DSDPlus Feature Requests

[troymail]

*P25 Phase 2 support*

There are enough of these P2 TDMA systems on the air now, with the TIA standard published for over 2 years, that we should have this in DSD and DSD+ at this point.

Yep - would love to see this...

To piggy back on earlier request - config/filter option for pass through/block of TGIDs and/or RIDs

Also perhaps auto rename/timestamp on the captured audio file.....

Great program - I stumbled into it while research SDR and FunCube Dongle Pro (I still need to get back to that!)

 

[mtindor]

*P25 Phase 2 support*

There are enough of these P2 TDMA systems on the air now, with the TIA standard published for over 2 years, that we should have this in DSD and DSD+ at this point.

You better get right on it then. What's holding you up? We're all waiting for you to implement it.

M

 

[slicerwizard]

There are enough of these P2 TDMA systems on the air now, with the TIA standard published for over 2 years, that we should have this in DSD and DSD+ at this point.

So did you purchase these standards and make them available to any developers?

 

[dmb41crash]

Wirelessly posted (Opera/9.80 (J2ME/MIDP; Opera Mini/7.1.32052/34.818; U; en) Presto/2.8.119 Version/11.10)

Extremely helpful replies, thank you both.

 

[SCPD]

To put this in perspective, the "full rate" vocoder was published on November 30, 1995. DSD appeared in early 2010.

 

[slicerwizard]

Extremely helpful replies, thank you both.

Sorry for pointing out the obvious. I'm sure there are a few of us here who could figure out what to add to DSD - if we had the relevant P25p2 documentation. I don't think it's fair to expect the worker bees to also buy the docs.

To put this in perspective, the "full rate" vocoder was published on November 30, 1995. DSD appeared in early 2010.

Not sure I'd want to tackle voice synthesis on a 1995 PC. We've all seen how the Pi is faring in that regard.

 

[KA1RBI]

could figure out what to add to DSD - if we had the relevant P25p2 documentation.

OP25 has released code under the GPL version 3 (including the proper QPSK 6KHz differential demodulator and FEC decoding) which carries the P25P2 decode process up to the point where the "b" vector (b0 - b8) are decoded. There is some overlap, but the DSD code (actually, it's in mbelib) ambe3600x2250.c in function mbe_decodeAmbe2250Parms() picks up from there and does full voice decoding starting with "b".

P25P2 downlinks as noted can use simulcast QPSK which is basically LSM (except at 6 Kc instead of 4.8) and so as a consequence all of the simulcast distortion maladies are going to happen if you use a disc tap, or other FM demodulation function (regardless of whether hardware or software), because LSM signals are irrevocably and unrecoverably corrupted by the FM demodulation function (when simulcast distortion is present). The solution is to use differential QPSK demodulation....

Max

 

[SCPD]

Max - what happened to the op25 source repository? The oldest code there is only four weeks old. It's like someone did a slash and burn of all the source control history.

 

[Boatanchor]

Delete this post - Please

 

[KA1RBI]

Max - what happened to the op25 source repository? The oldest code there is only four weeks old. It's like someone did a slash and burn of all the source control history.

Excellent question - we've recently made two major changes and still getting caught up. For one thing the introduction of GNU Radio v3.7 has necessitataed a fundamental restructuring of the modules and directories and so forth. Part of this involved a change from GNU autoconf/automake over to cmake instead. Secondly we've also switched from svn (subversion) to git. The source control history is something that could (probably) be recreated if someone wanted to spend the time to do so - so far no one has. The API changes and restructuring in order to be GR v3.7 compliant resulted in non-trival code restructuring - which would cause huge amounts of gratuitous differences, with the result that many of the change histories would have a pitifully low S/N ratio...

Best

Max

 

[SCPD]

Thanks Max. Apologies for the off-topic question. Back to DSD+ ...

 

[mancow]

I wonder how difficult it would be to implement a CVSD decoder? Granted, most are encrypted but it would be neat to have none the less.

Also, I wonder what DSD+ would do on Inmarsat Mini-M? I believe it's somewhat encrypted or scrambled but would it attempt to decode? I no longer have an antenna setup so I can't receive that range any longer.

 

[nd5y]

All I want is NXDN RAN to show up like DMR color code does.

 

[bainino]

I posted this at the general DSD+ post, but I think this one is the way to go.

IDAS dPMR decode.

the RAW audio it's uploaded here:

Zippyshare.com - idas-dpmr.wav

73

 

[AZScanner]

OP25 has released code under the GPL version 3 (including the proper QPSK 6KHz differential demodulator and FEC decoding) which carries the P25P2 decode process up to the point where the "b" vector (b0 - b8) are decoded. There is some overlap, but the DSD code (actually, it's in mbelib) ambe3600x2250.c in function mbe_decodeAmbe2250Parms() picks up from there and does full voice decoding starting with "b".

P25P2 downlinks as noted can use simulcast QPSK which is basically LSM (except at 6 Kc instead of 4.8) and so as a consequence all of the simulcast distortion maladies are going to happen if you use a disc tap, or other FM demodulation function (regardless of whether hardware or software), because LSM signals are irrevocably and unrecoverably corrupted by the FM demodulation function (when simulcast distortion is present). The solution is to use differential QPSK demodulation....

Max

Man... I think I understood... some... of that. You guys are some serious geniuses for figuring all this out. All I can say. If OP25 can do Phase 2 then I might have to rethink my Windows only stance.

Grins wickedly... can you guys add AES-256 to the decryption module? I would DEFINITELY try OP25 if it included that.

-AZ

 

[jakkemate]

I would like a percentage of error based on datas captured the last 10 seconds, this would help to tune all the system (frequency, audio level and filters). I tried Dmrdecode but the input audio level is different than DSD +.
Thanks.

 

[poltergeisty]

Decode TETRA. :lol:

 

[oh6mwq_]

Vote for that, too!

To continue: would be great to be able to receive other dPMR signals, too.
https://dl.dropboxusercontent.com/u/13612948/hami/sdr_samples/sdr_samples.zip contains some Zastone and Kirisun transmissions recorded by SDR#. If someone is interested, I can do some disc tap recordings as well.

 

[CqDx]

My vote for TETRA as well!

 

[LimaZulu]

+1 for TETRA