Section: 4.2 Behaviour of the MS in MM Idle state, GMM-DEREGISTERED state and GMM-REGISTERED state
Content: In this subclause, the detailed behaviour of the MS in the main states MM IDLE, GMM-DEREGISTERED and GMM-REGISTERED is described. Subclauses 4.2.1 to 4.2.3 refer to the state MM IDLE, whereas subclauses 4.2.4 and 4.2.5 refer to the states GMM-DEREGISTERED and GMM-REGISTERED, respectively. The MM IDLE state is entered when none of the MM procedures are running and no RR connection exists. It is left when one of the MM procedures are triggered or a RR connection is established. The specific behaviour in the MM IDLE state depends on the service state of the mobile station as described in subclause 4.1.2.1.2. The service state depends in particular on the update status which is defined in subclause 4.1.2.2. How an appropriate service state is chosen after power on is described in subclause 4.2.1, and the specific behaviour of the mobile station in MM IDLE state is described in subclause 4.2.2. The service state chosen when the MM IDLE state is returned to from any state except NULL state is described in subclause 4.2.3. It should be noted that transitions between the various MM idle states are caused by (e.g.): - results of procedures on RR connected mode (see subclause 4.2.3); - insertion or removal of the SIM/USIM; - cell selection/reselection (see also 3GPP TS 43.022[ None ]  [82] and 3GPP TS 25.304[ None ]  [98]); - PLMN search; - loss of coverage. How various MM procedures affects the service state and the update status is described in the detailed descriptions of the procedures in subclauses 4.3 to 4.5.