What do cell phones require to work?

high-frequency microwaves
the Global Positioning System
satellites tuned to their wavelength
ultraviolet rays

Cell phones require high-frequency microwaves to work, which are transmitted and received by radio antennas. The Global Positioning System (GPS) and satellites tuned to their wavelength may be used for location tracking and navigation, but they are not required for a cell phone to function. Ultraviolet rays are not related to the operation of cell phones.