Java program to decode DMR

[SCPD]

Bben95 thanks for the call alert log! Any chance you could do something similar for text messaging?

I'll have a go sometime, but I don't think it will be anywhere near as simple. I'm guessing the text messages will be split into multiple packets depending on how long the message is. Does anyone know what encoding they use? Probably ASCII right?
I don't have any keypad and display models yet though, so I'll have to wait until I get one to try this out.

 

[SCPD]

Not sure if everyone has seen this document, but its incredibly useful:
http://dmrassociation.org/wp-content/uploads/2012/06/How-DMR-Works-Conventional-Tier-2.pdf
Has lots of good info about frame layout. Skip the first half with all the basic stuff we all know, and you can see all the info about sync and how it carries payloads with FEC etc

 

[IanWraith]

Hi Ben

I would do it myself but I don't have any idea how to code java (or any language really for that matter)

Thanks,
Ben

My thanks for this fantastic info. I will add it to build 71 which I hope to release in the next week or two.

Cheers

Ian

 

[SCPD]

Hi Ben



My thanks for this fantastic info. I will add it to build 71 which I hope to release in the next week or two.

Cheers

Ian

Thanks Ian, I look forward to the release, will be excited to test it out.
Does anyone have any links to any good documents about LRRP and the text messaging used my motorola?

 

[IanWraith]

Hi Folks

Right I have just added support for the CSBKO=31 and CSBKO=32 Call Alert and Call Alert ACK (which bben95 told us about) to the upcoming build 71 but you can see the source here ..

https://github.com/IanWraith/DMRDecode/commit/31b5632d6427addcb007ef13a093965ed0b914fc

Note the thanks to bben95 and this forum. Anyone who provides info like this will always be credited in the DMRDecode source code. Sharing of information (and providing credit) is the only way we will move forward with this hobby.

I must admit call alert has caused me some grief since it seems to be in a supplemental DMR standard but not the ETSI standard. However bben95s info will soon allow a decode.

Regards

Ian

 

[inigo88]

I'll have a go sometime, but I don't think it will be anywhere near as simple. I'm guessing the text messages will be split into multiple packets depending on how long the message is. Does anyone know what encoding they use? Probably ASCII right?
I don't have any keypad and display models yet though, so I'll have to wait until I get one to try this out.

Ian can correct me, but I believe some progress was made with figuring out how the text messaging data was split into multiple data packets per the ETSI standard (i.e. "preamble, xx packets to follow" and then "DMR Data packet x of y", etc). I believe where we ran into trouble was when someone provided a sample text message log and it did NOT follow standard ASCII. Since it appears Motorola uses their own custom binary encoding for each character, it might be worth just sending and logging one letter text messages to figure out the binary equivalents of A-Z and 0-9. Might take a long time, but that would be what I'd do if I had a mototrbo radio.

 

[IanWraith]

Hello All

Ian can correct me, but I believe some progress was made with figuring out how the text messaging data was split into multiple data packets per the ETSI standard (i.e. "preamble, xx packets to follow" and then "DMR Data packet x of y", etc). I believe where we ran into trouble was when someone provided a sample text message log and it did NOT follow standard ASCII. Since it appears Motorola uses their own custom binary encoding for each character, it might be worth just sending and logging one letter text messages to figure out the binary equivalents of A-Z and 0-9. Might take a long time, but that would be what I'd do if I had a mototrbo radio.

No I could decode the text (which was Unicode encoded) the problem was recognising that a PDU contained that kind of traffic and decoding it as such. I need to get back to working on this problem at some point.

Ian

 

[inigo88]

Hello All



No I could decode the text (which was Unicode encoded) the problem was recognising that a PDU contained that kind of traffic and decoding it as such. I need to get back to working on this problem at some point.

Ian

Sorry, my mistake! Is there anything the rest of us could help with in that regard?

 

[IanWraith]

Hi Folks
Rivet build 71 is out and available for download from the usual place ..

DMRDecode Download

New features are ..

Change so that if a quick log file exists ask the user if they want to overwrite it or append to the existing file.

Change so that if log file exists ask the user if they want to overwrite it or append data to the existing file.

Add support for CSBKO=31 FID=16 (Call Alert) and CSBKO=32 FID=16 (Call Alert Ack) this information kindly provided by bben95.

Decode Tier III Sys_Parms Short LCs

I haven't been able to test this as yet so any reports gladly received.

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

Also if you start seeing Sys_Parms Short LCs then congrats you are monitoring a brand new trunked Tier III DMR system. Over time I will add full Tier III support to DMRDecode.

Regards

Ian

 

[Forts]

Is it just me, or does it seem every time Ian says he will have a new version out in a week or so it's usually a day or two haha. Great work as always! I'll give it a spin today hopefully.

Question regarding Tier III..... Capacity Plus would be Tier III, correct?

 

[IanWraith]

Hi Forts

I aim to be quick !!

No Tier III isn't Capacity Plus. Tier III is a fully open digital trunking standard using DMR. Its proper trunking as well with control channels and the like - none of this rest channel nonsense The aim is that you can have a trunked system with different manufacturers radios operating on it. So far I have only come across one report of a Tier III system in action but I have been told to expect several here in the UK in the first half of this year.

Ian

 

[Forts]

Ah ok... good to know, thanks!

 

[cg]

I am getting that exact message on a 454MHz system here in Connecticut. I seem to be seeing the site number matching the Color Code on each of the frequencies. I believe it is in error as I don't think they are at different sites (but perhaps they are).
Running 47% bad frames on a very strong local signal on 3 of the 4 frequencies I can pick up.

chris

 

[highstupid]

Problem with running

every time i go to run dmrdecode either by clicking on the file or though command prompt, it says that it cant find the main class? Am I missing something?

 

[Forts]

Just with the new version? Did previous versions work OK? Is your Java runtime up to date?

 

[highstupid]

yeah java is up to date, and i tried it with b57 and b71

 

[Forts]

I haven't seen that one before, but I'm thinking it must be something with your Java install. I would re -install Java 7 and try it again. Or do you have another PC you can try it on?

 

[RonnieUSA]

yeah java is up to date, and i tried it with b57 and b71

The latest build of Java is, Java SE 7u45
Java SE - Downloads | Oracle Technology Network | Oracle

 

[highstupid]

ive tried it on 2 different computers

 

[highstupid]

installed jdk and its now working thanks