Radio comms... what's next? Digital?

[xchief23]

Anyone want to gaze into their crystal ball and predict what's next on the horizon for radio frequency and communications? In talking with a radio dealer today, he said that the next possible change would be to digital communications. Nothing in writing yet, but he believed this would be the next logical change in the narrowbanding requirements. Of course, he wants to sell us digital radios that are backward compatible to analog. Any thoughts on what's next, and if the switch to digital radios would be worth it?

[Doc603]

xchief23,
I couldn't begin to tell you or our other brothers and sisters here on FH what the "great" pencil pushers at the FCC might come up with next but here is what I can tell you.

Here in the great state of NH the state issued (New Old Stock) digital mobile and portable radios to Police, Fire and EMS.

It seems most of the PD in the state have gone to digital. I know of very few Fire and EMS agencies that have gone digital.

In my LIMITED experience with digital I have one HUGE problem. As of right now the digital radios we've all been given get fuzzed up by "extraneous noise." What kind of noise? Oh noise like breathing/speaking through a SCBA mask, chain saw in the back ground, dogs barking, etc.

What the (smarter than me) radio guys have explained to me is this: The processor (?vocoder? I think they called it??) that changes our voices to digital (data packets) and then decodes the digital back to voice on the other end gets "fooled" into thinking this noise in the background is actually straight up data that is supposed to be transmitted as data (Like a mobile data terminal would send/receive).

Point in case, you're trapped in a partial collapse and attempt to call a MAYDAY! Your, "MAYDAY, MAYDAY, MAYDAY!" Could come out on the other end as GERDBERTIT GRRRR BEEP GRRRRR DAAAA (digital sounding noise).

Granted my experience may be limited, but this is what my experience has been with digital communications on the fire ground. Not something I want to see, that's a safety issue that none of us can accept. Maybe down the road when the hardware works better, maybe. But I don't see where it would get any of us ahead.

Narrowbanding gets us more room to allow more frequency usage, I get that. But where does going digital get us, beside putting more money in the pockets of those making and selling the infrastructure?

Sorry if this is long winded, but wanted to try to give a detailed explanation of what I have experienced.

If you want to hear my thoughts on the analog voice performance of our new radios, well that will be another long and negative response, LOL.

Hope this helps, and remember this is just my $0.02 worth.

[islandfire03]

Doc: You are not far off on the digital vocoder issues. Some brands had more problems than others.
Digital systems often require more infrastructure than analog. With analog a weak signal will still work.
With Digital , it either works or it doesn't, no in between.
That said: You should not be using a digital repeated channel on the fireground. You should have a simplex non repeater channel for ops, so you don't encounter electronic noise problems.

[ChiefKN]

There is a migration to digital... and I think that's okay to a limited degree.

Fireground should remain analog and simplex, imo.

[STATION2]

Our department, and county wide agencies, have been using 800Mhz systems for 20+ years. We have gone from Type I, to Type II, to Type IIi, to Smart Net to Smart Zone (All previous analog) and now we are preparing for the migration to digital. All radios, portable and mobile, purchased in last 3-years are either digital capable (flash upgradable) or digital. Granted we have been very successful with grant funds to cover all these costs (60+ portables and 20+ mobiles) but the constant "migration" is tiring.

An additional consideration is that when the final version of digital is placed in service the ability to "patch" or simulcast with a VHF paging system will be gone as the final digital version will not be able to transmit 2-tone tones. This, in conjunction with all VHF and UHF paging needing to be narrow-banded by 2013, will effectively end our voice paging over VHF simulcast. We are planning on implementing individual, or group, radio alerting.

Definetly a brave new world ahead of us in terms of radios and technology.

Be safe.