4G EMM States in MME

EMM sublayer states in the MME

1. EMM-DEREGISTERED

In the state EMM-DEREGISTERED, the MME has no EMM context or the EMM Context is marked as detached. The UE is detached. The MME may answer to an attach or a combined attach procedure initiated by the UE. The MME may also answer to a tracking area updating procedure or combined tracking area updating procedure initiated by a UE if the EMM context is marked as detached. If ISR is not activated or ISR is deactivated during a routing area updating or combined routing area updating procedure or an inter-system handover to A/Gb mode or Iu mode, the MME enters the state EMM-DEREGISTERED after the successful completion of the procedure.

2. EMM-COMMON-PROCEDURE-INITIATED

The MME enters the state EMM-COMMON-PROCEDURE-INITIATED, after it has started a common EMM procedure and is waiting for a response from the UE.

3. EMM-REGISTERED

In the state EMM-REGISTERED, an EMM context has been established and a default EPS bearer context has been activated in the MME.

4. EMM-DEREGISTERED-INITIATED

The MME enters the state EMM-DEREGISTERED-INITIATED after it has started a detach procedure and is waiting for a response from the UE.