Question: What type of transmissions are supported by the MCPTT-IOPS-3 reference point between the IOPS distribution function and the MCPTT client for both uplink and downlink?
Option 1: IP Multicast Transmissions
Option 2: Circuit Switched Voice Calls
Option 3: IP Unicast Transmissions
Option 4: Broadcast Messaging Services
Explanation: The MCPTT-IOPS-3 reference point is specifically defined for supporting IP unicast transmissions. This is crucial in the context of Mission Critical Push To Talk (MCPTT) services, where reliable and direct communication between devices is paramount. IP unicast ensures that data packets are delivered from the source to a single, specific destination, which aligns with the requirements of MCPTT for efficient and secure communication in public safety scenarios.