(Low-Earth Orbit) A communications satellite in orbit 400 to 1600 miles above the earth. Being much closer than 22,282 mile-high geosynchronous satellites (GEOs), LEO signals make the round trip from earth much faster. Thus, low-powered "pizza dishes" and handheld devices can be used. LEOs are also better suited to interactive conferencing. Unlike GEOs, which travel at earth speed, LEOs revolve around the globe every couple of hours, and any single LEO is in view for only a few minutes. In order to maintain continuous communications, multiple LEOs must be used. From 48 to 66 LEOs are needed to cover the earth. See Iridium, Teledesic, GEO and MEO.
It Takes a Lot of LEOs
While the footprint of a GEO can cover the bulk of a continent, it takes many LEOs to cover the same area. Signals also travel to and from LEOs faster, making them more suitable for real-time applications than GEOs.
