New ITU VHF band plan changes 2017

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jaspence

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VHF band plan

Your question needs to be clarified with specific details. DMR is already used on VHF, both for hams and commercially.
 

ecps92

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Interesting, if we believe ALL we read on the internet, the USCG is basically going to give up 21, 22, 23, 81, 82 and 83

Let's see if the US Approves this, I have not seen anything on the USCG Pages about this.
U.S. VHF Channels
INTERNATIONAL VHF MARINE RADIO CHANNELS AND FREQUENCIES

There use-to-be a VHF Narrowband break-down on the USCG Pages for Future, but it was removed about 5 yrs ago.

 

radioshane

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It was specific I said what digital modes are ships going over to has I've been doing a lot of heavy research and can't find anything
 

mmckenna

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It was specific I said what digital modes are ships going over to has I've been doing a lot of heavy research and can't find anything

I read through the above referenced documents and I did not see anything that suggested an digital standard was chosen for voice.
What I did see was that narrow band FM was recommended for the first step to 12.5KHz wide channels. The second step to 6.25KHz channels would require digital, but no mention was made of a chosen mode.
They also talked about the drawbacks of doing a 2 stage migration, how it would be problematic for users needing to purchase multiple radios through the entire process, first a narrow band FM radio and then a digital radio.

I'm not clear why there needs to be a push to 6.25. I read the document and I see where they are going, but I'm wondering if simply re-farming the service to narrow band and inserting channels in the spaces wouldn't be good enough.

6.25KHz is good enough for digital voice (think NXDN) but it's too narrow for anything other than short data bursts. Seems like that could be limiting things down the road. Easy enough to send an AIS position or DSC call over 6.25, but that's about it.
Seems like 12.5 would be "good enough" and wouldn't necessarily alienate everyone.
DMR would fit in the 12.5 channels, but not sure it's really necessary. NXDN would fit in the 6.25 channels just fine, but not sure that many channels is really needed. VHF marine does get a lot of use, but even with my time in the USCG and living in Seattle I never heard that much congestion.

There were a lot of good suggestions in that document, though. Doing away with several of the "ship to shore" telephone reserved channels is a good idea. Can't remember the last time I heard a phone call on Marine VHF.

Still, in the USA, this is going to be difficult. There are a lot of VHF Marine radios out there that will require replacement. Considering the political climate, forcing recreational users to replace their radios is going to be a problem.

Having two separate band plans wouldn't be out of the question. Every VHF Marine radio I've seen has a USA/International switch, so it wouldn't take too much to make this happen.


Some of the other documents talked about data and using data streams between ships, shore and other users. It was a bit vague, but it did talk about C4FM and some other digital modulation methods. This was strictly for data transmission, not for voice.
 

902

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Without considering the sociopolitical and economic factors (which are significant on their own merits), DMR in this application would not be spectrally efficient for 6.25 kHz.

Here's why: DMR achieves its 6.25 kHz equivalency by using TDMA. Radio on timeslot 1 transmits for a portion of time, radio on timeslot 2 transmits on the other portion of time. The thing that makes this efficient is the repeater station that can accommodate the two users by handling alternating data packets from slot 1 and slot 2.

Narrow NXDN (4K00 emission) would be suitable and would not only be "equivalent" but compliant to 6.25 kHz efficiency without infrastructure.

Would that be the choice? Who knows!

Last time I heard a VHF marine operator call was 1990, when I was servicing the New York Harbor and Inland Waterways public coast operations. I had a boat radio in my company service truck. Cellular had taken such a bite out of the system (pretty much Motrac-era IMTS stations with home-brewed T2-2R using telco inband signaling and 2 leased lines... sometimes over a few hundred miles), that I was tasked to replace the RT lines with "Wee Patch" microprocessor controllers that used carrier detect to dial a pre-programmed number over POTS lines rather than keep dedicated lines open. Guard on Channel 16 was also discontinued at that time (those were nothing more than Motorola "Plectron-type" desktop stations with antenna splitters between the station RX and duplexer). Just after that, it got sold to an investor named Murray, and now, MariTel and Motorola "own" the frequencies.

I kinda enjoyed listening to $7/min. operator-assisted calls with everybody else listening in, too.
 

slapshot0017

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These digital pushes are getting to be ridiculous and unnecessary... Marine works perfectly fine on wide band analog... LEAVE IT THAT WAY... I can see absolutely no reason other than voice clarity and spectrum efficiency, but Marine VHF works great on the high seas already and other than boaters who like to sit and BS about what they caught yesterday they're really aren't many users on it... Important freight liners and cruise liners use HF anyway for long range comms and when they come into port a pilot gets on and they use the ports radio system anyway... Just unnecessary to force all these people to buy radios they probably won't buy...
 

902

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These digital pushes are getting to be ridiculous and unnecessary... Marine works perfectly fine on wide band analog... LEAVE IT THAT WAY... I can see absolutely no reason other than voice clarity and spectrum efficiency, but Marine VHF works great on the high seas already and other than boaters who like to sit and BS about what they caught yesterday they're really aren't many users on it... Important freight liners and cruise liners use HF anyway for long range comms and when they come into port a pilot gets on and they use the ports radio system anyway... Just unnecessary to force all these people to buy radios they probably won't buy...

You make a valid point. But how can you sell radios if the old one lasts for 25, 30 years - or longer?

I'm being facetious with that, but I think that's the mentality. The people making the push are not necessarily the ones using the equipment. Any need for additional bandwidth would probably be resolved by pressing the button to go to 1 Watt output power. Then, the channel could be reused between other boaters. And, without infrastructure (land-based towers, satellites, etc.), what kind of data are you going to send 50 miles off shore - and to what?
 

mmckenna

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And, without infrastructure (land-based towers, satellites, etc.), what kind of data are you going to send 50 miles off shore - and to what?

If you take a look at the second document, they talk about that. Some of the highlights:
Map updates (like things change that often)
Fishing catch reports to DFG
e-Mail between ship/shore and ship/ship (don't see a big market for this)

But, I agree, some of this seems foolish. Going to narrow band FM makes a ton of sense. Going to digital doesn't.
I'd also add that "forcing" recreational users to upgrade their radios wouldn't be a bad idea. Some of these 30+ year old radios need to go for safety sake. I'd bet most recreational users ever have them checked out.
 

slapshot0017

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I don't know, narrowband seems to degrade the signal... I agree with upgrading for the purposes of safety and the fact that most boaters don't take care of their radios, but not for "spectrum efficiency" which brings down the range quite a bit.
 

mmckenna

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Yeah, good point.
However if you compare a 30 year old VHF marine radio to something modern, the sensitivity/selectivity is probably going to be a whole lot better.

Looks like they want to keep the RF power levels the same, 25 watts for ship, 1 watt on some channels, and 50 for shore.

So, a couple of things they could do better:
Higher quality radio, better receive specs, not really a big deal.
Force more channels to 1 watt, or at least have them default to 1 watt.
Find a way to get through to consumers that it really is all about the antenna. Some of the crap I see installed on boats makes you wonder if the thing even works at all.
 

MidLimNet

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In mainland Europe (River Rhine States) abt. 24 of all VHF Maritime channels are 1Watt channels, specific for the Netherlands Governments urges to use 1W. on all chnnels, due to heavy comms traffic overhere.
This is for Inalnd Shipping traffic, this is organised in the "Basel treaty" on Maritime Comms.

Btw didn't hear untill now abt. the digital comms, I doubt if will be a success, as there is nearly 100% GSM range, a smartphone is superb in this matter.
 

radioshane

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In mainland Europe (River Rhine States) abt. 24 of all VHF Maritime channels are 1Watt channels, specific for the Netherlands Governments urges to use 1W. on all chnnels, due to heavy comms traffic overhere.
This is for Inalnd Shipping traffic, this is organised in the "Basel treaty" on Maritime Comms.

Btw didn't hear untill now abt. the digital comms, I doubt if will be a success, as there is nearly 100% GSM range, a smartphone is superb in this matter.

I agree are there is lots of people on ybw boating forum south of England saying it's forced upon people
And on the ITU it is very vague what actually digitally mode the ships will use and some one else said on some of these channels it only be able to take data
and a lot of ybw people said not all channels are even full at the moment
When I was at uks biggest port channels was manic but not all channels were being used
Also in the middle of marine is alsar channels so they will have to be moved else they'll interfere with these new chanels
Also surely it will be gradual because boaters will be slower to get the new sets than ultra large vessels
 

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Some of the crap I see installed on boats makes you wonder if the thing even works at all.
A lot of the time they do transmit.

Usually on Channel 16.

For days until the battery runs down.

Being in a coastal area, I've let myself get pulled into a few self-activated searches by the local ham community. They mostly lead to private marinas and boats that have a decent amount of corrosion... sometimes inside microphones and connectors. Too bad most of those radios don't have time-out timers in them.

One of the reasons I gave up on listening to VHF 16.
 

radioshane

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Yes I really enjoy listening to ch 16 sometimes you get awacs search and rescue choppers to normal boats , lifeboats , and coastguard it's very exiting.
But does anyone have an idea what mode the new channels will use?
 

mmckenna

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I think you'll be fine with analog for quite a while to come.
There are millions of VHF marine radios out there that would need to replaced, and that won't happen over night.
Any migration to digital will probably be 20 years or more out. A digital standard wasn't chosen, and that argument would go on for a while. There's a lot of issues with doing that, so I'd doubt we'd see any change before then. Analog systems are just to prevalent to be replaced anytime soon.
 

ka3jjz

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When I read the comments about digital on VHF marine, my first thought was the use of AIS, which already has a toehold in that band anyway. Perhaps the ITU is thinking of expanding this service, or one like it?

AIS is already a very busy application, and in some areas, I can imagine that 2 channels wouldn't always be enough. Mike
 
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