Section: 5.40.5 Handling when a Disaster Condition is no longer applicable
Content: When a UE detects a Disaster Condition is no longer applicable, the UE performs PLMN selection as described in TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [17] and TS 24.501[ Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 ]  [47] and may return to the PLMN previously with Disaster Condition. A PLMN providing Disaster Roaming: - May trigger the Disaster Inbound Roaming UEs to return to the PLMN previously with Disaster Condition when the Disaster Inbound Roamers attempt to transit to 5GMM-CONNECTED mode. - May trigger the Disaster Inbound Roaming UEs to return to the PLMN previously with Disaster Condition by triggering Deregistration procedure. - May trigger the Disaster Inbound Roaming UEs to return to the PLMN previously with Disaster Condition by rejecting Registration Request message. - May trigger the Disaster Inbound Roaming UEs to return to the PLMN previously with Disaster Condition by rejecting Service Request message. - Shall organise the return of the Disaster Roaming UEs in a manner that does not cause overload (e.g. of signalling) in the PLMN that previously had the Disaster Condition. - Stop broadcasting of providing Disaster Roaming service as specified in clause 5.40.3. - May determine that the disaster condition has ended and the UE which is registered for disaster roaming services has an emergency PDU session, the AMF initiates the UE configuration update procedure to indicate that the UE is registered for emergency services as described in TS 24.501[ Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 ]  [47]. - May determine that the disaster condition has ended and inform the UE by initiating the UE configuration update procedure indicating re-registration from UE is required as specified in clause 5.4.4 of TS 24.501[ Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 ]  [47] if the UE is in CM-CONNECTED mode. NOTE: Whether and how long the PLMN waits before paging the Disaster Inbound Roamers upon being notified that a Disaster Condition no longer applies is up to operator's policy. The HPLMN i.e. the UDM may trigger the Disaster Inbound Roaming UEs to return to the PLMN previously with Disaster Condition by triggering Deregistration procedure.