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Thread: Voting Rx in Non-Simulcast Situations - Why "The Look"?

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    Default Voting Rx in Non-Simulcast Situations - Why "The Look"?

    I must be missing something. It happens. Sometimes too much.

    Every time I ask why isn't there a voting solution which can help in situations where the "talk-back" side of the communication equation is challenged, I get "the look".

    But I don't really get the answer.

    Sure, Motorola has the voting receiver thing (GCM 8000) but only for simulcast deployments. And Daniels appears to be working on a single, standalone site "digital voting" talk-back enhancement, but the fine print somewhere points to simulcast-only application. From the number of times I've received "the look" when trying to push for an answer, and now from direct "no, only in simulcast" answers, I'm kinda losing hope that such a solution exists.

    But that's ok, if a reason exists.

    Does anyone know why there doesn't seem to be some way to deploy a voting solution in a non-simulcast P25 trunking solution?

    Thanks.
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis


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    There is, P25 multicast voting. Multiple P25 repeaters with the same input frequency and different output frequencies. Pair that with conv voting scan in the subscriber and a comparator and you have a wide area voted multicast network.

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    Hi Vette86,
    Thanks for the reply. I'm not entirely clear on what you're explaining.

    Are you suggesting putting out more sites (with repeaters and site controllers) to cover the area which hears but cannot talk-back to the trunking tower?

    Which repeaters should be set to the same rx freq? All of them? Or a subset at the main trunking site? Or the remote receiver sites?

    Thanks!
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis

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    I am surprised Motorola doesn't support this, I know they DO support rx only sites in there new analog IP based simulcast and I thought they did with the P25 IP simulcast as well.
    "Don't worry about what I am, cause I'm a state agent so what you need to do is make sure your doing the right thing **** boy" -J. Dewitte

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    Quote Originally Posted by jimbo View Post
    I must be missing something. It happens. Sometimes too much.

    Every time I ask why isn't there a voting solution which can help in situations where the "talk-back" side of the communication equation is challenged, I get "the look".

    But I don't really get the answer.


    Sure, Motorola has the voting receiver thing (GCM 8000) but only for simulcast deployments. And Daniels appears to be working on a single, standalone site "digital voting" talk-back enhancement, but the fine print somewhere points to simulcast-only application. From the number of times I've received "the look" when trying to push for an answer, and now from direct "no, only in simulcast" answers, I'm kinda losing hope that such a solution exists.

    But that's ok, if a reason exists.

    Does anyone know why there doesn't seem to be some way to deploy a voting solution in a non-simulcast P25 trunking solution?

    Thanks.
    The GCM8000 does support non-simulcast P25 recieve voting. Not sure y you have been told it only suports simulcast.

    It says it does right in the brochure for the product too.

    The GCM 8000 Comparator supports up to 15
    trunking sub-sites and up to 64 conventional sites
    for simulcast or receiver voting. It performs frameby-
    frame voting on multiple received signals and
    recombines the frames to produce a signal with the
    best possible audio quality.

    You can also purchase RX only GTR's,
    Kinda Like the Astrotac's Recievers, which is nothing more than a Quantar without the TX parts.
    Last edited by moetorola; Oct 24, 2013 at 07:53 PM.
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    Quote Originally Posted by moetorola View Post
    The GCM8000 does support non-simulcast P25 recieve voting. Not sure y you have been told it only suports simulcast.

    It says it does right in the brochure for the product too.

    The GCM 8000 Comparator supports up to 15
    trunking sub-sites and up to 64 conventional sites
    for simulcast or receiver voting. It performs frameby-
    frame voting on multiple received signals and
    recombines the frames to produce a signal with the
    best possible audio quality.

    You can also purchase RX only GTR's,
    Kinda Like the Astrotac's Recievers, which is nothing more than a Quantar without the TX parts.
    Hi Moe,

    You are right - the product literature SAYS it can do it, but when I get the rep in the room, with supporting engineering staff, I get the "only in a simulcast model" answer. I'm not sure why either. It's frustrating.

    Here's a diagram of what I was hoping to achieve. I could be screwed up with my positioning of the comparator (don't know if it's something that would be at the site or at the core, but you get the idea.)
    Voting Rx in Trunking.png
    Maybe I'm just not seeing something. I figured this would have been child's play. I figured wrong, I guess. (Story of my life...)

    Thanks!
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis

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    Sounds like you need to speak with someone else. I Show in my Motorola Training manual/s set up for Trunked voting. And a seperate one for Trunked Simulcast.

    What version sytem are you? Or will be?
    Radio Referenced...Those who think they know it all are very annoying to those of use who do.

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    Just to follow up on this, my Moto rep and his team informed me that with R7.14, the functionality that I was looking for in terms of voting receive in the multicast P25 VHF trunking context is supported. Don't really have time to look into it right now, as we're up to our eyeballs here in the main effort, but when it comes time, I'm going to dive into this and report back.
    Thanks for the help, everyone!
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis

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    syntrx No Longer Registered

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    Quote Originally Posted by jimbo View Post
    Hi Vette86,
    Thanks for the reply. I'm not entirely clear on what you're explaining.

    Are you suggesting putting out more sites (with repeaters and site controllers) to cover the area which hears but cannot talk-back to the trunking tower?

    Which repeaters should be set to the same rx freq? All of them? Or a subset at the main trunking site? Or the remote receiver sites?

    Thanks!
    The technique Vette86 described is for conventional only.

    If you added satellite receivers in a dead spot, you would need to add a receiver for every channel on the parent site anyway. Just one channel isn't going to do. Given the equipment outlay required to do this, you might be better off simply building a new fully fledged site.

    If the dead zone is an enclosed environment (e.g. shopping mall, tunnel) you could install a bunch of BDAs and point those, via yagis back to a (preferably quite distant) trunking site. You can do this for small outdoor locations as well, in certain circumstances and with great care.

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    The scenario we're faced with sees us on an excellent hill top for transmitting but with several other very strong stations creating a serious noise floor. A gent at a different website called it an "alligator" situation - all mouth and no ears. Great transmit, but it's like this: you can be the best trumpet player in the orchestra, and everyone can adore how well you play, but you'll never be able to hear someone in the audience talking to you because they're completely drowned out.

    So if I remote my "ears", I'd be further ahead. The problem with a new, fully fledged site is the need to indent for more frequencies, put new transmit capacity in, and the resulting power demands - which might outstrip the capacity of the installed plant. It seems natural to me that to put just a simple receive site in place, with the appropriate number of receivers and a single microwave or landline backhaul, (and no emitter noise-floor to deal with) you'd make out pretty well. When I get a chance, I'll price out the rx-only solution in more detail, but just scanning our price list, it looks much less expensive to set up a receive-only rig. The economics are important, as you implied.
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis

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    http://www.simulcastsolutions.com/

    Deal with someone who knows what they are talking about. Stop talking to Motorola employees. They don't know **** except how to bring you a PO to sign so they can meet their quarterly numbers

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    Also ask the schmucks why they have option CA02208AA - ADD : DIGITAL CONVENTIONL BR VOTING TO SIMULCAST UPGRADE in their catalog if you can only vote simulcast systems

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    Quote Originally Posted by jimbo View Post
    Just to follow up on this, my Moto rep and his team informed me that with R7.14, the functionality that I was looking for in terms of voting receive in the multicast P25 VHF trunking context is supported. Don't really have time to look into it right now, as we're up to our eyeballs here in the main effort, but when it comes time, I'm going to dive into this and report back.
    Thanks for the help, everyone!
    It looks like Motorola is giving him what he needs.

    I would of told them from the get go, thats to bad Moto you can't do trunked Muilticast voting, we have a meeting with a company that says they can make it happen. That would of gotten the sales/ enginneers doing a little research real quick.

    Glad your are getting what you want/need out of Moto. It will be much cheaper with just RX'sites. Sometimes you gotta threaten. But it will be a heck of a system in the end.
    Radio Referenced...Those who think they know it all are very annoying to those of use who do.

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    If it's worth noting, we currently operate a trunked VHF system from Moto that is a hybrid simulcast system. Single TX, multiple RX utilizing ATAC receivers, ATAC3000 comparators and Quantar repeaters.

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    Single TX = nothing simulcast about it. Where are you getting the term "hybrid simulcast"?

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    Quote Originally Posted by d119 View Post
    Single TX = nothing simulcast about it. Where are you getting the term "hybrid simulcast"?
    We operate a Moto "simulcast" system but we only have one Quantar per channel. All of the infrastructure is setup to be true simulcast, it thinks it's simulcast, but we don't require a full set of Xmitter's since our inbound paths are the issue. That and we also operate multiple simulcast cells and IR sites to make it more of a "hybrid" multi-cast / simulcast system. While this is non-P25, Moto is trying to upsell up to 7.x infrastructure to do the same job.

    So yes if you want to argue wording it's a hybrid system with a single Xmitters per channel, multicast transmissions on simulcast hardware.

    Tada

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    Reading through this thread I didn't see if the OP was running a Conventional or Trunking system. Maybe I missed it.

    Either way, I run a VHF non-simulcast conventional system with six transceivers that are tied into my voting system. We currently utilize the Raven M4X SNR voting system for all out recieve audio. It took some finagling to get it set up correctly, but the Ravens do support transmitter steering as well if programmed correctly.

    I don't know if this what you're looking for or not, but I figured I would throw it out there.

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    Quote Originally Posted by jmfirefighter20 View Post
    Reading through this thread I didn't see if the OP was running a Conventional or Trunking system. Maybe I missed it...
    Trunking.

    Quote Originally Posted by jmfirefighter20 View Post
    ... We currently utilize the Raven M4X SNR voting system for all out recieve audio. It took some finagling to get it set up correctly, but the Ravens do support transmitter steering as well if programmed correctly.
    I'll check that out. There's no need to hit everything with trunking and there are places where a voting system will be a better solution (economy, reliability, etc.) Thanks for the reference.
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis

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    SNR voting and P25 don't mix, do they?

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    Quote Originally Posted by noaffiliatefan View Post
    SNR voting and P25 don't mix, do they?
    I should have prefaced my post with the fact that we use the Ravens on the analog side of our system. Our P25 side is run through AstroTacs.

    The Ravens are pretty robust little boxes, I wouldn't be surprised if they already do this. I like them, they work well but we'll be getting rid of them soon when we set up our simulcast system.