RR trunking reference database

[opticalc]

Im trying to wrap my head around the database...

An example:

In Alabama, Dallas County is listed as being part of the State of Alabama EDACS system. But when I click on that system to get info, there are no cities/sites from Dallas County listed with any frequencies.

Now, supposing that I did live in Jefferson County, in Birmingham, there are some freqs listed there as site 003. But none of those freqs are red/blue. All the freqs for site 003 are black, so im assuming that those freqs are for the actual FM audio?

But doesnt each site HAVE to have towers with control channels???

[Unitrunker]

Originally Posted by opticalc

But doesnt each site HAVE to have towers with control channels???

Yes. Most likely the person that submitted the site information you see didn't think it was important to identify which channels can operate as control channels.

[opticalc]

OK, heres an idea, I do all my freq/location searching from the FCCs database:
http://wireless2.fcc.gov/UlsApp/UlsS...chAdvanced.jsp

The only problem here is identifying which local systems are part of individual trunked systems - this may not be possible to get this info from the FCC database.

But, It looks like its possible to identify which freqs at each site are the control channels. For example, 856.26250 in Huntsville Alabama is red, so its a primary control channel. If you do an FCC search for that freq in AL, it pops up in Huntsvill as "station class type" of FB2C. Im assuming that FB2C means that its a trunking data channel?

Like I said a few sentences ago, it looks like an entire trunked system is not identified by a single FCC call sign. It appears that each site within a trunked system has its own FCC call sign. Is it possible that a trunked system is identified by collections of call signs that all share the same FRN? If so this would be an ideal way to look up info

[LEH]

Originally Posted by opticalc

Im trying to wrap my head around the database...

An example:

In Alabama, Dallas County is listed as being part of the State of Alabama EDACS system. But when I click on that system to get info, there are no cities/sites from Dallas County listed with any frequencies.

Now, supposing that I did live in Jefferson County, in Birmingham, there are some freqs listed there as site 003. But none of those freqs are red/blue. All the freqs for site 003 are black, so im assuming that those freqs are for the actual FM audio?

But doesnt each site HAVE to have towers with control channels???

Yes, they do, BUT for an EDACS system the control channels are really a mute point. EDACS, unlike Motorla, requires that all the frequencies be entered and that the frequencies be entered in LCN (Logical Channel Number) order.

What you are seeing for the Alabama State system are the districts covered by specific sites. Find the district(s) closest to Dallas county and load them into your scanner. How to load an EDACS system varies from scanner to scanner, so read your instructions there.

The LCN number is included in the RR DB as the light grey number next to the frequency.

Using your example so you can see the difference between an EDACS and a Motorla system, take a look at the Huntsville (Madison county, actually, you'll need to go to the list of trunked systems for AL and select Huntsville's public safety, the map is not working for Madison county). You will see that Huntsville has twenty frequencies, but only four are shown as control channels. Also note the lack of the greyed numbers to the left of the frequency.

Where you see a specific control channel on an EDACS system, it could be that this is the only channel used for control, or it was the channel active when the information was submitted.

[opticalc]

Originally Posted by LEH

What you are seeing for the Alabama State system are the districts covered by specific sites. Find the district(s) closest to Dallas county and load them into your scanner.

None of those 9 sites are within 200 miles of Dallas County. So I dont think this trunking system is available there. So what radio systems does the state patrol use? Also, I noticed the same thing for the State of GA. There seem to be many areas that the trunking systems arent available. So in that case, how does the State Patrol fleet communicate?

[LEH]

Originally Posted by opticalc

None of those 9 sites are within 200 miles of Dallas County. So I dont think this trunking system is available there. So what radio systems does the state patrol use? Also, I noticed the same thing for the State of GA. There seem to be many areas that the trunking systems arent available. So in that case, how does the State Patrol fleet communicate?

Well, the only area of Alabama I am fairly familiar with is Huntsville. My job used to take me there routinely. So, I am just guessing. But you might want to try looking here and see if any of these work.

What could be happening is that the Statewide EDACS system is being phased in and Dallas county (and surrounding areas) just have not been brought on line.

You may want to ask one of the moderators to move this to the Alabama thread as there are probably more people familiar with what's going on there than here.

[Unitrunker]

Originally Posted by opticalc

There seem to be many areas that the trunking systems aren't available.

It's possible that no one in your area has bothered to submit data. Have you tried using your radio to scan for control channels in your area? You just might score a new find - and a chance to make the RR DB more accurate.

[opticalc]

Please dont move this... I dont live in Alabama and rarely visit there, and really was just using AL as an example to slide in to a further question that I posted in this thread after the OP. My questions in this thread are mainly geared towards the RR database and the FCC's database. It just seems to me that with the extent of the info available from the FCC's ULS advanced search ( I am *thoroughly* impressed with the wealth of DETAILED info you can get from these 2 sites:
http://wireless2.fcc.gov/UlsApp/UlsS...chAdvanced.jsp
https://fjallfoss.fcc.gov/coresWeb/advancedSearch.do

You can even do a geosearch for transmitters around a specific address/GPSCoords, etc)

that we should be able to determine how any trunked system and sites within that trunked system are freq allocated? Just about the only thing not listed is the trunking system type or LCNs.

A problem with my idea here is that it does look like some trunking systems do span across multiple call signs (annoying) and I guess its possible that sometimes even across different FRNs (this would be even more annoying).

An example of multiple call signs in the same trunking system is the Atlanta Public Safety System described on RR here:
http://www.radioreference.com/apps/db/?sid=398 where the first freq listed is 856.46250 which corresponds to callsign/FRN of WNZG246/0001825231 in Radio Service YP. The last freq listed is 867.31250 which is a different callsign (KNNH557 ) but in the same FRN (0001825231) 867.31250 also has a different Radios Service Code of YF, I guess because its in a different FCC band than the first freq. Now, this FRN has 27 active callsigns split between various radio services, both trunking and non-trunking so obviously they dont build entire (even multi site) trunking systems based either on a single callsign or a single FRN. Also, between these 2 callsigns there are about 100 unique freqs (some even in the 811 - 815 MHz range, sorta odd freq range to me), with many more control channels (Im assuming that "station class" FB2 identifies a control channel. All the freqs in red are FB2)than the 4 control channels listed in red.

So has anyone been able to pull of a reverse engineer of a trunking freq plan using the FCC db like I am describing? The more I think about it the more I suspect its not possible to do it this way (but it seems like it should be. maybe the FCC DB, while at first is impressive, just isnt as good as it first looked to me).

So how do you guys do this in the field? Do you just examine every single data channel you can find and look for common systemids?

[DickH]

Originally Posted by opticalc

... An example of multiple call signs in the same trunking system is the Atlanta Public Safety System described on RR here: ...

You are ceating a problem. All those freqs. and control channels are probably for Intellirepeater, or "fill-in", sites. Certain radios in the system are affiliated to various sites to improve coverage. You don't need to worry about any of that. Just put in the 4 control channels and you should hear everything.

I think our system here in Portland, OR is similar. We use around 90 freqs., but with only the 4 control channels we hear everything. They are used in the 4 simulcast sites around the main part of the city and there are 9 Intellirepeater sites scattered around.

A few of the freqs. are non-trunked for portable to portable use in difficult buildings and terrain.

See my answer to your post in the Georgia forum.

[DickH]

Originally Posted by opticalc

... (some even in the 811 - 815 MHz range, sorta odd freq range to me), ...

Those are the input freqs. (mobile and portable units). In the 800MHz band, the inputs are 45MHz lower than the output freqs. You don't need to worry about the input freqs.