Chuck / Jim, Chuck, your last paragraph says it all. THAT'S the bottom line on all of these new P25/digital voice systems - they are "not ready for prime time". Public Safety radio requires a level of reliability that I don't think ANY vendor has been able to meet with P25 technology. Unfortunately, I see someone being hurt before this issue is truly realized.
Jim... yes, many systems are engineered/designed around mobile access reliability/availability (the Illinois state system - STARCOM21 - specified 95% mobile access reliability in their RFP, I think. I have the system design document - 20 MB in PDF format...) and currently they are adding additional towers to accommodate portable access in higher populated areas, as well as more channels at the tower sites to accommodate the level of traffic on the system. But I think this will take YEARS before all the bugs get worked out. My biggest issue, as is yours, is the "it's either there or not" problem with digital voice technology right now. (I hope the manufacturers are listening to this!!) In the ham world, we use digital to communicate when you can't even DETECT the signal, but with these voice systems, it has to be PERFECT in order to be decoded properly. IMHO, we need to scrap the current VOCODER technology in favor of something more "tolerant" of a bit error level (or maybe employ error correction??). At least with analog, it the signal was down in the noise, you could still, in most cases, be able to discern what the person was trying to say. The other problem with the digital technology is that it does NOT play well with ANY background noise. Canine officers, officers at alarm calls, firefighters and others have experienced this first hand... and this is why they the fire service currently insists on analog on the fireground. Yes, the technology has GREAT potential but, IMHO, right now it is WAY too new for large scale deployment to public safety. Mark - N9WYS -----Original Message----- From: Repeater-Builder@yahoogroups.com On Behalf Of Chuck Kelsey While this may be true in many instances, the New York State system was intended to accommodate a huge number of users. I read the engineering results several months ago (so some of the detail has already become a bit faded in the old brain), and lack of coverage was a minor issue in the entire scope of the rejection of the contract - there were plenty of other serious flaws indicated. Sure, Tyco has filed a lawsuit. I think everyone expected that. You don't simply take loosing a $3 Billion contract (more when you start adding user radios) lying down. Do I think New York State was worried about paying the bill right now with the economy where it is? Sure. But I don't think that the supporting data after several rounds of failed testing is fabricated "political solution" either. And for those who don't know, the radios for the NYS system all did P25 in addition to OpenSky format. Not sure if the OpenSky radios in Pennsylvania would do P25. I was personally disappointed in the system -- I was really thinking it was going to work and be the solution. And it may eventually be made to work - but it's not public safety grade right now, at least not in my opinion, based on outside engineering reports and a few, direct, personal experiences. We'll see what the courts say about it. Chuck ----- Original Message ----- From: "wd8chl" <wd8...@gmail.com> To: <Repeater-Builder@yahoogroups.com> Sent: Wednesday, April 08, 2009 9:24 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? > The problem with both systems (and is also a problem with Ohio MARCS, > which is Motorola Smartnet w/P25 audio, and MI too), is that they were > designed and spec'd BY THE GOV'T to provide mobile coverage, not > handheld coverage, and they are trying to use it with mostly handhelds. > Also it was only designed to serve a few agencies (less capacity), and > they are cramming everybody and their brother on it, so it overloads > VERY fast. > I've seen this time and time again, where an agency goes for a new > system, and in order to save a buck, doesn't listen to the engineers, > and they wind up with a system that doesn't cover what they want.
