Correlating Multiple Detections of Wireless Devices Without a Unique Identifier

• US 20090327333A1
• Filed: 06/30/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hart, Brian Donald, Sugar, Gary L., Diener, Neil R., Kloper, David, Gutkin, Igal
• Granted Patent: US 8,369,305 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

At a plurality of first devices, wireless transmissions are received at different locations in a region where multiple target devices may be emitting. Identifier data associated with reception of emissions from target devices at multiple first devices is generated. Similar identifier data associated with received emissions at multiple first devices are grouped together into a cluster record that potentially represents the same target device detected by multiple first devices. Data is stored that represents a plurality of cluster records from identifier data associated with received emissions made over time by multiple first devices. The cluster records are analyzed over time to correlate detections of target devices across multiple first devices.

Claims

1. A method comprising:

at a plurality of first devices, receiving wireless energy at different locations in a region where multiple target devices may be emitting;

generating identifier data associated with reception of emissions from target devices at multiple first devices;

grouping together similar identifier data associated with received emissions at multiple first devices into a cluster record that potentially represents the same target device detected by multiple first devices;

storing data representing a plurality of cluster records from identifier data associated with received emissions made over time by multiple first devices.

2. The method of claim 1, wherein grouping comprises comparing identifier data associated with detected target device emissions at multiple first devices.

3. The method of claim 2, wherein comparing comprises comparing identifier data generated by only those first devices which are determined to be capable of receiving transmissions from the same target device.

4. The method of claim 2, wherein comparing comprises comparing identifier data associated with detected target device emissions which are received within a time range of each other at multiple first devices.

5. The method of claim 2, wherein generating identifier data comprises generating, depending on a particular received emission, one or more of:

a unique identifier of the target device if contained in the received emission;

a semi-unique identifier of one or more target devices of a particular type if contained in the received emission;

a synchronization word associated with the received emission;

radio frequency characteristics associated with the received emission including bandwidth and center frequency;

modulation type of the received emission; and

device type if determined for the received emission.

6. The method of claim 5, wherein comparing comprises comparing the device type information contained in the identifier data from multiple first devices, and comparing additional information contained in the identifier data from multiple first devices only for identifier data containing the same device type or for identifier data containing a device type that could be reasonably incorrectly identified as a different device type based on radio frequency characteristics detected by different first devices.

7. The method of claim 6, wherein comparing additional information comprises comparing select information in the identifier data depending on device type.

8. The method of claim 1, wherein analyzing the cluster records comprises designating one identifier data of a cluster record as being the representative identifier data for the cluster record.

9. The method of claim 8, wherein designating comprises designating the identifier data that has the strongest received signal strength or signal-to-noise ratio as said representative identifier data for the cluster record

10. The method of claim 8, wherein analyzing comprises comparing the representative identifier data for multiple cluster records and merging together identifier data for multiple cluster records whose representative identifier data are substantially similar.

11. The method of claim 8, wherein analyzing comprises changing the representative identifier data for a cluster based on newly generated identifier data.

12. The method of claim 8, wherein analyzing comprises splitting a cluster record into multiple cluster records when identifier data of the cluster record are no longer substantially similar to each other and/or to the representative identifier data for the cluster record.

13. The method of claim 1, wherein grouping is repeated over time in order to make adjustments to cluster records based on newly generated identifier data, and further comprising analyzing the cluster records over time to correlate detections of target devices across multiple first devices

14. The method of claim 13, wherein the analyzing comprises comparing cluster records using a level of similarity required for grouping of cluster records that changes over time.

15. The method of claim 1, and further comprising buffering identifier data generated over a period of time prior to performing said grouping.

16. A system comprising:

a plurality of radio devices positioned at different locations in a region and configured to receive wireless emissions where multiple target devices may be emitting and to generate identifier data associated with reception of emissions from target devices;

a computing device coupled to receive identifier data generated by the plurality of radio devices, wherein the computing device is configured to;

group together similar identifier data associated with received emissions at multiple radio devices into a cluster record that potentially represents the same target device detected by multiple radio devices; and

store data representing a plurality of cluster records from identifier data associated with received emissions made over time by multiple radio devices.

17. The system of claim 16, wherein the computing device is configured to group similar identifier data by comparing identifier data associated with detected target device emissions at multiple radio devices.

18. The system of claim 17, wherein the computing device is configured to compare identifier data generated by only those radio devices which are determined to capable of receiving emissions from the same target device.

19. The system of claim 16, wherein the radio devices are configured to generate identifier data that comprises, depending on a particular received emission, one or more of:

a unique identifier of the target device if contained in the received emission;

an semi-unique identifier of one or more target devices of a particular type if contained in the received emission;

a synchronization word associated with the received emission;

radio frequency characteristics associated with the received emission including bandwidth and center frequency;

modulation type of the received emission; and

device type if determined for the received emission.

20. The system of claim 19, wherein the computing device is configured to compare the device type information contained in the identifier data from multiple radio devices, and to compare additional information contained in the identifier data from multiple radio devices only for identifier data containing the same device type or for identifier data containing a device type that could be reasonably incorrectly identified as a different device type based on radio frequency characteristics detected by different radio devices.

21. The system of claim 16, wherein the computing device is further configured to analyze the cluster records over time to correlate detections of target devices across multiple radio devices.

22. The system of claim 21, wherein the computing device is configured to analyze the cluster records by designating one identifier data of a cluster record as being the representative identifier data for the cluster record.

23. The system of claim 20, wherein the computing device is configured to analyze the cluster records by comparing the representative identifier data for multiple cluster records and merging together identifier data for multiple cluster records whose representative identifier data are substantially similar.

24. The system of claim 16, wherein the computing device is configured to compare cluster records using a level of similarity required for grouping of cluster records that changes over time.

25. Logic encoded in one or more tangible media for execution and when executed operable to:

grouping together similar identifier data associated with received emissions at multiple radio devices into a cluster record that potentially represents the same target device detected by multiple radio devices;

storing data representing a plurality of cluster records from identifier data associated with received emissions made over time by multiple radio devices; and

analyzing the cluster records over time to correlate detections of target devices across multiple radio devices.

26. The logic of claim 25, wherein the logic for generating the identifier data comprises logic for generating, depending on a particular received emission, one or more of:

a unique identifier of the target device if contained in the received emission;

a semi-unique identifier of one or more target devices of a particular type if contained in the received emission;

a synchronization word associated with the received emission;

radio frequency characteristics associated with the received emission including bandwidth and center frequency;

modulation type of the received emission; and

device type if determined for the received emission.

27. The logic of claim 25, wherein the logic for analyzing comprises logic for designating one identifier data of a cluster record as being the representative identifier data for the cluster record.

28. The logic of claim 25, wherein the logic for analyzing comprises logic for comparing the representative identifier data for multiple cluster records and merging together identifier data for multiple cluster records whose representative identifier data are substantially similar.

29. The logic of claim 25, wherein the logic for analyzing comprises logic for comparing cluster records using a level of similarity required for grouping of cluster records that changes over time.