How does a cellular phone work?
Wireless network carriers use a system of areas or “cells” that are served by radio communications for handling the connections of all the phone calls of their customers. The signal footprint of each radio antenna defines the location and size of its cell. As the mobile phone moves, the call is dropped by the cell being exited and simultaneously picked up by the cell being entered. This switching takes place automatically and is transparent to the user. The radio cells range in size from 100 yards (100 meters) in busy downtown corridors to several miles (10 kilometers) in rural areas. The antennas can be mounted on freestanding towers, poles, rooftops, lamp posts, trees or flagpoles. Antennas are often integrated (hidden) into the design of the buildings and surroundings. The size of a cell area also depends on the local terrain. Radio signals can be blocked by trees, buildings, hills and valleys, so base stations may have to be located closer together. If the location of a phone is no
