Section: 4.7.2.2 Periodic routing area updating
Content: The periodic routing area updating procedure is used to periodically notify the availability of the MS to the network. The procedure is controlled in the MS by timer T3312. The value of timer T3312 is sent by the network to the MS in the messages ATTACH ACCEPT and ROUTING AREA UPDATE ACCEPT. The value of timer T3312 shall be unique within a RA. If the value of timer T3312 received by the MS in A/Gb mode or received in Iu mode in a message with integrity protection contains an indication that the timer is deactivated or the timer value is zero, then timer T3312 is deactivated and the MS shall not perform the periodic routing area updating procedure. In Iu mode, if the value of timer T3312 is received in a message without integrity protection and the indicated value is larger than the last received value, or the indicated value is "deactivated" or zero, the MS shall use the last received value. If there is no last received value, then the MS shall use the default value. In A/Gb mode, the timer T3312 is reset and started with its initial value, when the READY timer is stopped or expires. Timer T3312 is stopped and shall be set to its initial value for the next start when the READY timer is started. If after a READY timer negotiation the READY timer value is set to zero, timer T3312 is reset and started with its initial value. If the initial READY timer value is zero, the timer T3312 is reset and started with its initial value, when the ROUTING AREA UPDATE REQUEST message is transmitted. In Iu mode, timer T3312 is reset and started with its initial value, when the MS changes from PMM-CONNECTED to PMM-IDLE mode. Timer T3312 is stopped when the MS enters PMM-CONNECTED mode. If the MS is attached for emergency bearer services, when timer T3312 expires, the MS shall not initiate a periodic routing area updating procedure, but shall locally detach from the network. When the MS is camping on a suitable cell, it may re-attach to regain normal service. If the MS is not attached for emergency bearer services, when timer T3312 expires, the periodic routing area updating procedure shall be started and timer T3312 shall be set to its initial value for the next start. If the MS is in a state other than GMM-REGISTERED.NORMAL-SERVICE when timer T3312 expires, the periodic routing area updating procedure is delayed until the MS returns to GMM-REGISTERED.NORMAL-SERVICE. In A/Gb mode, if the MS in MS operation mode B is in the state GMM-REGISTERED.SUSPENDED when timer T3312 expires the periodic routing area updating procedure is delayed until the state is left. If ISR is activated, the MS shall keep both timer T3412 and timer T3312. The two separate timers run in the MS for updating the MME and the SGSN independently. The MS shall start timer T3323 if timer T3312 expires, and timer T3346 is running or the MS is in one of the following states: - GMM-REGISTERED.NO-CELL-AVAILABLE; - GMM-REGISTERED.PLMN-SEARCH; - GMM-REGISTERED.UPDATE-NEEDED; or - GMM-REGISTERED.LIMITED-SERVICE. The MS shall initiate the routing area updating procedure and stop timer T3323 when the MS enters the state GMM-REGISTERED.NORMAL-SERVICE before timer T3323 expires. After expiry of timer T3323 the MS shall deactivate ISR by setting its TIN to "GUTI". If timer T3323 expires, the MS shall memorize that it has to initiate a routing area updating procedure when it returns to state GMM-REGISTERED.NORMAL-SERVICE. The network supervises the periodic routing area updating procedure by means of the mobile reachable timer. If the MS is not attached for emergency bearer services, the mobile reachable timer shall be longer than timer T3312. In this case, by default, the mobile reachable timer is 4 minutes greater than timer T3312. NOTE 1: According to subclause 4.7.5.1.5, if a periodic routing area updating procedure fails repeatedly, it can take more than 7 minutes before the MS starts using MM specific procedures. The network may include timer T3312 extended value IE in the ATTACH ACCEPT message or ROUTING AREA UPDATE ACCEPT message only if the MS indicates support of the timer T3312 extended value in the MS network feature support IE. If the network includes the timer T3312 extended value IE in the ATTACH ACCEPT message or ROUTING AREA UPDATE ACCEPT message, the network shall use the timer T3312 extended value IE as the value of timer T3312. If ISR is not activated, when the mobile reachable timer expires, typically the network stops sending paging messages to the mobile and may take other appropriate actions. If the MS is attached for emergency bearer services, the SGSN shall set the mobile reachable timer with a value equal to timer T3312. When the mobile reachable timer expires, the SGSN shall locally detach the MS. In A/Gb mode, the mobile reachable timer is reset and started with the value as indicated above, when the READY timer is stopped or expires. The mobile reachable timer is stopped when the READY timer is started. In A/Gb mode, if after a READY timer negotiation the READY timer value is set to zero, the mobile reachable timer is reset and started with its initial value. If the initial READY timer value is zero, the mobile reachable timer is reset and started with its initial value, when the ROUTING AREA UPDATE REQUEST message is received. In Iu mode, the mobile reachable timer is reset and started with the value as indicated above, when the MS changes from PMM-CONNECTED to PMM-IDLE mode. The mobile reachable timer is stopped when the MS enters PMM-CONNECTED mode. If ISR is activated, upon expiry of the mobile reachable timer the network shall start the implicit detach timer. By default, the implicit detach timer is 4 minutes greater than timer T3323. If the implicit detach timer expires before the MS contacts the network, the network shall implicitly detach the MS and deactivate ISR. If ISR is not activated, upon expiry of the mobile reachable timer the network may start the implicit detach timer. The value of the implicit detach timer is network dependent. If the implicit detach timer expires before the MS contacts the network, the network shall implicitly detach the MS. If the network includes the T3324 value IE in the ATTACH ACCEPT message or ROUTING AREA UPDATE ACCEPT message and if the MS is not attached for emergency bearer services and has no PDN connection for emergency bearer services, the network shall set the active timer to a value equal to the value of timer T3324. If the MS has established a PDN connection for emergency bearer services after receiving the timer T3324 value IE in the ATTACH ACCEPT message or ROUTING AREA UPDATE ACCEPT message, the active timer shall not be started. When the active timer expires, typically the network stops sending paging messages to the mobile and may take other appropriate actions. In A/Gb mode, the active timer is reset and started with the value as indicated above, when the READY timer is stopped or expires. The active timer is stopped when the READY timer is started. In Iu mode, the active timer is reset and started with the value as indicated above, when the MS changes from PMM-CONNECTED to PMM-IDLE mode. The active timer is stopped when the MS enters PMM-CONNECTED mode. NOTE 2: ISR is not activated when the network includes the T3324 value IE in the ATTACH ACCEPT message or ROUTING AREA UPDATE ACCEPT message. If the SGSN includes timer T the ROUTING AREA UPDATE REJECT message or the SERVICE REJECT message and timer T3346 is greater than timer T3312, the SGSN sets the mobile reachable timer and the implicit detach timer such that the sum of the timer values is greater than timer T3346. NOTE 3: According to subclause 4.7.5.1.5, if a periodic routing area updating procedure fails repeatedly, it can take more than 7 minutes before the MS starts using MM specific procedures. If the MS is both IMSI attached for GPRS and non-GPRS services, and if the MS lost coverage of the registered PLMN and timer T3312 expires or timer T3323 expires, then: a) if the MS returns to coverage in a cell that supports GPRS and that indicates that the network is in network operation mode I, then the MS shall either perform the combined routing area update procedure indicating "combined RA/LA updating with IMSI attach"; or b) if the MS returns to coverage in a cell in the same RA that supports GPRS and that indicates that the network is in network operation mode II, then the MS shall perform the periodic routing area updating procedure indicating "Periodic updating"; or c) if the MS was both IMSI attached for GPRS and non-GPRS services in network operation mode I and the MS returns to coverage in a cell in the same LA that does not support GPRS, then the MS shall perform the periodic location updating procedure. In addition, the MS shall perform a combined routing area update procedure indicating "combined RA/LA updating with IMSI attach" when the MS enters a cell that supports GPRS and that indicates that the network is in network operation mode I; or d) if the MS returns to coverage in a new RA, the description given in subclause 4.7.5 applies. If this subclause specifies that the MS shall perform a periodic routing area updating procedure, but subclause 4.7.5 specifies the MS shall perform a normal or combined routing area updating procedure, the description in subclause 4.7.5 takes precedence. If the MS is both IMSI attached for GPRS and non-GPRS services in a network that operates in network operation mode I, and if the MS has camped on a cell that does not support GPRS, and timer T3312 expires or timer T3323 expires, then the MS shall start an MM location updating procedure. In addition, the MS shall perform a combined routing area update procedure indicating "combined RA/LA updating with IMSI attach" when the MS enters a cell that supports GPRS and indicates that the network is in operation mode I. If timer T3312 expires or timer T3323 expires during an ongoing CS connection, then a MS operating in MS operation mode B shall treat the expiry of T3312 when the MM state MM-IDLE is entered, analogous to the descriptions for the cases when the timer expires out of coverage or in a cell that does not support GPRS. In A/Gb mode, timer T3312 and timer T3323 shall not be stopped when a GPRS MS enters state GMM-REGISTERED.SUSPENDED.