Methods and network nodes for positioning based on displacement data

1. A method, performed by a radio network node, of obtaining a location estimate, wherein the location estimate indicates a location of a target radio node, the method comprising:

obtaining a reference point for the target radio node, wherein information associated with the obtained reference point comprises:

a location reference (loc_ref) of the target radio node;

a time (t_ref) when obtained the location reference (loc_ref) of the target node; and

obtaining displacement information indicating displacement, in relation to the reference point, of the target radio node, wherein displacement information comprises:

a velocity (vel_est) of the target radio node; and,

a time (time_meas) when obtained the velocity (vel_meas) of the target radio node, wherein the time (time_meas) is carried by one of the following:

a systemFrameNumber field in an Observed Time Difference of Arrival (OTDOA) signal;

a measurementReferenceTime field in an Assisted Global Positioning System (AGPS) signal; or,

a systemFrameNumber field in an Evolved-Cell Identification (ECID) signal; and

wherein the method further comprises at least one of the following:

sending at least the displacement information to another network node; and

obtaining the location estimate by dead reckoning based on the displacement information and the reference point by calculating the following:

a time displacement (td) = t _meas − t _ref; and,

the location estimate (loc_meas) =loc_ref +vel_est * td.

2. The method according to claim 1 , wherein the obtaining of displacement information comprises one or more of:

receiving the displacement information from the target radio node;

determining the displacement information;

receiving the displacement information from another network node; and

obtaining the displacement information according to a pre-defined rule.

3. The method according to claim 1 , wherein the obtaining of the reference point comprises one or more of:

receiving the reference point from the target radio node;

determining the reference point;

receiving the reference point from another network node; and

obtaining the reference point according to a pre-define rule.

4. The method according to claim 1 , comprising:

receiving, from a positioning node or the target radio node, an indication to start using dead reckoning when performing the obtaining of the location estimate.

5. The method according to claim 1 , comprising:

receiving, from a positioning node, at least one configuration parameter for dead reckoning and/or assistance data for dead reckoning.

6. The method according to claim 5 , wherein the at least one configuration parameter comprises one or more of:

requested number of consecutive predictions,

maximum number of consecutive predictions,

total prediction time span, and

maximum total prediction time span.

7. The method according to claim 1 , wherein the method is performed by a Location Service (LCS) client executed in the radio network node.

8. The method according to claim 1 , wherein the obtaining of the location estimate by dead reckoning further comprises dynamically predicting the location estimate based on the displacement information and the reference point.

9. The method according to claim 1 , comprising performing hybrid positioning by combining the obtaining of the location estimate by dead reckoning with a further positioning method.

10. The method according to claim 1 , comprising:

obtaining a prediction result quality for the location estimate.

11. The method according to claim 10 , wherein the prediction result quality depends on one or more of the following parameters or characteristics:

a number of consecutive location estimates,

a time elapsed from the location estimate and/or the reference point,

a displacement characteristic or maneuver characteristic,

a quality of the reference point,

a quality of the displacement information, and

a type of the radio node.

12. A method, performed by a wireless device, of obtaining a location estimate, wherein the location estimate indicates a location of the wireless device, wherein the wireless device is operated to obtain the location estimate by use of functionality provided by a cellular telecommunication system, the method comprising:

obtaining a reference point for the wireless device, wherein information associated with the obtained reference point comprises:

a location reference (loc_ref) of the target radio node;

a time (t_ref) when obtained the location reference (loc_ref) of the target node; and

obtaining displacement information indicating displacement, in relation to the reference point, of the wireless device, wherein displacement information comprises:

a velocity (vel_est) of the target radio node; and,

a time (time_meas) when obtained the velocity (vel_meas) of the target radio node, wherein the time (time_meas) is carried by one of the following:

a systemFrameNumber field in an Observed Time Difference of Arrival (OTDOA) signal;

a measurementReferenceTime field in an Assisted Global Positioning System (AGPS) signal; or,

a systemFrameNumber field in an Evolved-Cell Identification (ECID) signal; and

wherein the method further comprises at least one of the following:

sending at least the displacement information to another node; and

obtaining the location estimate by dead reckoning based on the displacement information and the reference point by calculating the following:

a time displacement (td) = t _meas − t _ref; and,

the location estimate (loc_meas) =loc_ref +vel_est * td.

13. The method according to claim 12 , wherein the obtaining of displacement information comprises one or more of:

receiving the displacement information from the wireless device;

determining the displacement information;

receiving the displacement information from another network node; and

obtaining the displacement information according to a pre-defined rule.

14. The method according to claim 12 , wherein the obtaining of the reference point comprises one or more of:

receiving the reference point from the wireless device;

determining the reference point;

receiving the reference point from another network node; and

obtaining the reference point according to a pre-define rule.

15. The method according to claim 12 , comprising:

receiving, from a positioning node or the radio network node, an indication to start using dead reckoning when performing the obtaining of the location estimate.

16. The method according to claim 12 , comprising:

receiving, from a positioning node, at least one configuration parameter for dead reckoning and/or assistance data for dead reckoning.

17. The method according to claim 16 , wherein the at least one configuration parameter comprises one or more of:

requested number of consecutive predictions,

maximum number of consecutive predictions,

total prediction time span, and

maximum total prediction time span.

18. The method according to claim 12 , wherein the method is performed by a Location Service (LCS) client executed in the wireless device.

19. The method according to claim 12 , wherein the dead reckoning comprises dynamically predicting the location estimate based on the displacement information and the reference point.

20. The method according to claim 12 , comprising performing hybrid positioning by combining the obtaining of the location estimate by dead reckoning with a further positioning method.

21. The method according to claim 12 , comprising:

obtaining a prediction result quality for the location estimate.

22. The method according to claim 21 , wherein the prediction result quality depends on one or more of the following parameters or characteristics:

a number of consecutive location estimates,

a time elapsed from the location estimate and/or the reference point,

a displacement characteristic or maneuver characteristic,

a quality of the reference point,

a quality of the displacement information, and

a type of the radio node.

23. A method, performed by a positioning node, of obtaining a location estimate, wherein the location estimate indicates a location of a target radio node, the method comprising:

obtaining a reference point for the target radio node, wherein information associated with the obtained reference point comprises:

a location reference (loc_ref) of the target radio node;

a time (t_ref) when obtained the location reference (loc_ref) of the target node;

obtaining displacement information indicating displacement, in relation to the reference point, of the target radio node, wherein displacement information comprises:

a velocity (vel_est) of the target radio node; and,

a time (time_meas) when obtained the velocity (vel_meas) of the target radio node, wherein the time (time_meas) is carried by one of the following:

a systemFrameNumber field in an Observed Time Difference of Arrival (OTDOA) signal;

a measurementReferenceTime field in an Assisted Global Positioning System (AGPS) signal; or,

a systemFrameNumber field in an Evolved-Cell Identification (ECID) signal; and

obtaining the location estimate by dead reckoning based on the displacement information and the reference point by calculating the following:

a time displacement (td) = t _meas − t _ref; and,

the location estimate (loc_meas) =loc_ref +vel_est * td.

24. The method according to claim 23 , comprising:

sending, to the target radio node, at least one configuration parameter relating to the estimation of the location estimate.

25. The method according to claim 24 , wherein the at least one configuration parameter comprises one or more of:

requested number of consecutive predictions,

maximum number of consecutive predictions,

total prediction time span, and

maximum total prediction time span.

26. The method according to claim 23 , comprising:

sending an indication to start using dead reckoning to the target radio node.

27. The method according to claim 23 , wherein the obtaining of the location estimate by dead reckoning further comprises dynamically predicting the location estimate based on the displacement information and the reference point.

28. The method according to claim 23 , comprising:

obtaining a prediction result quality for the location estimate.

29. The method according to claim 28 , wherein the prediction result quality depends on one or more of the following parameters or characteristics:

a number of consecutive location estimates,

a time elapsed from the location estimate and/or the reference point,

a displacement characteristic or maneuver characteristic,

a quality of the reference point,

a quality of the displacement information, and

a type of the radio node.

30. A radio network node configured to obtain a location estimate, wherein the location estimate indicates a location of a target radio node, the radio network node comprising a processing circuit configured to:

obtain a reference point for the target radio node, wherein information associated with the obtained reference point comprises:

a location reference (loc_ref) of the target radio node;

a time (t_ref) when obtained the location reference (loc_ref) of the target node; and

obtain displacement information indicating displacement, in relation to the reference point, of the target radio node, wherein displacement information comprises:

a velocity (vel_est) of the target radio node; and,

a time (time_meas) when obtained the velocity (vel_meas) of the target radio node, wherein the time (time_meas) is carried by one of the following:

a systemFrameNumber field in an Observed Time Difference of Arrival (OTDOA) signal;

a measurementReferenceTime field in an Assisted Global Positioning System (AGPS) signal; or,

a systemFrameNumber field in an Evolved-Cell Identification (ECID) signal; and

wherein the processing circuit further is configured to enable at least one of the following:

send at least the displacement information to another network node, and/or

obtain the location estimate by dead reckoning based on the displacement information and the reference point by calculating the following:

a time displacement (td) = t _meas − t _ref; and,

the location estimate (loc_meas) =loc ref +vel_est * td.

31. A wireless device configured to obtain a location estimate, wherein the location estimate indicates a location of the wireless device, wherein the wireless device is operated to obtain the location estimate by use of functionality provided by a cellular telecommunication system, the wireless device comprising a processing circuit configured to:

obtain a reference point for the wireless device, wherein information associated with the obtained reference point comprises:

a location reference (loc_ref) of the target radio node;

a time (t_ref) when obtained the location reference (loc_ref) of the target node; and

obtain displacement information indicating displacement, in relation to the reference point, of the wireless device, wherein displacement information comprises:

a velocity (vel_est) of the target radio node; and,

a time (time_meas) when obtained the velocity (vel_meas) of the target radio node, wherein the time (time_meas) is carried by one of the following:

a systemFrameNumber field in an Observed Time Difference of Arrival (OTDOA) signal;

a measurementReferenceTime field in an Assisted Global Positioning System (AGPS) signal; or,

a systemFrameNumber field in an Evolved-Cell Identification (ECID) signal; and

wherein the processing circuit further is configured to enable at least one of the following:

send at least the displacement information to another network node, and/or and

obtain the location estimate by dead reckoning based on the displacement information and the reference point by calculating the following:

a time displacement (td) = t —l meas − t _ref; and,

the location estimate (loc_meas) =loc_ref +vel_est * td.

32. A positioning node configured to obtain a location estimate, wherein the location estimate indicates a location of a target radio node, the positioning node comprising a processing circuit configured to:

obtain a reference point for the target radio node, wherein information associated with the obtained reference point comprises:

a location reference (loc_ref) of the target radio node;

a time (t_ref) when obtained the location reference (loc_ref) of the target node;

obtain displacement information indicating displacement, in relation to the reference point, of the target radio node, wherein displacement information comprises:

a velocity (vel_est) of the target radio node; and,

a time (time_meas) when obtained the velocity (vel_meas) of the target radio node, wherein the time (time_meas) is carried by one of the following:

a systemFrameNumber field in an Observed Time Difference of Arrival (OTDOA) signal;

a measurementReferenceTime field in an Assisted Global Positioning System (AGPS) signal; or,

a systemFrameNumber field in an Evolved-Cell Identification (ECID) signal; and

obtain the location estimate by dead reckoning based on the displacement information and the reference point by calculating the following:

a time displacement (td) = t _meas − t _ref; and,

the location estimate (loc_meas) =loc_ref +vel_est * td.

33. The method according to claim 1 , wherein the location estimate (loc_meas) is obtained using the time (t_meas) carried by the systemFrameNumber field in the OTDOA signal, the method further comprises:

using the obtained location estimate (loc_meas) to estimate a timing error and location error of the radio network node, and

compensating for the estimated timing error and the estimated location error to enhance an accuracy of the obtained location estimate (loc_meas).

34. The method according to claim 1 , wherein the location estimate (loc_meas) is obtained using the time (t_meas) carried by the systemFrameNumber field in the ECID signal, the method further comprises:

pairing the obtained location estimate (loc_meas) with radio measurements to improve a quality of the information associated with the reference point.