3GPP 23.501 v20.2.0 — the document's own text
5.3.2.2.2 RM-DEREGISTERED state
Taught in 9. Registration, reachability and paging (The 5G system architecture, in depth), 4. Knowing who you are and where you are (The 5G system architecture, overview).
In the RM-DEREGISTERED state, the UE is not registered with the network. The UE context in AMF holds no valid location or routing information for the UE so the UE is not reachable by the AMF. However, some parts of UE context may still be stored in the UE and the AMF e.g. to avoid running an authentication procedure during every Registration procedure.
In the RM-DEREGISTERED state, the UE shall:
- attempt to register with the selected PLMN using the Initial Registration procedure if it needs to receive service that requires registration (see clause 4.2.2.2 of TS 23.502 [3]).
- remain in RM-DEREGISTERED state if receiving a Registration Reject upon Initial Registration (see clause 4.2.2.2 of TS 23.502 [3]).
- enter RM-REGISTERED state upon receiving a Registration Accept (see clause 4.2.2.2 of TS 23.502 [3]).
When the UE RM state in the AMF is RM-DEREGISTERED, the AMF shall:
- when applicable, accept the Initial Registration of a UE by sending a Registration Accept to this UE and enter RM-REGISTERED state for the UE (see clause 4.2.2.2 of TS 23.502 [3]); or
- when applicable, reject the Initial Registration of a UE by sending a Registration Reject to this UE (see clause 4.2.2.2 of TS 23.502 [3]).