Determining subset of candidate positioning anchors

1 . An apparatus comprising at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:

receive assistance information associated with at least one of: at least one positioning anchor of the apparatus to be replaced, or at least one positioning anchor to be added for the apparatus;

determine, based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of one or more candidate positioning anchors fulfil at least one criterion associated with at least one of: the at least one positioning anchor of the apparatus to be replaced, or the at least one positioning anchor to be added for the apparatus; and

transmit measurement information associated with the subset of one or more candidate positioning anchors;

wherein the assistance information comprises an identifier of the at least one positioning anchor to be replaced.

2 . The apparatus according to claim 1 , wherein the transmitted measurement information does not include measurement information associated with other candidate positioning anchors than the determined subset of one or more candidate positioning anchors.

3 . The apparatus according to claim 1 , wherein the at least one criterion is indicated by the assistance information or comprised in the assistance information.

4 . The apparatus according to claim 1 , wherein the assistance information comprises or indicates a cause for replacing the at least one positioning anchor to be replaced.

5 . The apparatus according to claim 1 , wherein the assistance information comprises or indicates one or more geometrical characteristics of a positioning anchor relative to the apparatus, wherein the positioning anchor comprises at least one of: the at least one positioning anchor to be replaced or the at least one positioning anchor to be added.

6 . The apparatus according to claim 5 , wherein the one or more geometrical characteristics of the positioning anchor comprise at least one of: an angle of the positioning anchor relative to a boresight direction of the apparatus, or a geographical area of the positioning anchor relative to the apparatus.

7 . The apparatus according to claim 1 , further being caused to:

receive, from the set of one or more discovered candidate positioning anchors, location information of the set of one or more discovered candidate positioning anchors, wherein the subset of one or more candidate positioning anchors is determined based at least on the location information and the assistance information.

8 . The apparatus according to claim 1 , further being caused to:

obtain measurement information associated with the set of one or more discovered candidate positioning anchors by measuring one or more signals received from the set of one or more discovered candidate positioning anchors,

wherein the transmitted measurement information associated with the subset of one or more candidate positioning anchors is obtained by selecting a subset of measurement information from the measurement information associated with the set of one or more discovered candidate positioning anchors, the subset of measurement information corresponding to the subset of one or more candidate positioning anchors.

9 . The apparatus according to claim 1 , wherein the at least one criterion comprises at least a criterion for a signal metric of a reference signal.

10 . The apparatus according to claim 9 , further being caused to:

transmit, to the set of one or more discovered candidate positioning anchors, information comprising at least the criterion for the signal metric; and

receive one or more signals from the subset of one or more candidate positioning anchors, wherein the one or more signals are transmitted from the subset of one or more candidate positioning anchors based on the subset of one or more candidate positioning anchors fulfilling the criterion for the signal metric,

wherein the measurement information associated with the subset of one or more candidate positioning anchors is obtained by measuring the one or more signals received from the subset of one or more candidate positioning anchors.

11 . The apparatus according to claim 1 , wherein the at least one criterion comprises at least a threshold for geometric dilution of precision.

12 . The apparatus according to claim 1 , wherein the assistance information comprises a group identifier indicating a group of positioning anchors to be added for the apparatus.

13 . An apparatus comprising at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:

generate assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the assistance information is associated with at least one of: at least one positioning anchor of the user device to be replaced, or at least one positioning anchor to be added for the user device;

transmit the assistance information to the user device; and

receive, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, wherein the subset of one or more candidate positioning anchors fulfil at least one criterion associated with at least one of: the at least one positioning anchor of the user device to be replaced, or the at least one positioning anchor to be added for the user device;

wherein the assistance information comprises at least one of: an identifier of the at least one positioning anchor to be replaced, or a cause for replacing the at least one positioning anchor to be replaced.

14 . The apparatus according to claim 13 , further being caused to:

select, based at least on the measurement information, one or more positioning anchors from the subset of one or more candidate positioning anchors; and

transmit, to the user device, a message indicating the selected one or more positioning anchors to be used for supporting positioning of the user device.

15 . The apparatus according to claim 13 , wherein the received measurement information does not include measurement information associated with other candidate positioning anchors than the subset of one or more candidate positioning anchors.

16 . The apparatus according to claim 13 , wherein the assistance information comprises or indicates one or more geometrical characteristics of a positioning anchor relative to the user device, wherein the positioning anchor comprises at least one of: the at least one positioning anchor to be replaced or the at least one positioning anchor to be added.

17 . The apparatus according to claim 16 , wherein the one or more geometrical characteristics of the positioning anchor comprise at least one of: an angle of the positioning anchor relative to a boresight direction of the user device, or a geographical area of the positioning anchor relative to the user device.

18 . The apparatus according to claim 13 , wherein the at least one criterion comprises at least a criterion for a signal metric of a reference signal.