Ottawa EDACS/OFS

[DaveH]

Can someone (preferrably who submitted the data) explain how on Ottawa
EDACS, OFS can have "talkaround" and "simplex" channels which are also
talkgroups on the system? To my understanding this is a contradiction.

I've been logging the system on Etrunk going back to 1998, and since OFS
joined later, and found some of the new ones listed have been logged as
actual TGs, albeit not within the last few years

Perhaps the radio display shows something like 2-0 which would appear to
map it into a TG just before 2-1; but that is not an actual system TG.

I would think simplex uses the 859MHz frequencies, which are not part of
the EDACS system.

Dave

 

[ocscan]

When I saw the update this morning I checked my logs, Since 2010-01-02 I have been logging this system almost continuously and have not yet logged these "Simplex" talk groups. I think Dave is correct in thinking these were talk group numbers deduced from what is displayed on the actual radios.

 

[Forts]

Simplex 'talkgroups' will not be part of the trunking system... they will be conventional channels, so you will not see any activity from those on UniTrunker etc.... Unless! It is patched back to a talkgroup which they may do in a VR setup... but then you would normally just see the regular talkgroup active.

 

[Jammin_Jay]

Ottawa fire Does use simplex frequencies , VRs


Dave is correct, 859 output frequencies area districts simplex frequencies

District 1 859.6125
District 2 859.8125
District 3 859.8625

But they are also patched as TG's

 

[DaveH]

OK, interesting. If the EDACS radios can talk to each other in TG mode on
simplex, or talkaround which may include non-trunked operation as part of
failsoft mode, that would make sense. But it doesn't explain CTCSS on the
VR outputs, unless they can operate in CTCSS mode (don't see how CTCSS
can coincide with TG operation at the same time).

It also doesn't explain how I logged these simplex TGs on the trunked system
side, and at that, nothing recently. When I get the chance I'll see whether I can
decode EDACS TG info from a VR output. One could also check the 814MHz
inputs, but I'm thinking the EDACS uplink data format is not compatible with the
the downlink format, which scanners decode.

Side question, why are the VR frequencies "archived" on the Wiki pages? Just
because they were removed from certain vehicles, they are still in use; or did they
drop some of them? Related information has been "lost" such as CTCSS and
input frequencies.

Dave

 

[Jammin_Jay]

Dave, What are the CTCSS values you are getting? These for the VR's?

IF the VR's are patched then they would be on an affiliated TG, even if they are in CTCSS mode
the patched TG would be still show. Whats the AFS your getting when you logged the system

 

[mikewazowski]

Ottawa fire Does use simplex frequencies , VRs

Vehicular Repeaters are not simplex frequencies.

They're duplex and repeated.

It was either last year or the previous year that I logged one during a visit to Ottawa.

It was during a call in an office building and I was close enough to hear the repeater directly. It was simulcast on the trunk system.

 

[mikewazowski]

I think somebody has made some assumptions based on what he saw on a system radio and submitted that to the database.

Most of the Talkaround (or simplex) channels that were submitted are of the form, xx-yyz with z=0.

When z (subfleet) is equal to zero, the group is an All Call type group for all radios within that subfleet.

10-080 which was submitted as Talkaround1, D1 Central Simplex would actually be the All Call talkgroup for the D1 Central talkgroups.

10-100 would be the All Call talkgroup for D2 West Central.

I'm not sure if a users radio would have access to that talkgroup.

Normally it's reserved for Dispatch or a Chief's radio.

I'll bet (based on other Fire Services) that the first channel in the Zone or the last channel in the Zone is setup as a talkaround channel.

The submitter knew that the first trunking channel in the Zone was on channel 2 and incorrectly assumed that the first channel would be one talkgroup lower on the system.

Take a look at how the York Region system's fire channels are setup.

The trunking talkgroups start on channel 2. Vaughan Fire's first trunking channel is Channel A2.

If you look at the conventional channels, Vaughan Fire's first conventional channel is A1.

I have a feeling this is how Ottawa's radios are setup as well.

 

[dchiefjock]

Okay, this is puzzling to many, especially me, as I worked for OFS, was a Chief, submitted the data, which was given to me by our Comms Chief. Unlike the past, this lad (Also retired now) was VERY radio savvy, and was a HAM, etc. I can only add how the system worked in our hands. Firstly, there are NO chiefs' vehicle repeaters. They have been gone for 5 years now, maybe more. Chiefs' vehicle and portable radios are no different than any other in the service. Only pumps have repeaters now, and there is a deployable, internal building repeater that the Haz-Mat Unit has, but I'm not aware of it ever being deployed.

We had too many instances of repeaters fighting each other and locking the system up. When we tried to activate *a* repeater with a portable, it would activate all the repeaters on scene - even some on trucks as far away as the City yards, if they were on the same working channel. Also, we were originally told all portables had to go to the VR channel and dial in. Wrong again. All this would do, was again, lock up the system as every portable would keep trying to dial in until it got a digital reply from a repeater. The portables were/are not tied to a specific pumper repeater - e.g. the portables from Pump 23 could only activate Pump 23's repeater - not the case. It would activate any repeater that was tuned to the working frequency, in this case normally Ch. 2.1 DEC 1361 AFS 10-101. When these lock-ups occurred, the only solution was to go to "Talkaround" or Simplex. I admit, I wasn't quite sure how this was working on a trunked system, and even less with EDACS. A radio mind would obviously believe that this would be portable to portable direct, Tx and Rx on the same frequency, BUT as I was in the Car as I/C, I could still talk back & forth to the portables that were on Talkaround using my vehicle radio still set on Ch. 2.1. There are probably better minds than mine on here that can explain this, but to me, it suggests that the trunking system is involved here in some manner. I posed the question to our Comms Chief and asked how I could receive the "Talkaround" transmissions on my office scanner, which to that point, I couldn't. His reply was, "Simple. Just add Talk Group 10-100 (DEC 1360) to your scanner and you can hear the transmissions if you are within range. Same for the other 9 channels." Made sense to me, and I never thought much about it. The other solution to the lock-ups was to have any repeater needed *manually activated* by the Pump Operator I figured there were those on this site that would be interested in this info. I didn't expect to stir up a conversation on, "Einstein's theory of EDACS" and start to feel you people think I'm some no-mind from CB-land. So there you have it. That's how and why the data on this was submitted. I got it from a very reliable source. Was just trying to help some fellow scanner users with what they may be hearing or may want to hear. That's all. As I said, I was pretty close to it - a lot closer than those discussing it, I would think. I feel bad that this lead to a thread of doubts, but as you can see, there is more to this "Talkaround" "Simplex" thing on the OFS system than anyone here has suggested. It's just not as simple as one might think. Also, BTW for something less brain-shattering, we have NEVER changed our district designations since before amalgamation. District 1 is still Central, 2 Western, 3 Southern and 5 Eastern. The only change was the addition of District 4 which is designated Deep West. Not pretty, but that's the ID. Rural areas go by Sectors as opposed to Districts as there are no hard & fast boundries. E. g. Sector 6 is not designated Rural North/West - it is a good indicator but it's not a designation, proper. I'll crawl back in my cave now. 10-4 Good Buddies. ;-)

 

[mciupa]

Subcategories and descriptions for the Fire Service have been updated to keep in line with their proper designations.

 

[exkalibur]

Well I can tell you that on an actual system portable, the talkgroups like 2-0, 3-0, etc... are "Channel 1" on the knob. They're also conventional. I don't know the frequencies though. The way to tell - if you remove the antenna from an EDACS radio, it'll show "CC SCAN" meaning it is trying to find a control channel. Conventional channels obviously don't do this - an OFS radio doesn't do this on a "-0" channel, thus it isn't trunked.

I seriously suspect that the channels listed in the conventional listings are what these "talkgroups" are.

To touch on the 10-100 talkgroup idea - do EDACS radios work as an "announcement group" on those talkgroups? IE, if you program in TG 10-100, will the radio receive all the subfleet talkgroups in there as well? That would certainly explain why listening to TG 10-100, you'd hear TG's 2-1, 2-2, 2-3 and 2-4. Also, if they ARE used as VR channels, you'd hear whatever happens on the 2-0 conventionally channel onto the respective talkgroup because they'd be patched in.

Next time I'm up there I'll bring along a close-call scanner and have a look.

 

[dchiefjock]

No. That is NOT how it works. I used these things since the system was introduced. As a matter of fact, I used to instruct on it. This thing with the repeater lock-up problem etc., all came from Ericsson. *We* had to figure out how to stop this from happening and stop putting our crews in danger. I don't think *they* even knew how the system worked. 1 on the knob is 1.1, 2 is 2.1, 3 is 3.1 right up to 10 = 10.1 (But there are 20 knob positions - read further). If you want to change to a talk group within a channel (Say 2.2) you had to do a bunch of button gymnastics to get the portable there, and the same with the vehicle radio, but not as bad. It is far too cumbersome to try and do on the fireground. Hell, it was hard to do in training sessions unless you did it daily to keep up on it. You have to unlock the portable (2 buttons in sequence), hit the Options button and cycle through it to get the channel you are looking for (2.2, 2.3, 2.4, TALKAROUND). Impossible to do in a smokey environment with heavy gloves on. That's why you'll probably never hear x.2 to x.4 ever used. I think I would be safe in saying you could remove them from your scanner and you wouldn't miss a thing. The only exception is 3.2 which we use to communicate with the Ottawa Airport FD, as we don't have 00-84 and 00-85 on our vehicle radios/portables and they don't have 3.1 (Well thought-out, eh?). Now, to further explain/complicate things, the Emerg Srv, InterOp and Training channels .2 to up to .4 did have their own position on the channel knob. Why they have those channels easily changeable, instead of the working district channels and the Airport FD is far beyond me, but it would have made life much easier for all of us. Basically the way it's set up, there are 30 talk groups (.2 to .4 x 10) totally devoid of practical use, with only 1 used out of necessity.
To activate a repeater you have to unlock it (Two buttons in sequence within a given time), hit the VR Convert button on the side (Which was conveniently not marked) then hit the Dial-up button above it and hope you didn't activate every repeater on the working channel between downtown Ottawa, Arnprior and Rockland. Again why I could hear/talk to the "Talkaround" portables on the working channel on my vehicle radio without touching it, and not 2.2 - 2.4 (I had to change to them) baffles me, as you needed to do the same button sequence to get there. There is obviously some kind of frequency piggy-backing going on there. The logical thing would to be to have to put your vehicle radio on Talkaround (I don't think it even had that setting, but I'm not SURE.), or have to grab a portable and put it on Talkaround so that you can talk to the troops - but I never had to do that. I was at several incidents, in different districts (Different working channels) and I never had to do anything other than pick up the mic and talk to a Talkaround portable. I know it sounds weird, but thats the way it works. For what it's worth, from a safety and logistical point of view, I'm glad that part of it works that way. Cheers!

 

[exkalibur]

That is damn complex.

The radio I had my hands on didn't quite work exactly as described, so perhaps some reprogramming has been done. This one was a new radio that was being deployed (Harris XG something or other) had channels on the channel knob, and zones with the up/down buttons.

I wonder if it is some kind of setup similar to what London Fire uses then - their setup is quite complex, but works really well.

 

[Forts]

I believe in London's portables, VR is just another system. The main system let's the radios roam the 4 primary towers but when they switch to VR it registers to the 5th tower site that the VR creates. Not sure how they enable the VR on the truck but it seems pretty painless.