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[aprssig] OT: Yaesu to release digital amateur radio gear

Daron Wilson daron at wilson.org
Fri Jan 6 20:39:14 UTC 2012


>>Just for the sake of discussion, is there a P25 hardware codec available
>>for
>>free?  (since P25 is an open non-proprietary protocol by definition)

>NO!   

>Only part of P25 protocol is open.  The over-the-air digital transport of
>the data stream, error correction, selective calls to other station(s),
>group calls addressed to multiple other stations , setup & handshaking for
>trunking modes, console-to-transmit-site interfaces, etc are open
>standards.  

>However, the "secret sauce" AMBE (Advanced Multi-Band Excitation) codec
>used for voice coding/decoding   (that compresses analog voice to a 4.8 or
>2.4 kilobits/sec data stream in P25 systems)  is NOT!      It is the
>proprietary intellectual property of DVSI (Digital Voice Systems Inc) who
>collects a royalty of anywhere from $20 to $100 PER RADIO.     

Exactly my point.  Anyone can buy the necessary hardware and implement the
technology.  You could invest thousands of dollars and develop your own
hardware and software for digital voice.  I suspect you would also want to
recoup your investment..

>>And...

>>Is there any thing about the JARL Dstar protocol that prevents someone
>>from developing their own CODEC solution?

>It also uses the AMBE codec.  In principle, one could reverse-engineer the
>codec and homebrew a compatible piece of software.  However this is
>criminalized in the US by the vile DCMA (Digital Millenium Copyright Act)
>that makes it a Federal Crime to reverse-engineer proprietary software. 
>Even if you create completely new code to duplicate the same function.   

Yes, my point exactly again.  

Plain and simple, someone spent a buttload of money developing a product,
and wants to sell it.  If you don't want it, seriously, don't buy it!  But
it is unrealistic that they shouldn't be able to sell their product, and it
is also unrealistic to expect someone to develop a similar hardware and
software and just hand it out for free.






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