Question: In a multicast MBS (Multicast Broadcast Service) session for a VAL (Vertical Application Layer) service group, what triggers the efficient utilization and control of NG-RAN (Next Generation Radio Access Network) resource reservation by the VAL server?
Option 1: Periodic UE Session Join Requests from all affiliated UEs (User Equipment)
Option 2: Activation/De-activation procedure based on VAL data availability to be delivered
Option 3: Direct allocation of NG-RAN resources by the NRM (Network Resource Management) server without input from the VAL server
Option 4: MB-SMF (Multicast Broadcast Service Management Function) initiating activation/de-activation based on notifications from MB-UPF (Multicast Broadcast User Plane Function)
Explanation: The correct answer is Option 2 because the VAL server efficiently utilizes and controls NG-RAN resource reservation through the activation and de-activation procedure with the NRM server, specifically based on whether there is VAL data available to be delivered via the multicast MBS session, allowing for flexibility and efficient use of resources.