SDRTrunk DMR Decoding Question

[KC1UA]

Hello,

I will admit out of the gate that I am a new SDRTrunk user so I may be missing the obvious. I am using v0.5.0-alpha4, which has added the ability to decode DMR. I am attempting to decode Site 12 of this system: Industrial Communications and Electronics (DMR) Trunking System, Regional, Multi-State - Scanner Frequencies . When I created the channel configuration I opted to have it pick "All" frequencies. When I play the system it does find the proper control channel (I need to update the RR info for CC's for this site and will do so shortly). However, the only voice traffic I am hearing is in slot 2 of the frequency of the control channel. However, in the events tab I am seeing channel grants for the other system channels.

So...I am missing something obvious or DMR is a work in progress. I'm guessing the former! Audio sounds great when I do hear traffic.

Thanks in advance for any handhold!

 

[Kazzaw]

I'd guess that SDRTrunk isn't set up to utilise trunking, the system you are listening to is a trunking system. The reason why you are only hearing TS2 is because TS1 is the control channel (hence why you can see all the other information) and TS2 is a voice slot.

So yes, DMR Trunking is a work in progress. Non-trunking DMR is fine (from what I hear, I don’t use SDR Trunk)

 

[KC1UA]

I'm familiar with how DMR trunking systems function. My point is that despite seeing voice grants that are being sent to other LCN's, SDRTrunk is not moving to that frequency to decode the audio, like it does with a P25 system. Therefore I'm either screwing something up or as you say it's not yet equipped to handle DMR Connect Plus systems.

 

[Kazzaw]

not yet equipped to handle DMR Connect Plus systems.

I'd put my money on this

 

[DSheirer]

sdrtrunk supports trunking for Connect Plus systems.

Make sure you configure the LCN Frequency map in the DMR decoder configuration. If you create the channel configuration by using the radio reference import in the Playlist Editor, it will automatically create the LCN Frequency map for you.

You can find the LCN Frequency map values if you click on the individual site details in the radio reference web page for the system that you're trying to monitor. The site frequency table for the site you're monitoring is here: Falmouth Site Details (Industrial Communications and Electronics (DMR))

Denny

 

[KC1UA]

Thanks Denny. I am definitely missing something critical here as once again I am only hearing voice traffic on slot 2 of the LCN that is in use for the control channel. I download the site from Radio Reference. It appears to sort the frequencies into proper LCN order. Then I click on the Create Channel Configuration button and it adds the channel to my playlist. The LSN order appears to be correct. Are the frequencies in the "Source" section of the channel editor exclusively for control channels?

My apologies if there is specific documentation for using DMR; I didn't find it.

 

[DSheirer]

Scott, I replied on the sdrtrunk support group. Can you post a screen shot of your channel configuration that show the LSN map in the DMR decoder section?

 

[GTR8000]

Con+ is broken in alpha 4, I just verified and reported to Denny via email. It will only tune to voice traffic on slot 2 of the control channel, it will not tune to any other traffic channels.

I rolled back to the last DMR build of alpha 3 and it started tuning to traffic channels again. Unfortunately I don't believe that separate alpha 3 DMR branch is in GitHub anymore, looks like it was all merged into the Master branch for alpha 4.

(I posted this in the SDRTrunk support group as well)

 

[UNICATIONWAVES]

Im using the latest sdrtrunk version, i took the info from rr Lakewood Township Public Works Trunking System, Lakewood, New Jersey - Scanner Frequencies and Im not getting audio, just data packets.