Adaptive Enhanced Cell Identity Positioning

• US 20090117907A1
• Filed: 10/07/2005
• Published: 05/07/2009
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Wigren, Torbjorn
• Granted Patent: US 8,315,632 B2
• Time in Patent Office: Days
• 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

The present invention introduces methods and devices for provision of position determination assisting data as well as methods, devices and systems 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 (41). The cell relation configuration being 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 embodiments polygons, which preferably are re-calculated successively, automatically and on-line. The recalculations are based on high-precision position measurements of opportunity, clustered (42) 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:

establishing a cell relation configuration for a user equipment;

said cell relation configuration comprising at least cell identities of cells, in which signals to/from said user equipment fulfil at least a specific radio condition criterion when received;

performing a high-precision position determination for said user equipment;

repeating said establishing and performing steps a plurality of times;

clustering results of said high-precision position determinations belonging to the same cell relation configuration in separate clustered results;

associating an area definition with at least one of said clustered results;

creating position determination assisting data comprising a relation between said cell relation configurations and said associated area definitions.

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

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

4. The method according to claim 1, wherein said cell relation configuration further comprises an ordering of the comprised cell identities.

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

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

signal strength;

path loss; and

signal-to-interference ratio.

7. The method according to claim 1, wherein said associated area contains a predetermined percentage of said clustered results.

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

9. The method according to claim 8, wherein said associated area definition is a polygon.

10. The method according to any of the claims 1-7, wherein said associated area definition is a polygon.

11. The method according to claim 10, wherein said associating step in turn comprises the steps of:

encompassing at least one of said clustered results of said high-precision position determinations, belonging to one cell relation configuration by a polygon;

altering the position of corners of said polygon along predetermined paths to improve a predetermined criterion while maintaining at least a predetermined percentage of said high-precision position determinations of the cluster within the polygon.

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

13. The method according to claim 11, wherein said step of altering is repeated until another altering step would invalidate said predetermined percentage of high-precision position determinations of the clustered results within the polygon.

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

15. The method according to claim 11, wherein said predetermined criterion is an as large distance reduction as possible between the centre of gravity of all high-precision position determinations within the area and said altered corner.

16. The method according to claim 11, wherein said predetermined path is a curve through the original corner position and a centre of gravity for said high-precision position determinations of the clustered results within the polygon.

17. The method according to claim 16, wherein said curve is a straight line through the original corner position and a centre of gravity for said high-precision position determinations of the clustered results within the polygon.

18. The method according to claim 11, wherein said altering step comprises altering of one corner position at a time, allowing one of said high-precision position determinations of said clustered results to be placed outside said polygon, but not two of said high-precision position determinations.

19. The method according to claim 11, wherein more than one of said high-precision position determinations of said clustered results are allowed to be placed outside said polygon at least one of said altering steps.

20. The method according to claim 18, wherein said altering alters one corner position at a time and brings one of said high-precision measurements of said clustered results to be placed on a linear segment between the corner that is altered and a neighbouring corner.

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

22. The method according to claim 1, wherein, in said clustering step, said results of said high-precision position determinations to be clustered are selected according to a further criterion.

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

24. The method according to claim 23, further comprising the step of recording a measuring instant of said high-precision position determinations, whereby said further criterion is based on at least said measuring instant.

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

26. The method according to claim 24, wherein only results of said high-precision position determinations being 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 the step of recording a type of radio access bearer used during said high-precision position determinations, whereby said further criterion is based on at least said type of radio access bearer.

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

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

30. The method according to claim 29, wherein said 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 the step of storing the last achieved position determination assisting data at a computer readable medium.

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

33. A method for radio network planning, comprising the steps of:

obtaining position determination assisting data provided according to claim 1;

said step of performing a high-precision position determination being performed on demand; and

evaluating said 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 the steps of:

obtaining position determination assisting data provided according to claim 1;

establishing a cell relation configuration for said user equipment;

said cell relation configuration comprising at least cell identities of cells, in which signals to/from said user equipment fulfil at least a specific radio condition criterion when received; and

determining, by said position determination assisting data, an area definition related to said cell relation configuration as defining an area in which said user equipment is positioned.

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

providing at least one of auxiliary information about circumstances of signalling and auxiliary measurements of signalling properties;

whereby said step of determining an area definition is based also on said at least one of auxiliary information about circumstances of signalling and auxiliary measurements of signalling properties.

36. The method according to claim 34, wherein said area definition is a polygon.

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

determining an initial position of said user equipment according to claim 34; and

refining said initial position by a refined positioning method.

38. The method according to claim 37, wherein said refined positioning method is based on UTDOA measurements.

39. The method according to claim 37, wherein said refined positioning method is based on RTT measurements.

40. The method according to claim 37, wherein said refined positioning method is based on assisted GPS.

50. A computer readable medium 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:

means for establishing a cell relation configuration for a user equipment;

said cell relation configuration comprising at least cell identities of cells, in which signals to/from said user equipment fulfil at least a specific radio condition criterion when received;

means for performing a high-precision position determination for said user equipment;

means for clustering results of said high-precision position determinations belonging to the same cell relation configuration in separate clustered results; and

means for associating an area definition with at least one of said clustered results and creating position determination assisting data comprising a relation between said cell relation configurations and said associated area definitions.

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

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

means for establishing a cell relation configuration for said user equipment;

said cell relation configuration comprising at least cell identities of cells, in which signals to/from said user equipment fulfil at least a specific radio condition criterion when received; and

means for determining, by said position determination assisting data, an area definition related to said cell relation configuration as defining an area in which said user equipment is positioned.

43. The arrangement according to claim 42, further comprising:

means for refining said area in which said user equipment is positioned by a refined positioning method.

44. The arrangement according to claim 43, wherein said means for refining comprises means for performing a UTDOA positioning.

45. The arrangement according to claim 43, wherein said means for refining comprises means for performing a KIT positioning.

46. The arrangement according to claim 43, wherein said means for refining comprises assisted GPS means.

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

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

base station;

base station controller;

radio network controller;

service mobile location centre; and

stand alone service mobile location centre.

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