalling between the MS and the network) which are not in SM state PDP-INACTIVE on the network side, but are indicated by the MS as being in state PDP-INACTIVE.

If the MBMS context status information element is included in the SERVICE REQUEST message, then the network shall deactivate all those MBMS contexts locally (without peer to peer signalling between the MS and network) which are not in SM state PDP-INACTIVE on the network side, but are indicated by the MS as being in state PDP-INACTIVE. If no MBMS context status information element is included, then the network shall deactivate all MBMS contexts locally which are not in SM state PDP-INACTIVE on the network side.

For a Service Request of type "data", the MS may include the Uplink data status information element in the SERVICE REQUEST message. The Uplink data status information indicates which preserved PDP contexts have pending uplink data to be sent. If the Uplink data status information element is included in the SERVICE REQUEST message with service type "data", the network may use this information to determine which of the RABs for the preserved PDP contexts to re-establish.

4.7.13.2 GMM common procedure initiation

The network may initiate GMM common procedures, e.g. the GMM identification or the GMM authentication and ciphering procedure, depending on the received information such as GPRS ciphering key sequence number and P-TMSI.

4.7.13.3 Service request procedure accepted by the network

If the SERVICE REQUEST message was sent in PMM-IDLE mode, the indication from the lower layers that the security mode control procedure is completed shall be treated as a successful completion of the procedure. The service request attempt counter shall be reset, timer T3317 shall be stopped, and the MS enters GMM-REGISTERED state and PMM-CONNECTED mode.

If the SERVICE REQUEST message was sent in PMM-CONNECTED mode, then the reception of the SERVICE ACCEPT message shall be treated as a successful completion of the procedure. The timer T3317 shall be stopped and the MS remains in PMM-CONNECTED mode.

Upon reception of the SERVICE REQUEST message, if the EMM Combined UE Waiting Flag is ‘true’, the SGSN shall complete the procedure and perform a detach procedure for non-GPRS services only as described in subclause 4.7.4.2.

If the SERVICE REQUEST message was sent in a CSG cell and the CSG subscription has expired or was removed for a MS, but the MS has a PDN connection for emergency bearer services established, the network shall accept the SERVICE REQUEST message and deactivate all non-emergency PDP contexts by initiating PDP context deactivation procedure. The PDP contexts for emergency services shall not be deactivated.

At successful completion of a service request procedure with Service type "data", the MS shall start timer T3319. The timer T3319 shall be stopped when the MS returns to PMM-IDLE mode or when the network releases the radio access bearer of any active PDP context. The MS shall not issue another Service Request with service type "data" while timer T3319 is running unless the Service request is being generated from a PDP context for which the flag in the Uplink data status IE has not been set in the last Service Request.

The network may indicate a value for timer T3319 in the ATTACH ACCEPT or ROUTING AREA UPDATE ACCEPT messages. The last provided value of T3319 shall be used by the MS. If the information element T3319 value is not included in the ATTACH ACCEPT or ROUTING AREA UPDATE ACCEPT messages, the default value shall be used. If the T3319 value received by the MS contains an indication that the timer is deactivated or the timer value is zero, then the MS shall use the default value.

If the PDP context status information element is included in the Service Accept, then the MS shall deactivate locally (without peer to peer signalling between the MS and the network) all that PDP contexts which are not in SM state PDP-INACTIVE on MS side but are indicated by the Network as being in state PDP-INACTIVE. If there is a default PDP context among the PDP contexts to be deactivated, an MS supporting S1 mode shall locally deactivate all PDP contexts associated to the same PDP address and APN as the default PDP context without peer-to-peer SM signalling to the network; an MS not supporting S1 mode may apply the same behaviour.

If the MBMS context status information element is included in the SERVICE ACCEPT message, then the MS shall deactivate all those MBMS contexts locally (without peer to peer signalling between the MS and network) which are not in SM state PDP-INACTIVE in the MS, but are indicated by the network as being in state PDP-INACTIVE. If no MBMS context status information element is included, then the MS shall deactivate all those MBMS contexts locally which are not in SM state PDP-INACTIVE in the MS.

If a service request is received from an MS with a LIPA PDN connection, and if:

– a L-GW Transport Layer Address is provided by the lower layer together with the service request, and the GGSN address associated with the PDP context of the LIPA PDN connection is different from the provided L-GW Transport Layer Address (see 3GPP TS 25.413 [19c]); or

– no L-GW Transport Layer Address is provided together with the service request by the lower layer,

then the SGSN explicitly deactivates all PDP contexts associated with the LIPA PDN connection by initiating the PDP context deactivation procedure (see subclause 6.1.3.4.2).

If a service request is received from an MS with a SIPTO at the local network PDN connection, the following different cases can be distinguished:

1) if the PDN connection is a SIPTO at the local network PDN connection with collocated L-GW and if:

– a SIPTO L-GW Transport Layer Address is provided by the lower layer together with the service request, and the GGSN address associated with the PDP context of the SIPTO at the local network PDN connection is different from the provided SIPTO L-GW Transport Layer Address (see 3GPP TS 25.413 [19c]); or

– no SIPTO L-GW Transport Layer Address is provided together with the service request by the lower layer,

2) if the PDN connection is a SIPTO at the local network PDN connection with stand-alone GW and if:

– a LHN-ID value is provided by the lower layer together with the service request, and the LHN-ID stored in the PDP context of the SIPTO at the local network PDN connection is different from the provided LHN-ID value (see 3GPP TS 25.413 [19c]); or

– no LHN-ID value is provided together with the service request by the lower layer,

then the SGSN explicitly deactivates all PDP contexts associated with the SIPTO at the local network PDN connection by initiating the PDP context deactivation procedure (see subclause 6.1.3.4.2).

4.7.13.4 Service request procedure not accepted by the network

If the Service request cannot be accepted, the network returns a SERVICE REJECT message to the mobile station.

Based on local policies or configurations in the network, if the network determines to change the periodic routing area update timer (T3312), or if the network determines to change the PSM usage or the value of the timer T3324 in the MS for which PSM is allowed by the network, the network may return a SERVICE REJECT with the cause #10 "implicitly detached" to the MS.

If the service request for mobile originated services is rejected due to general NAS level mobility management congestion control, the network shall set the GMM cause value to #22 "congestion" and assign a back-off timer T3346.

An MS that receives a SERVICE REJECT message containing a reject cause other than GMM cause value #25 or the message is integrity protected, shall reset the service request attempt counter, shall stop the timer T3317.

If the SERVICE REJECT message containing GMM cause value #25 was received without integrity protection, then the MS shall discard the message.

The MS shall then take different actions depending on the received reject cause value:

# 3 (Illegal MS); or

# 6 (Illegal ME);

– The MS shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2), shall delete the list of equivalent PLMNs and enter the state GMM-DEREGISTERED.NO-IMSI. Furthermore, it shall delete any P-TMSI, P-TMSI signature, RAI and GPRS ciphering key sequence number and shall consider the SIM/USIM as invalid for GPRS services until switching off or the SIM/USIM is removed. If the message has been successfully integrity checked by the lower layers and the MS maintains a counter for "SIM/USIM considered invalid for GPRS services", then the MS shall set this counter to MS implementation-specific maximum value.

– A GPRS MS operating in MS operation mode A or B shall in addition set the update status to U3 ROAMING NOT ALLOWED, shall delete any TMSI, LAI and ciphering key sequence number. If the MS is operating in MS operation mode A and an RR connection exists, the MS shall abort the RR connection, unless an emergency call is ongoing. The SIM/USIM shall be considered as invalid also for non-GPRS services until switching off or the SIM/USIM is removed or the timer T3245 expires as described in subclause 4.1.1.6. If the message has been successfully integrity checked by the lower layers and the MS maintains a counter for "SIM/USIM considered invalid for non-GPRS services", then the MS shall set this counter to MS implementation-specific maximum value.

If S1 mode is supported in the MS, the MS shall handle the EMM parameters EMM state, EPS update status, GUTI, last visited registered TAI, TAI list and KSI as specified in 3GPP TS 24.301 [120] for the case when the service request procedure is rejected with the EMM cause with the same value.

# 7 (GPRS services not allowed);

– The MS shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2.9) and shall delete any P-TMSI, P-TMSI signature, RAI and GPRS ciphering key sequence number. The SIM/USIM shall be considered as invalid for GPRS services until switching off or the SIM/USIM is removed. The new state is GMM-DEREGISTERED. If the message has been successfully integrity checked by the lower layers and the MS maintains a counter for "SIM/USIM considered invalid for GPRS services", then the MS shall set this counter to MS implementation-specific maximum value.

A GPRS MS operating in MS operation mode A or B which is already IMSI attached for CS services is still IMSI attached for CS services in the network.

A GPRS MS operating in MS operation mode A or B in network operation mode I shall then proceed with the appropriate MM specific procedure.

NOTE 1: Optionally the MS starts the timer T3340 as described in subclause 4.7.1.9.

# 8 (GPRS services and non-GPRS services not allowed);

The MS shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2) and shall delete any P-TMSI, P-TMSI signature, RAI and GPRS ciphering key sequence number. The new GMM state is GMM-DEREGISTERED.NO-IMSI.

The MS shall set the update status to U3 ROAMING NOT ALLOWED, shall delete any TMSI, LAI and ciphering key sequence number. The MS shall delete the list of equivalent PLMNs. If the MS is operating in MS operation mode A and an RR connection exists, the MS shall abort the RR connection, unless an emergency call is ongoing. The SIM/USIM shall be considered as invalid for GPRS and non-GPRS services until switching off or the SIM/USIM is removed. If the message has been successfully integrity checked by the lower layers and the MS maintains a counter for "SIM/USIM considered invalid for GPRS services", then the MS shall set this counter to MS implementation-specific maximum value. If the message has been successfully integrity checked by the lower layers and the MS maintains a counter for "SIM/USIM considered invalid for non-GPRS services", then the MS shall set this counter to MS implementation-specific maximum value.

NOTE 2: Optionally the MS starts the timer T3340 as described in subclause 4.7.1.9.

# 9 (MS identity cannot be derived by the network);

– The MS shall set the GPRS update status to GU2 NOT UPDATED (and shall store it according to subclause 4.1.3.2), enter the state GMM-DEREGISTERED.NORMAL-SERVICE, and shall delete any P-TMSI, P-TMSI signature, RAI and GPRS ciphering key sequence number. If the rejected request was not for initiating a PDN connection for emergency bearer services, the MS may subsequently, automatically initiate the GPRS attach procedure.

# 10 (Implicitly detached);

– A GPRS MS operating in MS operation mode B in network operation mode I is IMSI detached for both GPRS and CS services.

A GPRS MS operating in MS operation mode A in network operation mode I is detached for GPRS services. If no RR connection exists then the MS is also IMSI detached for the CS services.

– The MS shall change to state GMM-DEREGISTERED.NORMAL-SERVICE. If the rejected request was not for initiating a PDN connection for emergency bearer services, the MS shall then perform a new attach procedure. The MS should also activate PDP context(s) that were originally activated by the MS to replace any previously MS activated PDP context(s). The MS should also perform the procedures needed in order to activate any previously active multicast service(s).

If S1 mode is supported in the MS, the MS shall handle the EMM state as specified in 3GPP TS 24.301 [120] for the case when the service request procedure is rejected with the EMM cause with the same value.

NOTE 3: In some cases, user interaction may be required and then the MS cannot activate the PDP and MBMS context(s) automatically.

# 11 (PLMN not allowed);

– The MS shall delete any RAI, P-TMSI, P-TMSI signature and GPRS ciphering key sequence number, shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2) and enter the state GMM-DEREGISTERED. The MS shall delete the list of equivalent PLMNs.

– The MS shall store the PLMN identity in the "forbidden PLMN list" and if the MS is configured to use timer T3245 (see 3GPP TS 24.368 [135] or 3GPP TS 31.102 [112]) then the MS shall start timer T3245 and proceed as described in subclause 4.1.1.6. If the message has been successfully integrity checked by the lower layers and the MS maintains a PLMN-specific attempt counter for that PLMN, then the MS shall set this counter to the MS implementation-specific maximum value.

The MS shall start timer T3340 as described in subclause 4.7.1.9.

– If no RR connection exists, the MS shall perform the following additional actions immediately. If the MS is operating in MS operation mode A and an RR connection exists, the MS shall perform these actions when the RR connection is subsequently released:

– A GPRS MS operating in MS operation mode A shall set the update status to U3 ROAMING NOT ALLOWED and shall delete any TMSI, LAI and ciphering key sequence number. The new MM state is MM IDLE.

– The MS shall perform a PLMN selection according to 3GPP TS 23.122 [14].

An MS in GAN mode shall request a PLMN list in GAN (see 3GPP TS 44.318 [76b]) prior to perform a PLMN selection from this list according to 3GPP TS 23.122 [14].

# 12 (Location area not allowed);

– The MS shall delete any RAI, P-TMSI, P-TMSI signature and GPRS ciphering key sequence number, shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2) and shall change to state GMM-DEREGISTERED.LIMITED-SERVICE.

– The mobile station shall store the LAI in the list of "forbidden location areas for regional provision of service".

The MS shall start timer T3340 as described in subclause 4.7.1.9.

– If the MS is IMSI attached, the MS shall set the update status to U3 ROAMING NOT ALLOWED, shall delete any TMSI, LAI and ciphering key sequence number and shall reset the location update attempt counter. The new MM state is MM IDLE.

– The MS shall perform a cell selection according to 3GPP TS 43.022 [82] and 3GPP TS 25.304 [98].

NOTE 4: The cell selection procedure is not applicable for an MS in GAN mode.

# 13 (Roaming not allowed in this location area);

– The MS shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2) and shall change to state GMM-REGISTERED.LIMITED-SERVICE.

– The MS shall store the LAI in the list of "forbidden location areas for roaming".

The MS shall start timer T3340 as described in subclause 4.7.1.9.

– If the MS is IMSI attached, the MS shall set the update status to U3 ROAMING NOT ALLOWED and shall reset the location update attempt counter. The new MM state is MM IDLE.

– The MS shall perform a PLMN selection according to 3GPP TS 23.122 [14].

An MS in GAN mode shall request a PLMN list in GAN (see 3GPP TS 44.318 [76b]) prior to perform a PLMN selection from this list according to 3GPP TS 23.122 [14].

If S1 mode is supported in the MS, the MS shall handle the EMM parameters EMM state and EPS update status as specified in 3GPP TS 24.301 [120] for the case when the service request procedure is rejected with the EMM cause with the same value.

# 15 (No Suitable Cells In Location Area);

– The MS shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2) and shall change to state GMM-REGISTERED.LIMITED-SERVICE.

– The MS shall store the LAI in the list of "forbidden location areas for roaming".

The MS shall start timer T3340 as described in subclause 4.7.1.9.

– If the MS is IMSI attached, the MS shall set the update status to U3 ROAMING NOT ALLOWED and shall reset the location update attempt counter. The new MM state is MM IDLE.

– The MS shall search for a suitable cell in another location area or a tracking area according to 3GPP TS 43.022 [82] and 3GPP TS 25.304 [98] or 3GPP TS 36.304 [121].

NOTE 5: The cell selection procedure is not applicable for an MS in GAN mode.

#22 (Congestion);

If the T3346 value IE is present in the SERVICE REJECT message and the value indicates that this timer is neither zero nor deactivated, the MS shall proceed as described below, otherwise it shall be considered as an abnormal case and the behaviour of the MS for this case is specified in subclause 4.7.13.5.

If the rejected request was not for initiating a PDN connection for emergency bearer services, the MS shall abort the service request procedure and enter state GMM-REGISTERED, and stop timer T3317 if still running.

The MS shall stop timer T3346 if it is running.

If the SERVICE REJECT message is integrity protected, the MS shall start timer T3346 with the value provided in the T3346 value IE.

If the SERVICE REJECT message is not integrity protected, the MS shall start timer T3346 with a random value from the default range specified in table 11.3a.

The MS stays in the current serving cell and applies normal cell reselection process. The service request procedure may be started by CM layer, if it is still necessary, when timer T3346 expires or is stopped.

A GPRS MS operating in MS operation mode A or B which is already IMSI attached for CS services in the network is still IMSI attached for CS services in the network.

# 25 (Not authorized for this CSG)

– Cause #25 is only applicable in UTRAN Iu mode and when received from a CSG cell. Other cases are considered as abnormal cases and the specification of the mobile station behaviour is given in subclause 4.7.13.5.

– The MS shall set the GPRS update status to GU3 ROAMING NOT ALLOWED (and shall store it according to subclause 4.1.3.2) and shall change to state GMM-REGISTERED.LIMITED-SERVICE.

– If the CSG ID and associated PLMN identity of the cell where the MS has sent the SERVICE REQUEST message are contained in the Allowed CSG list stored in the MS, the MS shall remove the entry corresponding to this CSG ID and associated PLMN identity from the Allowed CSG list.

– If the CSG ID and associated PLMN identity of the cell where the MS has sent the SERVICE REQUEST message are contained in the Operator CSG list, the MS shall proceed as specified in 3GPP TS 23.122 [14] subclause 3.1A.

The MS shall start timer T3340 as described in subclause 4.7.1.9.

If the MS is IMSI attached for non-GPRS services, the MS shall set the update status to U3 ROAMING NOT ALLOWED and shall reset the location update attempt counter. The new MM state is MM IDLE.

– The MS shall search for a suitable cell according to 3GPP TS 43.022 [82] and 3GPP TS 25.304 [98].

– If S1 mode is supported in the MS, the MS shall handle the EMM parameters EMM state and EPS update status as specified in 3GPP TS 24.301 [120] for the case when the service request procedure is rejected with the EMM cause with the same value.

# 40 (No PDP context activated)

– The MS shall deactivate locally all active PDP and MBMS contexts and the MS shall enter the state GMM-REGISTERED.NORMAL-SERVICE. If the rejected request was not for initiating a PDN connection for emergency bearer services, the MS may also activate PDP context(s) that were originally activated by the MS to replace any previously MS activated PDP context(s). The MS may also perform the procedures needed in order to activate any previously active multicast service(s).

NOTE 6: In some cases, user interaction may be required and then the MS cannot activate the PDP and MBMS context(s) automatically.

Other values are considered as abnormal cases. The specification of the MS behaviour in those cases is described in subclause 4.7.13.5.

4.7.13.4a Service request procedure for initiating a PDN connection for emergency bearer services not accepted by the network (UTRAN Iu mode only)

If the service request for initiating a PDN connection for emergency bearer services cannot be accepted by the network, the MS shall perform the procedures as described in subclause 4.7.13.4. Then if the MS is in the same selected PLMN where the last service request was attempted, the MS shall:

a) inform the upper layers of the failure of the procedure; or

NOTE 1: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain) or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229 [95] that can result in the emergency call being attempted to another IP-CAN.

b) detach locally, if not detached already, attempt GPRS attach for emergency bearer services.

If the service request for initiating a PDN connection for emergency bearer services fails due to abnormal case a) in subclause 4.7.13.5, the MS shall perform the procedures as described in subclause 4.7.13.5 and inform the upper layers of the failure to access the network.

NOTE 2: This can result in the upper layers establishment of a CS emergency call (if not already attempted in the CS domain) or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229 [95] that can result in the emergency call being attempted to another IP-CAN.

If the service request for initiating a PDN connection for emergency bearer services fails due to abnormal cases b), c) or d) in subclause 4.7.13.5, the MS shall perform the procedures as described in subclause 4.7.13.5. Then if the MS is in the same selected PLMN where the last service request was attempted, the MS shall:

a) inform the upper layers of the failure of the procedure; or

NOTE 3: This can result in the upper layers establishment of a CS emergency call (if not already attempted in the CS domain) or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229 [95] that can result in the emergency call being attempted to another IP-CAN.

b) detach locally, if not detached already, attempt GPRS attach for emergency bearer services.

4.7.13.5 Abnormal cases in the MS

The following abnormal cases can be identified:

a) Access barred because of access class control, EAB or ACDC

If the service request procedure is started in response to a paging request from the network, access class barring, EAB or ACDC is not applicable.

The service request procedure shall not be started. The MS stays in the current serving cell and applies normal cell reselection process. The service request procedure may be started by CM layer if it is still necessary, i.e. when access is granted or because of a cell change.

If access is barred because of access class control, the service request is initiated due to a request from upper layers for PS signalling connection, ACDC is applicable to the request and the MS supports ACDC, then the service request procedure shall be started.

If access is barred for a certain ACDC category, and if the service request is initiated due to a request from upper layers for PS signalling connection for a higher ACDC category and the MS supports ACDC, then the service request procedure shall be started.

If an access request for an uncategorized application is barred due to ACDC , and if the service request is initiated due to a request from upper layers for PS signalling connection for a certain ACDC category and the MS supports ACDC, then the service request procedure shall be started.

b) Lower layer failure without "Extended Wait Time" received from lower layers before the security mode control procedure is completed, SERVICE ACCEPT or SERVICE REJECT message is received

The procedure shall be aborted except in the following implementation option cases b.1, b.2 and b.3.

b.1) Release of PS signalling connection in Iu mode (i.e. RRC connection release) before the completion of the service request procedure

The service request procedure shall be initiated again, if the following conditions apply:

i) The original service request procedure was initiated over an existing PS signalling connection; and

ii) No SECURITY MODE COMMAND message and no Non-Access Stratum (NAS) messages relating to the PS signalling connection were received after the SERVICE REQUEST message was transmitted.

b.2) RR release in Iu mode (i.e. RRC connection release) with cause different than "Directed signalling connection re-establishment", for example, "Normal", or "User inactivity" (see 3GPP TS 25.331 [23c] and 3GPP TS 44.118 [111])

The service request procedure shall be initiated again, if the following conditions apply:

i) The original service request procedure was initiated over an existing RRC connection and,

ii) No SECURITY MODE COMMAND message and no Non-Access Stratum (NAS) messages relating to the PS signalling connection were received after the SERVICE REQUEST messge was transmitted.

NOTE: The RRC connection release cause different than "Directed signalling connection re-establishment" that triggers the re-initiation of the service request procedure is implementation specific.

b.3) RR release in Iu mode (i.e. RRC connection release) with cause "Directed signalling connection re-establishment" (see 3GPP TS 25.331 [23c] and 3GPP TS 44.118 [111])

The routing area updating procedure shall be initiated followed by a rerun of the service request procedure if the following condition applies:

i) The service request procedure was not due to a rerun of the procedure due to "Directed signalling connection re-establishment".

c) T3317 expired

The MS shall enter GMM-REGISTERED state.

If the MS is in PMM-IDLE mode then the MS shall increment the service request attempt counter, abort the procedure and release locally any resources allocated for the service request procedure. If the service request procedure is initiated to establish a PDN connection for emergency bearer services or the MS has a PDN connection for emergency bearer services established or the MS is an MS configured to use AC11 – 15 in selected PLMN, the service request counter shall not be incremented. If the service request attempt counter is greater than or equal to 5, the MS shall start timer T3325. The MS shall not attempt service request until expiry of timer T3325 unless:

– the service request is in response to paging from the network;

– the MS is an MS configured to use AC11 – 15 in selected PLMN;

– the service request is initiated to establish a PDN connection for emergency bearer services;

– the MS has a PDN connection for emergency bearer services established; or

– the MS is registered in a new PLMN.

If the MS is in PMM-CONNECTED mode, then the procedure shall be aborted.

d) SERVICE REJECT received, other causes than those treated in subclause 4.7.13.4, and cases of GMM cause values #22 and #25, if considered as abnormal cases according to subclause 4.7.13.4

The procedure shall be aborted.

e) Routing area update procedure is triggered

If a cell change into a new routing area occurs and the necessity of routing area update procedure is determined before the security mode control procedure is completed, a SERVICE ACCEPT or SERVICE REJECT message has been received, the Service request procedure shall be aborted and the routing area updating procedure is started immediately. Follow-on request pending may be indicated in the ROUTING AREA UPDATE REQUEST for the service, which was the trigger of the aborted Service request procedure, to restart the pending service itself or the Service request procedure after the completion of the routing area updating procedure. If the Service type of the aborted SERVICE REQUEST was indicating "data", then the routing area update procedure may be followed by a re-initiated Service request procedure indicating "data", if it is still necessary. If the Service type was indicating "MBMS multicast service reception", or "MBMS broadcast service reception" the Service request procedure shall be aborted.

f) Power off

If the MS is in state GMM-SERVICE-REQUEST-INITIATED at power off, the GPRS detach procedure shall be performed.

g) Detach procedure collision

GPRS detach containing detach type "re-attach required" or "re-attach not required":

If the MS receives a DETACH REQUEST message from the network in state GMM-SERVICE-REQUEST-INITIATED, the GPRS detach procedure shall be progressed and the Service request procedure shall be aborted. If the GMM cause IE, in the DETACH REQUEST message, indicated a "re-attach required", the GPRS attach procedure shall be performed. If the DETACH REQUEST message contains detach type "re-attach not required" and GMM cause #2 "IMSI unknown in HLR", the MS will follow the procedure as described below for the detach type "IMSI detach".

GPRS detach containing detach type "IMSI detach":

If the MS receives a DETACH REQUEST message from the network in state GMM-SERVICE-REQUEST-INITIATED, the network and the MS shall progress both procedures.

h) "Extended wait time" for PS domain from the lower layers

The MS shall abort the service request procedure, enter state GMM-REGISTERED, and stop timer T3317 if still running.

If the SERVICE REQUEST message contained the low priority indicator set to "MS is configured for NAS signalling low priority", the MS shall start timer T3346 with the "Extended wait time" value.

In other cases the MS shall ignore the "Extended wait time".

The MS stays in the current serving cell and applies normal cell reselection process. The service request procedure is started, if still necessary, when timer T3346 expires or is stopped.

m) Timer T3346 is running

The MS shall not start the service request procedure unless:

– the MS receives a paging; or

– the MS is an MS configured to use AC11 – 15 in selected PLMN; or

– the MS has a PDN connection for emergency bearer services established; or

– the MS is establishing a PDN connection for emergency bearer services; or

– the MS has a PDN connection established without the NAS signalling low priority indication or is establishing a PDN connection without the NAS signalling low priority indication, the timer T3302 and the timer T3311 are not running and the timer T3346 was started due to rejection of a NAS request message (e.g. ATTACH REQUEST, ROUTING AREA UPDATE REQUEST or SERVICE REQUEST) which contained the low priority indicator set to "MS is configured for NAS signalling low priority".

The MS stays in the current serving cell and applies normal cell reselection process. The service request procedure is started, if still necessary, when timer T3346 expires or is stopped.

4.7.13.6 Abnormal cases on the network side

The following abnormal cases can be identified:

a) Lower layer failure

If a low layer failure occurs before the security mode control procedure is completed, a SERVICE ACCEPT or SERVICE REJECT message has been sent to the MS, the network enters/stays in PMM-IDLE.

b) Protocol error

If the SERVICE REQUEST message is received with a protocol error, the network shall return a SERVICE REJECT message with one of the following reject causes:

#96: Mandatory information element error;

#99: Information element non-existent or not implemented;

#100: Conditional IE error;

#111: Protocol error, unspecified.

The network stays in PMM-IDLE mode.

c) More than one SERVICE REQUEST received and the procedure has not been completed (i.e., the security mode control procedure has not been completed or SERVICE ACCEPT, SERVICE REJECT message has not been sent)

– If one or more of the information elements in the SERVICE REQUEST message differs from the ones received within the previous SERVICE REQUEST message, the previously initiated Service request procedure shall be aborted and the new Service request procedure shall be progressed;

– If the information elements do not differ, then the network shall continue with the previous Service request procedure and shall not treat any further this SERVICE REQUEST message.

d) ATTACH REQUEST received before the security mode control procedure has been completed or an SERVICE ACCEPT or an SERVICE REJECT message has been sent

If an ATTACH REQUEST message is received and the security mode control procedure has not been completed or an SERVICE ACCEPT or an SERVICE REJECT message has not been sent, the network may initiate the GMM common procedures, e.g. the GMM authentication and ciphering procedure. The network may e.g. after a succesful GMM authentication and ciphering procedure execution, abort the Service request procedure, the GMM context, PDP contexts and MBMS contexts, if any, are deleted and the new ATTACH REQUEST is progressed.

e) ROUTING AREA UPDATE REQUEST message received before the security mode control procedure has been completed or an SERVICE ACCEPT or an SERVICE REJECT message has been sent

If an ROUTING AREA UPDATE REQUEST message is received and the security mode control procedure has not been completed or an SERVICE ACCEPT or an SERVICE REJECT message has not been sent, the network may initiate the GMM common procedures, e.g. the GMM authentication and ciphering procedure. The network may e.g. after a successful GMM authentication and ciphering procedure execution, abort the Service request procedure and progress the routing area update procedure.

f) If the Service Type indicates ‘data’ and the network fails to re-establish some or all RAB(s) then the SGSN may determine if PDP Context Modification or PDP Context Deactivation should be initiated.
The appropriate action is an operator choice and depends on the QoS profile of the PDP Context, and the Uplink data status.