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• Inmarsat was set up in the early eighties as
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an intergovernmental organisation to provide a world-wide communications network for maritime safety. In 1999 it changed to a limited company and has since expanded its commercial activities, although the maritime function remains at its core.
The backbone of the service is a fleet of satellites in geo-stationary orbit some 35,600km above the Equator. There are currently nine satellites in orbit, controlled from the firm's headquarters in London. Four of the satellites are current-spec Inmarsat-3 models which provide the basic coverage, while fifth Inmarsat-3 and the four previous-generation Inmarsat-2s are in place as backups. A new generation is being built for deployment in 2004.
The relevance of these new satellites is that each generation provides a major increase in capacity, not just in the number of calls that can be handled but also, more importantly, increased bandwidth, or the amount of data that can be transmitted simultaneously. There is also increased use of 'spot beams', which are aimed at specific areas requiring higher capacity, Most people will have experienced the practical application of lnmarsat's service by watching live news coverage of events in Afghanistan via videophone, The ability to provide this level of capacity would have been impossible as recently as 18 months ago. The hardware for this is now little larger than a laptop computer, the whole system fitting into a bag small enough to use as airline hand luggage.
The map of Inmarsat's guaranteed coverage falls slightly short of being 100% global as the polar areas are excluded, but it's safe to say that the system covers anywhere in the world that a commercial haulier could operate,