Patent ID: 7720465
Filing Date: 2010-05-18
Classification: H04M,H04Q,H04W,Y02D

Abstract:
1. A method of operating a wireless network, the method including: sending, by at least one transmitter node, a wakeup tone and at least one second tone, the at least one second tone being one of (i) a tone in a frequency different from the wakeup tone and (ii) a pattern of tones in at least one frequency different from the wakeup tone; operating a receiver node in a sleep mode to conserve energy; periodically waking up, by the receiver node, from the sleep mode to listen for the wakeup tone; upon receiving the wakeup tone, listening, by the receiver node, for the at least one second tone; and upon receiving the at least one second tone, performing an action based on the at least one second tone; wherein the at least one transmitter node includes at least two transmitter nodes, at least one of which transmits the wakeup tone, and each of which simultaneously transmits at least one further tone distinct from one another to collectively form the at least one second tone received by the receiver node.