System and method for locationing in a communications network

• US 7,742,456 B2
• Filed: 11/04/2005
• Issued: 06/22/2010
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Kawaguchi, Dean, Le, Vinh-Phuong Tra
• Primary Examiner(s): Kincaid; Lester
• Assistant Examiner(s): MITCHELL, NATHAN A
• Application Number:
  US11/266,929
• Publication Number:
  US 20070104157A1
• Time in Patent Office: 1,691 Days
• Field of Search: 370/331, 370/332, 370/338, 455/404.2, 455/456.1
• US Class Current: 370/338
• CPC Class Codes: H04W 12/122 Counter-measures against attacks; Protection against rogue devices
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Described is a method for locationing in a communications network. A wireless access point receives a signal corresponding to activity of a plurality of wireless devices on a predetermined bandwidth. The signal is processed to generate a plurality of subsignals using a predetermined signal processing procedure. An energy level of a particular subsignal of the plurality of subsignals is determined. A location of a corresponding wireless device is determined as a function of the energy level and a predetermined locationing procedure.

Claims

1. A method, comprising:

providing a wireless access point configured to communicate to a plurality of mobile units through a wireless communication protocol and further configured to receive a frequency band in addition to communicating to the plurality of mobile units;

receiving, by the wireless access point, a signal encompassing multiple activities occurring at the same time from a plurality of wireless devices operating on multiple different frequencies within the frequency band having a predetermined bandwidth, the multiple activities being received simultaneously by the wireless access point;

processing the signal to generate a plurality of subsignals using a predetermined signal processing procedure;

determining an energy level of a particular subsignal of the plurality of subsignals;

identifying a signal signature of the particular subsignal, the signal signature being indicative of a corresponding wireless device of a local area network;

responsive to identifying the signal signature of the wireless device of the local area network, demodulating the signal to determine a source and a destination associated with the signal;

determining whether the source and the destination each comprise authorized devices; and

determining a location of the corresponding wireless device as a function of the energy level and a predetermined locationing procedure, wherein the location of the corresponding wireless device is determined only when the energy level is greater than a predetermined threshold level corresponding to a predetermined network condition.

2. The method according to claim 1, wherein the corresponding wireless device includes one of a cell phone, a network interface card, an image-based scanner, a laser-based scanner, an RFID reader, a cordless phone, a wireless speaker, a microwave oven and a rogue access point.

3. The method according to claim 1, wherein the bandwidth includes one of a 2.4 and a 5 GHz band.

4. The method according to claim 1, wherein the signal processing technique includes a Fast Fourier Transform.

5. The method according to claim 1, wherein the processing step further includes the following substep:

dividing the signal into a predetermined number of bins having a predetermined resolution, each bin including a portion of the signal corresponding to one subsignal of the plurality of subsignals.

6. The method according to claim 5, wherein the resolution is the bandwidth divided by the number.

7. The method according to claim 1, wherein the first determining step includes the following substep:

determining an amplitude of the particular subsignal, the amplitude being indicative of the energy level of the particular subsignal.

8. The method according to claim 1, wherein the predetermined locationing technique is a triangulation.

9. The method according to claim 1, further comprising:

disabling the corresponding wireless device.

19. The method according to claim 1, wherein the wireless access point comprises a first wireless access point, and the method further comprising:

providing a second wireless access point and a third wireless access point, wherein each of the second wireless access point and a third wireless access point are configured to communicate to a plurality of mobile units through a wireless communication protocol and further configured to receive a frequency band in addition to communicating to the plurality of mobile units; and

utilizing triangulation as the predetermined locationing technique based on signals detected by each of the first wireless access point, the second wireless access point, and the third wireless access point.

10. A system, comprising:

a plurality of wireless devices transmitting signals on multiple different frequencies within a frequency band having a predetermined bandwidth; and

an access point receiving the signals as an input signal encompassing multiple activities in the frequency band occurring at the same time from the plurality of wireless devices, the multiple activities being received simultaneously by the access point, the access point and processing the input signal to generate a plurality of subsignals using a predetermined signal processing procedure, the access point determining an energy level of a particular subsignal of the plurality of subsignals and identifying a signal signature of the particular subsignal, the signal signature being indicative of a corresponding wireless device;

wherein the access point is configured to communicate to a subset of the plurality of wireless devices through a wireless communication protocol and further configured to receive the frequency band in addition to communicating to the subset, the subset comprising wireless local area network devices;

wherein the access point identifies a signal signature of the particular subsignal, the signal signature indicative of the corresponding wireless device of a local area network,

wherein responsive to the access point identifying the signal signature of a wireless local area network mobile unit, the access point is configured to demodulate the signal to determine a source and a destination associated with the signal and to determine whether the source and the destination each comprise authorized devices, and

wherein the access point determines a location of the corresponding wireless device as a function of the energy level and a predetermined locationing procedure only when the energy level is greater than a predetermined threshold level corresponding to a predetermined network condition.

11. The system according to claim 10 wherein the corresponding wireless device includes one of a cell phone, a network interface card, an image-based scanner, a laser-based scanner, an RFID reader, a cordless phone, a wireless speaker, a microwave oven and a rogue access point.

12. The system according to claim 10, wherein the bandwidth includes one of a 2.4 GHz band and a 5 GHz band.

13. The system according to claim 10, wherein the signal processing technique includes a Fast Fourier Transform.

14. The system according to claim 10, wherein the predetermined locationing technique is a triangulation.

15. A computing arrangement, comprising:

a communication arrangement receiving a signal encompassing multiple activities occurring at the same time from a plurality of wireless devices operating on multiple different frequencies within a frequency band having a predetermined bandwidth, the multiple activities being received simultaneously by the wireless access point;

the communication arrangement further communicating over a channel through a wireless communication protocol to a subset of the plurality of wireless devices comprising wireless local area network devices; and

a processor processing the signal to generate a plurality of subsignals using a predetermined signal processing procedure,

wherein, the processor determines an energy level of a particular subsignal of the plurality of subsignals,

wherein, the processor identifies a signal signature of the particular subsignal, the signal signature being indicative of a corresponding wireless device of a local area network,

wherein responsive to the processor identifying the signal signature of a wireless local area network mobile unit, the processor is configured to demodulate the signal to determine a source and a destination associated with the signal and to determine whether the source and the destination each comprise authorized devices, and

wherein, the processor determines a location of a corresponding wireless device as a function of the energy level and a predetermined locationing procedure only when the energy level is greater than a predetermined threshold level corresponding to a predetermined network condition.

16. The arrangement according to claim 15, wherein the bandwidth includes one of a 2.4 GHz band and a 5 GHz band.

17. The arrangement according to claim 15, wherein the signal processing technique includes a Fast Fourier Transform.

18. The arrangement according to claim 15, wherein the processor identifies a signal signature of the particular subsignal, the signal signature indicative of the corresponding wireless device.