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DIGITAL SELECTIVE CALLING (DSC) |
The latest marine radio technology is called Digital Selective Calling (DSC)
and should be incorporated into all marine radios within a few years. The
radio's "mayday button" initiates an automated distress call which is heard by
all nearby vessels and the Coast Guard. The digital (not voice) transmission
will contain an encoded distress call including vessel information such as your
location (the radio should be connected to a Loran or GPS) and the radio
user's personal information (if provided to the Coast Guard ). It receives and
stores messages, provides "caller-ID", automatically issues a "Mayday" and
stores a reply if you are disabled.
DSC radio users need to register the radio's identity with the Coast Guard
plus have an identification number encrypted in their radio for it to work
properly in an emergency. Digital selective calling (DSC) is now used on VHF, MF
and HF maritime radios as part of the GMDSS system. Channel 70 (VHF) and
2187.5 KHz (MF) is reserved exclusively for DSC safety and distress calls.
(There are DSC calling channels in each HF band.)
Register Your New Radio Now and help the Coast Guard help you!
If you've recently
purchased a new VHF radio for your boat, it is probably equipped with a Digital
Selective Calling (DSC) feature that allows selective calling on VHF Ch70. To
make a digital call each radio must have an identity, a 9-digit Maritime Mobile
Service Identity (MMSI) number. Your owner’s manual will tell you more about
this feature and how to make a DSC call to another boat or to a shore station
that has DSC capability. MMSI numbers are assigned, free of charge, by Industry
Canada.
One important feature of
a VHF DSC radio is that it can also send a Distress Alert which will tell the
Coast Guard and other boaters in your area that you require immediate
assistance.
As well, if your
boat is equipped with a GPS receiver, it is highly recommended that it be
connected to your DSC radio. This will ensure that your position is
automatically sent when a Distress Alert is transmitted. Rescuers will then
immediately know your exact location and assistance will arrive sooner.
(Please note, DO NOT TEST this Distress Alerting feature, there is no test
feature, and in fact it is an offence under both the Canada Shipping Act and the
Radio communication Act to send a false distress message.)
Just imagine the scene:
you’re out cruising with your family in your boat, when you suddenly smell
smoke. You immediately stop the engine, and grab a fire extinguisher and check
it out. You discover that the whole engine compartment is on fire!
The cabin is filling with
deadly smoke, and you don't have enough time to get a mayday call out, but you
do have time enough to hold the Distress Key on your radio down for 5 seconds,
before you and your family abandon ship. A Distress Alert has been automatically
transmitted on Ch70, clearly identifying you by the MMSI number, and your
location, thanks to the GPS.
The call is received by
the Coast Guard, who immediately send out the appropriate rescue resources.
All you had to do is hold
the Distress Button in for 5 seconds and help was on the way! This feature is
only enabled on those radios that have been assigned a MMSI number.
A properly installed and registered DSC
radio could help save your life. The Coast Guard urges you to complete the
application form for recreational boaters (.PDF) or call Industry Canada at 1-800-667-3780 for more information. Your
completed application form can be either faxed or emailed to your local Industry
Canada Office.
What is happening to
Digital
Selective Calling?
Manufacturers have been trying to hit a moving target
for several years, since the specification for what constitutes a DSC radio has
changed repeatedly. And as this specification has been changing, there has been
the specter of failing Type Acceptance at the FCC unless the radio being
submitted met the standard!
For consumers, there have been virtually no
benefits from DSC, although it has caused tons of confusion. Many
customers purchased DSC radios, mistakenly believing that their boating would
somehow improve. It will, because Canada and USA subscribed to the
GMDSS (Global Maritime Distress
and Safety System) and this would be a requirement to be in place.
Luckily, the situation is changing dramatically over
the past year, and we are beginning to see a time when the benefits of DSC
radios will be realized.
What is and what isn't DSC? :
Digital Selective Calling is a technology in
which a VHF radio can (selectively) call another radio using digital messages,
much like the modem on a computer. You call the DSC code of the specific vessel
you are calling, and only the radio on the vessel called receives the message.
All other radios are unaffected. The key advantage is that VHF messages are more
like "direct dial" and less like a "party line."
Furthermore, when a DSC VHF is connected to the data
output of a GPS receiver, it is possible to transmit your ID code, the fact that
you are having a Mayday emergency, and your position to rescue agencies
(generally the Coast Guard).
The problem is that the Coast Guards (Canada and US) do
not have the infrastructure to listen for DSC distress calls in all areas yet.
So, while you may be able to transmit, no one might be listening. So, there is
practically no advantage to having a DSC radio for recreational boaters, unless
they're betting on the future.
Has the outlook changed?
Yea, measures are being taken to monitor these DSC calls by the Coast Guard.
When it will be fully in force is another matter. As soon as we find out more
about this process we will keep you posted on this website.
Another major change was the introduction of the
Standard Horizon Intrepid VHF, which is the first type-accepted DSC SC-101 radio
that we know of. While other radios have fallen short of the mark in one way or
another, we believe the Intrepid is the first in a series of compliant radios
which actually offer benefits to boaters. Two features of particular importance:
the Intrepid can be programmed from the front panel, so you can enter your
vessel's identification code without a visit to the electronics repair shop, and
the Intrepid is affordable.
What other benefits will arise from the use of DSC
radios? We understand there is a move toward using digital information to access
public correspondence stations on shore. This would theoretically allow you to
dial your party's phone number from your VHF radio without having to go through
a marine operator. At ranges that will far exceed cellular telephones, and
prices dramatically less than current ship-to-shore rates, this is an exciting
extension to VHF service. And, finally, if you want to tell your fishing buddy
where you are, but you don't want to tell anyone else, a DSC radio may soon make
it possible to simply dial in your buddy's radio ID code, and send him your
position secretly!
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