GMDSS Changes For 2024 ?

[BOBRR]

Hello,

I tried digging this all out myself, really, but beyond
me these days. Blame it on old age.

Regarding the GMDSS changes that are apparently
now effective in 2024:

Might someone please list the most likely frequencies
to pick something up ? (I'm right outside of Boston)

*And, what always confuses me, what mode(s) to use ?

Much thanks,
Bob

 

[merlin]

Here is a list of frequencies:

• VHF-CH16 (156.8 MHz)
• 2 182 kHz
• 4 125 kHz
• 6 215 kHz
• 8 291 kHz
• 12 290 kHz
• 16 420 kHz

These are still active and will be for a long time, but looks like eventually moving to Imarsat LEO constelation.
VHF is FM, HF is USB.

 

[hill]

2182 is no longer monitored by USCG.

They stopped it on 01AUG2013.

 

[INDY72]

VHF is NFM. In not so distant future 6.25 spacing, and most likely NXDN for digital.

 

[kayn1n32008]

VHF is NFM. In not so distant future 6.25 spacing, and most likely NXDN for digital.

When did marine go narrow?

 

[sonm10]

@kayn1n32008

Marine band going digital

Marine band going digital with a modified version of the dPMR the ECC have produced a report and ETSI modifying the DPMR standard with manufacturers. https://docdb.cept.org/download/3503?fbclid=IwAR1tGdhlzA5PkEWEi36JdbN1D5_sRmIQz_FSqLmv9YuR-Cpw_S_59DQc0Pk...

forums.radioreference.com

 

[mmckenna]

VHF is NFM. In not so distant future 6.25 spacing, and most likely NXDN for digital.

VHF marine is NOT narrow band FM. Yet.

There are plans to go to narrow band FM, but it has not been adopted yet, and it'll probably be decades before that really happens.

As for digital, that's way out past the narrow band plan. The ITU has been looking at it and has considered 6.25KHz digital, but they have absolutely NOT called it NXDN. While it may ultimately be, it's way too early to start calling it that. I suspect we'll all be long gone before digital Marine VHF every really takes off.

 

[kayn1n32008]

@kayn1n32008

Marine band going digital

Marine band going digital with a modified version of the dPMR the ECC have produced a report and ETSI modifying the DPMR standard with manufacturers. https://docdb.cept.org/download/3503?fbclid=IwAR1tGdhlzA5PkEWEi36JdbN1D5_sRmIQz_FSqLmv9YuR-Cpw_S_59DQc0Pk...

forums.radioreference.com

This does not answer the question. AFIAK, marine VHF operations are still wideband, and there hasn't been any move to narrow band or digital modes.

A brief look at the document in that thread shows some limited testing was done with NXDN @ 6.25kHz, in Estonia and the Netherlands, but a digital mode still needs to be decided on, and if it is NXDN or dPMR, the format needs to be modified to meet the needs of marine users.

 

[kayn1n32008]

VHF is NFM. In not so distant future 6.25 spacing, and most likely NXDN for digital.

It will likely be an existing protocol that is modified to meet the needs of the marine industry. So not likely NXDN.

 

[kayn1n32008]

Interesting comments from one of the locations that tested digital voice. 6.25kHz NXDN was used for the digital testing. However, a future digital protocol for marine use has not been settled on as of yet.

 

[mmckenna]

So, here is the USCG page on Narrow band on VHF marine:

Maritime VHF Narrowband Channels - 12.5 KHZ | Navigation Center

Narrow band VHF is permitted, but it is not well adopted. Not well adopted, as in try and find a VHF marine band radio that supports it.

Per USCG:
Limited operation on narrowband channels is permitted in ITU-R Radio Regulations Appendix 18, and is allowed in the US on public correspondence channels under 47 CFR 80.371(c)(iii) (Third R&O PR Docket 92-257 released 9 July 1998).
"Public Correspondence channels". That's marine operator channels.
As for digital on VHF Marine:

" 6.25 kHz is currently not authorized in the maritime service in either ITU-R or U.S. regulations."

As it says on the bottom of this page:

Maritime VHF Narrowband Channels - 12.5 KHZ | Navigation Center