Section: 4.6.2.1 EMM-DEREGISTERED
Content: In the EMM-DEREGISTERED state, the EMM context in MME holds no valid location or routing information for the UE. The UE is not reachable by a MME, as the UE location is not known. In the EMM-DEREGISTERED state, some UE context can still be stored in the UE and MME, e.g. to avoid running an AKA procedure during every Attach procedure. During the successful Inter-RAT TAU/RAU/handover procedure and ISR activated is not indicated to the UE, the old S4 SGSN/old MME changes the EMM state of the UE to GPRS-IDLE/PMM-DETACHED/EMM-DEREGISTERED.