Question: What is the primary role of the BM-SC Proxy and Transport Function in relation to MBMS GWs/GGSNs and other BM-SC sub-functions, considering its interaction over SGmb and Gmb reference points?
Option 1: To manage multicast payload transmission directly to User Equipment (UE) without involving the MBMS GW or GGSN.
Option 2: To act solely as a charging gateway for content providers, generating records based on transmitted data volumes.
Option 3: To serve as a Proxy Agent for signalling, ensuring transparent routing of interactions and potentially handling MBMS services from multiple physical network elements.
Option 4: To terminate MBMS sessions at the network edge, caching content for faster delivery to subscribers.
Explanation: The BM-SC Proxy and Transport Function's primary role is to manage signalling over reference points, ensuring transparency in routing interactions between MBMS GWs/GGSNs and other BM-SC sub-functions, and handling services from multiple network elements, aligning with its description in Multimedia Broadcast/Multicast Service (MBMS) architecture.