Java program to decode DMR

[IanWraith]

Hello

The system I'm logging uses Privacy on their groups... could this be some sort of patch setup where the Privacy is disabled to they can connect to other agencies? (Although I would assume for this scenario you would just program in an InterOP channel into the radio and not enable Privacy... but who knows).

That does sound like a possibility. Out of interest are you seeing any PI messages on this system ?

Ian

 

[Forts]

Hello



That does sound like a possibility. Out of interest are you seeing any PI messages on this system ?

Ian

I see lots of:

Slot Type ; Colour Code 7 PI Header

if that's what you mean...

Here's another new one I logged last night..

Service Options : Emergency/Broadcast/OVCM Call/Priority 1

Now would that be an emergency button on a radio being pushed perhaps?

 

[IanWraith]

Hi

I see lots of:
Slot Type ; Colour Code 7 PI Header
if that's what you mean...

Yes that's the message. These aren't defined in the DMR spec are are left to the manufacturer to sort out hence the program can't decode them. I assume it tells the radio which encryption method and key are in use.

Ian

 

[Forts]

That would be handy... if there was a way to determine if a group was using Basic or Enhanced Privacy.

 

[apcofan]

Any idea, how to decode simplex transmissions? I mean group numbers and stations ID`s... Is there a chance that DMRdecode will provide such functionality?

 

[IanWraith]

Hello

Eventually yes but simplex DMR frames are very different containing fewer bits (as there is no CACH) also at the moment the programs symbol timing acquisition routine is far to slow to cope with simplex and will need updating. I also have the slight problem of having no simplex DMR transmissions around here (yet) to test it on.

So in other words yes I do plan on adding it eventually but it may take a while.

Regards

Ian

 

[nycap]

simplex decoding

the system i was trying to monitor is trbo simplex. maybe this is why the program is working?

 

[apcofan]

Hi!

Thanks for reply. Great work Ian, DMRdecode is a great piece of software so keep up the good work and keep up us informed about next versions.

 

[IanWraith]

the system i was trying to monitor is trbo simplex. maybe this is why the program is working?

Yes the program can only currently cope with signals that are the output of DMR repeaters.

Regards

Ian

 

[nycap]

yes that would explain my lack of success being that im trying to monitor a mototrbo system that is simplex. do you know if the other program on that runs on linux will decode the simplex mototrbo?

 

[racingfan360]

>do you know if the other program on that runs on linux will decode the simplex mototrbo?

DSD does decode simplex TRBO...I think from version 1.4 onwards (the earlier versions didn't).

 

[inigo88]

Hey Ian,

Would you be interested in testing a MotoTRBO "Connect Plus" channel grant CSBK frame in the next build?

Well it's looking very likely CSBKO=3 + FID=6 are "Connect Plus Channel Grants."

Format:

24 bits: Source ID
24 bits: Group ID
5 bits: LCN (I have never seen it go above 15, the maximum allowed LCN)

After the LCN field, the remaining bits are always "00000000010." I was originally thinking the last two could be the time slot (01 for 1 and 10 for 2?), but I have never seen it end in 1 so the way the trunking system assigns the time slot per LCN is still a mystery.

 

[IanWraith]

Hello

Would you be interested in testing a MotoTRBO "Connect Plus" channel grant CSBK frame in the next build?

Yes very please send me any info you have.

My apologies for seeming to vanish but I haven't had any email notifications of activity on these threads. That combined with being very busy at work means I haven't had time to check.

Anyway I'm back now !

Ian

 

[Forts]

Here's an odd one... I was out and about yesterday trying to log a new system I have come across. I was able to park right next to the facility, 5 bars on the scanner, super clean signal... and the program wouldn't decode anything. No sync. But.... if I was to move away several blocks (to the point where the signal was somewhat scratchy on the tapped scanner) it would decode like nobody's business. That make any sense to anyone? I found it quite odd. I moved around several times, and the stronger the signal was the more difficulty I had with it. Weird eh?

 

[IanWraith]

Here's an odd one... I was out and about yesterday trying to log a new system I have come across. I was able to park right next to the facility, 5 bars on the scanner, super clean signal... and the program wouldn't decode anything. No sync. But.... if I was to move away several blocks (to the point where the signal was somewhat scratchy on the tapped scanner) it would decode like nobody's business. That make any sense to anyone? I found it quite odd. I moved around several times, and the stronger the signal was the more difficulty I had with it. Weird eh?

Hi Forts

I have seen this before here. What appears to be happening is that the signal is so strong it is overloading one of your radios amplifiers. When you look at the discriminator output the waveform is usually clipped and distorted so the program is unable to make sense of it.

Regards

Ian

 

[Forts]

Ah ok, I wondered if it may be something like that. I tried turning the attenuator on, but that didn't make any difference either. Good to know, thanks Ian!

 

[IanWraith]

Hi Folks

Just a quick note to let you know I have just uploaded build 41 to Github ..

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

This new version contains various new features including changes to the quick log and better support for Connect Plus systems.

As usual please post bug reports and feature requests to this forum please.

Regards

Ian

 

[Forts]

Did some playing with the new version yesterday.... Looks great Ian! Thanks again for your hard work on this great program.

 

[IanWraith]

Did some playing with the new version yesterday.... Looks great Ian! Thanks again for your hard work on this great program.

Thanks for your kind words Forts I enjoy working on the program but just wish I had more time.

I would also like to thank everyone who assists me either by testing new builds or providing me with info to incorporate in the program.

Ian

 

[mikewazowski]

I'll second what Forts has posted.

Lot's of fun figuring out these new systems!