Patent ID: 7212828

Claim:
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.