Sidelink ranging with road-side unit assistance

A method of wireless positioning performed by a first user equipment (UE) that is participating in a sidelink (SL) ranging session with a second UE, the method comprising:

• detecting a road-side unit (RSU) with SL ranging capability;
• adding the RSU to the SL ranging session;
• performing SL ranging with the RSU;
• and
• at least one of:
• receiving, from the RSU, a range between the first UE and the second UE;
• or
• receiving, from the RSU, first ranging information comprising at least a round-trip time (RTT) between the RSU and the first UE and second ranging information comprising at least a RTT between the RSU and the second UE, and calculating a range between the first UE and the second UE based on the first ranging information and the second ranging information.

A road-side unit (RSU), comprising:

• a memory;
• at least one transceiver;
• and
• at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:
• join a first sidelink (SL) ranging session between a first user equipment (UE) and a second UE;
• perform SL ranging with the first UE to determine first ranging information comprising at least a round-trip time (RTT) to the first UE;
• perform SL ranging with the second UE to determine second ranging information comprising at least a RTT to the second UE;
• and
• at least one of:
• send, via the at least one transceiver, the first ranging information and the second ranging information to at least one of the first UE or the second UE;
• or
• calculate a range between the first UE and the second UE based on the first ranging information and the second ranging information, and send, via the at least one transceiver, the range to at least one of the first UE and the second UE.

A user equipment (UE), comprising:

• a memory;
• at least one transceiver;
• and
• at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:
• detect a road-side unit (RSU) with SL ranging capability;
• add the RSU to a SL ranging session between the UE and a second UE;
• perform SL ranging with the RSU;
• and
• at least one of:
• receive, from the RSU via the at least one transceiver, a range between the UE and the second UE;
• or
• receive, from the RSU via the at least one transceiver, first ranging information comprising at least a round-trip time (RTT) between the RSU and the UE and second ranging information comprising at least a RTT between the RSU and the second UE, and calculate a range between the UE and the second UE based on the first ranging information and the second ranging information.