Cell phone towers are part of the wireless communications network that makes cellular radio telephone calls possible. Antennae on each tower receive high-frequency radio waves from cell phones. Their range varies from distances as short as 1.5 to 2.4 km (1.0 to 1.5 mi) to distances as long as 48 to 56 km (30 to 35 mi). Cell phone towers are now commonly seen along roadways as cell phone communication has become increasingly popular.