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Old 08-10-2017, 16:16   #61
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Re: DSC (Digital Selective Calling) Explanation

cburger,
The short answer is: No
You can still use the radio to talk on cruiser's nets, and ham radio operations (assuming you're a licenses ham?), as well as use it to receive all sorts of signals (WeFax, SSB Voice weather, shortwave broadcasts, etc.)...
And, of course if you're within range (~ 5000 miles of Mobile, AL) of WLO, you can still use the radio to make and receive ship-to-shore telephone calls....
{and, if you're within range of USCG's NMN or NMC....or AMSA, or NZ Maritime radio/Taupo....then you could still use your radio to call them on SSB Voice, as they continue to maintain an SSB Voice radio watch on a few frequencies...}
Quote:
Originally Posted by cburger View Post
Does this mean that my older non DSC SSB is no longer serviceable ?
The long answer is....well it is long!
But, in the context of using a non-DSC HF radio to call / signal other vessels (or to call / signal the >80 HF-DSC shore stations, or the >450 MF-DSC shore stations, currently operating worldwide), then the answer is: Yes, it is no longer serviceable...and hasn't been since Jan 1999...


Please remember the GMDSS (Global Maritime Distress and Safety System) which mandated Digital Selective Calling (DSC) on both VHF and MF/HF radios (as well as 406mhz EPIRB's, INMARSAT-C, NAVTEX, and SART's), was implemented in 1992....and became mandatory for all signatory nations and all SOLAS vessels in Jan 1999...
So, this has been around / in use daily for decades now...



If you read this thread, from the beginning....and watch the videos, in their entirety....then you should be able to see that all of this is well explained...

I hope this clarifies things??
Fair winds...

John
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Old 08-10-2017, 19:33   #62
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Re: DSC (Digital Selective Calling) Explanation

Quote:
Originally Posted by cburger View Post
Does this mean that my older non DSC SSB is no longer serviceable ?
You can use a software app to do DSC on an older SSB radio. It is called PersonalDSC.

https://m.ebay.com/itm/Personal-DSC-...%257Ciid%253A1
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Old 21-04-2018, 21:16   #63
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Re: DSC (Digital Selective Calling) Explanation

How do these new Uniden Radios do Text messages to an MMSI ?

https://www.uniden.com/shop/communic...e-radio/#specs
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Old 22-04-2018, 11:21   #64
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Re: DSC (Digital Selective Calling) Explanation

Well, you can download the manual. But since that page says you must USE A SMARTPHONE AND BLUETOOTH to set that up, presumably you just send a regular SMS message from the smartphone, by bluetooth, to radio. Which just passes it on to the MMSI/DSC system.

Older equipment, even LORANs, allowed you to enter text just by menu'ing to the text entry screen, then using the up/down arrows to choose letters. Slow, but no fancy keyboard or phone required.
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Old 22-04-2018, 11:54   #65
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Re: DSC (Digital Selective Calling) Explanation

Quote:
Originally Posted by hellosailor View Post
Well, you can download the manual. But since that page says you must USE A SMARTPHONE AND BLUETOOTH to set that up, presumably you just send a regular SMS message from the smartphone, by bluetooth, to radio. Which just passes it on to the MMSI/DSC system.

Older equipment, even LORANs, allowed you to enter text just by menu'ing to the text entry screen, then using the up/down arrows to choose letters. Slow, but no fancy keyboard or phone required.
I did read the manual, and my take-away was that you can optionally use an IOS or Android APP over Bluetooth to setup the VHF radio and send "text Messages". But there is also a way to enter a message and send it only using the keypad and screen on the VHF and an MMSI. Without Cell service over VHF frequencies.

Anybody know anything about that ?
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Old 22-04-2018, 14:01   #66
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Re: DSC (Digital Selective Calling) Explanation

JM-
In theory you can send SMS across any systems, any devices. All that is required is a "gateway" across the networks. SMS originally was just sending single-packet text messages across the command/control channel of the cellular system. What they call "text messaging": now goes way beyond that.
The cellular companies got fancy and all put up gateways to the internet email system, so you can send an email to "123-123-4567@phonecarriersgateway.com" and it goes as a regular email, is received at the gateway, and then is forwarded in the cellular system. All transparent to the user.
For that to work from DSC there would have to be gateways set up within relay range of your radio. There could be--I've just never heard of it. Any junior high school programmer could set up the gateway...question is who's going to pay for it? Or why would they? (Quickly, call Mark Zuckerberg.(G)
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Old 22-04-2018, 14:07   #67
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Re: DSC (Digital Selective Calling) Explanation

JM, Hellosailor, et al,

Don't over think this....(and in reality since it's a Uniden specific product feature, it's probably not a great addition to this thread, and deserves its own discussion...but oh well.)

This seems to be Uniden's marine version of the original "gotenna" system...the original gotenna, allowed you to use your cellphone, via Bluetooth to the gotenna radio, to send SMS (texts) to another gotenna radio/user, using the gotenna radio on the VHF "MURS" channels..

It is also similar to the "Beartooth" system, although they allow voice comms and use the 902-928mhz band.

But, it appears that this is not a "mesh" network, as I don't think that is allowed on VHF maritime freqs, as this could cause serious frequency congestion / interference to the discrete Maritime VHF system!


And, specifically on-point, it appears that this does use VHF-DSC signaling functions (as you must have the MMSI# of any vessel you wish to send an SMS message to, programmed into the radio)...but unsure if your actual SMS /"text" is sent on another VHF-FM channel and the radio then sends this to your phone via Bluetooth, but this appears to be the case...
And/or, you can use the radio's buttons/screen to compose/send a SMS/text, without a phone linked to the radio.

Might be a nice toy to play with...but again, Uniden specific...


Fair winds.

John
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Old 22-04-2018, 14:17   #68
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Re: DSC (Digital Selective Calling) Explanation

Oh goodness, Pizzazz,
I didn't see this posting until now...

What you linked to is a fairly un-workable solution...aside from a few hobbyists, I cannot think of anyone who would consider a piece of software running on a windows laptop, etc., to be a workable solution for HF-DSC comms, where most of what the average sailor/cruiser needs from it, is Urgency or Distress signaling to RCC's and/or SOLAS vessels...

I can't think of anyone who'd be booting-up a computer, starting some software/APP and then verifying the radio is connected and working, etc. all to send a Distress or Urgency message, when in a dire situation...

Although, their software may work, in my personal opinion this is a ridiculous product to promote to those sailing offshore...


Fair winds....and again, sorry I missed this, 6 months ago.

John
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Old 22-04-2018, 14:52   #69
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Re: DSC (Digital Selective Calling) Explanation

Gotenna, Beartooth...Thanks John. "Yet Another Incompatible Proprietary Piece of ...."

But when you consider that SMS started out the same way, tagged onto a back channel, it might actually make sense to standardize something to provide that.

"Nossir, I didn't see that bridge pier, I was texting on my DSC radio at the time."
(Seen that movie before?(G)
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Old 29-07-2018, 13:29   #70
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Re: DSC (Digital Selective Calling) Explanation

While some here-abouts cringe when they see a posting from me with those three letters, DSC....this is just a radio propagation update....so, no ranting about DSC from me today!

There haven't been many changes to the GMDSS....there are a few....like Iridium's new offering from their "NEXT" satellites (Certus) awaiting GMDSS certification, and INMARSAT's Fleet Broadband waiting on the same.....
But, with the prices of those systems and airtime/data costs, it's unlikely any of my fellow budget-conscience cruisers will be ordering any of those anytime soon!!

And, of course just a reminder that the USCG no longer monitors any MF / 2Mhz channels, not 2182 on SSB, nor 2187.5 DSC....
But, of course, DO monitor the remaining 5 GMDSS DSC freqs 24/7, from multiple locations!

https://www.navcen.uscg.gov/?pageName=cgcommsCall



So, there are of course parts of the GMDSS that we all use daily, and many other parts that we equip our boats with....and while the GMDSS was designed to work without specially-trained personnel, it is good to know something about radios, radiowave propagation, MF/HF-DSC, etc....
So, that's why I made all the videos that I did...

This fall, it will be a few years since I recorded/uploaded these videos...

And, while neither the radio nor the basic approach to using it has changed, what has changed is the ~ 11yr solar cycle (which regulates the foibles of long-range radio communication)....

As you can see from this graph, when I recorded most of these videos in Oct 2013 (and again in early 2015), the sunspot cycle wasn't great (avg SSN of 55 to 60), it was much higher than today, in 2018...




So...
So, this month (July 2018) I did another video, updating and describing current HF radiowave propagation for the offshore mariner (whether they use maritime or ham bands)...

This new video, together with my earlier video regarding channel / frequency choice and the basics of Radiowave Propagation, should give many of you some assistance in getting the most out of your HF communications system on-board.



Have a look:









I've also added it to a few Playlists, so it will be available to all when the need it...




HF-DSC Communications
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX




Maritime HF Communications
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y




Offshore Weather
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY




Icom M-802 Instruction Videos
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr




Fair winds.


John
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Old 03-09-2018, 14:01   #71
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Re: DSC (Digital Selective Calling) Explanation

Hello to all,
I just recently uploaded a couple new videos, showing LIVE, real-world Ship-to-Ship HF-DSC calls...

I've added them to my HF-DSC Playlist...please have a look....(and, please watch the playlist in order, so that it all will make sense)

https://www.youtube.com/playlist?list=PLnN6ygtZ3h2n3z5nlv-ga2zYuPozhUXZX



And, for those completely familiar with their radio and with HF-DSC, here are the videos:

"Live, Ship-to-Ship HF-DSC Calling, on GMDSS HF-DSC Calling Freqs"
And, "LIVE, Routine Ship-to-Ship HF-DSC Calling, on ALTERNATIVE HF-DSC Freqs"

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Old 03-09-2018, 22:46   #72
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Re: DSC (Digital Selective Calling) Explanation

Great new videos John, that explained a lot in regards to ship to ship individual calls. It seemed odd previously why you would need additional dsc calling frequencies, but becomes clear when you realize HF has potentially global range and contention/congestion becomes an issue (issues dsc vhf does not have and all messages are transmitted on ch 70 as there is little concern for congestion with the limited range of vhf.)

I agree it needs a new thread, but the comments regarding SMS was interesting. Notice the new vhf marine frequency charts show what channels are acceptable to send a short message (vdsms.) I'd imagine to send a short message, eventually it will be q combination of a dsc message to tell the receiving radio to auto tune to channel 68 for example to receive a short message.

It was mentioned short message is a toy, I disagree, I think it is something that will finally bring dsc mainstream and accepted/used by most. For example think how useful it would be on a missed individual call, to leave a message "call me back at 1800z".



Thoughts?

PS. I don't think it's Uniden specific, it looks like vdsms is a standard Uniden was first to adopt, but any mfr radio can send a short message to any other radio (I should remove SMS from my post as it has nothing to do with cellular SMS, just links to your phone via bluetooth so you can use a keyboard on the phone instead of the clumsy radio text entry.
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Old 28-07-2020, 11:28   #73
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Re: DSC (Digital Selective Calling) Explanation

Hello to all,

Once again I'd like to add some clarifying information.



Due to my efforts to promote HF-DSC, I unfortunately went too far and inadvertently caused some confusion....please ignore and forget my comments specifically dealing with "routine" HF-DSC signaling (you can skip that video, as well), unless you have some unique/specific need to investigate / learn about "routine" signaling....

Please just stick with the "Distress" (MayDay) signaling and "Safety" (Securite`) signaling (for weather, navigation, communications testing).



Those of us on private yachts, with the Icom M-802, etc., will mostly be using MF/HF-DSC for "Distress" signaling (MayDay) or "Safety" signaling (for weather, navigation / communications testing, etc.)....and that's probably it...


And, you're going to be using one of the six Int'l GMDSS DSC "Safety" / "Calling" frequencies
[2187.5khz; 4207.5khz; 6312.0khz; 8414.5khz; 12577.0khz; 16804.5khz]



Although, I already mentioned that the USCG offers "automated DSC Testing" on 4207.5khz, from 3 of their locations, if you are beyond 4mhz comms range, they do accept DSC "Safety" calls for testing / verifying proper HF-DSC system operation, as long as you don't do this often (typically once per year / once per season, or only prior to an ocean passage).



Some additional supporting info for this:
From US FCC Part 80 Rules & Regs (Maritime Mobile Service):

80.359 Frequencies for digital selective calling (DSC).

(b) Distress and safety calling. The frequencies 2187.5 kHz, 4207.5 kHz, 6312.0 kHz, 8414.5 kHz, 12577.0 kHz, 16804.5 kHz and 156.525 MHz may be used for DSC by coast and ship stations on a simplex basis for distress and safety purposes, and may also be used for routine ship-to-ship communications provided that priority is accorded to distress and safety communications. The provisions and procedures for distress and safety calling are contained in ITU-R M.541-9 (incorporated by reference, see § 80.7), and § 80.103(c).



And, some further info (primarily dealing with the equipment and crew familiarity):

Quote from US Gov't Pub 117:


Use of GMDSS Equipment for Routine Telecommunications; GMDSS telecommunications equipment should not be reserved for emergency use only.

The IMO has issued COMSAR/Circ.17 (dated 9 March 1998) which recommends and encourages mariners to use that equipment for routine as well as safety telecommunications. The following recommendation is extracted from Circ.17:

Use of GMDSS equipment for transmission of general radiocommunications is one of the functional requirements specified in SOLAS chapter IV, regulation 4.

Regular use of GMDSS equipment helps to develop operator competency and ensure equipment availability. If ships use other radio communication systems for the bulk of their business communications, they should adopt a regular program of sending selected traffic or test messages via GMDSS equipment to ensure operator competency and equipment availability and to help reduce the incidence of false alerts.


This policy extends to all GMDSS equipment suites including Digital Selective Calling (DSC) on VHF, MF and HF, to the Inmarsat systems, and to any duplicated VHF and long-range communications facilities.



{Over the years, I've attempted to be a bit less USA-centric, trying to point to the international uses of the GMDSS.....and I've mentioned some sailors recommendations for using MF/HF-DSC in ocean rallies, etc., as well as encouraging the use of "regional MMSI's" for regional-group calling... but these are rather specialized / niche uses, and I now realize that those interested in them will either already be aware or will be smart enough to ask/learn....so, no need for me to be rambling on about them... }



Without going into the weeds of the original GMDSS plan, nor specifically Digital Selective Calling (DSC), please remember that this system was originally designed/planned in the late 1980's / early 1990's, and implemented starting in 1992....so, much has changed....not the least of which most "public correspondence" (ship-to-shore phone calls) is handled via sat comm, as are most "data comms" that aren't being handled privately via PACTOR....


While the MF/HF-DSC system (as well as the VHF-DSC system) is an integral part of the GMDSS (Global Maritime Distress and Safety System), the main use these days is the "Distress" signaling and "Safety" signaling, not the "Routine" signaling that was intended to be used for both ship-to-shore and shore-to-ship signaling, by both "public coast stations" (for "public correspondence" and ship's/fleet's business) and "private coast stations" (usually for ship's/fleet's business, using SITOR/FSK)...


So, while we can continue to rely on the GMDSS to be there when we need it [406mhz EPIRB's; NAVTEX; VHF-DSC-FM; MF/HF-DSC-SSB; SafetyNET broadcasts; INMARSAT-C (and now / soon-to-be INMARSAT FB and Iridium Certus); SART's (AIS-SART's or SART-X's)], we should remember (or rather I should accept?) that most sailors/cruisers (except those using NAVTEX...mostly in Europe or Asia), these days only use the GMDSS in times of "Distress"....so...


So, perhaps we could learn something from the IMO (International Maritime Organization) that started the whole SOLAS (Safety-Of-Life-At-Sea) idea, and came up with the GMDSS in the first place?



Maybe we should heed their advice?


Have a look again at what their advice / recommendations are:
Use of GMDSS equipment for transmission of general radiocommunications is one of the functional requirements specified in SOLAS chapter IV, regulation 4.


Regular use of GMDSS equipment helps to develop operator competency and ensure equipment availability. If ships use other radio communication systems for the bulk of their business communications, they should adopt a regular program of sending selected traffic or test messages via GMDSS equipment to ensure operator competency and equipment availability and to help reduce the incidence of false alerts.


This policy extends to all GMDSS equipment suites including Digital Selective Calling (DSC) on VHF, MF and HF, to the Inmarsat systems, and to any duplicated VHF and long-range communications facilities.



Perhaps this is simply what I should have recommended from the beginning, some ~ 17 years ago, when I first started touting "HF-DSC"? But, whatever the case, that's what I recommending today!


I do hope this info is helpful to you all.

Fair winds.

John


P.S. Don't forget the "stickies" here, on Maritime HF Comms

Marine SSB Stuff (how-to better use / properly-install SSB, & troubleshoot RFI, etc.)
https://www.cruisersforum.com/forums...tc-133496.html


HF-SSB Radio, Proper Installation Tips/Techniques, etc.

https://www.cruisersforum.com/forums...tc-198305.html


And, for those looking for the easy-peasy link to a free video series / Playlists, have a look here:


HF-DSC Comms

https://www.youtube.com/playlist?list=PLnN6ygtZ3h2n3z5nlv-ga2zYuPozhUXZX


VHF-DSC Comms

https://www.youtube.com/playlist?list=PLnN6ygtZ3h2m-IejYg7J6QugtO2epizxF


Generic Maritime HF comms
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nPNdApNsZDo_Jk3NB_Bt1y


Offshore Weather
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2mPZAx2vWzdjTJjHlChruyY


Icom M-802 Instruction Videos
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2npivDjoFrC-8QKVyMb4tVr


Offshore Sailing
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nbwAGh5DKgTCj15iyl6qoY
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Old 28-07-2020, 12:54   #74
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Re: DSC (Digital Selective Calling) Explanation

Interesting.


Before dsc radios, I imagined when I call a ship with dsc, the ship "must" respond.


So I wonder what happens with the calls we place but nobody collects?


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