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Thread: [Split thread] P25 Phase I/II, TRBO comparison, etc

  1. #1
    flecom No Longer Registered

    Default [Split thread] P25 Phase I/II, TRBO comparison, etc

    [Note by Mars: This thread split from the Arizona FF deaths thread.]

    Quote Originally Posted by Mars View Post
    I acknowledge what you're saying is unfortunately factual in some circumstances, but there's also the concern about liability. If someone assumes a task, and does so negligently, they may be held liable. I wouldn't want to be held liable if things went south. There's always the option of respectfully declining a task if insufficiently trained to do so, and outlining why one would be refusing the task, and how with proper training, one could do it, blah blah blah.

    In the real world, say no, and they'll find someone else to do it and you end up on the **** list.
    if you knew the stores I knew man... if you only knew...

    lets just say agencies do some really messed up stuff, sometimes (often) knowingly putting their people in danger...

    fortunately I myself have never been put in that place but I agree I would probably also walk away.. I could not sleep knowing that I may have had a hand in some disaster like this

    but then again, I know what I don't know... a trait a lot of highly technical (or quasi-technical whatever the case may be) persons lack... if you ask me to program your harris radio, no problem, I can make them do just about anything (even the whiz-bang stuff!) a /\/\oto radio for conventional, sure I can manage... /\/\oto trunking? I would have to defer to someone else

    reading articles like this then hearing about how P25 will fix interoperability (when P25 phase 1 & 2 are incompatible) makes me wonder what the future will hold.. it seems that things are more fragmented than ever... P25 1 & 2, conventional, trunking of all sorts, DMR, NXDN, blah blah blah... yet these guys couldn't even get conventional analog w/PL right?


  2. #2
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    P25 has turned into another marketing ploy. It's not really much of a "standard", when a big vendor like Motorola tries giving away encryption algorithms like ADP, which is not recognized as a standard, and renders communications between agencies using P25, incompatible, in terms of vendor neutrality.

    Can someone tell me again why analog (besides the fact it is a bandwidth hog) wasn't compatible/sufficient for "interagency" communications? Yes, patched audio can sound bad -- but that's the fault of the techs who aren't doing it right. I'm not much of a hammy fan, but check out K6JSI's whitepaper on "flat audio" - http://www.carolina440.net/flataudio_.pdf‎ - that's how you do it!

    P25 is nice for clarity and voice security, but it's not the easiest air interface/infrastructure to link-up between agencies. TRBO infrastructure (DMR) works much easier/better for that purpose, on the cheap.

  3. #3
    flecom No Longer Registered

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    ya DMR seems much more thought out which is ironic considering it's not considered up to "public safety grade"

    I am a fan of regular analog, can't get more vendor neutral than that... as far as bandwidth until you get to P25 phase 2 there is really no difference... but even that isn't totally set in stone and yet DMR is already ready to go?

    I wish Hytera made some 800mhz DMR stuff that would really change everything

    /edit: reading that paper on flat audio, good reading material right there for anyone who's ever wondered why their repeater sounds like mush
    Last edited by flecom; Oct 20, 2013 at 10:20 AM.

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    DMR and P25 Phase II sound identical. Both are using the same codec (AMBE+2) @ 2450bps, with 1150bps FEC. The air interface is different, so they're obviously not compatible. But it's basically the same thing. I personally used to hate TRBO, but have come to realize it does serve a purpose and can be used in a small-->moderate size operation -- even public safety, if the right consoles/programming are done. It's not unreliable by any means, but the radios are not built to PS standards.

    P25 Phase II is overpriced hype. It does conserve bandwidth by offering 2-slot TDMA voice channels, but it's definitely not a crowd-favorite in terms of audio quality!

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    Quote Originally Posted by Mars View Post
    but check out K6JSI's whitepaper on "flat audio"...
    Hover over your link in post in #2, looks like some gibberish was tacked on to the end of it

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    Quote Originally Posted by p47r4ck View Post
    Hover over your link in post in #2, looks like some gibberish was tacked on to the end of it
    I know. It only does it in Firefox. Use IE and the gibberish is gone. Makes no sense. The source code (post) is fine.

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    That's because most interfaces don't stick to the strict standards of Internet usage that Mozilla does. It's also why it is harder to infest with malware.... It's a minor inconvenience we put up with.
    "God as my witness" - Jeremy Dewitte - Felon