Thrane&Thrane TT-3080A, User Manual, Page: 13 / 124

Hardware interfaces Hardware interfaces Hardware interfaces Hardware interfaces Description of the service Description of the service Description of the service Description of the service
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2 Description of the service
The Inmarsat Global Area Network service is based on 4 Geo-
stationary satellites situated above the equator. Geo-stationary
means that the satellites are always located in the same position,
i.e. they move at the same speed as that of the earth. Each
satellite covers a certain area (footprint) and each satellite
supports a number of powerful spot-beams making the service
available on virtually all land masses on the earth between
approximately 70°N and 70°S. Please see Chapter 10 for more
detailed maps.
The Four Geo-Stationary Inmarsat Satellites
The Four Geo-Stationary Inmarsat Satellites The Four Geo-Stationary Inmarsat Satellites
The Four Geo-Stationary Inmarsat Satellites
The satellites are your connection to the world wide networks,
and they are managed by the Network Co-ordination Stations
(NCSs), run by Inmarsat. The primary functions of the NCSs are to
constantly keep track of which terminals are logged on to the
system, and assign a free channel when a call is made.
The gateway between the public network and the satellites are
operated by Land Earth Stations (LES). The LESs are run by
different operators, around the world.
The services supported by the Global Area Network
encompasses: