Question: What is the primary requirement for the common time reference in a non-isolated TDD-unicast area for gNB synchronization?
Option 1: Alignment with the local operator's network time
Option 2: Traceability to the Global Positioning System (GPS) time
Option 3: Traceability to the Coordinated Universal Time (UTC)
Option 4: Synchronization with the nearest cellular tower's clock
Explanation: In a non-isolated TDD-unicast area, ensuring all gNBs are synchronized to a universal standard is crucial for seamless operation and to avoid inter-cell interference. Traceability to Coordinated Universal Time (UTC) provides a globally recognized time standard, facilitating synchronization across different networks and operators, which is essential for maintaining the integrity of the cellular network's timing requirements.