Question: In a TDD (Time Division Duplex) system for UEs (User Equipment) supporting HSDPA (High-Speed Downlink Packet Access), how is the HS-DSCH (High-Speed Downlink Shared Channel) data throughput measured for fixed reference channels?
Option 1: By analyzing the UE's transmission power levels over a set period.
Option 2: Through direct measurement of data packets at the Serving Station (SS) before transmission.
Option 3: By monitoring the signal-to-noise ratio (SNR) of the downlink signals received at the UE.
Option 4: By counting the amount of data successfully received at the UE, as indicated by ACK/NACK signalling on the HS-SICH (High-Speed Shared Control Channel) received at the SS.
Explanation: This method directly assesses the successful receipt of data at the UE, providing an accurate measure of throughput. Monitoring ACK/NACK signals on the HS-SICH allows for the quantification of successfully transmitted data packets, reflecting the actual throughput experienced by the UE in a TDD system supporting HSDPA.