These waves come from weak TV, radio,andmobilephone signals surrounding us. The power harvested is very small, but is enough to allow the phone to stay in standby mode indefinitely without needing to be plugged in.
The trick is that Nokia has devised aphonethatuses circuits needing less power than it is able toharvestformradio waved. The goal is 50 milliwatts, enough tochargethebattery slowly. The phone could be o n the market in threetofiveyears.