Question: In a Terminal Conformance Test for Radio Transmission and Reception (TDD), what triggers the computation of the RLC SDU error rate by the System Simulator (SS)?
Option 1: Receipt of the 'UE TEST LOOP MODE 3 RLC SDU COUNTER RESPONSE' from the UE, reporting the received RLC SDU counter value.
Option 2: Expiration of a predefined test duration timer set by the SS.
Option 3: Completion of a fixed number of transmitted RLC SDU blocks on the MCCH radio bearer.
Option 4: Manual intervention by the test operator to initiate error rate calculation.
Explanation: The correct answer is Option 1 because the SS computes the RLC SDU error rate after receiving the 'UE TEST LOOP MODE 3 RLC SDU COUNTER RESPONSE' from the UE, providing the necessary received RLC SDU count for calculating the error rate compared to the transmitted RLC SDUs count maintained by the SS, assessing data transmission reliability between the SS and the UE.