Multiple pass location processor

• US 20050024265A1
• Filed: 08/11/2004
• Published: 02/03/2005
• Est. Priority Date: 01/08/1999
• Status: Active Grant

• Current Assignee: Skyhook Holding, Inc. (Liberty Broadband Corp.)
• Original Assignee: TruePosition Incorporated
• Inventors: Anderson, Robert J., Ward, Matthew L., Stilp, Louis A.
• Granted Patent: US 7,023,383 B2
• Time in Patent Office: Days
• US Class Current: 342/465
• CPC Class Codes: G01S 1/026 of associated receivers
• CPC Class Codes: G01S 2205/06 Emergency
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0244 Accuracy or reliability of position solution or of measurements contributing thereto
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A multiple pass location processing method, for use in a wireless location system (WLS), comprises identifying a received transmission as requiring multiple pass location processing whereby the WLS produces a first, lower quality location estimate and then subsequently produces a second, higher quality location estimate. The WLS then produces the first location estimate and provides it to a first location application, and then produces the second location estimate. The second location estimate may be a more accurate estimate than the first location estimate and/or of a higher confidence than the first location estimate. This method is suitable, but not limited, for use in connection with locating a wireless transmitter involved in an emergency services call and routing the call to a call center.

Claims

1. A multiple pass location processing method for use in a wireless location system (WLS) capable of locating a wireless transmitter based on a transmission received from the wireless transmitter, comprising the steps of:

(a) producing a first location, lower quality location estimate and providing said first location estimate to a first location application; and

(b) subsequently producing a second location, higher quality location estimate for delivery to a second location application, wherein the second location application may be the same as the first location application or different from the first location application.

2. A method as recited in claim 1, wherein the second location estimate is a more accurate estimate than the first location estimate.

3. A method as recited in claim 1, wherein the second location estimate is of a higher confidence than the first location estimate.

4. A method as recited in claim 1, further comprising identifying a plurality of received transmissions as requiring multiple pass location processing.

5. A method as recited in claim 1, further comprising identifying one or more wireless transmitters as requiring multiple pass location processing.

6. A method as recited in claim 1, wherein the received transmission is identified as requiring multiple pass location processing based on the identity of the first location application.

7. A method as recited in claim 1, wherein the received transmission is identified as requiring multiple pass location processing based on a calling number of the wireless transmitter.

8. A method as recited in claim 1, further comprising identifying one or more location applications for which multiple pass location processing is required.

9. A method as recited in claim 1, wherein, in providing the first location estimate, the WLS selects a subset of the received transmission for use in providing a rough estimate of the location of the wireless transmitter.

10. A method as recited in claim 1, further comprising determining a priority level to be associated with location processing for the wireless transmitter.

11. A method as recited in claim 1, further comprising determining a time limit for signal collection for producing the first location estimate.

12. A method as recited in claim 1, further comprising determining a time limit for signal processing for producing the first location estimate.

13. A method as recited in claim 1, further comprising determining a time limit on total latency for providing the first location estimate.

14. A method as recited in claim 1, further comprising determining a signal power threshold.

15. A method as recited in claim 1, further comprising determining a time limit for delivery of a location estimate to the first location application.

16. A method as recited in claim 1, further comprising determining multiple location applications to which the first location estimate is to be provided.

17. A method as recited in claim 1, further comprising determining a time limit for signal collection for the second location estimate.

18. A method as recited in claim 1, further comprising determining a time limit for signal processing for the second location estimate.

19. A method as recited in claim 1, further comprising determining a time limit for total latency for the second location estimate.

20. A method recited in claim 1, further comprising determining a location accuracy threshold for the first location estimate.

21. A method as recited in claim 1, further comprising determining a velocity accuracy threshold for the first location estimate.

22. A method as recited in claim 1, wherein the second location estimate is independent of the first location estimate.

23. A method as recited in claim 1, wherein the first location estimate is used in deriving the second location estimate.

24. A method as recited in claim 1, wherein the first and second location estimates are derived in parallel.

25. A method as recited in claim 1, further comprising providing the second location estimate to the first location application.

26. A method as recited in claim 1, further comprising providing the second location estimate to a second location application, wherein the second location application is different from the first location application.

27. A method as recited in claim 1, further comprising providing multiple location estimates in step (b).

28. A method as recited in claim 1, wherein the first location estimate is provided with an information element identifying it as a lower quality estimate.

29. A method as recited in claim 1, wherein the second location estimate is provided with an information element identifying it as a higher quality estimate.

30. A multiple pass location processing method for use in a wireless location system (WLS) capable of locating a wireless transmitter involved in an emergency services call, based on a transmission received from the wireless transmitter, and routing the call to a call center, comprising the steps of:

(a) producing a first location, lower quality location estimate and providing said first location estimate to a first location application; and

(b) producing a second location, higher quality location estimate;

wherein the first location estimate is less accurate than the second location estimate but is sufficient for call routing purposes.

31. A wireless location system (WLS), comprising:

(a) a plurality of geographically separated receiver systems for receiving a transmission from a wireless transmitter;

(b) means for producing a first, lower quality location estimate;

(c) means for providing said first location estimate to a first location application;

(d) means for producing a second, higher quality location estimate; and

(e) means for providing said second location estimate to the first or a second location application.

32. A WLS as recited in claim 31, wherein the second location estimate is a more accurate estimate than the first location estimate.

33. A WLS as recited in claim 31, wherein the second location estimate is of a higher confidence than the first location estimate.

34. A WLS as recited in claim 31, further comprising means for identifying a plurality of received transmissions as requiring multiple pass location processing.

35. A WLS as recited in claim 31, further comprising means for identifying one or more wireless transmitters as requiring multiple pass location processing.

36. A WLS as recited in claim 31, wherein the received transmission is identified as requiring multiple pass location processing based on the identity of the first location application.

37. A WLS as recited in claim 31, wherein the received transmission is identified as requiring multiple pass location processing based on a calling number of the wireless transmitter.

38. A WLS as recited in claim 31, further comprising means for identifying one or more location applications for which multiple pass location processing is required.

39. A WLS as recited in claim 31, wherein, in providing the first location estimate, the WLS selects a subset of the received transmission for use in providing a rough estimate of the location of the wireless transmitter.

40. A WLS as recited in claim 31, further comprising means for determining a priority level to be associated with location processing for the wireless transmitter.

41. A WLS as recited in claim 31, further comprising means for determining a time limit for signal collection for producing the first location estimate.

42. A WLS as recited in claim 31, further comprising means for determining a time limit for signal processing for producing the first location estimate.

43. A WLS as recited in claim 31, further comprising means for determining a time limit on total latency for providing the first location estimate.

44. A WLS as recited in claim 31, further comprising means for determining a signal power threshold.

45. A WLS as recited in claim 31, further comprising means for determining a time limit for delivery of a location estimate to the first location application.

46. A WLS as recited in claim 31, further comprising means for determining multiple location applications to which the first location estimate is to be provided.

47. A WLS as recited in claim 31, further comprising means for determining a time limit for signal collection for the second location estimate.

48. A WLS as recited in claim 31, further comprising means for determining a time limit for signal processing for the second location estimate.

49. A WLS as recited in claim 31, further comprising means for determining a time limit for total latency for the second location estimate.

50. A WLS as recited in claim 31, further comprising means for determining a location accuracy threshold for the first location estimate.

51. A WLS as recited in claim 31, further comprising means for determining a velocity accuracy threshold for the first location estimate.

52. A WLS as recited in claim 31, wherein the second location estimate is independent of the first location estimate.

53. A WLS as recited in claim 31, wherein the first location estimate is used in deriving the second location estimate.

54. A WLS as recited in claim 31, wherein the first and second location estimates are derived in parallel.

55. A WLS as recited in claim 31, further comprising means for providing the second location estimate to the first location application.

56. A WLS as recited in claim 31, further comprising means for providing the second location estimate to a second location application, wherein the second location application is different from the first location application.

57. A WLS as recited in claim 31, further comprising means for providing multiple location estimates.

58. A WLS as recited in claim 31, wherein the first location estimate is provided with an information element identifying it as a lower quality estimate.

59. A WLS as recited in claim 31, wherein the second location estimate is provided with an information element identifying it as a higher quality estimate.

60. A WLS as recited in claim 31, wherein the WLS supports multiple pass location processing with multiple pass location records in which a flag is included to indicate a maximum time limit before which a particular application must receive a rough estimate of location and a second maximum time limit in which the same or another application must receive a final location estimate.

61. A WLS as recited in claim 31, wherein a flag is included in a location record to indicate the first pass or second pass status of the location estimate contained in the record.

62. A multiple pass location processing means for use in a wireless location system (WLS) capable of locating a wireless transmitter involved in an emergency services call, based on a transmission received from the wireless transmitter, and routing the call to a call center, comprising:

(a) means for producing a first location, lower quality location estimate and providing said first location estimate to a first location application; and

(b) means for producing a second location, higher quality location estimate;

wherein the first location estimate is less accurate than the second location estimate but is sufficient for call routing purposes.

63. A multiple pass location processing means as recited in claim 62, further comprising a means for identifying transmissions for which a first, lower quality estimate is required, including multiple pass location records in which a flag is included to indicate a maximum time limit before which a particular application must receive a rough estimate of location and a second maximum time limit in which the same or another application must receive a final location estimate.

64. A multiple pass location processing means as recited in claim 62, wherein a flag is included in a location record to indicate the first pass or second pass status of the location estimate contained in the record.

65. A wireless location system (WLS), comprising:

(a) a plurality of geographically separated receiver systems for receiving a transmission from a wireless transmitter; and

(b) a processor and executable instructions for producing a first, lower quality location estimate, and for subsequently producing a second, higher quality location estimate, wherein said first location estimate may be communicated to a first location application for call routing purposes.

66-86. -86. (Canceled).

87. A method for use in a Wireless Location System in locating a mobile transmitter involved in an emergency services call and routing the call to the correct call center using a first location attempt bounded by the time to produce a first timely but lower accuracy location estimate for routing and a second location estimate bounded by the accuracy required for the purposes of caller location.

88. A method as recited in claim 87, wherein a site density factor is employed in determining the amount of signal collection and/or signal processing to use to produce the first location estimate.

89. A method as recited in claim 87, wherein a site density factor is employed in determining the scheduling of receiver resources to use to produce the first location estimate.

90. A method as recited in claim 87, wherein a site density factor is employed in determining the amount of signal collection and/or signal processing to use to produce the second location estimate.

91. A method as recited in claim 90, wherein a site density factor is employed in determining the scheduling of receiver resources to use to produce the second location estimate.

92-99. -99. (Canceled).