Cellular telephony provides communication between two devices. One or both may
A cellular service area is divided into cells.
Advanced Mobile Phone System (AMPS) is a first-generation cellular phone
Digital AMPS CD-AMPS) is a second-generation cellular phone system that is a digital version of AMPS.
Global System for Mobile Communication CGSM) is a second-generation cellular phone system used in Europe. Interim Standard 95 CIS-95) is a second-generation cellular phone system based on CDMA and DSSS.
The third-generation cellular phone system will provide universal personal communication. A satellite network uses satellites to provide communication between any points on Earth.
A geostationary Earth orbit CGEO) is at the equatorial plane and revolves in phase with Earth.
Global Positioning System CGPS) satellites are medium-Earth-orbit (MEO) satellites that provide time and location information for vehicles and ships.
Iridium satellites are low-Earth-orbit (LEO) satellites that provide direct universal voice and data communications for handheld terminals.
Teledesic satellites are low-Earth-orbit satellites that will provide universal broadband Internet access.