Question: What action does the UE take when Reporting of Access Availability is required by the network after a Multi-Access (MA) PDU session is established?
Option 1: The UE sends a PMF-Access Report to the gNB.
Option 2: The UE performs detection of the unavailability and availability of an access and then sends no report.
Option 3: The UE establishes a new MA PDU session for reporting.
Option 4: The UE sends the PMF-Access Report to the UPF via the user plane of any available access of the MA PDU session.
Explanation: When Reporting of Access Availability is required by the network, the UE detects the availability and unavailability of an access. To report this information, the UE sends a PMF-Access Report to the UPF (User Plane Function) via any available access of the MA PDU session. This allows the UPF to determine which access can be used for delivering downlink packets.