Question: In NG-RAN, what is primarily utilized by the Sidelink Round Trip Time Positioning (SL-RTT) method to determine the distance between a target UE and one or more peer UEs?
Option 1: SL Rx-Tx time difference measurements alone
Option 2: Only SL-PRS-RSRP and/or SL-PRS-RSRPP measurements
Option 3: Cell ID and Global Navigation Satellite System (GNSS) data
Option 4: Handover history and UE velocity estimates
Explanation: The SL-RTT positioning method fundamentally relies on measuring the time difference between the transmission and reception of sidelink signals between UEs. While SL-PRS-RSRP and/or SL-PRS-RSRPP measurements are optionally used, the primary mechanism for determining distances (and thus, for positioning) is through SL Rx-Tx time difference measurements. This method allows calculating the range between pairs of UEs, which can then be used to triangulate the target UE's location relative to known positions of peer (anchor) UEs in the NG-RAN environment.