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

exchange, connecting calls from ships to shore subscribers and from
shore to ship. (Land Earth Station means a station, on land, on the earth's
surface - as opposed to a satellite, which is a 'space station'). In some
publications, LESs are also known as Coast Earth Stations (CES). Calls
can be made from ship, through a LES, to anywhere in the world where
normallandline communications are available. In addition to providing
normal telephone, fax, data and telexle-mail messaging services, each
LES has a direct connection with a Maritime Rescue Coordination Centre
(MRCC) for emergency communications - and can usually provide
connection to a hospital/medical centre, when medical advice is required
(see Chapter 5).

Each satellite has a telephone country code and a telex country

code. Callers from-shore dial their call as a normal international

call, but including the particular satellite country code instead of the

country where the LES is situated. Countries that have no LES

locally, normally route to-ship calls to a country that does have an

LES - for connecting to the vessel.

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" IMRCC I

··L~~~~~~ Internationat Radio

Medical

• : (Cl RM Centre Roma)
  I NCS t, ...... MRCC
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............ signalling channel

~ __ -+ traffictworking channel

Figure 8.2

Inmarsat Ground Infrastructure

A number of Land Earth Stations (LES) work through each satellite, providing the

various telecommunications services required by ships and shore subscribers. There

is one Network Co-ordination Station (NCS) for each service (Inmarsat-A/ B/ C etc),

in each Ocean Region.

MARINE COMMUNICATIONS 155