Why do VHF radios only come with a AIS receiver not a transceiver?

[tanglewood]

Originally Posted by continuouswave

In the USA the FCC has already considered the problem of AIS transmitters that are not registered properly: the selling vendor MUST pre-configure the device with the customer's MMSI and GNSS sensor location data.

And I for one am thankful for it after seeing how many unprogrammed and incorrectly programmed AIS devices there are on boats from other countries.

[continuouswave]

A further problem for combining a VHF Marine Band DSC radio and an AIS transponder into one unit will be the marketing and distribution. Typically now in the USA a VHF Marine Band radio is sold without any involvement of the seller; the sealed box containing the radio is taken off the shelf by the seller and delivered to the customer.

If the radio is combined with an AIS transponder, the seller (in the USA) has much more involvement in the transfer to the customer. The seller has to get the customer's MMSI information and vessel data. The seller has to open the manufacturer's sealed box, power-up the new device device, and configure the AIS portion of the device with the customer's MMSI and vessel data for GNSS sensor location. Then the seller has to repackage the device, seal the box, and deliver it to the customer. The seller has much more overhead costs involved in selling the radio-AIS combination that he would have with just selling a radio. This added cost for the seller will likely be represented in higher selling prices for a combination device.

Also, will a seller of a combination DSC radio and AIS also program the DSC radio with the same MMSI as used in the AIS transponder? That seems like an obvious task, but, again, it puts more burden on the seller. What if the customer gets the radio-AIS combination and programs the radio with a different MMSI? More possibilities for confusion.

A further problem may be getting such a combination device certified. The typical regulatory demands for certification are different for radios than for AIS transponders, that is, different standards apply. Harmonizing one device to comply with two different sets of standards may be more difficult than making two separate devices, each compliant with the separate relevant standards.

As far as I can find, no manufacturer has a combination device with a VHF Marine Band DSC radio and an AIS transponder combined into one unit. Standard-Horizon announced about two years ago they were bring such a product to the market (the GX6500), but at this moment they have not fulfilled that promise.

[svmobert]

These issues will get sorted out pretty soon..

First, if there was a combo AIS+DSC+VHF unit, it would likely have only one screen/control interface and also likely combine the MMSI programming such that you program it with one MMSI and it uses that for AIS and DSC, this is trivial really.

As far as dealer programming being involved. Currently in the US, as you mention, it's more complex to purchase an AIS transponder than a VHF DSC radio due to the laws, but again, this will be solved soon...

1.) VHF radios often go unprogrammed by boat owners who buy a VHF and don't really understand DSC or the MMSI, and/or simply ignore it. This is a problem that is slowly being resolved but definitely needs to be solved for good.

2.) I know of one AIS manufacturer right now that will be releasing a new AIS transponder soon, and it will be consumer programmed (in a way that guarantees accuracy) even in the US. In any case, the dealer will not need to program it, and the programming will no longer need to be done before delivery to the consumer.

So, if you look out to the future, and you put AIS, DSC, VHF, and other digital modes onto a combined product roadmap, plus the fact that radio is moving to software defined where a single device can send, receive, and coordinate signals between AIS, DSC, and audio, even muxing AIS and DSC data into a digital voice signal, and then you consider that the VHF and AIS mounted in a vessel should have the same MMSI anyway, AND manufacturers have found a way to legally allow a consumer to program their AIS without the dealer involved... It's just going to work itself out in time. Just a matter of how much time. Despite my ridiculous runon sentence. ;-)

[continuouswave]

Originally Posted by Sea-TechSystems

...I know of one AIS manufacturer right now that will be releasing a new AIS transponder soon, and it will be consumer programmed (in a way that guarantees accuracy) even in the US....

That is certainly very interesting news. I assume you would rather not disclose which manufacturer, so I won't ask.

[svmobert]

Originally Posted by continuouswave

That is certainly very interesting news. I assume you would rather not disclose which manufacturer, so I won't ask.

NDA for now.. but it will be released soon and I'll have it on my website and announce it. Should be a pretty competitive offering to whats on the market today.

[Karanga]

Originally Posted by transmitterdan

A transceiver unit should never hear its own MMSI because the receive section is blanked during transmission. So hearing one's own MMSI can only happen if two receivers are on board. We already know that's a bad idea. But there are other reasons not to have multiple receivers.

Fragmented messages are just how it works. The ship information like name and other parameters are sent much less frequently than the navigation data (speed, location, heading, etc.). So a display must hold a data base of information to match up with incoming messages before it can show the full vessel status. Multiple receivers may output similar but not exactly the same information thus confusing a display. Also, the duplicate messages generate unnecessary waste of memory and processing time. Every position message will not be an exact duplicate because the relative location of the targets will never match. That's because the receive antenna locations on your vessel are approximated by you. So the relative position of a target when reported by two receivers will likely jump around and this can cause displays to get confused if they try to compute relative closing speed and bearing. It's impossible to avoid the problems. Don't use multiple AIS systems at the same time is all I can recommend.

I need a new VHF, and an AIS transponder. I have been thinking of the AIS display being provided by Opencpn.
But for redundancy and backup , I thought it would be good to have the icom 506 VHF, because it includes an AIS receiver and its own dot matrix display.
It seems that you are suggesting this is not a good idea to have more than one AIS system on board?
Can you please confirm how bad this idea is?
Thank you

[transmitterdan]

Originally Posted by DangermouseBlue

I need a new VHF, and an AIS transponder. I have been thinking of the AIS display being provided by Opencpn.
But for redundancy and backup , I thought it would be good to have the icom 506 VHF, because it includes an AIS receiver and its own dot matrix display.
It seems that you are suggesting this is not a good idea to have more than one AIS system on board?
Can you please confirm how bad this idea is?
Thank you

I think it’s not a great idea. The typical VHF AIS display is fairly limited. You have to also make sure that the VHF AIS can be programmed to ignore its own MMSI else it constantly thinks you are colliding with yourself. I don’t know if the VHF AIS can be told to ignore its own MMSI.

It would be ok if you can turn off the AIS function in the VHF until your main AIS transceiver fails. Then a backup receiver could be useful. But running two receivers simultaneously on the same vessel is going to lead to confusion generally.

[svmobert]

Originally Posted by transmitterdan

I think it’s not a great idea. The typical VHF AIS display is fairly limited. You have to also make sure that the VHF AIS can be programmed to ignore its own MMSI else it constantly thinks you are colliding with yourself. I don’t know if the VHF AIS can be told to ignore its own MMSI.

It would be ok if you can turn off the AIS function in the VHF until your main AIS transceiver fails. Then a backup receiver could be useful. But running two receivers simultaneously on the same vessel is going to lead to confusion generally.

It's not an issue. The ic-m506 has the ability to block MMSIs, for example your own MMSI if you have a separate transponder..

From the ic-m506 Manual...

" ID BLOCKING
The transceiver blocks AIS transponders that are entered into the ID blocking list. Enter your vessel’s transponder ID or other vessel’s transponder IDs if necessary to prevent the transceiver from detecting them as dangerous targets.
You can enter maximum of 10 transponder IDs."

Having it integrated into the radio makes it easy to select a target and make a DSC call to that vessel on the VHF. The only other way to do that is to use an AIS with a display (Icom MA500, Vesper Vision2, etc) where you can select a target on the transponder itself and send the DSC call to the VHF over NMEA.

[tanglewood]

Originally Posted by Sea-TechSystems

It's not an issue. The ic-m506 has the ability to block MMSIs, for example your own MMSI if you have a separate transponder..



From the ic-m506 Manual...



" ID BLOCKING

The transceiver blocks AIS transponders that are entered into the ID blocking list. Enter your vessel’s transponder ID or other vessel’s transponder IDs if necessary to prevent the transceiver from detecting them as dangerous targets.

You can enter maximum of 10 transponder IDs."



Having it integrated into the radio makes it easy to select a target and make a DSC call to that vessel on the VHF. The only other way to do that is to use an AIS with a display (Icom MA500, Vesper Vision2, etc) where you can select a target on the transponder itself and send the DSC call to the VHF over NMEA.

Yes, added in a later sw release after they buggered it up initially. And lots of other unresolved defects in their N2K implementation.

[Amaleo]

It is possible that modern pirates use AIS to target vessels, as off the coast of Honduras.
Due to this I have heard of some cruisers who turn off their AIS, even their VHF, however
this unnecessary since w/out a transceiver they would not be seen on an AIS. Radar probably, but otherwise no. All the more reason for cruisers to keep an eye out for other cruisers since they won't show on their AIS either. I especially watch for fast pangas closing in on me when in areas that are known to have piracy.

[continuouswave]

Here is a list of recently approved AIS devices for the USCG, a prerequisite for later FCC approval:

Recent Approvals for AIS Transponders - CONTINUOUSWAVE

Notice nothing there about Standard-Horizon GX6500.

The proffered explanation about a delay in the GX6500 coming to market being related to patent infringement might be true, but that would not be stopping the USCG from approving the GX6500. The USCG does not enforce intellectual property law in the USA. That is up to the person whose property is being infringed and the federal courts to enforce US Patent Law.

[denverd0n]

Originally Posted by continuouswave

The proffered explanation about a delay in the GX6500 coming to market being related to patent infringement might be true, but that would not be stopping the USCG from approving the GX6500.

I suspect the issue is that the probability (threat) of a patent infringement lawsuit has caused Standard Horizon to delay even asking the Coast Guard to approve it. I'm sure they don't want to go through the (somewhat expensive) approval process only to have to redesign the radio and then go through the whole approval process yet again.

[transmitterdan]

Originally Posted by Amaleo

It is possible that modern pirates use AIS to target vessels, as off the coast of Honduras.

Due to this I have heard of some cruisers who turn off their AIS, even their VHF, however

this unnecessary since w/out a transceiver they would not be seen on an AIS.

Amalie,

VHF radios with DSC capability can automatically give away their position when queried by another VHF DSC radio. All that is needed is to know the MMSI. Perhaps that is why some cruisers turn off their VHF in pirate waters. But they would do better to read the manual of their radio. On all radios it is possible to turn off the automatic response to a position query.

But many leave the automatic position response feature turned on to make it easier to find their vessel in a dark anchorage. A handheld DSC radio can be used to find its mother ship using DSC position query even if no one is on board.

[svmobert]

Originally Posted by transmitterdan

Amalie,

VHF radios with DSC capability can automatically give away their position when queried by another VHF DSC radio. All that is needed is to know the MMSI. Perhaps that is why some cruisers turn off their VHF in pirate waters. But they would do better to read the manual of their radio. On all radios it is possible to turn off the automatic response to a position query.

But many leave the automatic position response feature turned on to make it easier to find their vessel in a dark anchorage. A handheld DSC radio can be used to find its mother ship using DSC position query even if no one is on board.

If the boat is not transmitting AIS, it is extremely unlikely that a random nefarious vessel will have the MMSI of your vessel to send the position request over VHF. If the vessel is in VHF range, it's likely that the pirate already knows where the boat is, and can see it physically. If it's out of VHF range then it can't perform the position poll request anyway.

If your boat IS transmitting AIS, then any boats in range with an AIS receiver will have the position of your boat from AIS and hence not need to do a position request.

In any case, I feel like this is worrying about a non-issue. Finding your boat in an anchorage at night using position polling is pretty cool, or finding a buddy boat nearby when you aren't quite sure exactly where they are.

That said, I do know that some boaters silence their AIS transponder in certain areas for safety reasons, which may have value if it is expected that local pirates are watching AIS for lone small vessels to pursue.

If you are NOT transmitting AIS and a pirate has your MMSI already, then you are likely a valuable target, probably have security in place, and the pirates are tracking YOU, not some small unsuspecting sailboat.

Just my opinion of course.

[svmobert]

Originally Posted by tanglewood

Yes, added in a later sw release after they buggered it up initially. And lots of other unresolved defects in their N2K implementation.

Good thing it's updatable then.. In fact the most recent firmware update from Icom for the m506 came out November 7th.