Question: In a TDD system for UEs supporting HSDPA, how is the HS-DSCH data throughput measured for fixed reference channels?
Option 1: By analyzing the UE's processing power and memory capacity.
Option 2: By counting the amount of data successfully received at the UE, monitored through ACK/NACK signalling on the HS-SICH.
Option 3: Through periodic feedback from the UE to the SS about the quality of the downlink signal.
Option 4: By measuring the total transmission time for a fixed amount of data from the SS to the UE.
Explanation: This is correct because, according to telecom standards for testing and measuring throughput in wireless communications, specifically for HSDPA-capable UEs in TDD mode, the actual data successfully received (as indicated by ACK/NACK signals on the HS-SICH) directly reflects the effective throughput. This method ensures that only successfully transmitted data is counted, providing an accurate measure of the UE's capability to receive data under test conditions.