Aircraft Telephones (Wireless Networks)

Aircraft Telephones
Aircraft telephones allow people on an airplane to initiate telephone calls with the public telephone system through connection via land based radio or satellite transmission systems. Recently, some aircraft telephone systems have been upgraded to allow calls to be received on the airplane.

Aircraft telephone systems are ordinarily a hybrid wireless system that is a terrestrial wireless system (land-based) combined with satellite service. The terrestrial system is used to connect telephone calls when the aircraft is above land and is within distance of a ground transmitter. For the terrestrial-based system, the phone handset in the airplane is connected to a transmitter in the plane’s belly that connects the call down to one of the ground antennas located strategically throughout the country. The call is routed to a ground switching station that connects the call to the receiving party.

The satellite system is used mainly over the water, where calls are out of reach of the ground antennas. For the satellite-based system, the phone handset on the plane is connected to an antenna on the top of the plane that connects the signal up to an orbiting satellite. The call is then sent down to earth by the satellite frequencies to its satellite earth station, then to one of the main ground switching stations that routes the call to the PSTN.

Aircraft phone systems normally have handsets in a common area or handsets that are located in the back of passenger seats. If the handset is located in the seat, some aircraft phone systems allow incoming calls. For someone to reach you on an aviation telephone system, the person on the aircraft must first get an telephone access number and temporary identification code by registering with the aviation telephone operator. The person placing the call from the ground dials the access number and enters the temporary identification code and the call will be routed to the aviation telephone.

Figure 1 shows a public aircraft telephone system. This diagram shows that aircraft may be served by terrestrial (land-based) systems or satellite communication systems. In either case, the aircraft communicates with a gateway that links the radio system to the public telephone system.


Figure 1: Public Aircraft Telephone System