Question: What condition allows an MCPTT (Mission Critical Push To Talk) client to release itself from an ongoing IOPS (Isolated Operation for Public Safety) group call without transmitting any signaling?
Option 1: The MCPTT client initiates a new individual call, automatically releasing it from the group call.
Option 2: The IOPS group call has been inactive for a specific duration set by the MCPTT service provider's policy.
Option 3: Another MCPTT client in the group call explicitly removes the client from the call.
Option 4: The MCPTT client's network connection is temporarily lost, triggering an automatic release.
Explanation: This option is correct because it aligns with the specified condition under which an MCPTT client can self-release from an IOPS group call without signaling - namely, when the call has been inactive for a duration determined by the service provider's policy. This highlights an important aspect of managing resources and call states in mission-critical communication scenarios, where efficient use of network resources is paramount, especially in isolated operation modes designed for public safety.