Question: In a TDD system, for a User Equipment (UE) supporting High-Speed Downlink Packet Access (HSDPA), what is the implication of detecting event Em on the High-Speed Shared Control Channel (HS-SCCH)?
Option 1: Successful transmission of data packets via HS-DSCH (High-Speed Downlink Shared Channel)
Option 2: Activation of the UE's receiver for dedicated channel transmission
Option 3: Observation of Discontinuous Transmission (DTX) in the corresponding HS-SICH/NACK field when signaled on HS-SCCH
Option 4: Initiation of a handover procedure to another cell
Explanation: The detection of event Em relates to observing Discontinuous Transmission (DTX) in the HS-SICH/NACK field on HS-SCCH, indicating a mismatch between expected and actual transmissions, highlighting potential issues with downlink signaling for HSDPA-capable UEs in TDD mode.