METHOD FOR SIDELINK-AIDED MULTI-ROUND TRIP TIME POSITIONING WITH SERVING GNB INVOLVEMENT

1 . A method for Sidelink-Aided multi-Round Trip Time Positioning (RTT) with at least one serving gNB involvement in a wireless communication system, characterized by, that single-sided or double-side multi-round trip time (RTT)-of wireless communication signals-based positioning involving the sidelink (SL) in the wireless communication system in coordination with at least one base-station (gNB) is proceeded by using an initiator node and a position of a target user equipment UE is computed.

2 . The method according to claim 1 , whereby single-sided or double-side multi-round trip time (RTT) measurements are performed related to SL-PRS transmissions.

3 . The method according to claim 1 , characterized by, that one or more anchor UE(s) to be included in the multi-RTT procedure by sharing an accuracy requirement is identified and the multi-RTT procedure is terminated if required by progressively reducing the accuracy requirement.

4 . The method according to claim 1 , characterized by, that an initiator node seeks additional nodes for participation in double-side multi-RTT when there are not enough nodes already known to it.

5 . The method according to claim 1 , characterized by, that the initiator is chosen by a positioning protocol or a higher layer depending on the positioning requirement.

6 . The method according to claim 5 , characterized by, if serving gNB/LMF requires position of a target UE in its coverage it can initiate multi-RTT, else if target UE itself needs to compute its position, it can initiate the procedure.

7 . The method according to claim 5 , characterized by, that if an anchor UE requires the position of a target in its vicinity; then the anchor UE can initiate the procedure.

8 . The method according to claim 7 , characterized by, that the anchor UE is a road side unit (RSU).

9 . The method according to claim 1 , characterized by, that message exchanges between the nodes involved in the multi-RTT procedure are performed over an SL positioning protocol or directly using physical layer signaling if communication is over the SL.

10 . The method according to claim 1 , characterized by, that the signaling over the SL is using the SCI and/or PSSCH and/or MAC CE.

11 . The method according to claim 10 characterized by, that physical layer signaling is SCI and/or PSSCH or MAC CE.

12 . The method according to claim 4 characterized by, that if the initiator is the serving gNB/LMF, the target UE, neighboring gNB(s) and in-coverage anchor UE(s) if involved, are involved directly in multi-RTT, while any out-of-coverage anchor UE(s) are involved indirectly via the target UE.

13 . The method according to claim 4 characterized by, that if the initiator is the target UE, then the serving gNB/LMF and the anchor UE(s) known to the target UE are involved directly in multi-RTT, while any neighbor gNB(s) and in-coverage anchor UE(s) unknown to the target UE initially are involved indirectly via the serving gNB/LMF.

14 . The method according to claim 4 characterized by, that if the initiator is an in-coverage anchor UE, the target UE, serving gNB/LMF and anchor UE(s) known to the initiating anchor UE are involved directly in multi-RTT, while any neighbor gNB(s) and in-coverage anchor UE(s) unknown to the initiating anchor UE are involved indirectly via the serving gNB/LMF.

15 . An initiator node which is responsible for identifying anchor UE(s) and gNB(s) to be involved in a multi-RTT positioning and forwarding any resource allocation for positioning to the nodes.

16 . A target UE comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Is Received initiation for multi-RTT from serving gNB?

Forward initiation to out-of-coverage anchor UE(s) (if requested by serving gNB/LMF);

Send response to serving gNB/LMF;

Is Received resource allocation from gNB?

Forward resource allocation to out-of-coverage anchor UE(s);

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements;

Is Received measurements from out-of-coverage anchor UE(s)? and

Send measurements to serving gNB/LMF;

17 . A serving gNB/LMF comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Send initiation to target UE, in-coverage anchor UE(s) and neighbor gNBs;

Proceed with multi-RTT/Resend/Terminate;

Send request for resource allocation to neighbor gNB(s);

Allocate resources for PRS and measurement report exchange and send to target UE and anchor UE(s); and

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements,

18 . An in-coverage anchor UE comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Received initiation for multi-RTT from serving gNB?

Send response to serving gNB/LMF;

Received resource allocation from gNB?

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements; and

Send measurements to serving gNB/LMF.

19 . A neighbor gNB comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Received initiation for multi-RTT from serving gNB?

Send response to serving gNB/LMF;

Received request for resource allocation from serving gNB/LMF?

Send response to serving gNB/LMF; and

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements.

20 . An out-of-coverage anchor UE comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Is Received initiation for multi-RTT from target UE?

Send response to target UE; and

Is Received resource allocation from target UE?

21 . A target UE comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Is send initiation to serving gNB/LMF and anchor UE(s) out-of-coverage?

Proceed with multi-RTT/Resend/Terminate?

Send response to serving gNB/LMF;

Send request for resource allocation for multi-RTT to serving gNB;

Received resource allocation from gNB?

Forward resource allocation for out-of-coverage anchor UE(s) (if required);

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements;

Received measurements; and

Compute position.

22 . A serving gNB/LMF comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Received request for multi-RTT from target UE?

Send initiation to neighbor gNBs and in-coverage anchor UE(s) (if requested by target UE);

Received response from anchor UE(s) in-coverage and neighbor gNBs?

Send response to target UE;

Received resource allocation request for multi-RTT?

Send request for resource allocation to neighbor gNB(s);

Received resource allocation from neighbor gNB(s)?

Allocate resources for SL-PRS and measurement reports, send to target UE and anchor UE(s) in-coverage;

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements; and

Send measurements to target UE.

23 . An out-of-coverage anchor UE comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Received request for multi-RTT from target UE?

Send response to target UE;

Received resource allocation from target UE?

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements; and

Send measurements to target UE.

24 . An in-coverage anchor UE comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Received request for multi-RTT from serving gNB/LMF?

Send response to serving gNB/LMF:

Received resource allocation from gNB? and

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements,

25 . A neighbor gNB comprises a processor coupled with a non-transitory memory in which computer program instructions are stored, said instructions being configured to perform operations comprising:

Received request for multi-RTT from serving gNB/LMF?

Send response to serving gNB/LMF;

Received resource allocation request from serving gNB/LMF?

Send resource allocation for RTT with target UE to serving gNB/LMF;

Received resource allocation from serving gNB/LMF? and

Perform one-sided or two-sided multi-RTT-related SL-PRS transmissions and measurements,

26 . (canceled)