Question: What is a recommended approach to secure RLOS (Relay Node for Load Balancing and Overload Sharing) services for UEs (User Equipment) in Idle Mode State, given the absence of network authentication?
Option 1: Implementing additional NAS (Non-Access Stratum) layer encryption
Option 2: Enhancing AS (Access Stratum) protocol security features
Option 3: Utilizing UE's IMSI (International Mobile Subscriber Identity) for service validation
Option 4: Deploying application layer security mechanisms specific to each RLOS service
Explanation: Since RLOS connections for UEs in Idle Mode State bypass network authentication, traditional NAS and AS traffic protection measures are ineffective. Therefore, securing RLOS services relies on implementing security at the application layer, which varies by service, addressing the vulnerability without depending on network-level authentication.