Listening to 800Mhz traffic with your pager?

[koechler]

Since there is no 800Mhz pager because digital trunked radio is simply not suited for reliable alerting it looks like most departments are keeping their conventional UHF, VHF, low band frequencies for dispatch. The battery live of a P25 Pager would be a nightmare by the way.

I don't exactly understand how the P25-Traffic gets simulcasted on the analog network and I'm sure you guys could enlighten me. From what I understand a digital trunked radio system shares a number of frequencies with a large group of users and assigns the frequencies on an as needed basis to talk groups. When all the frequencies are busy it is not possible to establish any new communication. Now...so there can be multiple talk groups on the P25 network but only one on the analog network. Which P25 talkgroup will be simulcasted on the analog network and does this have to be done manually? I assume it wouldnt make sense to simulcast all P25 talkgroups to the single analog frequency...

Thanks for your help.

[tree68]

The miracle of computers....

Really. There are several ways it can happen, but they all involve a "gateway" between the digital system and an regular analog radio. It's a piece of hardware that turns the digital voice into analog and provides the keying that makes the radio transmit.

The incompatibility between straight tones (as opposed to voice) and digital throws a wrinkle into it, but it's not a big issue.

On trunked systems, talkgroups (and the gateway radio becomes just another talkgroup) can be patched together, either in the system configuration or by the dispatchers. This can either be done so that all traffic on the talkgroups is shared, or only that originated by the dispatcher. The result will be either that you hear all traffic on the talkgroup on your pager, or just what the dispatcher sends (ie, no mobiles, etc).

Paging notwithstanding, it means that at a major incident, all users who are players in the incident can be tied together using whatever talkgroups they choose (usually a tac group) even if they don't have the other agencies TGs in their radio. Fire TAC5 can be patched to police TAC6, etc.

[hwoods]

Hmmm............

We're about to go to a 700Mhz Digital Trunked System here. We will have a pair of Frequencies in the 155Mhz area for alerting and other such uses as may be determined later. From conversations with knowledgeable People in the Communications field, I've decided to wait a bit before going after any "Personal Communications" equipment. Digital Scanners that cover the 700Mhz Range are out there now (at Radio Shack, I just spent a bit of time going over one last week) and Digital Pagers are available as well........ Major, Major, Point in this is DO NOT turn off your old System until EVERYONE is Satisfied that the New System is Performing at 99.99%....... (Nobody, even the Fire Sevice, gets 100% in these times. )

[nmfire]

The short version of what Tree said. The hardware that runs the trunking system can be connected to an old radio. You tell it to patch talkgroup X into this VHF radio and it does it. It can hard wired or it can be dynamic controlled by a radio console. Very common.

[koechler]

Digital Pagers are available as well........

Thanks for the info but I wouldnt know of any P-25 pagers nor DMR or NEXEDGE. Are you maybe talking about a digital FLEX or POCSAG pager? I 100% agree that you must keep your analog frequencies at all cost.

[koechler]

Thanks for your help guys. I love this forum!

[hwoods]

Oops................

Thanks for the info but I wouldnt know of any P-25 pagers nor DMR or NEXEDGE. Are you maybe talking about a digital FLEX or POCSAG pager? I 100% agree that you must keep your analog frequencies at all cost.

My Apoligies, I misunderstood your Question. Our Current Pagers are Alpha-Numeric, so that we have a Printed Message to refer back to, when needed. Our new System will be digital, and we're looking at a new Alpha-Numeric Paging system that will be compatible. We like the Alpha-Numeric system because you can keep a message as long as it's needed, where the "Minitor" style Tone activated Voice Pagers are a "Get it the First Time because it's not repeated" Type of thing. In an organization such as ours, (And everywhere else around the East Coast) Our type of system is the only COST-EFFECTIVE system out there. Purchasing Portable Radios for the 700 Career Firefighters and 2,000 Volunteers in our Department would be a bit shaky.......

[tree68]

Thanks for the info but I wouldnt know of any P-25 pagers nor DMR or NEXEDGE. Are you maybe talking about a digital FLEX or POCSAG pager? I 100% agree that you must keep your analog frequencies at all cost.

To my knowledge, there are no pure pagers compatible with any trunking system. it's the nature of the beast.

As Harv points out, there are alphanumeric pagers available. People use them all the time - they were the "big thing" before cellphones, and particularly texting came around.

The ideal situation is your dispatch having a CAD system that can automatically send out an alphanumeric page on your own dedicated system.

Our CAD system can send out an e-mail, which is essentially what all text messages are. They limit the recipients to our chiefs (otherwise it would be an adminstrative headache for them), but will send it to a "group" such as Googlegroups, from which it can be broadcast to virtually anyone you want it to be. It's not a primary notification system, but it's fairly reliable (and has been known to beat the tone/voice pagers) and provides the same plus as A/N pagers - you've got it until you erase it. And you can "bounce" the message to regular email accounts as well.

[CaptOldTimer]

IF your dept used VHF or UHF and also utilize a Minitor receiver or something similar then the dept. should keep those receivers and simulcast or patch the 800 traffic will be heard on the receiver. BUT they have to keep the frequency which was used by the minitor or receiver.