Femto-Cell Location by Proxy Methods

• US 20100120394A1
• Filed: 11/11/2008
• Published: 05/13/2010
• Est. Priority Date: 11/11/2008
• Status: Active Grant

• Current Assignee: Skyhook Holding, Inc. (Liberty Broadband Corp.)
• Original Assignee: TruePosition Incorporated
• Inventors: Anderson, Robert J., Mia, Rashidus S., Ward, Matthew L.
• Granted Patent: US 8,200,239 B2
• Time in Patent Office: Days
• US Class Current: 455/404.200
• CPC Class Codes: H04W 64/003 locating network equipment
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Location of small, consumer deployed femto-cells cannot be determined by the usual site survey methods. Location of attached mobiles allows for a proxy location of the femto-cell that can then be used for wireless network planning including the provisioning of a calculated default emergency services location for the femto-cell.

Claims

1. A method for use by a wireless location system (WLS) in locating a femto-cell device operating in a wireless communications system, comprising:

discovering and initiating location of the femto-cell device;

determining an identification of a mobile station (MS) being served by the femto-cell device;

determining the location of the MS; and

determining the location of the femto-cell device using the location of the MS.

2. A method as recited in claim 1, further comprising determining a distance separating the femto-cell device from the MS;

and calculating the location of the femto-cell device using the location of the MS and the distance separating the femto-cell from the MS.

3. A method as recited in claim 1, wherein the step of initiating location of the femto-cell device comprises receiving a command from the wireless communications system.

4. A method as recited in claim 1, wherein the step of initiating location of the femto-cell device comprises receiving a wireless intelligent network trigger based on cell-ID information broadcast by the femto-cell device.

5. A method as recited in claim 1, wherein the step of initiating location of the femto-cell device comprises detection of a new cell-ID.

6. A method as recited in claim 5, wherein the new cell-ID is detected by a radio network monitor (RNM) associated with the WLS.

7. A method as recited in claim 5, wherein the new cell-ID is detected by a link monitoring system (LMS) associated with the WLS.

8. A method as recited in claim 1, wherein the wireless communications system comprises, in addition to said femto-cell, a plurality of macro-cells and at least one micro-cell.

9. A method as recited in claim 8, wherein said femto-cell is an under-lay femto-cell situated within a radio footprint of a single macro-cell.

10. A method as recited in claim 8, wherein said femto-cell is a border femto-cell situated within the radio footprints of multiple macro-cells.

11. A method as recited in claim 8, wherein said femto-cell is a remote femto-cell situated outside the radio footprint and coverage areas of all macro-cells of the wireless communications system.

12. A method as recited in claim 1, wherein the WLS includes a serving mobile location center (SMLC), a plurality of location measuring units (LMUs) in communication with the SMLC, a plurality of link monitors in communication with the SMLC, and a database in communication with the SMLC and containing cell locations and other radio aspects of the wireless communications system.

13. A method as recited in claim 1, wherein the location of the MS is calculated by the MS and provided by the MS.

14. A method as recited in claim 13, wherein the MS is a Global Navigation Satellite System (GNSS)-capable device comprising a receiver capable of receiving GNSS satellite signals.

15. A method as recited in claim 1, wherein the location of the MS is calculated by a network-based wireless location system (WLS).

16. A method as recited in claim 15, wherein the location of the MS is determined using MS uplink transmissions during a handover procedure.

17. A method for use by a wireless location system (WLS) in locating a femto-cell device operating in a wireless communications system, wherein the WLS includes a serving mobile location center (SMLC), a plurality of location measuring units (LMUs) in communication with the SMLC, a plurality of link monitors in communication with the SMLC, and an SMLC database in communication with the SMLC and containing cell locations and other radio aspects of the wireless communications system, the method comprising:

(a) discovering and initiating location of the femto-cell device, wherein said discovering and initiating comprises at least one of the following procedures;

(a1) receiving femto-cell ID information from the wireless communications system;

(a2) discovery of the femto-cell ID information via analysis of call detail records; and

(a3) discovery of the femto-cell ID information via monitoring of wireless communications system link traffic for new cell-IDs within messages related to call events;

(b) storing femto-cell identification information in the SMLC database;

(c) setting a trigger for location of the femto-cell, wherein said setting a trigger comprises at least one of the following procedures;

(c1) setting a femto-cell cell-ID trigger in the SMLC database via a wireless intelligent network (WIN) facility;

(c2) setting an internal femto-cell cell-ID trigger in the SMLC database to indicate to the WLS that mobile station (MS) location information should be examined to identify when the femto-cell device is serving the MS;

(c3) setting a femto-cell cell-ID trigger in a radio network monitor (RNM) or link monitoring system (LMS) associated with the WLS, wherein the WLS is configured such that detection of the femto-cell cell-ID provokes the WLS to attempt location of the femto-cell device;

(d) determining an identification of a MS being served by the femto-cell device;

(e) determining the location of the MS and providing MS location information to SMLC database;

(f) calculating the location of the femto-cell device using the location of the MS;

(g) calculating a confidence factor relating to the calculated location of the femto-cell; and

(h) comparing the calculated confidence factor with a confidence factor stored in the SMLC database.

18. A method as recited in claim 17, further comprising determining that the calculated confidence factor is better than the stored confidence factor, and updating location information in the SMLC database.

19. A method as recited in claim 17, further comprising determining that the calculated confidence factor is better than the stored confidence factor, and notifying an operator of the wireless communications system of an error in the stored location information associated with the femto-cell device.

20. A method as recited in claim 17, further comprising determining that the calculated confidence factor is below a prescribed value and attempting to obtain a more accurate location of the femto-cell device.

21. A method as recited in claim 17, further comprising use of the femto-cell location for RF planning and coordination.

22. A method as recited in claim 21, wherein said RF planning and coordination includes preventing the femto-cell device from interfering with other cells when the femto-cell device is re-located.

23. A method as recited in claim 17, further comprising use of the femto-cell location for emergency services.

24. A method as recited in claim 17, further comprising use of the femto-cell location for warning, alert and response network (WARN) services.

25. A method as recited in claim 17, further comprising use of the femto-cell location for commercial location services.

26. A method as recited in claim 17, further comprising determining a distance separating the femto-cell device from the MS;

and calculating the location of the femto-cell device using the location of the MS and the distance separating the femto-cell from the MS.

27. A method as recited in claim 17, wherein the wireless communications system comprises, in addition to said femto-cell, a plurality of macro-cells and at least one micro-cell.

28. A method as recited in claim 27, wherein said femto-cell is an under-lay femto-cell situated within a radio footprint of a single macro-cell.

29. A method as recited in claim 27, wherein said femto-cell is a border femto-cell situated within the radio footprints of multiple macro-cells.

30. A method as recited in claim 27, wherein said femto-cell is a remote femto-cell situated outside the radio footprint and coverage areas of all macro-cells of the wireless communications system.

31. A method as recited in claim 17, wherein the location of the MS is calculated by the MS and provided by the MS.

32. A method as recited in claim 31, wherein the MS is a Global Navigation Satellite System (GNSS)-capable device comprising a receiver capable of receiving GNSS satellite signals.

33. A method as recited in claim 17, wherein the location of the MS is calculated by a network-based wireless location system (WLS).

34. A method as recited in claim 33, wherein the location of the MS is determined using MS uplink transmissions during a handover procedure.

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

a serving mobile location center (SMLC);

a plurality of location measuring units (LMUs) in communication with the SMLC;

a plurality of link monitors in communication with the SMLC;

an SMLC database in communication with the SMLC and containing cell locations and other radio aspects of the wireless communications system; and

means for locating a femto-cell device operating in the wireless communications system, including;

means for discovering and initiating location of the femto-cell device;

means for determining an identification of a mobile station (MS) being served by the femto-cell device;

means for determining the location of the MS; and

means for determining the location of the femto-cell device using the location of the MS.

36. A WLS as recited in claim 35, further comprising means for determining a distance separating the femto-cell device from the MS;

and calculating the location of the femto-cell device using the location of the MS and the distance separating the femto-cell from the MS.

37. A WLS as recited in claim 35, wherein the means for initiating location of the femto-cell device comprises means for receiving a command from the wireless communications system.

38. A WLS as recited in claim 35, wherein the means for initiating location of the femto-cell device comprises means for receiving a wireless intelligent network trigger based on cell-ID information broadcast by the femto-cell device.

39. A WLS as recited in claim 35, wherein the means for initiating location of the femto-cell device comprises means for detection of a new cell-ID.

40. A WLS as recited in claim 39, wherein the means for detection of a new cell-ID comprises a radio network monitor (RNM).

41. A WLS as recited in claim 39, wherein the means for detection of a new cell-ID comprises a link monitoring system (LMS).

42. A WLS as recited in claim 35, wherein the wireless communications system comprises, in addition to said femto-cell, a plurality of macro-cells and at least one micro-cell.

43. A WLS as recited in claim 35, wherein the location of the MS is calculated by the MS and provided by the MS.

44. A WLS as recited in claim 43, wherein the MS is a Global Navigation Satellite System (GNSS)-capable device comprising a receiver capable of receiving GNSS satellite signals.

45. A WLS as recited in claim 35, wherein the WLS is a network-based WLS.

46. A WLS as recited in claim 45, wherein the location of the MS is determined using MS uplink transmissions during a handover procedure.

47. A subsystem for use by a wireless location system (WLS) in locating a femto-cell device operating in a wireless communications system, wherein the WLS includes a serving mobile location center (SMLC), a plurality of location measuring units (LMUs) in communication with the SMLC, a plurality of link monitors in communication with the SMLC, and an SMLC database in communication with the SMLC and containing cell locations and other radio aspects of the wireless communications system, the subsystem comprising:

(a) means for discovering and initiating location of the femto-cell device, wherein said discovering and initiating comprises at least one of the following procedures;

(a1) receiving femto-cell ID information from the wireless communications system;

(a2) discovery of the femto-cell ID information via analysis of call detail records; and

(a3) discovery of the femto-cell ID information via monitoring of wireless communications system link traffic for new cell-IDs within messages related to call events;

(b) means for storing femto-cell identification information in the SMLC database;

(c) means for setting a trigger for location of the femto-cell, wherein said setting a trigger comprises at least one of the following procedures;

(c1) setting a femto-cell cell-ID trigger in the SMLC database via a wireless intelligent network (WIN) facility;

(c2) setting an internal femto-cell cell-ID trigger in the SMLC database to indicate to the WLS that mobile station (MS) location information should be examined to identify when the femto-cell device is serving the MS;

(c3) setting a femto-cell cell-ID trigger in a radio network monitor (RNM) or link monitoring system (LMS) associated with the WLS, wherein the WLS is configured such that detection of the femto-cell cell-ID provokes the WLS to attempt location of the femto-cell device;

(d) means for determining an identification of a MS being served by the femto-cell device;

(e) means for determining the location of the MS and providing MS location information to SMLC database;

(f) means for calculating the location of the femto-cell device using the location of the MS;

(g) means for calculating a confidence factor relating to the calculated location of the femto-cell; and

(h) means for comparing the calculated confidence factor with a confidence factor stored in the SMLC database.

48. A subsystem as recited in claim 47, further comprising means for determining that the calculated confidence factor is better than the stored confidence factor, and updating location information in the SMLC database.

49. A subsystem as recited in claim 47, further comprising means for determining that the calculated confidence factor is better than the stored confidence factor, and notifying an operator of the wireless communications system of an error in the stored location information associated with the femto-cell device.

50. A subsystem as recited in claim 47, further comprising means for determining that the calculated confidence factor is below a prescribed value and attempting to obtain a more accurate location of the femto-cell device.

51. A subsystem as recited in claim 47, further comprising means for determining a distance separating the femto-cell device from the MS;

and means for calculating the location of the femto-cell device using the location of the MS and the distance separating the femto-cell from the MS.

52. A subsystem as recited in claim 47, wherein the location of the MS is calculated by the MS and provided by the MS.

53. A subsystem as recited in claim 47, wherein the location of the MS is calculated by the WLS.

54. A WLS as recited in claim 53, wherein the location of the MS is determined using MS uplink transmissions during a handover procedure.