Section: 4.3.4.1 IMSI detach initiation by the mobile station
Content: The IMSI detach procedure consists only of the IMSI DETACH INDICATION message sent from the mobile station to the network. The mobile station then starts timer T3220 and enters the MM sublayer state IMSI DETACH INITIATED. If no RR connection exists, the MM sublayer within the mobile station will request the RR sublayer to establish a RR connection. If establishment of the RR connection is not possible because a suitable cell is not (or not yet) available then, the mobile station shall try for a period of at least 5 seconds and for not more than a period of 20 seconds to find a suitable cell. If a suitable cell is found during this time then, the mobile station shall request the RR sublayer to establish an RR connection, otherwise the IMSI detach is aborted. For: - a shared GERAN in A/Gb mode, if the MS is a GERAN network sharing supporting MS, the chosen PLMN identity shall be indicated to the GERAN in the IMSI DETACH INDICATION message using the Skip Indicator IE as specified in subclause 10.3.1 and; - a shared UTRAN, the chosen PLMN identity shall be indicated to the UTRAN in the RRC INITIAL DIRECT TRANSFER message (see 3GPP TS 25.331[ None ]  [23c]). If a RR connection exists, the MM sublayer will release locally any ongoing MM connections before the IMSI DETACH INDICATION message is sent. The IMSI detach procedure may not be started if a MM specific procedure is active. If possible, the IMSI detach procedure is then delayed until the MM specific procedure is finished, else the IMSI detach is omitted.