The air-ground radiotelephone service operates on frequencies designated by the Federal Communications Commission and other similar regulatory agencies in order to minimize the possibility of interference with extremely sensitize airplane navigation equipment and air traffic control radio communication.
An air-ground radiotelephone transmits a radio signal somewhere in the 849 to 851 Megahertz range; this signal is sent to either a receiving ground station or a communications satellite depending on the design of the particular system. If it is a call from a commercial airline passenger radiotelephone, the call is then forwarded to a verification center to process credit card or calling card information. The verification center will then route the call to the Public Switched Telephone Network, which completes the call. For the return signal, ground stations and satellites use a radio signal in the 894 to 896 Megahertz range.