Question: What triggers the notification to UEs about changes in MCCH information, and how is this notification transmitted?
Option 1: The network notifies UEs about changes in MCCH information at random radio frames, and the notification is transmitted via PDSCH.
Option 2: The network notifies UEs about changes in MCCH information starting from the beginning of the MCCH modification period, and the notification is transmitted via PDCCH with a 1-bit bitmap.
Option 3: The network notifies UEs about changes in MCCH information starting from the beginning of the MCCH modification period, and the notification is transmitted via PDCCH with a 2-bit bitmap.
Option 4: The network notifies UEs about changes in MCCH information at the end of the MCCH modification period, and the notification is transmitted via PBCH.
Explanation: According to the specifications, the network notifies UEs about changes in MCCH information starting from the beginning of the MCCH modification period, and this notification is transmitted via PDCCH with a 2-bit bitmap. This ensures that UEs are informed about changes in MCCH information in a timely and efficient manner.