Back when they got that all going, one of the head guys emailed me all about it and why they started using Pro-No-Voice. He claimed the technology needed for it to work, made it unable to receive by the average public.
That's only half true. ProVoice uses the same IMBE vocoder that digital scanners use for P-25, but it uses a propriety set of protocols for modulation and error correction, and the company refuses to license these to scanner manufacturers so they can use it as a selling point for their systems(it even says so in the programming software help file, so I'd imagine you could find it in some sales literature too). Basically this is in contrast to the P-25 protocol which necessarily has to be openly published so that all the different radio manufacturers can use it to make their own implementation into radio platforms, yet still be assured it will work with other models of different make.
But hearing the fire dept. on analog tells me that they would still have great communication even on analog. To me, it's not Provoice that makes it work so well, but the high frequency in the 800Mhz. range that allows them to talk from basements all over town. Add to that, towers all around town to pick them up, sure it is better, but it doesn't have to be ProVoice to be that. They had some money to blow, so they blew it in for the best to keep the public out of their business.
Technically, your mostly right on this. It's not digital voice that makes a good system, but a thoroughly well designed and built out infrastructure makes a good radio system. Digital on top of this just works that much better. Unfortunately for you though, that system the city decided upon and built out was EDACS, and the only way to go digital on that is either AEGIS or ProVoice (developed to replace AEGIS). And AEGIS was originally designed in part to provide non-degraded voice when encryption is employed, and ProVoice does the same(as well as any digital voice in practice).
Now I will say this, ProVoice actually does sound pretty good when you listen to it on a radio(but therein lies the problem for the rest of us). In my now seasoned opinion, I would judge ProVoice to be superior in sound quality to P-25 in many instances, and I actually find it's unfortunate that it can't be used except for the very narrow proprietary purposes it's sold for. I would be quite the happy camper if I could use ProVoice with some of my buddies on the 70cm amateur band.
It's all about keeping the public in the dark. The city used to have phone patches in the 800 range. The night I heard a cop making a date with a lady other than his wife tells me they need their privacy. Yeah, I bet they do!!
The old system had a code mode when they wanted to air sensitive stuff. You'd hear this hash noise. Other calls like wrecks, routine stops, were clear. It's beyond me why they want even routine stuff kept private.
The rest of this is all truth brother. They may
say it's about keeping criminals from listening and thereby reducing crime, but they really
know that it's going to keep
everyone, not just a handful of criminals from listening, and they have no problem with that. Well, the results may have been that that handful of perps have gone without eavesdropping on the police, but it's not been accompanied by a promised and/or perceived drop in crime if your assessment of the situation there is accurate. And this has been at the expense of losing all the law abiding citizens such as yourself, who would probably call in a car or person that had been identified by the police over the scanner as being wanted or being searched for, becoming a free set of extra eyes for them, and reinforcing their communications and status with the community at large, not to mention that this does happen and it does help stop crime(by ending the ones in progress). What has happened though, just as they predicted, everybody at large would be in a radio blackout as far as police communications are concerned. For the lucky ones among us, we can get ahold of ProVoice radios and set them them up to listen, but that luck is about to be spread to everyone for free if you have a couple scanners and linux and some computer chops. Go look over in the control channel decoding forum and start reading up.
That's just plain paranoid.
Yeah, but when they catch
you acting paranoid, it means you're up to something and they have reason to be suspicious. But oh no! Don't try to reciprocate that logic on them. :wink: