Methods and apparatuses for sidelink positioning

A second terminal device comprising:

• at least one processor;
• and
• at least one memory storing instructions that, when executed by the at least one processor, cause the second terminal device at least to:
• receive, from a first terminal device, a positioning reference signal (PRS) along with capability information indicating a capability of the first terminal device to provide location information of the first terminal device;
• determine, based on the capability information, that the first terminal device transmits the PRS without the location information and has the capability to provide the location information;
• and
• transmit, to the first terminal device, a request for the location information of the first terminal device, wherein the request comprises at least one of the following:
• a list of at least one terminal device from which the second terminal device needs location information;
• a reference signal received power (RSRP) measurement by the second terminal device of a PRS transmitted by the first terminal device;
• an achieved accuracy performance of the positioning of the second terminal device;
• a requirement of accuracy performance of the positioning of the second terminal device;
• a line of sight (LOS)-non-line of sight (NLOS)-indicator measured for the at least one terminal device, wherein the LOS-NLOS-indicator comprises at least one of a hard-valued LOS-NLOS-indicator or a soft-valued LOS-NLOS-indicator;
• a number of the at least one terminal device that is available for absolute positioning of the second terminal device;
• an indication of at least one terminal device and the location information of the at least one terminal device, wherein the location information of the least one terminal device is used by the second terminal device;
• a request information for requesting the uncertainty of the location information;
• or
• a range for an accepted uncertainty of the location information.

A method, comprising:

• transmitting, at a first terminal device, capability information of the first terminal device along with a positioning reference signal (PRS), wherein the capability information indicates a capability to provide the location information of the first terminal device;
• receiving, from a second terminal device, a request for the location information of the first terminal device, wherein the request comprises at least one of the following:
• a list of at least one terminal device from which the second terminal device needs location information;
• a reference signal received power (RSRP) measurement by the second terminal device of a PRS transmitted by the first terminal device;
• an achieved accuracy performance of the positioning of the second terminal device;
• a requirement of accuracy performance of the positioning of the second terminal device;
• a line of sight (LOS)-non-line of sight (NLOS)-indicator measured for the at least one terminal device, wherein the LOS-NLOS-indicator comprises at least one of a hard-valued LOS-NLOS-indicator or a soft-valued LOS-NLOS-indicator;
• a number of the at least one terminal device that is available for absolute positioning of the second terminal device;
• an indication of at least one terminal device and the location information of the at least one terminal device, wherein the location information of the least one terminal device is used by the second terminal device;
• a request information for requesting the uncertainty of the location information;
• or
• a range for an accepted uncertainty of the location information;
• and
• based on receiving the request, transmitting the location information along with a subsequent PRS.