Section: 5.1.5 Coordination between EMM and MM
Content: UEs that operate in CS/PS mode 1 or CS/PS mode 2 of operation shall use the combined EPS/IMSI attach procedure in order to attach to both EPS and non-EPS services. UEs that operate in CS/PS mode 1 or CS/PS mode 2 of operation and are already attached to both EPS and non-EPS services shall use the combined tracking area updating and periodic tracking area updating procedures. UEs that operate in CS/PS mode 1 or CS/PS mode 2 of operation and are already attached to both EPS and non-EPS services shall perform a combined detach procedure in order to detach for non-EPS services. UEs that operate in CS/PS mode 1 or CS/PS mode 2 of operation should not use any MM timers related to MM specific procedures (e.g. T3210, T3211, T3212, T3213) while camped on E-UTRAN, unless the re-activation of these timers is explicitly described. If the MM timers are already running, the UE should not react on the expiration of the timers. If the UE is configured for eCall only mode as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [17] and moves from GERAN/UTRAN to E-UTRAN, the UE shall: - if timer T3242 is running, start timer T3444 with the time left on T3242 and stop timer T3242; - if timer T3243 is running, start timer T3445 with the time left on T3243 and stop timer T3243; - if the UE is attached for both EPS services and non-EPS services and timer T3242 or timer T3243 is running, perform a combined tracking area updating procedure; and NOTE 1: A UE configured for eCall only mode as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [17] being attached for both EPS services and non-EPS services upon moving from GERAN/UTRAN to E-UTRAN is only possible in the case when the UE has performed a combined attach in E-UTRAN, subsequently moved to GERAN/UTRAN and returned to E-UTRAN before timer T3242 or timer T3243 expires. - if the UE is attached for non-EPS services only and timer T3242 or timer T3243 is running, perform a combined attach procedure. NOTE 2: Timers T3242 and T3243 are specified in 3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  [13].