Did you know your cell phone is actually a radio?
April 14th, 2009 | by Mobile Data Group |One of the most interesting things about a cell phone is that it is actually a radio — an extremely sophisticated radio, but a radio nonetheless.
In the dark ages before cell phones, people who really needed mobile-communications ability installed radio telephones in their cars. In the radio-telephone system, there was one central antenna tower per city, and perhaps 25 channels available on that tower. This central antenna meant that the phone in your car needed a powerful transmitter — big enough to transmit 40 or 50 miles (about 70 km).
It also meant that not many people could use radio telephones — there just were not enough channels. The genius of the cellular system is the division of a city into small cells.