Class B AIS, part 2

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

9 Responses

  1. Anonymous says:

    The command to change frequencies can also be received over the AIS channels. Message 22 handles this.

  2. Ben Ellison Ben Ellison says:

    You’re right, and thank you, but my understanding is that the USCG still wants DSC reception in Class B.

  3. Anonymous says:

    That is my understanding as well.

  4. Mike O'Dell says:

    the thing i don’t understand about the “class B” version is that the boats which will carry it are likely to be significantly *faster* and much more agile than the big boats with class-A hardware. this means the reduced reporting rates for class-B transponders is exactly the *wrong* thing to do if one cares about the fidelity of situational awareness. i realize that the big boats don’t really care whether they see the little boats but there’s a big chance for a success disaster here if AIS becomes significantly deployed outside the “must-carry” universe.

  5. Fred Pot says:

    In response to Mike O’Dell’s point:
    The international community is afraid that a higher reporting rate for faster boats carrying a Class “B” device will contribute to overloading the available bandwidth.
    “Competent Authorities” like USCG are much more interested in tracking boats than in allowing boats to use AIS for collision avoidance purposes.
    Personally I don’t disgree with your point. Class “A” devices on ships faster than 14 knots while making a turn report their dynamic information every 2 seconds. Class “A” devices on ships faster than 23 knots report their dynamic information every 2 seconds even if they are not making a turn.
    Class “B” devices were handicapped right from the start of the international negotiations that led to the new Class “B” performance standard.

  6. Robert says:

    Is there any AIS equipment that support a NMEA2000 interface and has anyone tried them out? I would certainly like to pop a T into my 2000 backbone and attach an AIS receiver (or class B, when available…or class A, when I win the lottery 🙂 Seems to be plenty of 0183 outputs.
    I’ve seen some advertisements, but no reviews and sometimes the manufacturers claim compliance before they actually are (e.g. “compliance” sometimes means partial implementation).

  7. Ben Ellison Ben Ellison says:

    Robert, I don’t know of any NMEA 2000 receivers or transponders. I too would like to see them developed. Where did you see the ads?

  8. del says:

    Does the Y-tronic splitter thing comply with any ISO / IEC / ETSI standards? I’m thinking of transients when it switches from VHF to AIS modes in particular….

  9. Simon says:

    SRT has just launched a very low cost AIS Class transmit and receive technology solution. This will enable manufacturers to produce a professional Class B this year and retail it for $500. As standard DSC is implemented as is chanel agility. Thought you guys might want to know that we have been beavering away at this for 2 years and its now available.

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