Question: Upon expiry of Timer T4 (Inactivity) in an MCPTT (Mission Critical Push To Talk) scenario, what action(s) may the IWF (Interworking Function) floor control server take based on a configurable service provider policy if the application and signalling planes do NOT initiate an MCPTT call release?
Option 1: Immediately transition to 'Releasing' state without restarting Timer T4.
Option 2: Restart Timer T3 instead of T4 and remain in the 'G: Floor Idle' state.
Option 3: Restart Timer T4 (Inactivity) and remain in the 'G: Floor Idle' state.
Option 4: Directly terminate the MCPTT session without signaling the application plane.
Explanation: Upon Timer T4 (Inactivity) expiry, if there's no initiation for MCPTT call release by the application and signalling planes, the IWF floor control server, as per configurable policy, should restart Timer T4 to allow for potential further activity and remain in the 'G: Floor Idle' state, awaiting either new activity or a call release signal. This approach balances between resource management (by not indefinitely keeping resources allocated) and service responsiveness (by allowing for quick re-engagement).