S-MIM radio interface for mobile satellite services

Article By:

Scalise, Sandro Institute of Communications and Navigation, German Aerospace Center, Oberpfaffenhofen, Germany.

De Gaudenzi, Riccardo European Space Agency, Noordwijk, Netherlands.

Last reviewed:2014

DOI:https://doi.org/10.1036/1097-8542.YB150580

The use of spacecraft for data relay to provide radio coverage to the entire Earth dates back to 1945, when Arthur C. Clarke, at that time serving in the Royal Air Force as officer and radar specialist, published the visionary article in Wireless World entitled “Extra-Terrestrial Relays. Can Rocket Stations Give World-wide Radio Coverage?” Twelve years later, the first communications satellite, named Sputnik 1, was launched by the Russians. It carried two radio transmitters at 20.005 and 40.002 MHz, with batteries lasting 22 days. Today, the number of communications satellites listed in the National Space Science Data Center (NSSDC) Master Catalog is greater than 2000; the number of active communication satellites in geosynchronous orbits, characterized by an orbital period equal to one sidereal day, is almost 400; and the lifetimes of such satellites are typically around 15 years. Television and radio broadcasting are by far the most important markets for satellite manufacturers and operators, accounting today for almost 80% of the total satellite service revenue. In contrast, for many years, bidirectional communication services via satellite remained a relatively small, although important, market niche, mainly addressing institutional or professional applications. This was chiefly due to the high cost of satellite airtime and terminals and to the high latency due to the propagation delay. Only recently, affordable broadband-access satellite networks have been emerging in the United States, complementing the terrestrial networks' coverage in locations where wireline solutions are not economically viable. At the time of this writing (2014), Google has announced plans to invest in a fleet of satellites that will expand Internet access to unconnected regions of the world.

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