Monitoring changeable locations of client devices in wireless networks

• US 20040203908A1
• Filed: 12/31/2002
• Published: 10/14/2004
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hind, John R., Stockton, Marcia L.
• Granted Patent: US 7,212,828 B2
• Time in Patent Office: Days
• 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

Security of wireless networks is improved by rejecting traffic from a wireless device located outside a defined spatial boundary. The device'"'"'s spatial position with respect to the boundary is determined using directional antenna arrays on a plurality of measurement points, and calculating where the vectors intersect. Having thus determined a device'"'"'s location, access to a wireless network can be denied if the device is outside a predetermined spatial boundary. Or, the device'"'"'s location inside or outside of the spatial boundary can be used for monitoring a changeable location of one or more client devices in a wireless network, for example as a theft detection or theft deterrent mechanism.

Claims

1. A method of monitoring a changeable location of one or more client devices in a wireless local area network (“

WLAN”

), comprising steps of;

receiving, at a first device on the WLAN, measurement data from a plurality of measurement points on the WLAN, wherein the measurement data for each measurement point comprises a reading for a particular client device, the reading observed by a plurality of antenna elements of the measurement point, the antenna elements being capable of determining an angle to a source of radio transmission;

computing, by the first device, a current location of the particular client device using the received measurement data; and

determining, by the first device, whether the current location of the particular client device is within a predetermined spatial boundary.

2. The method according to claim 1, further comprising the step of allowing the particular client device to access the WLAN only if its current location is determined to be within the predetermined spatial boundary.

3. The method according to claim 1, further comprising the step of deactivating one or more functions of the particular client device if its current location is determined not to be within the predetermined spatial boundary.

4. The method according to claim 3, wherein the first device periodically transmits a cryptographic key from the first device to the particular client device, the cryptographic key being required to unlock at least one of the functions of the particular client device, and wherein the deactivating step further comprises the step of ceasing the transmission when the current location of the particular client device is determined not to be within the predetermined spatial boundary.

5. The method according to claim 1, further comprising the step of activating an alarm if the current location of the particular client device is determined not to be within the predetermined spatial boundary.

6. The method according to claim 1, further comprising the steps of:

maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

performing the receiving, computing, and determining steps for each of the plurality of client devices; and

if the current location of any of the client devices is determined not to be within the predetermined spatial boundary, activating an alarm.

7. The method according to claim 1, further comprising the steps of:

maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

performing the receiving, computing, and determining steps for each of the plurality of client devices; and

if the current location of any of the client devices is determined not to be within the predetermined spatial boundary, deactivating one or more functions of such devices.

8. The method according to claim 1, wherein the first device learns the predetermined spatial boundary at set-up time, further comprising steps of:

moving a training client device around a spatial boundary while the training client device communicates with a set-up application in the first device;

recording, by the set-up application, successive locations of the training client device from these communications; and

using, by the set-up application, the successive locations to define the predetermined spatial boundary.

9. A system for monitoring a changeable location of one or more client devices in a wireless local area network (“

WLAN”

), comprising;

means for receiving, at a first device on the WLAN, measurement data from a plurality of measurement points on the WLAN, wherein the measurement data for each measurement point comprises a reading for a particular client device, the reading observed by a plurality of antenna elements of the measurement point, the antenna elements being capable of determining an angle to a source of radio transmission;

means for computing, by the first device, a current location of the particular client device using the received measurement data; and

means for determining, by the first device, whether the current location of the particular client device is within a predetermined spatial boundary.

10. The system according to claim 9, further comprising means for allowing the particular client device to access the WLAN only if its current location is determined to be within the predetermined spatial boundary.

11. The system according to claim 9, further comprising means for deactivating one or more functions of the particular client device if its current location is determined not to be within the predetermined spatial boundary.

12. The system according to claim 11, wherein the first device periodically transmits a cryptographic key from the first device to the particular client device, the cryptographic key being required to unlock at least one of the functions of the particular client device, and wherein the means for deactivating further comprises means for ceasing the transmission when the current location of the particular client device is determined not to be within the predetermined spatial boundary.

13. The system according to claim 9, further comprising means for activating an alarm if the current location of the particular client device is determined not to be within the predetermined spatial boundary.

14. The system according to claim 9, further comprising:

means for maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

means for performing the means for receiving, means for computing, and means for determining for each of the plurality of client devices; and

if the current location of any of the client devices is determined not to be within the predetermined spatial boundary, means for activating an alarm.

15. The system according to claim 9, further comprising:

means for maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

means for performing the means for receiving, means for computing, and means for determining for each of the plurality of client devices; and

if the current location of any of the client devices is determined not to be within the predetermined spatial boundary, means for deactivating one or more functions of such devices.

16. The system according to claim 9, wherein the first device learns the predetermined spatial boundary at set-up time, further comprising:

means for moving a training client device around a spatial boundary while the training client device communicates with a set-up application in the first device;

means for recording, by the set-up application, successive locations of the training client device from these communications; and

means for using, by the set-up application, the successive locations to define the predetermined spatial boundary.

17. A computer program product for monitoring a changeable location of one or more client devices in a wireless local area network (“

WLAN”

), the computer program product embodied on one or more computer readable media readable by a computing system in a computing environment and comprising;

computer-readable program code means for receiving, at a first device on the WLAN, measurement data from a plurality of measurement points on the WLAN, wherein the measurement data for each measurement point comprises a reading for a particular client device, the reading observed by a plurality of antenna elements of the measurement point, the antenna elements being capable of determining an angle to a source of radio transmission;

computer-readable program code means for computing, by the first device, a current location of the particular client device using the received measurement data; and

computer-readable program code means for determining, by the first device, whether the current location of the particular client device is within a predetermined spatial boundary.

18. The computer program product according to claim 17, further comprising computer-readable program code means for allowing the particular client device to access the WLAN only if its current location is determined to be within the predetermined spatial boundary.

19. The computer program product according to claim 17, further comprising computer-readable program code means for deactivating one or more functions of the particular client device if its current location is determined not to be within the predetermined spatial boundary.

20. The computer program product according to claim 19, wherein the first device periodically transmits a cryptographic key from the first device to the particular client device, the cryptographic key being required to unlock at least one of the functions of the particular client device, and wherein the computer-readable program code means for deactivating further comprises the step of ceasing the transmission when the current location of the particular client device is determined not to be within the predetermined spatial boundary.

21. The computer program product according to claim 17, further comprising computer-readable program code means for activating an alarm if the current location of the particular client device is determined not to be within the predetermined spatial boundary.

22. The computer program product according to claim 17, further comprising:

computer-readable program code means for maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

computer-readable program code means for performing the means for receiving, means for computing, and means for determining for each of the plurality of client devices; and

if the current location of any of the client devices is determined not to be within the predetermined spatial boundary, computer-readable program code means for activating an alarm.

23. The computer program product according to claim 17, further comprising:

computer-readable program code means for maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

computer-readable program code means for performing the means for receiving, means for computing, and means for determining for each of the plurality of client devices; and

if the current location of any of the client devices is determined not to be within the predetermined spatial boundary, computer-readable program code means for deactivating one or more functions of such devices.

24. The computer program product according to claim 17, wherein the first device learns the predetermined spatial boundary at set-up time, further comprising:

computer-readable program code means for moving a training client device around a spatial boundary while the training client device communicates with a set-up application in the first device;

computer-readable program code means for recording, by the set-up application, successive locations of the training client device from these communications; and

computer-readable program code means for using, by the set-up application, the successive locations to define the predetermined spatial boundary.

25. A method of doing business by monitoring a changeable location of one or more client devices in a wireless local area network (“

WLAN”

), comprising steps of;

maintaining an enumeration of a plurality of client devices that should be present in the WLAN;

monitoring a current location of each of the client devices, further comprising the steps of;

receiving, at a first device on the WLAN, measurement data from a plurality of measurement points on the WLAN, wherein the measurement data for each measurement point comprises a reading for a particular one of the client devices, the reading observed by a plurality of antenna elements of the measurement point, the antenna elements being capable of determining an angle to a source of radio transmission;

computing, by the first device, the current location of the particular client device using the received measurement data; and

determining, by the first device, whether the current location of the particular client device is within a predetermined spatial boundary;

if the monitoring step determines that the current location of any of the client devices is not within the predetermined spatial boundary, deactivating one or more functions of such devices and/or activating an alarm; and

charging a fee for carrying out the maintaining, monitoring, and deactivating and/or activating steps.