Question: In a TDD (Time Division Duplexing) system, for UEs (User Equipment) supporting HSDPA (High-Speed Downlink Packet Access) from Release 7 onwards, how is the HS-DSCH (High-Speed Downlink Shared Channel) data throughput measured for fixed reference channels?
Option 1: By analyzing the uplink transmission power of the UE.
Option 2: Through direct measurement of downlink signal strength at the base station.
Option 3: 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).
Option 4: Via periodic feedback reports from the UE to the network about its throughput experience.
Explanation: The correct measurement method for HS-DSCH data throughput in this context involves monitoring the ACK/NACK signalling field of the HS-SICH received at the Serving Station (SS), which indicates successful data reception at the UE. This approach directly assesses the effectiveness of data transfer, making it the most relevant measure for evaluating throughput performance in HSDPA-capable UEs from Release 7 onwards in TDD systems.