DSD+ DMR Neighbor Control Channel map?
- Thread starter Mikek
- Start date
Go to the applicable system's RR database page. Click blue menu button on the top right then click "Downloads". Scroll down to "Other data downloads" and choose the two DSD formatted files boxed in red You'll need to copy these downloaded files to your DSD+ program directory. As long as the site name(s) & site number(s) appear correctly in the sites data file & both files are in your DSD+ directory then DSD+ should recognize the site(s) as a neighbor(s) if the site you're tuned to reports it/them as such
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This system is brand new and does not have a RR database entry. To make it more fun, it is a large, multi-site system that's being converted to from ConnectPlus to T3, using existing licenses and frequencies, so no new licenses in the FCC DB either. 
Much easier to get the system added to the RRDB than to create the needed files completely from scratch, get the syntax correct, etc IMHO, particularly with large systems
Agreed - but right now, all I have is a T3 control channel that has 2 (unknown) neighbors. The system has had zero traffic. It will be a while before sufficient data is available to submit. I'm not interested in making DSD+ 'pretty' with RRDB data, just trying to find out what the neighbors control channel frequencies are.
If you have a confirmed control frequency and an LCN for one site on the system you can use the LCN calculator linked in the thread here to try and determine the frequencies & LCNs of the other sites based on the data from the site you have. Next, examine the FCC license(s) of the target system(s) (which you claim haven't been created yet?) to confirm the frequencies are listed there. Lastly if you're able to get within range of the neighboring site(s) to ultimately confirm your findings that's your best bet before making a database submission
Here's the existing system
They are likely 'overlaying' the new T3 system using existing frequencies/licenses before deprecating the Con+ stuff. All I have now, is the control channel on 454.53125 off the Peasants Peak site. I don't believe DSD shows the relevant data needed by the calculator to get the frequencies for the neighbor lists. - Edit to add: The existing system is Con+, so any data aside from frequencies is irrelevant to my search.
They are likely 'overlaying' the new T3 system using existing frequencies/licenses before deprecating the Con+ stuff. All I have now, is the control channel on 454.53125 off the Peasants Peak site. I don't believe DSD shows the relevant data needed by the calculator to get the frequencies for the neighbor lists. - Edit to add: The existing system is Con+, so any data aside from frequencies is irrelevant to my search.
Welcome to the fun world of discovering Tier 3 systems. I've done a number of these in recent years, and yes there are ways to calculate the Channel Map in use on the system.
Multisite systems are sometimes a bit easier to decode than single site systems, and from what you're indicating that will be the one we're going to look at today.
What you need to gather to start building the channel map:
Frequency of Control Channel for two sites
DSDPlus captured neighbor list for each of the two sites.
All this data will be in the .event file in your DSDPlus folder.
So let's use an example system (this system came up as a "TIIInonStd (Mot)" in the status bar, but commonly is called a "Tier 3 Capacity Max" system) I've cleaned up a bit to make understanding this simpler:
Site 3: Control Channel 461.5875
Site 3's Neighbors: Site 4 CC=1661
Site 4: Control Channel 461.3875
Site 4's Neighbors: Site 3 CC=1693
In the above example Site 3 says that Site 4's CC=1661, and since we know Site 4's Control Channel frequency is 461.3875 we can make that association.
Same goes for what Site 4 says for Site 3, so Site 3's 461.5875 will be CC-1693.
Now we need to create the Channel Map. This can be done in a spreadsheet, but may require trial and error. The Channel ID's (or Logical Slot Numbers "LSN" as it's typically called) have two entries for every frequency, so we focus on the first entry, which will be the odd numbers, we then need to determine the increment of the frequencies.
In most cases the increment will be 12.5KHz steps, but I have seen 6.25KHz and 25KHz steps as well.
So my spreadsheet may start to look like this:
And so on. Of course this can be messy, especially with trial and error, but once you get the two known LSN's to match up, you're set, and you shouldn't have to fiddle with it again.
Alas, there's an easier way, another user here in the forum wrote a simple frequency calculator, that does all the math for you.
forums.radioreference.com
With the Frequency Calculator, you enter a reference frequency and it's confirmed LSN, then enter the LSN of the second frequency and it will tell you what the frequency is, along with a list of all the LSN's and frequencies.
Here's the frequency calculator showing my example frequencies
You'll also note that it reports a Logical Channel Number "LCN" - don't get them confused. DSDPlus uses LSN, Uniden radios use LCN.
As you log traffic on the site, you'll see more Channel ID's being called out - simply search for them in your spreadsheet or on the frequency calculator to get the matching frequencies. Add those entries to your DSDPlus.frequencies file and you should start hearing audio.
Good luck and happy researching!
Multisite systems are sometimes a bit easier to decode than single site systems, and from what you're indicating that will be the one we're going to look at today.
What you need to gather to start building the channel map:
Frequency of Control Channel for two sites
DSDPlus captured neighbor list for each of the two sites.
All this data will be in the .event file in your DSDPlus folder.
So let's use an example system (this system came up as a "TIIInonStd (Mot)" in the status bar, but commonly is called a "Tier 3 Capacity Max" system) I've cleaned up a bit to make understanding this simpler:
Site 3: Control Channel 461.5875
Site 3's Neighbors: Site 4 CC=1661
Site 4: Control Channel 461.3875
Site 4's Neighbors: Site 3 CC=1693
In the above example Site 3 says that Site 4's CC=1661, and since we know Site 4's Control Channel frequency is 461.3875 we can make that association.
Same goes for what Site 4 says for Site 3, so Site 3's 461.5875 will be CC-1693.
Now we need to create the Channel Map. This can be done in a spreadsheet, but may require trial and error. The Channel ID's (or Logical Slot Numbers "LSN" as it's typically called) have two entries for every frequency, so we focus on the first entry, which will be the odd numbers, we then need to determine the increment of the frequencies.
In most cases the increment will be 12.5KHz steps, but I have seen 6.25KHz and 25KHz steps as well.
So my spreadsheet may start to look like this:
| Frequency | LSN |
| 461.3875 | 1661 |
| 461.4 | 1663 |
| 461.4125 | 1665 |
And so on. Of course this can be messy, especially with trial and error, but once you get the two known LSN's to match up, you're set, and you shouldn't have to fiddle with it again.
Alas, there's an easier way, another user here in the forum wrote a simple frequency calculator, that does all the math for you.
LCN to Frequency calculator for DMR TIII
Thanks for the reply, @Kazzaw. It's the OrionMax network in NSW. I haven't forgotten about you, I just haven't had a chance to make it near a computer today to see what I have logged for around NSW. I'll have a look tomorrow and get back to you
With the Frequency Calculator, you enter a reference frequency and it's confirmed LSN, then enter the LSN of the second frequency and it will tell you what the frequency is, along with a list of all the LSN's and frequencies.
Here's the frequency calculator showing my example frequencies
You'll also note that it reports a Logical Channel Number "LCN" - don't get them confused. DSDPlus uses LSN, Uniden radios use LCN.
As you log traffic on the site, you'll see more Channel ID's being called out - simply search for them in your spreadsheet or on the frequency calculator to get the matching frequencies. Add those entries to your DSDPlus.frequencies file and you should start hearing audio.
Good luck and happy researching!
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