Adaptive enhanced cell identity positioning

• US 8,315,632 B2
• Filed: 10/07/2005
• Issued: 11/20/2012
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Wigren, Torbjörn
• Primary Examiner(s): Patel, Nimesh
• Application Number:
  US11/992,920
• Publication Number:
  US 20090117907A1
• Time in Patent Office: 2,601 Days
• Field of Search: 455/440, 455/456.1, 455/433, 455/446, 342/457, 342/465
• US Class Current: 455/440
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Position determination assisting data is provided for performing position determinations based on this assisting data. The position determination assisting data comprises area definitions, each of which being related at least to a respective cell relation configuration. The cell relation configuration is determined at least by cell-IDs of cells fulfilling a specific radio condition criterion when received. Preferably, the cell relation configuration is also dependent on relative radio conditions between different cells and/or transmission mode. The area definitions are in particular example embodiments polygons, which preferably are re-calculated successively, automatically and on-line. The recalculations are based on high-precision position measurements of opportunity, clustered at least with respect to prevailing cell relation configuration for that user equipment performing the high-precision position measurements. Preferably, the area definitions are calculated with a predefined confidence level.

Claims

1. A method for providing position determination assisting data in a cellular communications network, comprising the steps of:

receiving from each of multiple user equipments (UEs) having a global positioning system (GPS) receiver repeated determinations of a cell relation configuration and a measured high precision, GPS position of the UE, wherein the GPS position of the UE is determined using the UE'"'"'s GPS receiver,

wherein the cell relation configuration for each UE includes at least cell identity information of cells in which radio signals to or from the UE fulfill at least a specific radio condition criterion,

forming, in a network node, for one or more of the cell relation configurations a cluster listing multiple ones of the measured high-precision, GPS positions having that cell relation configuration,

wherein each cluster listing of measured high-precision, GPS positions identifies a specific geographic area;

deterministically associating, in a network node, an area definition that defines a geographic location area polygon in the cellular communications network for multiple ones of the cluster listings, wherein the area definition is associated with a confidence value; and

creating a database of position determination assisting data that specifies a relation between each of the multiple ones of the cell relation configurations and its deterministically associated area definition.

2. The method according to claim 1, wherein the specific radio condition criterion is one that is used in at least one of soft handover and softer handover.

3. The method according to claim 1, wherein the specific radio condition criterion is that the radio signal enables identification of the cell of the transmitting/receiving node.

4. The method according to claim 1, wherein the cell relation configuration further comprises an ordering of cell identities included in the cell identity information.

5. The method according to claim 4, wherein the ordering is associated with a signal-strength related quantity.

6. The method according to claim 5, wherein the signal-strength related quantity is selected from:

signal strength, path loss, and signal-to-interference ratio.

7. The method according to claim 1, wherein the area definition contains a predetermined percentage of the measured high-precision, GPS positions.

8. The method according to claim 7, wherein an area measure of the area definition is minimized.

9. The method according to claim 1, wherein the confidence value is determined from the number of high precision GPS positions in the associated cluster list and a pre-specified parameter.

10. The method according to claim 1, wherein the polygon is a polygon determined using a shrinking polygon algorithm, and wherein the associated confidence value is determined using the shrinking polygon algorithm.

11. The method according to claim 1, wherein the deterministic associating comprises:

encompassing each cluster list of the measured high-precision, GPS positions by its associated polygon;

altering positions of corners of the polygon along predetermined paths to improve a predetermined criterion while maintaining at least a predetermined percentage of the measured high-precision, GPS positions of the cluster within the polygon.

12. The method according to claim 11, wherein the improvement is an optimization of a current altering step.

13. The method according to claim 11, wherein the altering step is repeated until another altering step would invalidate the predetermined percentage of measured high-precision, GPS positions of the cluster list within the polygon.

14. The method according to claim 11, wherein the predetermined criterion is an as-large-an-area reduction of the polygon as possible.

15. The method according to claim 11, wherein the predetermined criterion is an as-large-a-distance reduction as possible between a center of gravity of all measured high-precision, GPS positions within the area definition and the altered corners.

16. The method according to claim 11, wherein the predetermined path is a curve through an original corner position and a center of gravity for the measured high-precision, GPS positions of the cluster list within the polygon.

17. The method according to claim 16, wherein the curve is a straight line through the original corner position and the center of gravity.

18. The method according to claim 11, wherein the altering comprises altering of one corner position at a time, allowing one but not two of the measured high-precision, GPS positions of the cluster list to be placed outside the polygon.

19. The method according to claim 18, wherein the altering alters one corner position at a time and brings one of the measured high-precision, GPS positions of the cluster list to be placed on a linear segment between the corner that is altered and a neighboring corner.

20. The method according to claim 11, wherein more than one of the measured high-precision, GPS positions of the cluster list are allowed to be placed outside the polygon.

21. The method according to claim 11, wherein the position of the corner of the polygon is tentatively altered along more than one predetermined path and the predetermined path is selected as the path giving the best results according to the predetermined criterion.

22. The method according to claim 1, wherein the measured high-precision, GPS positions to be clustered are selected according to a further criterion.

23. The method according to claim 22, wherein the further criterion is based on at least one of auxiliary information about circumstances of signaling and auxiliary measurements of signaling properties.

24. The method according to claim 23, further comprising the step of recording a measuring instant of the measured high-precision, GPS positions, wherein the further criterion is based on at least the measuring instant.

25. The method according to claim 24, wherein only results of the high-precision position determinations younger than a predetermined age are clustered.

26. The method according to claim 24, wherein only the measured high-precision, GPS positions measured during one or several predetermined time periods of a day, week, or year are clustered.

27. The method according to claim 23, further comprising recording a type of radio access bearer used during the high-precision, GPS position measurements, wherein the further criterion is based on at least the type of radio access bearer.

28. The method according to claim 23, further comprising recording a round trip time for a radio signal with respect to a particular base station, wherein the further criterion is based on at least the round trip time.

29. The method according to claim 1, wherein the forming, associating, and creating steps are performed continuously or intermittently.

30. The method according to claim 29, wherein the clustering, associating and creating steps are performed for at least one of possible cell relation configurations.

31. The method according to claim 30, further comprising storing a last measured high-precision, GPS position in a non-transitory, computer-readable memory.

32. The method according to claim 1, wherein the forming, associating, and creating steps are performed when a position determination is requested.

33. A method for radio network planning, comprising:

obtaining position determination assisting data provided according to claim 1,

wherein the high-precision, GPS position measurements are performed on demand, and

evaluating the position determination assisting data regarding actual radio propagation.

34. A method for determining a position of a user equipment in a cellular communications network, comprising:

obtaining position determination assisting data provided according to claim 1, and

determining, based on the position determination assisting data, an area definition defining a geographic area in which the user equipment is positioned.

35. The method according to claim 34, further comprising:

providing at least one of auxiliary information about circumstances of signaling and auxiliary measurements of signaling properties,

wherein the area definition is based also on the at least one of auxiliary information about circumstances of signaling and auxiliary measurements of signaling properties.

36. A method for determining a position of a user equipment in a cellular communications network, comprising:

determining an initial position of the user equipment according to claim 34, and

refining the initial position by a refined positioning method.

37. The method according to claim 36, wherein the refined positioning method is based on UTDOA measurements, on RTT measurements, or on assisted GPS.

38. The method according to claim 1, wherein the high-precision, GPS position measurements are assisted-GPS (A-GPS) measurements.

39. The method according to claim 1, wherein each of the high precision, GPS position measurements is a measurement of opportunity.

40. A non-transitory computer-readable memory device comprising position determination assisting data provided according to claim 1.

41. An arrangement for providing position determination assisting data in a cellular communications network, comprising:

a receiver configured to receive from each of multiple user equipments (UEs) having a global positioning system (GPS) receiver repeated determinations of a cell relation configuration and a measured high precision, global positioning system (GPS) position of the UE,

wherein the cell relation configuration for each UE includes at least cell identity information of cells in which radio signals to or from the UE fulfill at least a specific radio condition criterion, and

computer apparatus configured to;

form for one or more cell relation configurations a cluster listing multiple ones of the measured high-precision, GPS positions having that cell relation configuration,

wherein each cluster listing of measured high-precision, GPS positions identifies a specific geographic area;

deterministically associate an area definition that defines a geographic location area polygon in the cellular communications network for multiple ones of the cluster listings, wherein the area definition is associated with a confidence value; and

create a database of position determination assisting data that specifies a relation between each of the multiple ones of the cell relation configurations and its deterministically associated area definition.

42. An arrangement for determining a position of a user equipment in a cellular communications network, comprising:

an arrangement for obtaining position determination assisting data according to claim 41;

the computer apparatus being configured to determine, based on the position determination assisting data, an area definition defining a geographic area in which the user equipment is positioned.

43. The arrangement according to claim 42, wherein the computer apparatus is configured to refine the area in which the user equipment is positioned by a refined positioning method.

44. The arrangement according to claim 43, wherein the computer apparatus is configured to perform a UTDOA positioning.

45. The arrangement according to claim 42, wherein the high-precision, GPS position measurements are assisted-GPS (A-GPS) measurements, and wherein each of the high precision, GPS position measurements is a measurement of opportunity.

46. A node of a cellular communications network comprising an arrangement according to claim 42.

47. The node according to claim 46, being a node selected from the list of:

base station;

base station controller;

radio network controller;

service mobile location center; and

stand alone service mobile location center.

48. A cellular communications network, comprising an arrangement according to claim 42.