APCO-25 Audio Decoding

[jaystein327]

Hello all,

Ive been looking around online for some software which is capable of decoding a APCO-25 signal. Im not looking for decoding of the control channel, i.e. NOT programs like UniTrunker. (Still a very cool program!) Is anyone aware of such software? Or is this an impossible feat at this time?

Thanks

J.

 

[SCPD]

The newest WinRadio - with the P25 option - provides a PC hosted codec for listening.

 

[AZScanner]

Here is a link to the info. Very interesting.....

http://winradio.com/home/g305-apco25.htm

 

[jaystein327]

Very interesting indeed, I haven't looked into the WinRadio equipment much but it seems worthy of further investigation on my part.

My original hope was to find a software only solution. Where they only hardware requirement would be a scanner with a discriminator tap with possibly a data slicer. (is this possible?) Still good information though. Thanks!

 

[N_Jay]

Very interesting indeed, I haven't looked into the WinRadio equipment much but it seems worthy of further investigation on my part.

My original hope was to find a software only solution. Where they only hardware requirement would be a scanner with a discriminator tap with possibly a data slicer. (is this possible?) Still good information though. Thanks!

It would work, but would probably have reduced specs.

FM Discriminators are not the optimum demodulator for P25.

 

[mesocyclone]

The Codec for APCO-25 is patented and must be licensed (sigh). Wonderful, isn't it, when an association of government agencies chooses a standard like that.

Oh, and you can't get a license for just one radio. Licenses start at $250,000.

 

[DaveNF2G]

P25 was adopted (actually, it's still a work in progress) by government agencies and communications corporations. The project was coordinated by APCO (thus the "Project" designator), which is a professional association of public safety communicators and radio vendors.

 

[jaystein327]

mesocyclone, thanks for the info... I guess that means a software based APCO-25 decoder is pretty much out of the question at this point. Oh well, I guess its one more reason to shell out for one of them fancy new digital trunking scanners.

 

[PhaseLockedLunatic]

The project was coordinated by APCO (thus the "Project" designator), which is a professional association of public safety communicators and radio vendors.

The key word her is "was". The P25 standard now has it's own working group and is no longer part of APCO. The term "APCO-25" refers to an old standard and old working group that is obsolete. The correct term for the current work in progress is simply P25.

Note that "ASTRO" and "ASTRO-25" are not interchangeable with P25 in all cases. Those are Motorola trademarks. While ASTRO-25 systems will usually work with P25 systems, Motorola has a nasty habit of making certain things proprietary. P25 is to be an open standard so that any vendor can play with any other vendor. Motorola is very careful to sell ASTRO-25 equipment and not the open standard P25 so that they can legally keep the competition out.