What's the weirdest/most complicated Public Safety radio network you've seen?

[thisissparta789789]

For me, it would have to be
1. The monstrosity of a fire-EMS radio "network" that Nassau/Suffolk counties use, if it can even be called a network. Too many different dispatching centres operating on an excessive amount of paging and fireground frequencies, all utilising wildly different alerting tones. Interop must be a nightmare down there.

2. FDNY's dispatching frequencies, and duplex networks in general. Don't get me wrong, it's a heck of a lot more organised than the other 2 examples here, but... WHY... What's the point of splitting up the communications into 2 channels?

3. Various systems, primarily in Pennsylvania, that utilise or utilised multiple paging channels for one call. An example would be Cambria County's old fire paging system, which utilised one frequency to send out siren tones, and then, those tones would activate another encoder at the station that would transmit pager tones over an entirely different frequency. Colonie NY used the same system until about 25 years ago. These systems were often older than most of the dispatchers and firefighters that used them by the time they were ditched.

 

[ATTACKFF]

What freq. did Cambria County use to send tones out? I was under the impression that is was 33.70 low band that was used for all fire dispatching in the county(except Johnstown city). I know most stations had a "siren" and a "pager" tone, but both were activated off of 33.70 as far as I knew.

 

[druhe]

What freq. did Cambria County use to send tones out? I was under the impression that is was 33.70 low band that was used for all fire dispatching in the county(except Johnstown city). I know most stations had a "siren" and a "pager" tone, but both were activated off of 33.70 as far as I knew.

He's referring to the old Pelectrons that several stations through out the county had. The dispatch center would activate the siren then a secondary tone would be transmitted from the fire station to activate the Pelectrons.

 

[VE3RADIO]

Bell Fleetnet is a good one..

4 zones.. across a province that is bigger than several states put together.. Police, Fire, EMS, Roads, Natural Resources Police.. etc etc..

 

[Jay911]

Bell Fleetnet is a good one..

4 zones.. across a province that is bigger than several states put together.. Police, Fire, EMS, Roads, Natural Resources Police.. etc etc..

The crazy part about FleetNet to me is that the zones aren't interconnected (as far as I know). What happens for example if there's an incident halfway between Lindsay and Peterborough requiring agencies/units from Z1 and Z2? I can believe that units in those areas might have other zones' sites - maybe a couple - programmed in, but I can't imagine the workflow is at all seamless.

On the other hand, technology has come a long way in a few short years. Years past, the idea of the ultra-wide-area systems like Maritime TMR2, PPSTN, or AFRRCS were not feasible with the existing tech and backbone.

 

[thisissparta789789]

The crazy part about FleetNet to me is that the zones aren't interconnected (as far as I know). What happens for example if there's an incident halfway between Lindsay and Peterborough requiring agencies/units from Z1 and Z2? I can believe that units in those areas might have other zones' sites - maybe a couple - programmed in, but I can't imagine the workflow is at all seamless.

On the other hand, technology has come a long way in a few short years. Years past, the idea of the ultra-wide-area systems like Maritime TMR2, PPSTN, or AFRRCS were not feasible with the existing tech and backbone.

They actually have a radio network for an entire province in Canada with ONLY 4 zones?
How many frequencies are on each zone?

 

[thisissparta789789]

He's referring to the old Pelectrons that several stations through out the county had. The dispatch center would activate the siren then a secondary tone would be transmitted from the fire station to activate the Pelectrons.

Oh yeah. They were both on the old 33.7000 frequency. Colonie NY's fire dispatching system did, however, use 2 different frequencies for siren and pager tones. Until the 80s, the stations had Plectron encoders that would activate on each of their own frequencies. After the mid 80s, they switched to one paging channel for fire calls and they began using their old EMS ops frequency to tone out the then mostly FD-based ambulances alongside EMS operations. They kept their 40-something siren frequency until the late 90s/early 2000s.

 

[Jay911]

They actually have a radio network for an entire province in Canada with ONLY 4 zones?
How many frequencies are on each zone?

How many frequencies per zone is an odd way to measure. Each zone has between 35 and 60 sites, and most sites have between 5 and 8 frequencies.

Bell FleetNet - Ontario Provincial Government Zone 1 Trunking System, Southwest Zone, Ontario - Scanner Frequencies
Bell FleetNet - Ontario Provincial Government Zone 2 Trunking System, Southeast Zone, Ontario - Scanner Frequencies
Bell FleetNet - Ontario Provincial Government Zone 3 Trunking System, Northeast Zone, Ontario - Scanner Frequencies
Bell FleetNet - Ontario Provincial Government Zone 4 Trunking System, Northwest Zone, Ontario - Scanner Frequencies

 

[902]

There were two tunnel systems that I got brought into. They were both VHF simplex. The first was originally constructed with (get this) twinlead. There was a pre-SpectraTAC Motrac vintage comparator that used DC current to vote.

The second was used for both surface and underground. The surface had a SpectraTAC comparator, underground, there was this custom built audio summation bridge that summed everything together. It looked more like a wide area PA system than a radio network. But RF from the underground would leak out into the street and vice versa. There was a problem on one platform, where the underground and the surface stuff bled over into each other. I had to "fix it." I ended up taking the base for that zone, and turning it into a voting receiver with its own signal quality module. Worked like a champ. Problem was "train dust" getting into everything.

There was another that took AM radio from the outside, heterodyned it down to an IF frequency, then heterodyned it all up into channelized cards, and sent it to a big amplifier down the coax. There was a cut-in system that worked on the IF frequency that allowed messages to be broadcast out, except the frequency of the messages was about every 30 seconds and the messages were preceded and succeeded by these annoying tones. Actually made you want to turn your radio off rather than listen for information when you were stuck in a traffic jam.

And then, there was this trunked radio system that was half-LTR and half APCO-16 (Oy!)

I'll post s'more when all those memories I've tried hard to repress come to the surface again.

 

[slicerwizard]

Bell Fleetnet is a good one..

4 zones.. across a province that is bigger than several states put together.. Police, Fire, EMS, Roads, Natural Resources Police.. etc etc..

Fleetnet is neither weird or complicated. It's just four independent Motorola SmartZone networks.

 

[PACNWDude]

Mine was a network of 16 Motorola Quantar repeaters, and associated combiners/duplexers and cables for four antennas. This combination was for a fire department in Kirkuk, Iraq.

Obviously some Motorola dealer wanted to have the locals spend some of their oil money on recently obsolete equipment. There were enough spare parts to build another dozen or so repeaters.

All of these were to support an area nearby, about 2.5 miles by 3.5 miles. One repeater in service at a time worked just fine. With 16 in use, they had lots of problems with desensitizing each other.

 

[ResQguy]

How on earth could you think FDNY's communications is complicated? One frequency pair per borough and a single primary simplex fireground channel for the entire city of New York is complicated? The only thing less complicated would be using runners!

 

[Jay911]

How on earth could you think FDNY's communications is complicated? One frequency pair per borough and a single primary simplex fireground channel for the entire city of New York is complicated? The only thing less complicated would be using runners!

I admit not knowing the FDNY system fully, but the way I understand it, it operates completely opposite to how other conventional repeaters around the world are designed. The idea of manually enabling whether the mobile units' transmissions are rebroadcast out from the repeater site is unheard of anywhere else, and the point of it is hard for some of us to comprehend. It bewilders people who are used to "normal" communications systems.

 

[902]

The idea of manually enabling whether the mobile units' transmissions are rebroadcast out from the repeater site is unheard of anywhere else...

Not necessarily. Although this technique is archaic by today's standards, It was used very recently by the St. Louis City Fire Department, where they had a bunch of receivers all over the city on VHF, and pretty much an un-repeated transmitter. The mobiles would talk-in on one frequency, the dispatcher would have to parrot what the mobile said over the other. I hated this, because retransmitting only the words stripped the rest of the story from context (was the normally calm firefighter excited? was there unusual background noise? etc.).

This mode, semi-duplex, was more popular with law enforcement, especially highway patrols. The way it was explained to me by Missouri, historically, the dispatcher could be reading off lists of things and have the radio keyed down for a while. They needed a way for the mobiles to cut in. That's how they did it. I believe Los Angeles operated this way in the "Adam 12" days, and California Highway Patrol still does, with a marker tone that comes up rather than repeated audio (I could be wrong on that one, as the last time I heard them was a long time ago). I understand this was done for circuit discipline purposes, giving the dispatcher full control of the net.

FDNY's old VHF system allowed for the mobiles to break in while the dispatcher was talking. NYPD's old and current systems also bucked what everyone else had. Most agencies spec (for the lack of knowing better) this thing called "console priority." That means the dispatcher can key up and take over the audio path through the repeater with mobiles unable to interrupt. What they wanted and continue to have, is a system where the mobiles could interrupt the dispatcher as he or she talked. Console priority used to be a card in the older voting comparators that would literally switch the talkpath to whatever tone remote signal came down the line to its input. About the only thing it was good for was resetting a base when a stuck mic held it open and the repeater timed out (an argument for setting "time-out-timers").

NYC EMS, in the pre-FDNY Health and Hospitals Corp. days also used duplex base stations, comparators, and "mixers." This was nothing more than a tone remote command programmed for repeater "knock down" and "set up." Usually the "inspectional services unit" used it to ask the dispatcher what the status of a certain unit they were watching was, or a supervisor was giving some kind of information they didn't want repeated over a wide area.

 

[VE3RADIO]

Fleetnet is neither weird or complicated. It's just four independent Motorola SmartZone networks.

Agree.. was thinking size wise its a very large system.