DSDPlus Is there a Con+ LSN Formula Similar to NEXEDGE?

[Facsimile]

I've been having a great time with NEXEDGE and DSDPlus FL. A lot of stuff in my area needs updated. Had I just copied the info from the database to my scanner, I would be missing a ton of communications. I really enjoy putting the puzzle together myself with the help of DSDPlus FL - only to use the RRDB if I get stuck. With that said, I'm not sure I fully understand the process for determining the matching of LSN to frequency in Con+ systems.

I currently am tuned to a control channel. It's channel is ?. Some posts that I have read says that this will get calculated eventually after more traffic gets decoded. Is that true? I'm writing this at a time the system has clocked out for the night and the and the FCC DB is down, so I'm just kind of waiting. I know with NEXEDGE, I was able to use a formula to calculate the frequencies based on the channels and that made mapping simple. Is there a similar method for Con+? Or what exactly should I be doing with the information I currently have (assuming the RRDB couldn't be used) in the picture below to complete the system?

Thanks!

 

[wx5uif]

Based on the channel numbering looks like they are using a channel table and not calculatable band plan.

What I ended up doing when using DSD to figure systems out.. I find the frequencies on the site from the FCC database (This is not 100% right quite a bit of time) and used two dongles with two instances of DSD running. One holding on the CC and the other scanning the voice channels and see where they hit when the CC is showing a channel grant.

 

[mwjones]

Con+ does not typically use a bandplan (even some NEXEDGE systems do not). Based on what I'm seeing in the screenshot you've likely got some errors in your DSDPlus.frequencies file, as all of the relevant data is in RRDB already, unless the system changed up the frequencies (something I'm currently dealing with on a NEXEDGE system).

Since you are a premium subscriber to RadioReference, my suggestion is to use the recently added option to download the data from the RRDB in a DSDPlus.frequencies format (click the three line "Menu" button at the top right of the system page, then click "Downloads", there you'll see links to download the Site information, Frequency Information and Talkgroup information in formats that can be readily copied and pasted into your running DSDPlus files, just be sure to save a copy before you do that in case you inadvertently overwrite it).

Then let it run and see if you start getting valid calls.

 

[mwjones]

Oh, and I might add, the Control Channel showing a "?" is typically normal until it figures out where it resides (usually because of some traffic on the second talkpath of the control channel frequency).

 

[dave3825]

I really enjoy putting the puzzle together myself with the help of DSDPlus FL - only to use the RRDB if I get stuck. With that said, I'm not sure I fully understand the process for determining the matching of LSN to frequency in Con+ systems.

Based on what I'm seeing in the screenshot you've likely got some errors in your DSDPlus.frequencies file, as all of the relevant data is in RRDB already,

OP is trying to learn the process without having to rely on work others already did. Good to know the process because not all systems are in rr database.




@Facsimile

Some systems broadcast a repeater map. Started in 2.29 and changed in 2.71.

DSD+ 2.71

Handling of Con+ repeater map broadcasts has been automated;
DSD+ will tune VC FMPA/FMP24 to a traffic channel that is broadcasting a repeater map.
Repeater maps broadcast on the control channel carrier (on slot 2) are handled by CC DSD+.
Repeater maps are written to text files.
The file name format is "ConP <NID> Network Repeater Map v<mapVersion>.txt"

DSD+ 2.29

Con+ OTA frequency file decoding has been added; if a site is broadcasting a frequency file,
DSD+ will decode it and write its contents to the console log; DSD+ will also write a text
block that can be copied directly to the DSDPlus.frequencies file; see example below

 

[Facsimile]

What I ended up doing when using DSD to figure systems out.. I find the frequencies on the site from the FCC database (This is not 100% right quite a bit of time) and used two dongles with two instances of DSD running. One holding on the CC and the other scanning the voice channels and see where they hit when the CC is showing a channel grant.

I think I am going to have to go this route. I've searched the FCC database + geolocation and am unable to find the 454.2 mhz for my location. Assuming I had no other frequency clues to go on, would you just be looking for peaks to show in the spectrum, add the lines to the .frequencies file, then see if the conversations follow? I'd like to be able to pull up the different sites that I can pick up on the FCC database, but it strangely doesn't seem to be documented.

Oh, and I might add, the Control Channel showing a "?" is typically normal until it figures out where it resides (usually because of some traffic on the second talkpath of the control channel frequency).

Thanks, but I'm not sure it's ever going to give me the number. I've had activity all day but no channel has been assigned. Currently the channel order shows 4, 5, 6, 7, 8, 9, 10, 11, 12. Where is gets interesting is that I can hear voice traffic when channel 4 is active. This is when I am sitting on the control channel and my .frequencies file is empty. My thoughts then would be the control channel frequency of 454.2 would be channels 3 and 4. My only hesitancy is that why hasn't DSDPlus assigned it automatically? Why hasn't channel 1 and 2 shown up (system has been very busy)? Is the control channel number actually 1 and 2 as stated in the Radio Reference listing for this site? (Remember I am trying to not use this information )

Some systems broadcast a repeater map. Started in 2.29 and changed in 2.71.

It doesn't appear to be broadcasting a repeater map according to the log nor am I getting a generated .txt file

 

[mtindor]

Thanks, but I'm not sure it's ever going to give me the number. I've had activity all day but no channel has been assigned. Currently the channel order shows 4, 5, 6, 7, 8, 9, 10, 11, 12. Where is gets interesting is that I can hear voice traffic when channel 4 is active. This is when I am sitting on the control channel and my .frequencies file is empty. My thoughts then would be the control channel frequency of 454.2 would be channels 3 and 4. My only hesitancy is that why hasn't DSDPlus assigned it automatically? Why hasn't channel 1 and 2 shown up (system has been very busy)? Is the control channel number actually 1 and 2 as stated in the Radio Reference listing for this site? (Remember I am trying to not use this information )

Repeater maps aren't broadcast regularly, and sometimes never -- depending upon the system.

And yes, if you are sitting on the CC and hear voice and it shows ch 4, you are correct that the control channel would be LSN 3/4 (aka LCN 2)

So you have at least one.

LSN 3/4 (LCN 2) = 454.2
LSN 5/6 (LCN 3) =
LSN 7/8 (LCN 4) =
LSN 9/10 (LCN 5) =
LSN 11/12 (LCN 6) =

So you have some more to figure out. And it is best if you do that during the most active time of the day/week. Many systems are pretty much idle at night / over the weekend if they are the systems that rent radios.

That system is: ERS-OCI Wireless TRBOconnect Con+ Trunking System, Multiple, Multi-State

That site (127-3) is in the DB and lists:

003 (3)

Fort Wayne, IN

Allen, IN

01 454.275c

02 454.200

03 461.175

04 461.450

05 463.800

06 463.300

Those numbers above next to the freqs are LCNs.

01 = LSN 1/2 = 452.275
02 = LSN 3/4 = 454.200
03 = LSN 5/6 = 461.175
04 = LSN 7/8 = 461.45
05 = LSN 9/10 = 463.800
06 = LSN 11/12 = 463.300

Of course, those may not all be correct currently, but they likely mostly are. After all, somebody did submit them once upon a time.

And of course, they (ERS-OCI) are migrating to CAPMAX - ERS Wireless Indiana Trunking System, , Indiana . Annd there is a Fort Wayne site on there.

So if there is little to no activity on the CON+ system, maybe more of it is on the CAPMAX site now.

NOTE: The CAPMAX system is not fully mapped out. Only the last known control channel for each site is listed in the DB so far. So if you end up trying to monitor the CAPMAX, you will have to figure out all the active freqs in use.

Mike

 

[dave3825]

Assuming I had no other frequency clues to go on, would you just be looking for peaks to show in the spectrum, add the lines to the .frequencies file, then see if the conversations follow?

No, when you find a control channel, you track down the source and find its license. When you look at the license, you only want to focus on the freqs labeled base or fixed base. You don't want the mobile freqs. You can't just look for peaks on the spectrum because you have no idea what entity they will be licensed to and adding those freqs to your file without validating they are part of what your trying to listen to will only create headaches.

 

[mwjones]

Thanks, but I'm not sure it's ever going to give me the number. I've had activity all day but no channel has been assigned. Currently the channel order shows 4, 5, 6, 7, 8, 9, 10, 11, 12. Where is gets interesting is that I can hear voice traffic when channel 4 is active. This is when I am sitting on the control channel and my .frequencies file is empty. My thoughts then would be the control channel frequency of 454.2 would be channels 3 and 4. My only hesitancy is that why hasn't DSDPlus assigned it automatically? Why hasn't channel 1 and 2 shown up (system has been very busy)? Is the control channel number actually 1 and 2 as stated in the Radio Reference listing for this site? (Remember I am trying to not use this information )

Therein lies the problem, you have to have the information in the Frequencies file to begin with. Unlike P25 and some Tier III and NEXEDGE systems, the channel grants over the air never transmit the actual frequency, only the Logical Slot Number "LSN". The frequencies file is what maps one to the other. Without it, you're only going to get the "grants" that are being sent out by the control channel with no way to follow the voice (thus the activity that you're seeing).

So, if I'm starting with no information other than an FCC license, I would first find a control channel in those licensed frequencies with an "FB" Class (ignoring the "FX" and "MO" classes) to get the system ID and site number, and then populate my frequencies file with all the frequencies with an "FB" Class, and for LSN I would put a "?" (without the quotes). This tells DSDPlus the LSN in unknown. If DSDPlus figures out the LSN, it will post a message along the lines of "[Frequency] is first repeater (Ch1 and Ch2)" - you would then update the Frequencies file with the LSN replacing the "?".

The fact that you're hearing voice traffic when LSN 4 is active means that your control channel 454.2 is LSN 3 and 4 (the control channel only is using 3, while 4 is available for voice usage.

Likewise, most sites have a primary and a backup (or multiple backups) control channel, so the site can self-recover if one specific repeater is knocked offline or suffers from interference. Since what is listed in the Radio Reference Database is user submitted, it is possible the users that submitted the data had never heard the backup control channel being used, nor picked up an over the air repeater map (it will show them as well), and thus it doesn't show in the database as such.

It doesn't appear to be broadcasting a repeater map according to the log nor am I getting a generated .txt file

My experience with Con+ systems is that they usually only send an Over the Air repeater map if there's changes to the system (for example new frequencies or sites since the radios have to be updated with that information, and it makes sense to do an Over the Air update to get all radios updated at once). With Con+ reaching the end of life, many systems are shrinking and not growing, as they migrate to CapacityMax or other Tier III based systems, so you may be in for a challenge picking up one (and you still have to have your local site mostly mapped out to pick it up)

 

[ecps92]

No, when you find a control channel, you track down the source and find its license. When you look at the license, you only want to focus on the freqs labeled base or fixed base. You don't want the mobile freqs. You can't just look for peaks on the spectrum because you have no idea what entity they will be licensed to and adding those freqs to your file without validating they are part of what your trying to listen to will only create headaches.

and keep in mind for the OP the example freq provided is a Part 22 license , so harder to search in the FCC DB

For the OP, keep asking as it is the ONLY way to learn

 

[Facsimile]

And yes, if you are sitting on the CC and hear voice and it shows ch 4, you are correct that the control channel would be LSN 3/4 (aka LCN 2)

So you have at least one.

LSN 3/4 (LCN 2) = 454.2
LSN 5/6 (LCN 3) =
LSN 7/8 (LCN 4) =
LSN 9/10 (LCN 5) =
LSN 11/12 (LCN 6) =

So you have some more to figure out. And it is best if you do that during the most active time of the day/week. Many systems are pretty much idle at night / over the weekend if they are the systems that rent radios.

That system is: ERS-OCI Wireless TRBOconnect Con+ Trunking System, Multiple, Multi-State

That site (127-3) is in the DB and lists:

003 (3)

Fort Wayne, IN

Allen, IN

01 454.275c

02 454.200

03 461.175

04 461.450

05 463.800

06 463.300

Those numbers above next to the freqs are LCNs.

01 = LSN 1/2 = 452.275
02 = LSN 3/4 = 454.200
03 = LSN 5/6 = 461.175
04 = LSN 7/8 = 461.45
05 = LSN 9/10 = 463.800
06 = LSN 11/12 = 463.300

Of course, those may not all be correct currently, but they likely mostly are. After all, somebody did submit them once upon a time.

It is pretty active at least in my area/site which has been nice so far. Learning with it has been great too. A lot of those frequencies I have not been able to locate in the FCC database - like the control channel 454.2. The signal is so strong I'm pretty sure I'm right next to the tower but I just haven't had luck finding it documented. What is documented in here is two callsigns but neither contain this frequency. Whoever did document the others, I guess my question would be how did they find the other correct frequencies?

And of course, they (ERS-OCI) are migrating to CAPMAX - ERS Wireless Indiana Trunking System, , Indiana . Annd there is a Fort Wayne site on there.

So if there is little to no activity on the CON+ system, maybe more of it is on the CAPMAX site now.

NOTE: The CAPMAX system is not fully mapped out. Only the last known control channel for each site is listed in the DB so far. So if you end up trying to monitor the CAPMAX, you will have to figure out all the active freqs in use.

I have come across the CAPMAX system multiple times and have been saving that one for after I learn the methods for Con+. Cap+ was pretty easy. I've been using this Radio Reference Wiki page to supplement learning but noticed that CAPMAX isn't on it. Is there a good forum post that has the details to learn this system next? For one thing, the whole TIIInonStd vs TIIIStd has me a bit confused. I really appreciate the help and detailed explanation. I'd definitely like to help with the mapping process for the new system. I have a radio direction finder as well to help locate sites if necessary. RDFs are so much fun.

No, when you find a control channel, you track down the source and find its license. When you look at the license, you only want to focus on the freqs labeled base or fixed base. You don't want the mobile freqs. You can't just look for peaks on the spectrum because you have no idea what entity they will be licensed to and adding those freqs to your file without validating they are part of what your trying to listen to will only create headaches.

This is what I have normally done up to this point. This is one of the few times I have not be able to find the control frequency in the FCC database. If you have any advice on finding it or what I may be doing wrong I'd appreciate it! I've tried searching by geolocation for the county around me as well as the entire state. I was not able to find it.

Therein lies the problem, you have to have the information in the Frequencies file to begin with. Unlike P25 and some Tier III and NEXEDGE systems, the channel grants over the air never transmit the actual frequency, only the Logical Slot Number "LSN". The frequencies file is what maps one to the other. Without it, you're only going to get the "grants" that are being sent out by the control channel with no way to follow the voice (thus the activity that you're seeing).

So, if I'm starting with no information other than an FCC license, I would first find a control channel in those licensed frequencies with an "FB" Class (ignoring the "FX" and "MO" classes) to get the system ID and site number, and then populate my frequencies file with all the frequencies with an "FB" Class, and for LSN I would put a "?" (without the quotes). This tells DSDPlus the LSN in unknown. If DSDPlus figures out the LSN, it will post a message along the lines of "[Frequency] is first repeater (Ch1 and Ch2)" - you would then update the Frequencies file with the LSN replacing the "?".

Ok this is great! This is pretty much the process I do currently but have never confirmed that it was the correct way to do it. And just to verify, the "?" can be placed in the .frequencies file like this: Con+, 127, 3, ?, 454.2000, 0.0, 0

and keep in mind for the OP the example freq provided is a Part 22 license , so harder to search in the FCC DB

Is this only a Con+ thing? Or can it be for CAP+ and CAPMAX too? What is the best way to search for these? I'm without experience.

 

[dave3825]

This is one of the few times I have not be able to find the control frequency in the FCC database.

What county and state are you in? And what agency do you suspect the voice freqs belong to?

 

[Facsimile]

What county and state are you in? And what agency do you suspect the voice freqs belong to?

Allen County, Indiana. I'm not sure what you mean by agency but this is the listing for what I am trying to find.

 

[ecps92]

Ok this is great! This is pretty much the process I do currently but have never confirmed that it was the correct way to do it. And just to verify, the "?" can be placed in the .frequencies file like this: Con+, 127, 3, ?, 454.2000, 0.0, 0


Is this only a Con+ thing? Or can it be for CAP+ and CAPMAX too? What is the best way to search for these? I'm without experience.

Part 22 Paging Channels - The RadioReference Wiki

wiki.radioreference.com

Part 22 licenses are similar to your local TV/Radio station where they are assigned by Market vs a physical defined tower location.
Finding them in the FCC takes some blood n tears and time to scroll thru many of the allocations

Additionally the owner is allowed to use +/- the actual freq
ie: 454.2000 could also use 454.2125 and 454.1875 along with the 6.25 pairs

 

[mwjones]

Ok this is great! This is pretty much the process I do currently but have never confirmed that it was the correct way to do it. And just to verify, the "?" can be placed in the .frequencies file like this: Con+, 127, 3, ?, 454.2000, 0.0, 0

That would be the correct format, but now that you know 454.2 is LSN 3 and 4, you could replace the ? with a 3 (the odd numbered LSN), and DSDPlus will virtually understand that it is also 4.