Patent ID: 8204439

Claim:
A wireless communications system comprising: a reader configured to receive first wireless communication signals comprising data generated externally of the reader and to output second wireless communication signals; and a plurality of remote communications devices comprising radio frequency identification devices comprising communications circuitry configured to output the first wireless communication signals and to receive and to process the second wireless communication signals, wherein the remote communications devices are individually configured to sense at least one condition with respect to the respective remote communications device and to communicate data corresponding to the at least one sensed condition at a plurality of moments in time responsive to criteria originating within the respective remote communications device wherein each remote communications device is capable of powering down to conserve energy and capable of powering up in response to an electronic signal, and further includes a second receiver that is configured to screen a radio frequency transmission and provide, on the basis of specific data identified therein, the electronic signal in order to power up the remote communications device, the second receiver being adapted to draw less current than the communications circuitry while awaiting receipt of and listening for a radio frequency transmission.