Tracking location of mobile device in a wireless network

• US 9,197,996 B2
• Filed: 01/11/2012
• Issued: 11/24/2015
• Est. Priority Date: 11/19/2010
• Status: Active Grant

• Current Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Original Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Inventors: Sathyan, Thuraiappah, Hedley, Mark
• Primary Examiner(s): MIZRAHI, DIANE D
• Application Number:
  US13/885,881
• Publication Number:
  US 20140045518A1
• Time in Patent Office: 1,413 Days
• Field of Search: 342 52- 53, 342/107, 342/173, 375/136, 702/150, 702/181
• US Class Current: 1/1
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds

Abstract

A method and system for dynamically tracking the location of mobile nodes (104, 106, 108, 110_n) in a wireless network (102) is disclosed. The method comprises: for each mobile node, dynamically measuring the range between the mobile node and at least one neighboring node (step 202); and executing a Bayesian tracking algorithm for each mobile node (step 204). The algorithm has the measured range as an input, exchanges data with tracking algorithms for neighboring mobile nodes, and utilizes a statistical model of error in measured range and a statistical model of node motion to dynamically determine location.

Claims

1. A method for dynamically tracking the locations of mobile wireless devices in a wireless network, the method comprising the steps of:

dynamically measuring by each mobile wireless device the range between said mobile wireless device and at least one neighbouring wireless device;

transmitting by each mobile wireless device the respective range to a Bayesian tracking filter; and

executing, by said Bayesian tracking filter, a Bayesian tracking algorithm for each mobile wireless device, said algorithm having said measured range as an input, exchanging data with tracking algorithms for neighbouring mobile wireless devices, and utilising a statistical model of error in measured range and a statistical model of wireless device motion to dynamically determine location.

2. The method of claim 1, wherein said tracking algorithm determines location using a current data set and temporal tracking.

3. The method of claim 2, wherein said data includes wireless device location distribution information and said tracking algorithm uses a weighted least squares calculation to determine location.

4. The method of claim 3, wherein said tracking algorithm is implemented as a Kalman filter or interacting multiple models.

5. The method of claim 4, wherein said model of wireless device motion is nearly constant velocity.

6. The method of claim 1, wherein said tracking algorithm determines location directly using range measurements to neighbouring wireless devices and said range error model.

7. The method of claim 6, wherein said data includes location information and an uncertainty measure, and said tracking algorithm uses the range error model modified by neighbour wireless device location variance to determine location.

8. The method of claim 7, wherein said tracking algorithm is implemented as a particle filter or as interacting multiple model particle filters.

9. The method of claim 8, wherein said model of wireless device motion is nearly constant velocity.

10. The method of claim 1, wherein said statistical model of error in measured range is a likelihood function with constant positive value beyond the region of support, a plurality of motion models are used, and said wireless devices transmit data to an access point, and said tracking algorithm for at least some of said mobile wireless devices is executed via said access point.

11. The method of claim 1, wherein said neighbouring wireless devices each transceive data from each other, from which range is measured and location is determined, and wherein each said tracking algorithm is implemented on a respective said wireless device.

12. A wireless tracking system comprising:

a plurality of mobile wireless devices, each said mobile device including a transmission circuit for the sending data as radio signals, and a range estimation module for dynamically measuring the range between said device and at least one neighbouring device; and

a plurality of anchor wireless devices, each said anchor device being at a known location and including a range estimation circuit for dynamically measuring the range between said anchor device and at least one neighbouring device; and

a Bayesian tracking filter for each said mobile device for receiving said measured range as an input and exchanging data with tracking algorithms for neighbouring mobile nodes, said tracking filter utilising a statistical model of error in measured range and a statistical model of node motion to dynamically determine location.

13. The system of claim 12, wherein each mobile wireless device includes computational circuitry to implement the respective tracking filter, and said transmitter circuit additionally operates as a transceiver for exchanging data with neighbouring mobile devices.

14. The system of claim 13, wherein said tracking filters directly determine location using range measurements to neighbouring modes.

15. The system of claim 14, wherein said data includes location information and said tracking filters use the range error model directly or modified by neighbour node location variance to determine location.

16. The system of claim 15, wherein said tracking filters are implemented as particle filters or as interacting multiple model particle filters.

17. The system of claim 16, wherein said model of node motion is nearly constant velocity, wherein said model of error in measured range is a likelihood function with constant positive value beyond the region of support, and wherein a plurality of motion models are used in each tracking filter.

18. The system of claim 13, wherein each said tracking filter determines location using a current data set and temporal tracking.

19. The system of claim 18, wherein said data includes location distribution information and said tracking filters use a weighted least squares calculation to determine location.

20. The system of claim 19, wherein said tracking filters are implemented as a Kalman filter or as interacting multiple models.

21. The system of claim 20, wherein said model of node motion is nearly constant velocity.

22. The system of claim 12, wherein each mobile wireless device transmits range measurements to another computational device that executes the tracking filter for said mobile node and wherein each mobile wireless device transmits range measurements to one of a plurality of access points, and wherein said tracking filters are accessed via said access points.

23. A mobile wireless device comprising:

a transceiver circuit for sending and receiving data to neighbouring said mobile devices;

a range estimation module for dynamically measuring the range between said device and at least one neighbouring device; and

a Bayesian tracking filter that receives said measured range as an input and exchanges data with tracking algorithms for neighbouring mobile nodes, and utilises a statistical model of error in measured range and a statistical model of node motion to dynamically determine location.

24. The device of claim 23, wherein each said tracking filter determines location using a current data set and temporal tracking.

25. The device of claim 24, wherein said data includes location distribution information and said tracking filters use a weighted least squares calculation to determine location.

26. The device of claim 25, wherein said tracking filters are implemented as a Kalman filter or as interacting multiple models.

27. The device of claim 26, wherein said model of node motion is nearly constant velocity.

28. The device of claim 23, wherein said tracking filters directly determine location using range measurements to neighbouring modes.

29. The device of claim 28, wherein said data includes location information and said tracking filters use the range error model directly or modified by neighbour node location variance to determine location.

30. The device of claim 29, wherein said tracking filters are implemented as particle filters or interacting multiple model particle filters.

31. The device of claim 30, wherein said model of node motion is nearly constant velocity, wherein said model of error in measured range is a likelihood function with constant positive value beyond the region of support, and wherein at least two motion models are used in each tracking filter.

32. A mobile wireless device comprising:

a range estimation module for dynamically measuring the range between said device and said neighbouring devices; and

a transmitter circuit for sending measured ranges to a separate device having a Bayesian tracking filter for said mobile device, said Bayesian tracking filter utilising a statistical model of error in measured range and a statistical model of node motion to dynamically determine a location of said mobile device.