Question: In an Isolated Operation for Public Safety (IOPS) mode, how does the IOPS MC system facilitate the transport of Mission Critical (MC) service application data to UEs during a backhaul failure?
Option 1: Through a shared PLMN with commercial services using circuit-switched fallback.
Option 2: Via a single PLMN dedicated to IOPS mode, utilizing only signaling control plane.
Option 3: Using a single PLMN dedicated to IOPS mode, through both IP unicast and multicast transmissions over the application plane.
Option 4: By establishing direct device-to-device communications between UEs without the IOPS MC system.
Explanation: In IOPS mode during a backhaul failure, reliable communication for Mission Critical services is crucial. The correct answer highlights the use of a dedicated PLMN for IOPS, ensuring isolation and priority for these critical communications. It also specifies the utilization of both IP unicast (for targeted transmissions) and multicast (for efficient group communications) over the application plane, which is responsible for transporting MC service application data. This approach aligns with the need for robust, isolated, and efficient communication support in public safety scenarios.