Java program to decode DMR

[Forts]

Oddity I found tonight... My local public works guys recently switched to TRBO. Being a snowy night I figured they are likely out plowing and yapping away so I fired up the DMR program. Sure enough, I was able to gather some info (using the 'Invert Signal' option). Do I fire up DSD using the -xr option (invert signal) and nothing but gibberish. I try it again without the invert option and bingo, it starts decoding voice right away.

Why the difference?

 

[grosminet]

Isn't OpenSky encrypted 100%, end to end (kinda like TETRA)? Might be a futile effort.

Why then , they can decode TETRA !! ??

WAVECOM, the reference in data decoding see main page

 

[Forts]

Oddity I found tonight... My local public works guys recently switched to TRBO. Being a snowy night I figured they are likely out plowing and yapping away so I fired up the DMR program. Sure enough, I was able to gather some info (using the 'Invert Signal' option). Do I fire up DSD using the -xr option (invert signal) and nothing but gibberish. I try it again without the invert option and bingo, it starts decoding voice right away.

Why the difference?

Actually... I think you can disregard this. I tried DSD on a 2nd laptop and it won't work unless I specify inverted, so it appears to be a laptop or sound card issue.

 

[dkscan]

Why then , they can decode TETRA !! ??

WAVECOM, the reference in data decoding see main page

Decode but not decrypt. Quote from the brochure:

Encrypted data and voice poses specific problems for decoding as decryption of the payload is not attempted.

 

[Forts]

I was running DMR Decoder on a new TRBO system around here today, and one of the channels continuously would show errors like this:

Unknown CSBK : CSBKO=62 + FID=16 1100010000000000000000000000000000000000000000000000000000000000

3:11:08 PM DMR Data Frame

CACH : TACT Ch 2 Last fragment of LC

Slot Type : Colour Code 3 CSBK

Unknown CSBK : CSBKO=62 + FID=16 1110010000000000000000000000000000000000000000000000000000000000

3:11:08 PM Short LC : Unknown SLCO=15 000100000000010000000000

3:11:08 PM DMR Data Frame

CACH : TACT Ch 1 First fragment of LC

Slot Type : Colour Code 3 CSBK

Unknown CSBK : CSBKO=62 + FID=16 1100010000000000000000000000000000000000000000000000000000000000

3:11:08 PM DMR Data Frame

CACH : TACT Ch 2 Continuation fragment of LC

Slot Type : Colour Code 3 CSBK

Unknown CSBK : CSBKO=62 + FID=16 1110010000000000000000000000000000000000000000000000000000000000

3:11:08 PM DMR Data Frame

CACH : TACT Ch 1 Continuation fragment of LC

Slot Type : Colour Code 3 CSBK

Unknown CSBK : CSBKO=62 + FID=16 1100010000000000000000000000000000000000000000000000000000000000

3:11:08 PM DMR Data Frame

CACH : TACT Ch 2 Last fragment of LC

Slot Type : Colour Code 3 CSBK

Unknown CSBK : CSBKO=62 + FID=16 1110010000000000000000000000000000000000000000000000000000000000

3:11:08 PM Short LC : Unknown SLCO=15 000100000000010000000000

3:11:08 PM DMR Data Frame

CACH : TACT Ch 1 First fragment of LC

Slot Type : Colour Code 3 CSBK

Unknown CSBK : CSBKO=62 + FID=16 1100010000000000000000000000000000000000000000000000000000000000

And instead of the braaaap data burst you normally hear every 10 seconds or so, it was very rapid... like every couple of seconds.... to the point where my Pro-106 wouldn't even break squelch on it but you would see the S-Meter rising and falling with each transmission.

Keep up the great work by the way! I'm really enjoying checking out some of these systems around me to see what info I can pull from them. I installed Ubuntu on a 2nd partition on my laptop and have both DSD and DMR Decoder working great.

 

[IanWraith]

Hello

I was running DMR Decoder on a new TRBO system around here today, and one of the channels continuously would show errors like this:

Unknown CSBK : CSBKO=62 + FID=16 1100010000000000000000000000000000000000000000000000000000000000
3:11:08 PM DMR Data Frame
CACH : TACT Ch 2 Last fragment of LC
Slot Type : Colour Code 3 CSBK
Unknown CSBK : CSBKO=62 + FID=16 1110010000000000000000000000000000000000000000000000000000000000
3:11:08 PM Short LC : Unknown SLCO=15 000100000000010000000000

Those aren't errors as such but are unknown commands. What you are monitoring is either a Motorola Capacity Plus or Connect Plus system. For this system Moto have taken undefined DMR commands and use them for these systems trunking like functions. One of my local shopping centres has a 4 channel Capacity Plus system so I see these all the time.

If anyone has some spare time and an analytical mind you might want to look at these commands and try to understand their meanings.

Regards

Ian

 

[Forts]

Ahhhh.... ok. I sort of suspected this may be the case, as this site is a large university campus with a fair # of users. So would that channel be the control channel of sorts for the system?

 

[IanWraith]

Ahhhh.... ok. I sort of suspected this may be the case, as this site is a large university campus with a fair # of users. So would that channel be the control channel of sorts for the system?

From my understanding Capacity Plus doesn't have a control channel but while doing nothing the terminals sit on what is called the idle channel and when required are then sent to the other channels for conversations with presumably the rest channel being the last one used for a voice call. The shopping centre system doesn't have any one channel that sounds like yours but the commands are similar so I wonder if you have a Connect Plus system.

Can anyone here explain the difference between Capacity Plus and Connect Plus systems ?

Regards

Ian

 

[Forts]

From what I can see Capacity Plus is a single site trunking setup, where Connect Plus is multisite, with what looks to be a dedicated control channel.

Connect Plus: MOTOTRBO

Capacity Plus: MOTOTRBO Capacity Plus

Looks like Connect Plus also has more in the way of system security for keeping rogue radios out.

 

[rogal]

Hi!

I have another question for the author . Could you please add to the program sync words for simplex TRBO packets? I suppose there is no difference in frame structure - just the sync sequence differs for simplex. In my country there are a lot of simplex users of TRBO and all of them miss that functionality . The same sync is used also for repeater uplink so testing will be easy. Thanks again for the great tool.

best regards

 

[rbrtklamp2]

id go in another 500 with ray air if we could get opensky which is not encrypted 100% of the time and also p25 phase 2 tdma noww that would definetly be worth the money

 

[IanWraith]

Hello All

Just a quick update on progress with the decoder. Progress has been slow for the last couple of weeks due to being very busy at work and at home. Currently I'm working on a feature that will allow the user to filter out certain frames so for instance the program doesn't display Idle PDUs or frames that failed their error check. I'm also chasing a bug in the display code.

I do plan on adding a feature that will allow simplex DMR to be decoded but it isn't as simple as just recognising another sync sequence. The problem is that simplex transmissions don't include a CACH so the timing and number of bits is different.

Regards

Ian

 

[Forts]

Keep up the good work, it is greatly appreciated! While we are on the topic of wish lists, I'd like to see a simple activity GUI of some sort that would show the radio ID/group ID in use during a transmission... ala UniTrunker/Trunk88 etc style. That way you don't have to check the logs afterwards. You could potentially have one pc running DSD decoding audio, and your app running on a 2nd machine that would show you the transmission info in real time. But even as is, it's an excellent app that I have been having a lot of fun with. Thanks!

 

[IanWraith]

Hi Folks

Just a quick note to let you know that I have put build 31 on Github ..

https://github.com/IanWraith/DMRDecode/downloads

New features include ..

1) The "View" menu allows you to decide if you wish to view CACH info , Idle PDUs or frames with errors.

2) The status bar at the bottom of the screen now displays channel activity (great idea Forts !).

+ I have fixed a display bug.

As ever bug reports or feature suggestions to this forum please.

Regards

Ian

 

[Forts]

LOVE the new version. The channel activity is perfect! Thanks for throwing that in there!!

 

[Forts]

I have one more request.... If it's possible, can you have the log file show which timeslot a group was active on? ie instead of showing 2000 GROUP perhaps 2000 GROUP (TS1 or 2) (or both I suppose if it's a Capacity Plus system). Would make things a little easier after a long session of unattended logging.

I'm currently in Toronto right now on business and their are plenty of TRBO systems around here! Thanks, and keep up the great work!!

 

[IanWraith]

Hi Forts & all

Thats a good idea and a handy feature which I will add to my to do list. I have been a bit snowed under with things at home & work recently so haven't had much time to work on DMR Decode. But I'm hoping to be able to do something on it next week.

Ian

 

[Forts]

No rush at all... just thought I would throw the idea out there!

 

[Forts]

I've noticed something odd in the 'Save to file' functionality. When I'm monitoring for new systems, I will park on a frequency... lets say 451.1000 then select save to file. I'll enter 451-1000 for my filename and log for a while. When I want to move on I usually de-select the save to file button then move to another frequency, but when I go to re-select save to file more times than not the radio button is still highlighted... but I don't think it's actually still logging. Or.... and I just had this happen... was logging a file, deselected the save to file button. Changed channels, re-hit the button (and it lights up) but logging does not start (and I'm not presented with the dialog box for where to save the log).

 

[Jay911]

Hi,
Where do I unpack the zip archive to in order to make this work?

I am having the same issues as grosminet was in post #8. I tried the revised command posted in post #9 but got no results there either.

There is no .jar file in the zip I downloaded. Am I supposed to compile it somehow?

EDIT: I'm a toolbox. I downloaded the source files, not the compiled jar binary.