[hpsdr] Future projects?

[Tony Langdon]

At 07:50 AM 3/12/2007, Naylor Jonathan wrote:
>***** High Performance Software Defined Radio Discussion List *****
>
>Hi All
>
>I've been doing some thinking today about a couple of side projects
>that I think would benefit the SDR community. Let me run them past you.
>
>1. Define a network protocol, or take an existing one, for moving audio
>data between separate machines. This would allow for using (say) WSJT
>on a different machine to the SDR DSP processing. Such a protocol
>should include a negotiation system so that sample formats and sample
>rate information can be passed before the actual data. For use on a
>LAN, UDP would make sense for the audio data itself. As well as
>individual programs supporting it, a plug-in for Jack could also be
>written to use it.

That would be an excellent idea.  This protocol would want to have a 
soundcard emulator associated with it, so normal audio packages can 
use it.  With multiple PCs and a high degree of networking, I would 
get a lot of use out of this protocol.  I would also need 
implementations for at least Windows and Linux.

>2. Define and produce an open-source digital audio system. I am fearful
>that a proprietary system will eventually become the standard, and that
>isn't in keeping with ham spirit (IMNSHO). I'm sure we can find an
>adequate open-source codec (Speex?) and cross platform libraries exist
>so that producing software for all of the major platforms would be
>relatively straightforward.

Agreed.  There are a lot of open source bits and pieces that could be utilised.


>I would happily help with such projects, and surely there must be some
>developers out there that want to contribute to moving SDRs and amateur
>radio in general, forward.

Unfortunately, I don't have the software or DSP background, as I have 
a lot of ideas I would like to implement, many of them requiring 
some  degree of DSP.  I've hit the same barrier when playing with 
VoIP, but have been able to convince some programmers to write code 
so I could implement my ideas. :)

Anyway, because of my involvement in ham VoIP (IRLP and Echolink) and 
emergency comms (ironically on behalf of the US more than locally!), 
combined with living on a sparsely populated continent, I would like 
to see a way of linking HF with the VoIP systems.  I have had a 
degree of success using a combination of a good quality DSP unit and 
a tweaked VOX (as opposed to the more traditional analog syllabic 
squelch).  When combined with the networked audio idea, interfacing 
could be a breeze.  One requirement is any HF link has to be 
compatible with the installed base of ham gear - that means it has to 
work with HF SSB (tricky, I know).

This could also be used in a home station setup.  Say it's too cold 
to be out in the shack, or you're working in the back yard and 
waiting for a call.  Hook the HT up to the SDR and use it as a mini 
remote base.  DTMF control software could be written, so you can 
change frequencies and mode via your DTMF keypad (damn, now I want an 
auto antenna tuner! LOL).  If course, if inside, you could have it 
networked to a PC instead of using a UHF radio link.

Another idea.  As digital voice systems take over, it would be nice 
to be able to link radios using the same codec as we use on air (the 
fewer transcoding steps, the better the audio).  I used this approach 
in the EchoIRLP (and related dual system conference spinoffs) project.

Anyway, just brainstorming out loud, while we're discussing ideas. :)

73 de VK3JED
http://vkradio.com


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