Question: What happens to the UE Radio Capability information stored in the AMF when the UE's NG-RAN or E-UTRAN UE Radio Capability information changes while in CM-IDLE state?
Option 1: The AMF updates the UE Radio Capability information.
Option 2: The AMF deletes the UE Radio Capability information and the UE performs a new Registration procedure with "UE Radio Capability Update".
Option 3: The AMF sends the updated UE Radio Capability information to the RAN in the N2 REQUEST message.
Option 4: The AMF ignores the change and continues to use the old UE Radio Capability information.
Explanation: According to the text, when the UE's NG-RAN or E-UTRAN UE Radio Capability information changes while in CM-IDLE state, the UE shall perform the Registration procedure with the Registration type set to Mobility Registration Update and it also includes "UE Radio Capability Update". The AMF then deletes any UE Radio Capability information that it has stored for the UE.