Question: In UTRA TDD, what is the primary metric used to determine the performance requirement for a Dedicated Channel (DCH), and how is it applied to the User Equipment (UE)?
Option 1: Signal-to-Noise Ratio (SNR) for all possible data ratios of the DCH, regardless of UE support.
Option 2: Block Error Ratio (BLER) for each individual data ratio of the DCH, but only applicable if the UE supports all defined data ratios.
Option 3: Throughput for aggregate data ratios of the DCH, applying only to specific types of UTRA TDD UE.
Option 4: Block Error Ratio (BLER) for each individual data ratio of the DCH, with requirements applied based on the data ratios supported by the UE.
Explanation: The correct answer is Option 4 because it accurately reflects that the performance of a Dedicated Channel (DCH) in UTRA TDD systems is primarily evaluated using the Block Error Ratio (BLER), with specific BLER targets set for each individual data ratio of the DCH. Moreover, the requirements are tailored to the UE based on which data ratios it supports, ensuring fairness and relevance in conformance testing across various UEs with potentially different capabilities. This approach ensures that the performance assessment is both detailed (per data ratio) and applicable (only to supported ratios), making Option 4 the most accurate and comprehensive choice.