Question: In a Group Communication Service Application Server (GCS AS) utilizing Multimedia Broadcast/Multicast Service (MBMS), what is the primary purpose of the MB2 interface between the GCS AS and the Broadcast Multicast Service Center (BM-SC)?
Option 1: To manage dedicated bearers for unicast transmissions
Option 2: To handle only user plane data for multiple GCS AS sessions
Option 3: To carry both control plane signalling (MB2-C) and user plane data (MB2-U) for MBMS delivery
Option 4: To terminate MBMS bearers at the BM-SC for point-to-point communications
Explanation: The correct answer is Option 3 because, according to the specifications, the MB2 interface is utilized for both control plane signalling (via MB2-C) and user plane data (via MB2-U) between the GCS AS and BM-SC. This dual functionality enables efficient management and delivery of Group Communication Services over MBMS bearers.