The Inmarsat-4 satellites, or I-4 satellites are a

satellite constellation A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global pass (spaceflight), coverage, such that at any time everywhere on E ...

operated by Inmarsat. They provide the Inmarsat BGAN, FleetBroadband, and SwiftBroadband communications networks. They operate on the L band everywhere on

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

, except in polar regions. According to Inmarsat, their launch created the first global 3G mobile network. The first three were launched between 2005 and 2008. They had a mass (at launch) of 5.96 tonnes, and were intended to last 13 years The dimensions of the main body comparable to a double-decker bus at 7m x 2.9m x 2.3m. Including the solar arrays, however, the wingspan is 45 meters, closer to the size of a soccer pitch. The reflectors are 9 meters wide.

Data services

Both streaming and background data service is provided, where streaming allocates a fixed guaranteed bandwith to a user, and background uses the excess bandwith available to a satellite to eventually transmit data.

References

{{Reflist Communications satellites

Data services

See also

References