Question: In a UTRAN, which of the following methods can initiate an enhanced serving HS-DSCH cell change procedure for an FDD UE supporting HSDPA?
Option 1: A RRC message implying a change of the serving HS-DSCH cell or an HS-SCCH order sent on the target cell.
Option 2: Only a RRC message implying a change of the serving HS-DSCH cell, applicable to Release 7 and earlier.
Option 3: Solely an HS-SCCH order sent on the current serving cell, for UEs indicating support for HSDPA but not Target Cell Pre-Configuration.
Option 4: Through a NAS message directly from the Core Network, bypassing RAN signaling for Releases 8 and later.
Explanation: The correct answer is Option 1 because an enhanced serving HS-DSCH cell change procedure in UTRAN can be initiated by either a Radio Resource Control (RRC) message implying a change of the serving HS-DSCH cell or through a High-Speed Shared Control Channel (HS-SCCH) order sent on the target cell, aligning with efficient and flexible network operation principles for FDD UEs supporting HSDPA.