Monitoring changeable locations of client devices in wireless networks

• US 7,212,828 B2
• Filed: 12/31/2002
• Issued: 05/01/2007
• Est. Priority Date: 12/31/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hind, John R., Stockton, Marcia L.
• Primary Examiner(s): Kincaid; Lester G.
• Assistant Examiner(s): Sams; Matthew C
• Application Number:
  US10/334,263
• Publication Number:
  US 20040203908A1
• Time in Patent Office: 1,582 Days
• Field of Search: 455/404.2, 455/410, 455/411, 455/414.2, 4554561-4566, 3405681-570, 340571-5734, 340/539
• 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 computer-implemented method of ensuring that client devices remain inside a defined spatial boundary, comprising steps of:

identifying a plurality of client devices that are to remain inside a defined spatial boundary, each of the client devices participating in a wireless local area network (“

WLAN”

) with which the defined spatial boundary is associated; and

monitoring whether each of the client devices remains inside the defined spatial boundary, wherein the monitoring step further comprises, for each of the client devices, 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 indicating an angle of radio transmission observed upon a transmission by the client device, the angle 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 client device using the received measurement data;

comparing, by the first device, the computed location of the client device to the defined spatial boundary to determine whether the client device remains inside the defined spatial boundary; and

triggering, by the first device, an out-of-boundary action for the client device if the comparing step determines that the client device does not remain inside the defined spatial boundary;

wherein the defined spatial boundary is dynamically defined at set-up time, the dynamic defining further comprising steps of;

physically moving a training client device near selected ones of measurement points on the WLAN while the training client device repeatedly transmits to a set-up application in the first device and while the first device repeatedly receives boundary measurement data from the selected ones of the measurement points, wherein the boundary measurement data received from each selected measurement point comprises a boundary reading indicating the angle of radio transmission observed by the selected measurement point upon the transmission by the moving training client device as it transmits to the set-up application in the first device;

computing, by The first device, successive locations of the moving training client device using the received boundary measurement data; and

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

2. The method according to claim 1, further comprising the step of allowing each of the client devices to access the WLAN only while the comparing step determines that the client device remains inside the defined spatial boundary.

3. The method according to claim 1, wherein the out-of-boundary action comprises deactivating at least one function of each client device for which the out-of-boundary action is triggered.

4. The method according to claim 1 wherein the first device periodically transmits a cryptographic key from the first device to each of the client devices, the cryptographic key being required to unlock at least one of the functions of each of the client devices, and wherein the out-of-boundary action further comprises the step of ceasing the transmission to each of the client devices for which the comparing step determines that the client device does not remain inside the defined spatial boundary, thereby preventing access to the at least one function of that client device for which the cryptographic key is required for unlocking.

5. The method according to claim 1, wherein the out-of-boundary action comprises activating an alarm.

6. A system for ensuring that client devices remain inside a defined spatial boundary, comprising:

a plurality of client devices that are to remain inside a defined spatial boundary, each of the client devices participating in a wireless local area network (“

WLAN”

) with which the defined spatial boundary is associated; and

means for monitoring whether each of the client devices remains inside the defined spatial boundary, wherein the means for monitoring, for each of the client devices, further comprises;

means for receiving, at a first device an the WLAN, measurement data from a plurality of measurement points on the WLAN, wherein the measurement data for each measurement point comprises a reading indicating an angle of radio transmission observed upon a transmission by the client device, the angle 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 client device using the received measurement data;

means for comparing, by the first device, the computed location of the client device to the defined spatial boundary to determine whether the client device remains inside the defined spatial boundary; and

means for triggering, by the first device, an out-of-boundary action for the client device if the means for comparing determines that the client device does not remain inside the defined spatial boundary;

wherein the defined spatial boundary is dynamically defined at set-up time, the dynamic defining further comprising;

physically moving a training client device near selected ones of the measurement points an the WLAN while the training client device repeatedly transmits to a set-up application in the first device and while the first device repeatedly receives boundary measurement data from the selected ones of the measurement points, wherein the boundary measurement data received from each selected measurement point comprises a boundary reading indicating the angle of radio transmission observed by the selected measurement point upon the transmission by the moving training client device as it transmits to the set-up application in the first device;

means for computing by the first device, successive locations of the moving training client device using the received boundary measurement data; and

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

7. The system according to claim 6, further comprising means for allowing each of the client devices to access the WLAN only while the means for comparing determines that the client device remains inside the defined spatial boundary.

8. The system according to claim 6, wherein the out-of-boundary action comprises deactivating at least one function of each client device for which the out-of-boundary action is triggered.

9. The system according to claim 6, wherein the first device periodically transmits a cryptographic key from the first device to each of the client devices, the cryptographic key being required to unlock at least one of the functions of each of the client devices, and wherein the out-of-boundary action further comprises ceasing the transmission to each of the client devices for which the means for comparing determines that the client device does not remain inside the defined spatial boundary, thereby preventing access to the at least one function of that client device for which the cryptographic key is required for unlocking.

10. The system according to claim 6, wherein the out-of-boundary action comprises activating an alarm.

11. A computer program product for ensuring that client devices remain inside a defined spatial boundary, 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 for identifying a plurality of client devices that are to remain inside a defined spatial boundary, each of the client devices participating in a wireless local area network (“

WLAN”

) with which the defined spatial boundary is associated; and

computer-readable program code for monitoring whether each of the client devices remains inside the defined spatial boundary, wherein the computer-readable program code for monitoring, for each of the client devices, further comprises

computer-readable program code 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 indicating an angle of radio transmission observed upon a transmission by the client device, the angle 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 for computing, by the first device, a current location of the client device using the received measurement data;

computer-readable program code for comparing by the first device, the computed location of the client device to the defined spatial boundary to determine whether the client device remains inside the defined spatial boundary; and

computer-readable program code for triggering, by the first device, an out-of-boundary action for the client device if the computer-readable program code for comparing determines that the client device does not remain inside the defined spatial boundary;

wherein the defined spatial boundary defined at set-up time, the dynamic defining further comprising;

physically moving a training client device near selected ones of the measurement points on the WLAN while the training client device repeatedly transmits to a set-up application in the first device and while the first device repeatedly receives boundary measurement data from the selected ones of the measurement points, wherein the boundary measurement data received from each selected measurement point comprises a boundary reading indicating the angle of radio transmission observed by the selected measurement point upon the transmission by the moving training client device as it transmits to the set-up application in the first device;

computing, by the first device, successive locations of the moving training client device using the received boundary measurement data; and

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

12. The computer program product according to claim 11, further comprising computer-readable program code for allowing each of the client devices to access the WLAN only while the computer-readable program code for comparing determines that the client device remains inside the defined spatail boundary.

13. The computer program product according to claim 11, wherein the out-of-boundary action comprises deactivating at least one function of each client device for which the out-of-boundary action is triggered.

14. The computer program product according to claim 11, wherein the first device periodically transmits a cryptographic key from the first device to each of the client devices, the cryptographic key being required to unlock at least one of the functions of each of the client devices, and wherein the out-of-boundary action further comprises ceasing the transmission to each of the client devices for which the computer-readable program code for comparing determines that the client device does not remain inside the defined spatial boundary, thereby preventing access to the at least one function of that client device for which the cryptographic key is required for unlocking.

15. The computer program product according to claim 11, wherein the out-of-boundary action comprises activating an alarm.

16. A computer-implemented method of ensuring that client devices remain inside a defined spatial boundary, comprising steps of:

identifying a plurality of client devices that are to remain inside a defined spatial boundary, each of the client devices participating in a wireless local area network (“

WLAN”

) with which the defined spatial boundary is associated;

monitoring whether each of the client devices remains inside the defined spatial boundary, wherein the monitoring step, for each of the client devices, further comprises 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 indicating an angle of radio transmission observed upon a transmission by the client devices, the angle 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 client device using the received measurement data; and

determining, by the first device using the computed location of the client device, whether the client device remains inside the defined spatial boundary, the defined spatial boundary having been dynamically defined set-up time, the dynamic defining further comprising steps of;

physically moving a training client device near selected ones of the measurement points on the WLAN while the training client device repeatedly transmits to a set-up application in the first device and while the first device repeatedly receives boundary measurement data from the selected ones of the measurement points, wherein the boundary measurement data received from each selected measurement point comprises a boundary reading indicating the angle of radio transmission observed by the selected measurement point upon the transmission by the moving training client device as it transmits to the set-up application in the first device;

computing, by the first device, successive locations of the moving training client device using the received boundary measurement data; and

using, by the set-up application, the successive locations to dynamically define the spatial boundary; and

if the monitoring step determines that any of the client devices does not remain inside the defined spatial boundary, performing at least one of (1) deactivating at least function of such devices and (2) activating an alarm; and

charging a fee for carrying out the monitoring step.