Greetings ! I was wondering if anybody heard of a bluetooth/802.11/ 27 MHz range LAN transceiver (or maybe something like a radio transducer) that can operate by using power from received transmissions - thus requiring no coupled power source ? Also, which of these protocols could allow it technicly in the first place - that is, involves continous control signals by the "main" control unit or something, thus providing the necessary power for the modulated or separate return signal transmission ? Finally, if such transceiver circuits exist/are possible - would/do they require non-standard improved receiving capability of the units with which they communicate due to low transmission power ? Thanks. Live long and prosper.