Users of satellite communications networks have two kinds available for emergency response: geostationary satellite systems (GEO) and low Earth orbit satellites (LEO).

GEO satellites are located more than 22,000 miles above the Earth in a fixed position and provide service to a country or region. They can provide communication services, including voice, data and broadband data. GEO satellites operate in tandem with ground equipment -- from fixed antennas that are very large to mobile terminals that are the size of a cellular phone. There are nearly 300 commercial GEO satellites in orbit operated by global, regional and national satellite carriers.

LEO satellites operate in orbits that are between 484 miles and 930 miles aloft. They provide voice and low-speed data communications. LEO satellites can operate with handheld units that are about the size of a large cell phone. The highly portable nature of LEO-based units makes them another valuable solution for first responders.

To best use these capabilities, agencies should define as far in advance as possible what kind of terminals they'll need in the field before and after an emergency. Planning and understanding the system types are essential.

Systems for disaster mitigation, support and relief fall under three general categories:

Handheld Mobile Satellite Communications
When cellular, microwave and other communications facilities are immobilized during a disaster, handheld satellite communications can be reliable. They provide access through small cell-phone sized devices, pagers and in-vehicle units.

Portable and Transportable Mobile Satellites
These terminals are used for mobile communications and include equipment that can be transported and operated from inside a car, truck or maritime vessel, as well as helicopters and other aircraft.

Fixed Satellites
These would typically be installed in cases where the equipment is required for longer than a week, including predisaster applications and postdisaster recovery operations. They can be configured to provide anything from low-speed data transmission to broadband data and broadcast-quality video.

Source: Global VSTAT Forum