Essential Guide to Wireless Communications Applications, The

VSATs

With fiber taking over their traditional role in intercontinental links, satellites must compete by reaching customers directly. The innovation that made this possible was the directional antenna, first implemented in 1975 by a satellite called Satcom. It enabled satellites to focus their beam on one particular area of Earth’s surface, usually North America or Western Europe. Newer satellites launched from 2000 onward incorporate even narrower beams, which can switch rapidly between hotspots, such as individual towns.

With a well-focused beam, dishes can have a diameter of one meter or less, a small fraction of the earlier systems. These are known as VSATs (very small aperture terminals). All VSATs use geostationary satellites, so just ...