Question: What is the primary purpose of the Down-Link Power Control function in UTRAN, as utilized by the Serving Radio Network Controller (SRNC), and what additional role does it play in Frequency Division Duplexing (FDD) mode?
Option 1: To adjust uplink transmission power based on UE feedback, and to synchronize radio link handovers in FDD.
Option 2: To control the downlink transmitted power level, and in FDD, to correct downlink power drifting between multiple radio links.
Option 3: To manage interference by dynamically altering cell site transmit power, with no specific FDD-related adjustments.
Option 4: To optimize downlink data throughput by adjusting transmission power in response to UE signal strength reports.
Explanation: The correct answer is Option 2 because it accurately reflects the dual role of Down-Link Power Control. Firstly, it controls the overall level of downlink transmitted power for optimal signal strength at UEs. Secondly, in FDD mode specifically, it compensates for drifts in downlink power across multiple radio links, maintaining consistency and quality of service.