Patent ID: 8681674

Claim:
A network device for communicating with a wireless sensor network, the network device comprising: a battery; a wireless interface; and a processing unit coupled with the battery and the wireless interface, wherein the processing unit is configured to cause the network device to: periodically scan for beacons at a first scanning rate when the network device is associated with the wireless sensor network, wherein scanning for beacons comprises operating in a mode to detect a predetermined pattern using the wireless interface; determine that the network device no longer is associated with the wireless sensor network; periodically scan for beacons at a second scanning rate for a certain period of time after the determining the network device no longer is associated with the wireless sensor network, wherein the second scanning rate is higher than the first scanning rate; and periodically scan for beacons at a third scanning rate if, after the certain period of time, the network device is not associated with the wireless sensor network.