adio Coverage?" In his paper, Clarke proposed the concept of an orbiting platform that would serve as a relay facility for radio signals sent to it that could be turned around and retransmitted back to Earth with far greater coverage than was achievable through terrestrial trans- mission techniques. His platform would orbit at an altitude of 42,000 kilometers (25,200 miles) above the equator, where it would orbit at a speed identical to the rotation speed of the Earth. As a consequence, the satellite would appear to be stationary to Earth-bound users. Satellite technology may prove to be the primary communications gateway for regions of the world that do not yet have a terrestrial wired infrastructure, particularly given the fact that they are now capable of delivering broadband services. In addition to the United States, the largest markets for satellite coverage are Latin America and Asia, and particularly Brazil and China. Geosynchronous Satellites Clarke's concept of a stationary platform in space forms the basis for today's geostationary or geosynchronous satellites. Ringing the equator like a string of pearls, these devices provide a variety of services includ- ing 64 Kbps voice, broadcast television, video-on-demand services, broad- cast and interactive data, and point-of-sale applications, to name a few. And while satellites are viewed as technological marvels, the real magic lies more with what it takes to harden them for the environment in which they must operate and what it takes to get them there than it does their actual operational responsibilities. Satellites, in effect, are nothing more than a sophisticated collection of assignable, on-demand repeaters -in a sense, the world's longest local loop. From a broadcast perspective, satellite technology has a number of advantages. First, its one-to-many capabilities are unequaled. Informa- tion from a central point can be transmitted to a satellite in geostationary Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.c