GX1300
Page 36
9 DIGITAL SELECTIVE CALLING
9.1 GENERAL
WARNING
Digital Selective Calling (DSC) is a semi-automated method of establishing a
radio call. It has been designated by the International Maritime Organization
(IMO) as an international standard for establishing VHF, MF, and HF radio
calls. It has also been designated as part of the Global Maritime Distress and
Safety System (GMDSS). It is planned that DSC will eventually replace aural
watches on distress frequencies and will be used to announce routine and
urgent maritime safety information broadcasts.
This system allows mariners to instantly send a distress call with GPS
position (when connected to the transceiver) to the Coast Guard and other
vessels within range of the transmission. DSC will also allow mariners to
initiate or receive Distress, Urgency, Safety, Routine, POSITION REQUEST,
POSITION SEND, and Group calls to or from another vessel equipped with a
DSC transceiver.
9.2 MARITIME MOBILE SERVICE IDENTITY
(
MMSI
)
9.2.1 What is an MMSI?
An MMSI is a nine digit number used on Marine radios capable of using
Digital Selective Calling (DSC). This number is used like a telephone number
to selectively call other vessels.
THIS NUMBER MUST BE PROGRAMMED INTO THE RADIO TO
OPERATE DSC FUNCTIONS.
How can I obtain an MMSI assignment?
Please contact the Radio Licensing Authority for your country for information
on how to obtain an MMSI number.
The
GX1300
is designed to generate digital maritime distress and
safety calls to facilitate search and rescue. To be effective as a safety
device, this equipment must be used only within communication range
of a shore-based VHF marine channel 70 distress and safety watch
system. The range of signal may vary, however under normal condi-
tions should be approximately 20 nautical miles.
