Question: What is the purpose of the Deregistration procedure in the 5G System (5GS)?
Option 1: To allow the network to update the UE's location information.
Option 2: To enable the UE to switch between different PLMNs.
Option 3: To inform the network or the UE that access to the 5GS is no longer desired or allowed, and to specify whether this applies to 3GPP access, non-3GPP access, or both.
Option 4: To initiate a handover from one access type to another.
Explanation: The Deregistration procedure serves as a mechanism for the UE or network to indicate that access to the 5GS is no longer desired or allowed. This can be due to various reasons such as the UE not wanting to access the 5GS anymore, the network revoking access, or the UE's registered PLMN not being permitted to operate in the current location. The procedure allows for specification of whether this applies to 3GPP access, non-3GPP access, or both, making it a critical function for managing access and connectivity in the 5GS.