Question: In Enhanced Cell ID (E-CID) positioning for NG-RAN, which of the following measurements is **NOT** used for Uplink E-CID positioning when considering multiple Radio Access Technologies (RATs)?
Option 1: E-UTRA Reference Signal Received Power (RSRP)
Option 2: GERAN RSSI
Option 3: ng-eNB Rx – Tx time difference
Option 4: Angle of Arrival (AoA) from UE perspective
Explanation: E-UTRA RSRP (Option 1), GERAN RSSI (Option 2), and ng-eNB Rx – Tx time difference (Option 3) are all mentioned as measurements that can be used for E-CID positioning, including in the context of uplink E-CID when considering multiple RATs. Angle of Arrival (AoA) is indeed a measurement technique, but according to the provided context, AoA mentioned is from the ng-eNB perspective, not the UE's. The question specifically asks about measurements **from the UE perspective** for Uplink E-CID positioning across various RATs. Since AoA from the UE's perspective is not listed among the measurements used for uplink E-CID (and only ng-eNB's AoA is mentioned), it fits as the correct answer to this question.