Question: What is a prerequisite for a User Equipment (UE) to utilize improved Downlink Reference Signal Received Power (RSRP) measurement accuracy via Received Signal Strength (RSS) in RRC_IDLE mode?
Option 1: The UE must support Resynchronization Signals as defined in the E-UTRA specifications.
Option 2: The UE must be operating in RRC_CONNECTED mode to enable RSS-based measurements.
Option 3: The feature is mandatory for all UEs supporting E-UTRA; no additional prerequisites apply.
Option 4: The UE needs to have an active data session to utilize improved RSRP measurement accuracy.
Explanation: For a UE to support improved DL RSRP measurement accuracy through RSS in RRC_IDLE mode, it is prerequisite that the UE supports resynchronization signals. This indicates not all UEs may have this capability, making Option 1 correct. Options 2 and 4 are incorrect due to introducing unrelated conditions. Option 3 is also incorrect as it contradicts the prerequisite notion.