Question: In a UTRAN TDD network, when initiating an inter-RAT cell change order to transfer a UE's connection to GSM, in which states can this procedure be utilized?
Option 1: Only in the IDLE state
Option 2: Exclusively in the CELL_PCH state
Option 3: Both in the URA_PCH and CELL_FACH states
Option 4: In both the CELL_DCH and CELL_FACH states
Explanation: The correct answer is based on understanding the operational states of a User Equipment (UE) in a UTRAN (Universal Terrestrial Radio Access Network) environment. The CELL_DCH (Dedicated Channel) state is characterized by a dedicated connection for the UE, while the CELL_FACH (Forward Access Channel) state involves shared channels with lower speed. Given that an inter-RAT (Radio Access Technology) cell change from UTRAN TDD to GSM requires an active connection management, it logically aligns with states where the UE has an established connection pathway, making CELL_DCH and CELL_FACH the appropriate states for this procedure.