4.2.3 Reference points
23.5863GPPArchitectural Enhancements to support Ranging based services and Sidelink PositioningRelease 18TS
SR1: The reference point between the Sidelink (SL) Positioning and Ranging function in the UE and the SL Positioning/Ranging Server. This reference point is out of scope of this specification. It may be used for the configuration and application layer signaling.
SR5: The reference point between the Sidelink (SL) Positioning and Ranging function in UEs. It is carried over the PC5 reference point.
Editor’s note: Whether SR5 will be over PC5-RRC, PC5-D, PC5-U and/or PC5-S will be aligned with RAN WGs.
PC5: The reference point between the UEs. It also supports the Sidelink Positioning and Ranging operation defined by RAN WGs.