Ian Waugh - A Mariner\'s Guide to Marine Communications

Chapter 8

Mobile Satellite Installations

THIS CHAPTER COVERS THE VARIOUS INMARSAT SATELLITE SERVICES that are

used for GMDSS purposes and those that can be used in addition to

GMDSS. Covered here are the Inmarsat communications network,

satellite propagation, Inmarsat ship earth stations (SES - Inmarsat A, B

and C for GMDSS use and Inmarsat-M and Mini-M for non-GMDSS

use). Inmarsat-E - the Inmarsat EPIRB - is covered in ChapterlO. Also

covered are non-GMDSS high bandwidth satellite systems, and

combined cellular radio and satellite systems.

The Inmarsat Communications Network

The Inmarsat system utilises satellites orbiting above the equator,
at a speed that keeps them above the same longitude (hence the
expression geo-stationary satellite).

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Mobile Satellite Communication

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Figure 8.7

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The Inmarsat Satellite Constellation

The satellites are called Atlantic Ocean Region West (AOR-W); Atlantic Ocean

Region East (AOR-E); Indian Ocean Region (IOR) and Pacific Ocean Region (POR)

Land Earth Stations (LES)

LESs are owned and operated by telecommunications service
providers (e.g. France Telecom; Stratos; Telenor and Telstra in Australia

• see ALRS Vol. 1 for the full list of service providers) in various countries
  around the world. The LES operates as an international telephone

154 THE NAUTICAL INSTITUTE