Position detection and location tracking in a wireless network

• US 6,674,403 B2
• Filed: 09/05/2002
• Issued: 01/06/2004
• Est. Priority Date: 09/05/2001
• Status: Expired due to Term

• Current Assignee: Trapeze Networks Incorporated (Juniper Networks Incorporated)
• Original Assignee: Newbury Networks, Inc. (Juniper Networks Incorporated)
• Inventors: Peden, Jeffrey J. II, Gray, Matthew K., Chery, Yonald
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Mull, Fred H.
• Application Number:
  US10/235,338
• Publication Number:
  US 20030043073A1
• Time in Patent Office: 488 Days
• Field of Search: 342/463, 342/465, 342/453, 455/456, 455/457
• US Class Current: 342/463
• CPC Class Codes: G01S 5/0215 Interference
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method for performing real-time position detection and motion tracking of mobile communications devices moving about in a defined space comprised of a plurality of locales is provided. A plurality of access points are disposed about the space to provide an interface between mobile devices and a network having functionality and data available or accessible therefrom. Knowledge of adjacency of locales may be used to better determine the location of the mobile device as it transitions between locales and feedback may be provided to monitor the status and configuration of the access points.

Claims

1. A wireless device location and tracking system, comprising:

A. a network, including a plurality of uniquely identified network devices linked to one or more computing device coupled to a set of storage devices, wherein said network devices are configured to determine the signal strength of transmissions of a wireless device and for each network device there is defined an associated signal strength model;

B. area data stored within said set of storage devices and defining an area comprised of a set of defined locales; and

C. a location module coupled to said network and configured to;

1) create and maintain a state diagram related to said wireless device, wherein each state in said state diagram corresponds to at least one of said set of locales; and

2) determine a present location of said wireless device as a funtion of a correlation between a set of passively received signal strength data obtained from the wireless device, at least one signal strength model and a prior state of said wireless device.

2. A system as in claim 1, further comprising at least one application subsystem coupled to said network and including one or more applications, whrein said location module is further configured to:

3) selectively allow access by said wireless device to said one or more applications as a function of the present location of said wireless device.

3. A system as in claim 1, wherein said location module is further configured to:

3) selectively allow access by said data in said storage devices as a function of the present location of said wireless device.

4. A system as in claim 1, wherein said network includes a wireless locale area network.

5. A system as in claim 1, wherein said area data includes a digital definition of the area, including physical obstructions located therein.

6. A system as in claim 1, wherein said area data includes a statistical signal strength model correlated to said area.

7. A system as in claim 6, wherein said statistical signal strength model includes a pattern of signal strength data anticipated from a mobile device transmitting within the area.

8. A system as in claim 6, wherein at least a portion of the signal strength data used to generate said statistical signal strength model is data from said network devices.

9. A system as in claim 1, wherein said location module is further configured to compare said signal strength data against a signal strength model.

10. A system as in claim 1, further comprising:

D. a tracking module configured to track the wireless device as a function of a plurality of present locations determined over time.

11. A wireless device location and tracking system, comprising:

A. a network, including a plurality of uniquely identified network devices linked to one or more computing device coupled to a set of storage devices, wherein said network devices are configured to determine the signal strength of transmissions of a wireless device and for each network device there is defined an associated signal strength model;

B. area data stored within said set of storage devices and defining an area comprised of a set of defined locales, wherein each locale includes at least one network device; and

C. a location and tracking module coupled to said network and configured to determine a locale of said wireless device within the set of defined locales as a function of correlation between a set of received signal strength indicator (RSSI) values derived from passively sensed signal strength data obtained from the wireless device and from at least one signal strength model,

wherein said location and tracking module is configured to determine said location without data processing or message generation by said wireless device.

12. A wireless device location system, comprising:

A. a network, including a plurality of uniquely identified network devices linked to one or more computing device coupled to a set of storage devices, wherein said network devices are configured to determine the signal strength of transmissions of a wireless device and for each network device there is defined an associated signal strength model;

B. area data stored within said set of storage devices and defining an area comprised of a set of defined locales; and

C. a location module coupled to said network, comprising;

1) a clustering module, configured to apply pattern recognition to dynamically changing signal strength data derived from transmissions from said wireless device;

2) a trilateration module, configured to determine distances of said wireless device from a plurality of said network devices as a function of said dynamically changing signal strength data; and

3) a location determination module, configured to determine a present location of said wireless device as a function of said pattern recognition and said distances.

13. A system as in claim 12, further comprising:

D. a tracking module configured to track the wireless device as a function of determination of a plurality of present locations over time.

14. A wireless device location system, comprising:

A. a network, including a plurality of network devices linked to one or more computing device coupled to a set of storage devices, wherein said network devices are configured to determine the signal strength of transmissions of a wireless device and for each network device there is defined an associated signal strength model, and wherein said set of storage devices includes network device data uniquely identifying each of said network devices;

B. area data stored within said set of storage devices and defining an area comprised of a set of defined locales, wherein each locale includes at least one network device; and

C. a location module coupled to said network and configured to determine a locale of said wireless device within the set of locales as a function of a correlation between a set of received signal strength indicator (RSSI) values derived from passive signal strength data obtained from the wireless device and from at least one signal strength model, said module comprising;

1) an RSSI module, configured to apply pattern recognition to dynamically changing signal strength data derived from passively sensed transmissions from said wireless device; and

2) a feedback module, coupled between an output of said RSSI module and said set of storage devices, wherein said feedback module is configured to verify that network devices receiving the signal data correspond to the network device data in said set of storage devices.

15. A system as in claim 14, further comprising:

D. a tracking module configured to track the wireless device as a function of determination of a plurality of present locations over time.

16. A method of locating a wireless device in an area including a plurality of network devices linked via a network to one of more computing devices and a set of storage devices, wherein for each network device there is a defined signal strength model, said method comprising:

A. defining a set of locales within said area and representing said locales as area data within said set of storage devices;

B. defining a state diagram representing said locales;

C. determining signal strength data from said wireless device by one of more of said network devices, without data processing or message generation by said wireless device;

D. determining a prior state, if any, of said wireless device as a function of said diagram and said signal strength data; and

E. determining a present location of said wireless device as a function of said prior state, at least one signal strength model and said signal strength data.

17. A method as in claim 16, wherein said computing devices include at least one application subsystem coupled to said network and including one or more application, said method further comprising:

F. selectively allowing access by said wireless device to said one or more applications as a function of the present location of said wireless device.

18. A method as in claim 16, further comprising:

F. selectively allowing access to data in said storage devices as a function of the present location of said wireless device.

19. A method as in claim 16, further comprising:

F. tracking said wireless device by determining a plurality of present locations over time.

20. A method as in claim 16, wherein part A includes defining said area data to include a digital definition of the area, including physical obstructions located therein.

21. A method as in claim 16, wherein part A includes generating a statistical signal strength model correlated to said area.

22. A method as in claim 21, wherein generating said statistical signal strength model includes defining a pattern of signal strength data anticipated from a mobile device transmitting within the area.

23. A method as in claim 21, wherein generating said statistical signal strength model is accomplished using data from said network devices.

24. A method as in claim 16, further comprising, in part E, comparing said signal strength data against a signal strength model to determine said present location of said wireless device.

25. A method of locating a wireless device in an area including a plurality of network device linked via a network to one or more computing devices and a set of storage devices, said method comprising:

A. defining a set of locales within said area and representing said locales as area data within said set of storage devices;

B. defining a received signal strength indicator (RSSI) model for each network device in said area, and stoning each RSSI model in said set of storage devices;

C. determining RSSI data from said wireless device by one or more of the network devices, without data processing or message generation by said wireless device;

D. determining by said computing devices a present location of the wireless device as a function of a comparison between the RSSI model and the RSSI data.

26. A method as in claim 25, further comprising:

E. tracking said wireless device by determining a plurality of present locations over time.

27. A method of locating a wireless device in an area including a plurality of network devices linked via a network to one or more computing devices and a set of storage devices, said method comprising:

A. defining a set of locales within said area and representing said locales as area data within said set of storage devices;

B. applying pattern recognition to dynamically changing signal strength data derived from transmissions from the wireless device;

C. determining the distances of said wireless device from a plurality of the network devices, as a function of said dynamically changing signal strength data; and

D. determining a present location of said wireless device as a function of said distances.

28. A method as in claim 27, wherein network device data uniquely identifying each network device is represented in said storage devices, said method further comprising:

E. providing feedback of said signal strength data received by one more of said network devices; and

F. verifying that network devices receiving signal strength data correspond to network devices represented by said network device data, using the feedback of said signal strength data.

29. A method as in claim 27, further comprising:

E. tracking said wireless device by determining a plurality of present locations over time.