'regional' (like Thuraya - see Chapter 8), and provide service in the
waters in a particular region only. Other systems are considered 'global'
- not being restricted to a particular region.
Two 'global' systems designed for marine use are 'Inmarsat-M'
and 'Inmarsat Mini-M' Both systems offer:
Voice communications.
Slow-speed fax/slow-speed data services.
Inmarsat-M and Mini-M use similar (digital) technology to
Inmarsat-B, but using smaller dish antennas (hence the lower-quality
voice and slower fax/data rates). Inmarsat-M can communicate through
the Inmarsat satellites using the Inmarsat 'Global Beams' (between
approximately 70NI70S).
Mini-M uses 'spot-beam' technology and cannot be used in some
ocean areas, (particularly in the southern oceans) where the spot-beams
do not reach (see figures 4.1 and 4.2).
Calls through Cellular Radio, Inmarsat-M and Mini-M normally
use a very similar procedure to making an international call from home,
e.g. for a call to The Nautical Institute London, UK (telephone number
020 7928 1351) you would dial: 00 44 20 7928 1351 (followed by the *
key or, on cellular systems, the 'send' key).
Various manufacturers sell 'Mini-M' under their own trade name
(e.g. 'Mobiq' from LES Operators Stratos and Telenor - so it may not be
obvious that you are using 'Inmarsat Mini-M' unless you read the small
print of the operating manual. Mini-M may come with call charges 'pre-
paid', or may use the normal 'pay-as-you-use' system. Mini-M terminals
may be programmed to work through a single, designated LES in any
one Ocean Region (i.e. you cannot select a different LES to that pre-
programmed into the equipment).
70 THE NAUTICAL INSTITUTE
