Question: In UTRAN Iub interface, what triggers the Node B to initiate the Cell Synchronisation Failure procedure for TDD modes?
Option 1: Expiration of a timer related to handover procedures
Option 2: Inability to support Cell Synchronisation Burst (3.84Mcps TDD) or SYNC_DL Code (1.28Mcps TDD) transmission/measurement
Option 3: Detection of an incorrect scrambling code in uplink transmissions
Option 4: Receipt of a Radio Link Failure notification from User Equipment (UE)
Explanation: The Cell Synchronisation Failure procedure is specifically initiated by the Node B when it can no longer support critical synchronization functions, such as transmitting Cell Synchronisation Bursts for 3.84Mcps TDD or SYNC_DL Codes for 1.28Mcps TDD, impacting the cell's ability to maintain synchronization with both the network and connected UEs.