Question: In a UTRAN network, when Multicell E-DCH Transport Bearer Mode is set to "UL Flow Multiplexing Mode", how are Mac-d flows from different carriers handled at the Node B?
Option 1: Each carrier's Mac-d flow is transmitted over a shared Iub transport bearer, but with prioritization based on carrier signal strength.
Option 2: Mac-d flows from all carriers are multiplexed onto a single Iub transport bearer per Node B, regardless of the number of Mac-d flows.
Option 3: Carriers alternate in using a single Iub transport bearer for their Mac-d flows to prevent congestion.
Option 4: The Mac-d flows received on different carriers are multiplexed on one Iub transport bearer, specifically per Mac-d flow.
Explanation: In "UL Flow Multiplexing Mode", the Node B efficiently manages multiple carrier transmissions by combining (multiplexing) the Mac-d flows from these carriers onto a single Iub transport bearer. This is done on a per Mac-d flow basis, optimizing resource utilization without compromising data integrity or flow separation. This approach highlights the network's ability to handle complex, multi-carrier scenarios in UTRAN environments.