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WCDES Radio System Replacement

35 posts in this topic

It was never about space. We met with DES and the engineers when they were developing the current system and they told us the system would not work in our area and it clearly would not meet our needs. So we went out and developed our own system and they were correct it works better, even with mutual aid.

Thank you for the clarification. I didn't realize it was a coverage issues for some areas.

If the county has already decided what system they will be implementing there would have been studies as to why this new system would work well for Westchester. I have read some different posts about pros and cons between Digital as opposed to trunking. I am just curious if this would solve some of the coverage issues that some departments have with the current system? Could this really solve some of the issues we currently face with communications?

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And as far as digital anything being superior, TDMA is the reason why ATT wireless lost so many customers to Verizon, because the audio quality of the signal was so poor it caused them to ditch the whole system for GSM which is still sub par but somewhat acceptable.

You're comparing TDMA on a commercial cellular network to TDMA on a public safety grade P25 system...apples and oranges. Judging by your post, you've likely never experienced a P25 Phase II TDMA system with an APX radio. I have with Rockland's new system, and the fact is that Phase II TDMA with the AMBE+2 vocoder actually has better audio quality than Phase I FDMA with the IMBE vocoder. That's what it really comes down to, the quality of the vocoder determines the quality of the audio, and AMBE+2 is much improved over IMBE. Is the audio quality as good as 25 kHz analog? Of course not, no one is arguing that point. But for you to talk about signals on cell phones being bad, and somehow making the case for that being directly comparable to a P25 system, misses the mark.

Digital communication has no place on the fire ground, nor do trunking systems or 7/800 systems.

No one is arguing that point. The NFPA has been warning against the use of both digital and trunking for fireground communications for years, and with good reason. Fireground communications should follow the KISS principle, and should be analog simplex, period. Rockland is leaving fireground on UHF simplex, and I suspect so will Westchester. It sounds like you're under the impression that interior ops are going to take place on a digital trunked system...that is not the case.

Unless you have had your behind on the line and needed the cavalry you won't understand the importance of a basic system.

It cuts both ways. A well designed trunked system can actually improve coverage in some cases. How many times have guys been on portable on one of those "basic systems", and they're all static because the signal can't reach the receiver 5 miles away?

If we're going to have a discussion about these digital systems (which aren't going anywhere, by the way), let's at least be fair and deal with the facts.

hatr1k and E106MKFD like this

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No its a valid comparison. The error correction in TDMA is so sub par that it destroys the information so that its the ole talking in a fish tank. If you get even the most sensitive receiver you will still be dealing with the same nonsense. And then for the local govt.'s to be forced to pay 30 million to comply! If I can communicate with about 95% coverage with a cell phone tx'ing 600mw I should damn well be getting the same coverage with 4 or 5 and guess what, you don't.

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For those wondering what a P25 Phase II TDMA system actually sounds like, here is a short clip of some overnight activity on Rockland's system. The clip features both mobile and portable radios operating in several areas of the county, including Haverstraw, Pomona, and Spring Valley.

This audio was recorded on a PC connected directly to a Motorola APX 7500 Consolette, which is basically a mobile radio in desktop form. The audio was originally recorded as a .wav file, but was converted to .mp3 to make the file size more manageable online. Audio quality is slightly reduced from how it would sound directly out of the speaker of a radio on the system, but is still pretty representative of what these systems actually sound like in the field.

http://www.44-control.com/RCPSCS/RCPSCS_20131119.mp3

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But will I be able to talk to dispatch on a portable or will 60 continue to tell me "You're not making it on the portable, please switch to your mobile" (And impossibility when you are in the midst of patient care and/or quite a bit away from mobile).

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