GMDSS - A WAY AHEAD

The following is a summary of a presentation made to the 2010 RTCM conference in San Diego, USA.

GMDSS - A WAY AHEAD

What’s wrong with DSC?

 These days, the GMDSS is all about Satcoms, and the drive for more and more bandwidth to ships. No one uses the GMDSS HF gear…it sits in the corner of the bridge, gathering dust….right?

  
Wrong.

A typical GMDSS HF Coast Radio Station receives, on average, 6000 DSC calls per day. 6000 calls, distributed over 2 – 16 MHz….Even using a modest antenna system, you can hear calls on the 12 and 8 MHz DSC channels at least every minute, all day.

 

What’s the problem?

 The system is clearly being used and is working well technically – ships are communicating with coast stations and other ships.   DSC was originally designed to automate radiotelephone calls between ships at sea and telephone subscribers ashore.  However, satellite/cellular communications have replaced HF radio-based telephone systems for merchant ships. The result is that DSC is effectively designed around a function that no longer exists. This is evident in the number of redundant tele-commands incorporated in the DSC standard.

 

Confusion….it need not be so…

One of the great advantages of using a PC for coast station DSC software is that the operator interface can be easily modified or redesigned.  We can change labels, we can alter the layout and we can hide the more baffling DSC tele-commands to make the system operator friendly.   Alas, ships can’t do that...  They are faced with a myriad of menus, containing many superfluous commands, all which are never used. 

The DSC technical specification, ITU Resolution –M.493, has been revised 13 times since it was first published.    Many of the revisions incorporate very important operational and technical updates, which make the system much more efficient and easier to use.  Equipment performance standards are updated as a result of the revisions, and DSC manufacturers dutifully incorporate these updates into their latest products. 

However, where the good ship DSC hits the proverbial iceberg is real-world implementation - the revised performance standards apply only to new equipment…

There is no requirement for ships to update their DSC equipment to comply with new specification.

So, as a result, ships are sailing around with 1^st   and 2^nd generation DSC systems….old and clunky, full of redundant tele-commands, and thus a nightmare to use….

To their credit, the USCG has identified this problem. 

They put a paper to the recent IMO COMSAR meeting proposing that SOLAS Chapter 4 be modified to require the latest DSC software version to be used. This issue is moving forward through IMO, but it will take time to implement…

 

Oversight…

Despite all the DSC traffic, many ships are still making fundamental mistakes with the system. 

Using the latest software will go some way to fixing the problem – but, what is really needed is for some central body to take charge of DSC, and conduct an active monitoring and education campaign.   

 Internet technology allows remote control of DSC shore stations from anywhere in the world. 

 A number of DSC HF monitoring stations could easily be controlled from a central point, to provide world-wide coverage.    It would be a simple matter to match a ship’s DSC identity number (MMSI) to her Inmarsat number.   Ships which regularly breach DSC operational standards could be sent a polite reminder (or even an operational guide) via Inmarsat….. 

 

Don’t let small craft near DSC…!

 Many SAR agencies are reluctant to promote VHF DSC to recreational users because of a fear of false alerts. Any automated distress system will suffer a certain percentage of false alerts, either malicious or inadvertent.  Training, education and equipment design will address the majority of these problems - but there is one solution that would really solve the DSC false alert issue…Mandate that all DSC equipment is to be fitted with an inbuilt GPS/GNSS receiver.

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  Every distress call will contain a real position.
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  This will all but eliminate malicious false alerts.
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  Inadvertent alerts will be identified and localised.

 GPS receivers are small and cheap – they could be easily integrated into a VHF radio.

  

In summary - Fixing DSC…

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  Remove the remainder of superfluous tele-commands from the standard, to simplify the system as much as possible…DSC isn’t going to be used for setting up phone or fax calls……
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   Mandate updating of ship equipment to comply with the latest standards.
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   Become pro-active with monitoring and real time education/mentoring.
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   Fit an integrated GPS receiver to all new DSC radios.

 

 

UPDATING THE GMDSS

Let’s get rid of DSC….it is all too hard…

There has been ‘corridor discussion’ at IMO of removing MF DSC from Sea Area A2 and possibly A3 – this smacks of the ‘turn it off and ignore it’ philosophy demonstrated by some ships.  Abandoning DSC would be a serious mistake.   The inherent strength of the GMDSS is the multiplicity of communication links it provides over different satellite and terrestrial bearers.   If one system is down, you always have an alternative. 

 MF DSC provides ship-ship and ship-shore alerting in Sea Area A2 and ship-ship alerting in Sea Area A3. 

 What do we replace it with?  Satcom systems can not provide direct ship-ship alerting to all other vessels in the area of the ship in distress. Inmarsat C has demonstrated its worth time and time again for ship-shore alerting – it is one of the GMDSS’ standout sub-systems.  However, it can not replace DSC.

Yes, DSC has problems – but we must fix them, not just give up and say it is all too hard…..

 

NBDP?  Ditch it…

NBDP (aka radio telex) is a clunky old system that (to my knowledge) has never been used in anger for distress traffic.  A3 ships already have an option to dispense with it – this should logically be extended to all A3 ships. I know if the water was coming in the bridge wing door, I would rather be talking into a microphone than trying to type on a keyboard…

 

A truly global system?

Australia is still effectively running 2 distress systems in parallel – GMDSS and pre-GMDSS.  Australia is not alone in this – many developed nations still run old and new marine radio networks.

 Many areas of the world have no GMDSS infrastructure at all…

 Why? The GMDSS has been in place for more than 10 years….

 If we are going to modernise the system, then surely we need to start with making it universal.

 

Way ahead……it isn’t rocket science….

 

·         GMDSS shore infrastructure needs to be installed in the Pacific.

 

·         Marine Radio equipment standards for smaller, non-SOLAS vessels need to be modified to include DSC. 

 

·         Governments need to amend their marine legislation to require DSC equipment to be fitted to all ships - large and small.

 

·        GMDSS Sea Area A1 needs to be declared in areas of high shipping activity.

 

·       Governments need to develop a transition plan to eventually phase out voice watchkeeping and replace it with automated DSC watches.

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