Question: What type of signaling does the MBMS Registration procedure use to request the Core Network (CN) to de-register a Radio Network Controller (RNC) for a Multicast Service with an existing Iu signaling connection?
Option 1: Connectionless Signaling for all de-registration requests
Option 2: Connection-oriented Signaling only for initial registrations
Option 3: Connection-oriented Signaling, specifically when de-registering a service with an existing Iu signaling connection
Option 4: A combination of both connectionless and connection-oriented Signaling randomly chosen by the CN
Explanation: This is correct because, according to the MBMS Registration procedure specifics, when the Core Network (CN) is requested to de-register a Radio Network Controller (RNC) for a Multicast Service that already has an established Iu signaling connection, the procedure utilizes connection-oriented signaling. This ensures reliable communication for managing existing sessions.