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Inmarsat system

Inmarsat is a globally available mobile telecommunications system based on geostationary satellites( GEO). Inmarsat illuminates the earth's surface with four GEO satell ites. These satellites have so-called global beam antennas and each illuminate one third of the Earth's surface, leaving out the polar caps.

The first-generation Inmarsat system used Intelsat and Marisat satellites and still required stationary land earth stations( LES). The second generation Inmarsat system uses four Inmarsat satellites positioned over the Atlantic (West and East), Indian and Pacific Oceans.

In the third generation system, antennas for spot beams are used in addition to satellite antennas for global beams, allowing smaller and more powerful land earth stations to be used. There must be at least one land earth station in each coverage area. Usually, multiple stations are installed to provide redundancy in the event of a station failure. The second-generation satellites use the C-band at 4 GHz to 6 GHz for transmission between the land earth station and the satellite, and the L-band at 1.5 GHz and 1.6 GHz between the mobile land station and the satellite.

Inmarsat provides services for voice, text and data communications. These services follow uniform global standards and are marketed competitively by numerous providers. Deutsche Telekom is one of the providers of Inmarsat services.

Informations:
Englisch: Inmarsat system
Updated at: 23.03.2013
#Words: 205
Links: system, geostationary earth orbiter (satellite comm.) (GEO), global beam, third, energy aware radio and network technologies (Earth)
Translations: DE
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