Question: For a UTRA FDD UE supporting HSDPA, which Release version marks the introduction of the detection performance requirement based on event Em (P(Em)) for the optional enhanced performance requirements type 1?
Option 1: Release 5
Option 2: Release 7
Option 3: Release 6
Option 4: Release 8
Explanation: The detection performance requirement based on event Em (P(Em)) for a UTRA FDD UE supporting HSDPA, specifically for the optional enhanced performance requirements type 1, is applicable from Release 6 onwards. This indicates that the introduction of this requirement for type 1 enhancements aligns with the specifications outlined for Release 6, making it the correct answer. Releases before 6 do not apply to this specific scenario, and later releases (7 and 8) introduce requirements for different types.