Question: In UTRAN's Iub Interface for TDD mode, what is the relationship between a DSCH (Downlink Shared Channel) Data Stream and its corresponding An (User Plane Bearer) in terms of assignment to a UE (User Equipment)?
Option 1: One An can carry multiple DSCH Data Streams for different UEs served by the same Node B.
Option 2: For each DSCH used by an individual UE, there is one An exclusively assigned per Node B to that UE's communication context.
Option 3: Multiple Ans are required to carry a single DSCH Data Stream for a UE, depending on the data rate.
Option 4: The assignment of An to DSCH Data Streams is dynamic and shared among all UEs connected to the Node B.
Explanation: This correct answer reflects the one-to-one relationship between a DSCH (used by a single UE) and its assigned An, emphasizing exclusivity per Node B for each UE's communication context. This ensures dedicated resource allocation for efficient data transmission in TDD mode, highlighting the importance of tailored bearer management in UTRAN architectures.