Question: In NG-RAN, which of the following statements accurately describes how the location of a User Equipment (UE) is estimated using the UL-TDOA (Uplink Time Difference of Arrival) positioning method?
Option 1: The UE measures the DL-RTOA (Downlink Reference Time of Arrival) from multiple base stations and reports these measurements to the network for location estimation.
Option 2: Multiple Reception Points (RPs) measure the UL-RTOA (and optionally other signal strength metrics like UL-SRS-RSRP, UL-SRS-RSRPP, or UL-RSCP) of uplink signals from the UE, using assistance data from a positioning server for location estimation.
Option 3: The network estimates the UE's location based solely on the UE's transmission power and the signal attenuation reported by neighboring UEs.
Option 4: A single RP measures the round-trip time of a signal sent to the UE and back, calculating the UE's distance for location estimation.
Explanation: This is correct because UL-TDOA positioning in NG-RAN involves measuring the time difference of arrival of uplink signals at multiple Reception Points (RPs), utilizing assistance data. This method leverages the differences in signal arrival times from a single UE to multiple RPs to triangulate the UE's location, optionally enhancing accuracy with additional signal strength measurements.