Digital Pagers for volunteer Fire/EMS?

[iepoker]

Analog pushes better than digital. The range of the transmitter will be effected by what kind of system you use... transmitter height, hilly terrain, even the water table underground.

As a rule though, digital does not get the same range as analog.

I am NOT a fan of digital systems for many reasons: a) The expense of adding receive sites that you used to not need. b) The weird sounding audio along with the delay. c) As a dispatcher, you get used to how people talk, and can tell if they are stressed out and needing help just off that alone... digital takes that nuance out of the dispatchers ear (largely) because of the robotic sounding nature of the beast (think: Nextel).

...The one big benefit of digital systems I would imagine get reaped by Motorola/GE etc. by getting to not only sell you new super high tech gear, but youll need a lot more of it!

NOT a fan, not in the slightest sense of the word.

 

[thassler]

-->iepoker
..funny, most radio techs in my area would agree on the exact opposite; that digital has better coverage than narrowband analog. We have analog and digital systems (VHF) running on the same towers and digital has the better coverage by far. I am absolutely on-board about the audio though. I find myself switching over to an analog system every now and then just to remember what two-way radio should sound like....

-->op
If a portable digital or analog can succesfully transmit to a repeater then an analog pager should have no problems receiving from that same transmitter.

 

[SCPD]

Paging

Excuse me if I missed it, Rgur, but do you have paging now?
On the old system? Is this working fine?
I've been reading your post, and can't quite ascertain if the paging you are migrating from is all right.

If the current system is working fine, like others have said, why walk away from it. Here in Michigan, all the first responders around me are up on 800 Mhz. But all the paging has stayed put on the same old VHF freqs they have been using for 50 years. There was some preliminary talk of trying to get the handhelds to page. But smart thinking said "Why do I want to lug a 4 pound radio with me everywhere?"

If it's a case of the old system losing range, try running a new feedline. Like an old garden hose, old coax will leak RF. Radio vendors wouldn't sell half the systems they do if people put a new antenna and feedline up every ten years.

 

[iepoker]

I have been out of the game for a few years, and had stopped dispatching prior to the migration to narrow band... so you *may* be correct. But when I handled some digital equipment I was not satisfied with the audio quality AND when I was told about how much additional equipment would be needed I nearly laughed.

THAT MUCH MONEY FOR THIS QUALITY? I really was laughing at this point. The Moto guy was like "But its soooo clear sounding.". Sir, that is a perfectly clear robotic interpretation of my officer. I'd rather hear my officer. That dept, did NOT move to P25 digital after our initial testing phase.

I agree with the others Re: paging gear. Keep it where its at. Make it narrowband compliant and move forward. The FD in my area is up on 800 MHz, fixin to go to 700mhz digital, and our fire paging is on the same VHF-High freq that it has been on since... forever. 1960's maybe? The gear has changed, it is now narrowband (and still triggers my minitors), the technology has advanced... but the same old vhf pagers and QCII tones work. just. fine.

If it aint broke, don't fix it!

 

[SCPD]

Analog and Digital

Sometimes doing this comparison is like comparing apples and oranges.

When you migrate from analog to digital, more often than not, you are going from VHF to 800 Mhz.
Going from where a signal, regardless of the terrian, will do a decent job going quite a few miles, to where just about anything can reflect, refract and absorb the signal. You just can't lay a 800 Mhz antenna up under a coat and expect to get far. VHF is more tolerant of that. Here in my area, there was an accident where the responder was standing next to an aluminum semi-trailer and could not be heard until he moved over a couple lanes because the truck was absorbing the signal. Remember at 800/900, you're just about microwave. It's really not a good place for voice comms, I'm sorry. I know there's just way too much infrastructure in place to get away from it now, but I'm just saying. Yeah, it works out fairly well on flatlands, but even where I'm at, level land, it can go picket fence for no reason. Two people standing side by side, one is fine into the system, the other is garbled beyond recognition. No plausible explaination.
But that's what being up that high does.

As far as digital vs analog, here in Detroit, there is a VHF P-25 ham radio repeater. The digital can be heard three times as far as the analog, using the same radio into the same mixed mode machine. Like I said, this is VHF. It's the reason the federal alphabet agencies are staying put on VHF. They went digital, but they are not going up, and have the signal get intermittent. It's why Motorola don't bid the hills and mountains. Let OpenSky get egg on their face for trying to get a trunked system going in the Appalachian Mountains.

There's a lot of money to be made selling 800 Mhz multi-site microwave linked systems, and they are here to stay. So these type of problems are also here to stay. But don't blame the mode, blame the frequency.

 

[firefive76]

I thought this post was about pagers. To my knowledge, there are no digital voice pagers, correct? If you want voice paging, you have to use analog VHF/UHF. If you want digital, use alpha-numeric pagers.

 

[Firebuff880]

Good Morning,

I have a little different take on this based on the fact that I am in the messaging business.

First, digital can travel and be more effective than analog, BUT when you reach the end of digital coverage you reach the end and fall off the cliff. Where as analog coverage tends to tail off more slowly, the signal to noise just sort of degrades as you move beyond coverage.

Second, in today's world you really need more than one solution. As some of your users will be better off with portables on the system, while others may actually be more responsive to responding when needed to a cellular SMS based message. An a blend of all the technologies in between might fit depending on the size and nature of your department and activity levels.

One other factor to include is to look at the ISO standards, there has been some movement towards points / consideration for commercial secondary alerting.

Daniels has a good mix of paging solutions and transmitters, and I would look for a way, as many of said, to keep a alpha text and/or voice paging network active on a VHF / UHF license if feasible.

JMS
DAPage LLC creators of DAPage Notifications solutions for radio and cellular communications

 

[rgur]

Thanks everyone for the great feedback.

You can tell from the original post that I went in trying to determine what paging/notification options were available -- primarily to keep open the possibility for other (less intrusive) tower configurations to be kept in the running (satisfying the 95% coverage goal).

I came out much more well informed. Didn't really need to find another option -- Analog pagers are not the weak link (so some tower configurations had been discounted unnecessarily).

p.s.
Appreciate the last post as well; had been wondering if secondary-notification systems were an option. For notifying volunteers, seems that extending-the-coverage within and beyond the borders of the town by way of cell phones/etc. is a compelling idea.

 

[cg]

Secondary notification is only that, back up if the primary fails to get the message through. You never want to rely on a system that you don't have control over, ie cellular sms, commercial pagers, etc.

chris

 

[jhsands]

And you want your secondary notification radio to be on the repeater input frequency, so if the repeater fails, no big deal. Works great for us.

 

[kklyberg]

Fire Paging on a P25 Trunked Network

Relm Wireless has just completed a successful demonstration in Harris and Brazoria County Texas of their new Sentinel P25 Paging solution.
Basically the Relm engineers decided that DTMF could be used reliably on the P25 Simulcast network, the challenge was creating the interface to the dispatch console.
Using the P25 call alert feature Relm created a Sentinel Base Station that could affiliate using up to 64 unique P25 ID's (sentinel ID's), each ID would be mapped to a DTMF code which corresponded to a paging group. Each Fire Station was assigned a sentinel ID and their radios were programmed with an assigned DTMF code for the Page Group.
The Sentinel Base Station just needed to be located anywhere within the TXWARN system and affiliated, when the Dispatch Console sent out the Call Alert to the Individual Sentinel ID, the Sentinel Base received, acknowledged, and automatically acquired a voice channel on the Fire stations talk group, and sent the corresponding DTMF code, all the Fire radios with that DTMF code programmed would alert and unmute.

 

[rdale]

So these are hip-based pagers? Sounds like you're referring to something else.