Section: 10.2.1 Authenticated IMS Emergency Sessions 10.2.1.1 General
Content: Authenticated emergency services are provided to UEs in the following scenarios: a) A UE in RM-DEREGISTERED state requests IMS Emergency services In this scenario, the UE has a valid subscription and is authenticated when it registers with the network. b) A UE in RM-REGISTERED state initiates a PDU Session request to setup an IMS Emergency Session In this scenario, the UE is already registered with the network and share a security context with the AMF. The UE initiates a session management message to setup a new bearer for emergency services. The request for emergency services is sent protected by the current security context. The AMF may decide to re-authenticate the UE. If there is a redirection of the UE to EUTRAN for IMS Emergency services, the redirect command from the gNB to the UE shall be protected by the UE’s AS security context. The AMF shall send the ‘NG AP UE Initial Context setup’ message to enable the AS security context set up.