Enter the University of Washington's passive Wi-Fi
As a technological breakthrough, Passive Wi-Fi has some astonishing claims to its name.
Passive Wi-Fi works with off-the-shelf smartphones, too
That's the whole premise on which Passive Wi-Fi is based on, as it tries to re-imagine wireless radio communications without a critical analog component in it.
Soon, radio signals will provide all the power a simple Internet device needs through a technique called passive Wi-Fi
(see "Power from the Ar," page 66).
In tests, prototype passive Wi-Fi devices have beamed data as far as 100 feet and made connections through walls.
Smith says that passive Wi-Fi consumes just 1/10,000th as much power as existing Wi-Fi chipsets.
The researchers believe that tiny passive Wi-Fi devices could be extremely cheap to make, perhaps less than a dollar.