Question: In an Unauthenticated IMS Emergency Session in E-UTRAN, what happens to the NAS COUNT values when using EIA0 (NULL integrity algorithm) and they wrap around without a new KASME establishment?
Option 1: The NAS connection is terminated due to security protocol violation.
Option 2: The NAS COUNT values are reset to their initial state to prevent potential security breaches.
Option 3: The NAS connection is kept, and uplink/downlink NAS COUNT continues to increment for NAS messages using EIA0.
Option 4: The UE is forced to re-establish authentication with the network before proceeding.
Explanation: In unauthenticated IMS Emergency Sessions using EIA0, the specification allows NAS COUNT values to wrap around without a new KASME establishment. This prioritizes maintaining connectivity for emergency sessions. The NAS connection remains active, and NAS COUNT values continue to increment normally for all NAS messages utilizing EIA0, ensuring session continuity.