Method and apparatus for geolocation estimates in wireless networks

• US 7,224,983 B2
• Filed: 01/08/2003
• Issued: 05/29/2007
• Est. Priority Date: 01/08/2003
• Status: Active Grant

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Calin, Doru, Ji, Tingfang, Budka, Kenneth C.
• Primary Examiner(s): Feild; Joseph
• Assistant Examiner(s): NGUYEN, KHAI MINH
• Application Number:
  US10/338,222
• Publication Number:
  US 20040203912A1
• Time in Patent Office: 1,602 Days
• Field of Search: 4554561-4566, 455/422.1, 455/420, 455/440, 455/67.11, 455/39, 455/457, 455/421, 370328-338
• US Class Current: 455/456.1
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method and apparatus for increasing the accuracy and reliability of geolocation estimates for wireless communication networks devices includes calculating a geolocation estimate of a wireless communication device for a plurality of time periods, and selecting from the plurality of calculated geolocation estimates, a most reliable geolocation estimate of the wireless communication device.

Claims

1. A method, comprising:

calculating a plurality of geolocation estimates of a wireless communication device for a plurality of time periods, wherein each geolocation estimate comprises a position estimate and a reliability metric associated with said position estimate, wherein said reliability metric is determined using a number of base stations from which a pilot signal was received during said time period; and

selecting from said plurality of calculated geolocation estimates a most reliable geolocation estimate of said wireless communication device.

2. The method of claim 1, wherein said most reliable geolocation estimate comprises the geolocation estimate having associated with it the pilot signals with the greater signal strengths relative to the other detected base station pilot signals.

3. The method of claim 1, wherein said wireless communication device is a mobile telecommunications device.

4. The method of claim 1, wherein said calculating comprises:

subjecting information received from said wireless communication device to a positioning technique to determine thereby a range and direction of said wireless communication device relative to at least one base station;

said information received from said wireless communication device comprising detected pilot signal measurements from said at least one base station.

5. The method of claim 4, wherein information regarding respective locations of the detected base stations is stored in said wireless communication device and used to determine said range and direction.

6. The method of claim 5, wherein said information regarding the respective locations of the detected base stations is transmitted to said wireless communication device by a network system controller.

7. The method of claim 4, wherein said positioning technique comprises an Observed Time Difference of Arrival (OTDOA) technique.

8. The method of claim 4, wherein a Round Trip Time (RTT) measurement is used in conjunction with said positioning technique to increase the geolocation accuracy.

9. The method of claim 1, wherein system manipulation techniques are used to increase the accuracy and reliability of geolocation estimates.

10. The method of claim 9, wherein said system manipulation techniques comprise power management techniques, said power management techniques comprising at least one of exploiting departures of other calls, delaying of call initiations, forcing reduction of power for some calls, interruption and postponement of some ongoing calls, handling multiple geolocation requests, and cooperative user behavior.

11. A method, comprising:

receiving information from a wireless communication device, said information comprising measurements taken by said wireless communication device of detected pilot signals from at least one base station;

determining a time interval in which said wireless communication device continues to take measurements when fewer than three (3) base stations are detected by said wireless communication device;

selecting a most reliable measurement taken by said wireless communication device among the measurements taken by said wireless communication device when fewer than three (3) base stations are detected by said wireless communication device; and

calculating a geolocation estimate of said wireless communication device using said selected most reliable measurement.

12. The method of claim 11, wherein said most reliable measurement is a measurement comprising the pilot signals with the greater signal strengths relative to the other detected pilot signals.

13. The method of claim 11, wherein said wireless communication device is a mobile telecommunications device.

14. The method of claim 11, wherein said calculating comprises:

subjecting said selected measurement to a positioning technique to determine thereby a range and direction of said wireless communication device relative to at least one base station.

15. The method of claim 14, wherein information regarding the location of the detected base stations is stored in said wireless communication device and used to determine said range and direction.

16. The method of claim 15, wherein said information regarding the location of the detected base stations is transmitted to said wireless communication device by a network system controller.

17. The method of claim 14, wherein said positioning technique is an Observed Time Difference of Arrival (OTDOA) technique.

18. The method of claim 14, wherein a Round Trip Time (RTT) measurement is used in conjunction with said positioning technique to increase the geolocation accuracy.

19. The method of claim 11, wherein system manipulation techniques are used to increase the accuracy and reliability of geolocation estimates.

20. The method of claim 19, wherein said system manipulation techniques comprise power management techniques, said power management techniques comprising at least one of exploiting departures of other calls, delaying of call initiations, forcing reduction of power for some calls, interruption and postponement of some ongoing calls, handling multiple geolocation requests, and cooperative user behavior.

21. The method of claim 11, further comprising:

performing a triangulation operation to calculate a geolocation estimate of said wireless communication device when three (3) or more pilot signals from different base stations are detected by said wireless communication device.

22. An apparatus, comprising:

a geolocation estimator, for calculating geolocation estimates of a wireless communication device for a plurality of time periods, wherein each geolocation estimate comprises a position estimate and a reliability metric associated with said position estimate, wherein said reliability metric is determined using a number of base stations from which a pilot signal was received during said time period; and

a joint decision geolocation estimator (JDGE), said JDGE comprising a memory for storing information and program instructions, and a processor for executing said instructions, said JDGE configured to select, from said plurality of calculated geolocation estimates, a roost reliable geolocation estimate of said wireless communication device.

23. The apparatus of claim 22, wherein said plurality of geolocation estimates are stored in the memory of said JDGE.

24. The apparatus of claim 22, wherein said geolocation pre-estimator is a conventional estimator.

25. An apparatus, comprising:

a joint decision geolocation estimator (JDGE), said JDGE comprising a memory for storing information and program instructions, and a processor for executing said instructions, said JDGE configured for;

receiving information from a wireless communication device, said information comprising measurements taken by said wireless communication device of detected pilot signals from at least one base station;

determining a time interval in which said wireless communication device continues to take measurements when fewer than three (3) base stations are detected by said wireless communication device; and

selecting a most reliable measurement taken by said wireless communication device among the measurements taken by said wireless communication device when fewer than three (3) base stations are detected by said wireless communication device; and

a geolocation estimator, said geolocation estimator operable for calculating a geolocation estimate of said wireless communication device using said selected most reliable measurement.

26. The apparatus of claim 25, wherein said apparatus is further configured for:

performing a triangulation operation to calculate a geolocation estimate of said wireless communication device when three (3) or more pilot signals from different base stations are detected by said wireless communication device.

27. The apparatus of claim 25, further comprising a queuing facility to store the geolocation requests that need to be processed within said time interval.