There are billions of cell phone subscriptions in the world. With so many phones do you know how they work? In its simplest form a cell phone is a two-way radio. Inside the phone is a metal antenna. The phone converts your voice to an electronic signal. This signal is sent out from your phone as a radio wave. Inside a cell tower another antenna receives the signal from your phone. The signal is then passed along to other towers to complete your call. And all of this is done at the speed of light!