Section: 4.7.6.4 Abnormal cases on the network side
Content: The following abnormal cases can be identified: a) Lower layer failure If a lower layer failure is detected before the P-TMSI REALLOCATION COMPLETE message is received, the network shall consider both the old and the new P-TMSI as occupied until the old P-TMSI can be considered as invalid (see subclause 4.7.1.5). During this period the network: - may first use the old P-TMSI for paging for an implementation dependent number of paging attempts in the case of network-originated transactions. Upon response from the MS, the network may re-initiate the P-TMSI reallocation procedure. If no response is received to the paging attempts, the network may use the new P-TMSI for paging for an implementation dependent number of paging attempts. Upon response from the MS, the network shall consider the new P-TMSI as valid and the old P-TMSI as invalid. If no response is received to the paging attempts, the network may use the IMSI for paging for an implementation dependent number of paging attempts; NOTE: Paging with IMSI causes the MS to re-attach as described in subclause 4.7.9.1. - shall consider the new P-TMSI as valid if it is used by the MS (see subclause 4.7.1.5); or - may use the identification procedure followed by a new P-TMSI reallocation, if the MS uses the old P-TMSI. b) Expiry of timer T3350 The P-TMSI reallocation procedure is supervised by the timer T3350 (see example in figure 4.7.6/1). On the first expiry of timer T3350, the network shall reset and restart timer T3350 and shall retransmit the P-TMSI REALLOCATION COMMAND message. This retransmission is repeated four times, i.e. on the fifth expiry of timer T3350, the network shall abort the P-TMSI reallocation procedure and shall follow the rules for case a as described above. c) P-TMSI reallocation and GPRS attach procedure collision If the network receives an ATTACH REQUEST message before the ongoing P-TMSI reallocation procedure has been completed, the network shall proceed with the GPRS attach procedure after deletion of the GMM context. d) P-TMSI reallocation and an MS initiated GPRS detach procedure collision If the network receives a DETACH REQUEST message before the ongoing P-TMSI reallocation procedure has been completed, the network shall abort the P-TMSI reallocation procedure and shall progress the GPRS detach procedure. e) P-TMSI reallocation and a routing area updating procedure collision If the network receives a ROUTING AREA UPDATE REQUEST message before the ongoing P-TMSI reallocation procedure has been completed, the network shall abort the P-TMSI reallocation procedure and shall progress the routing area updating procedure. The network may then perform a new P-TMSI reallocation. f) P-TMSI reallocation and a service request procedure collision If the network receives a SERVICE REQUEST message before the ongoing P-TMSI reallocation procedure procedure has been completed, the network shall progress both procedures. Figure 4.7.6/1 3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ] : P-TMSI reallocation procedure