Question: How does a network notify UEs about changes to MCCH (Multicast Control Channel) information, and what triggers the UE to apply the new information?
Option 1: Via PDCCH at the beginning of an MCCH modification period; the UE applies the new info upon successful acquisition.
Option 2: Through a dedicated signaling channel sent directly to each interested UE; the change is applied immediately after notification receipt.
Option 3: By embedding the update within the MCCH itself, which UEs apply after a predefined delay from the last transmission of the old information.
Option 4: Using a broadcast message on a different channel, with UEs applying changes based on their individual scheduling configurations.
Explanation: According to the specified protocol for handling MCCH information updates, networks utilize the PDCCH to notify UEs of impending changes at the start of a modification period. This approach ensures synchronized updates across all affected UEs. Upon receiving this notification, each UE will acquire and then apply the new MCCH information from the designated starting point, ensuring continuity of service with updated configurations.