Re: Survey regarding GNU radio usage in amateur radio

[Daniel Estévez]

El 14/11/20 a las 9:11, Adrian Musceac escribió:
> Hello,
>
> I am doing a survey regarding the topic of GNU radio usage in amateur radio
> activities.

Hi Adrian,

My answers below.

> 1. Are you actively using GNU radio in amateur radio activities?

Yes.

> 2. If yes, how are you using GNU radio, please provide some details.

My main use of GNU Radio for "typical" Amateur radio activities is 
probably my QO-100 groundstation. There GNU Radio plays a central point. 
The station is based on a LimeSDR Mini that runs full duplex from a 
Beaglebone black SBC. The station is controlled through GNU Radio 
running on a laptop computer, with the Beaglebone only acting as a sort 
of LimeSDR <-> Ethernet bridge (custom C software, not GNU Radio).

GNU Radio is used on receive, for plumbing, to connect the full 600ksps 
RX to Linrad, which I use for listening SSB and viewing the specturm, 
and to connect a real 48ksps slice to fligi, WSJT-X, etc. It is also 
used as a full SSB transmitter, and to put the 48ksps audio out from 
fldigi, WSJT-X, etc into the 600ksps TX spectrum.

I also use GNU Radio for Amateur satellite with gr-satellites. I guess 
this still qualifies as Amateur radio. For example, I've used it for 
digital voice QSOs through LilacSat-1.

The rest of my GNU Radio activities are on the verge of "typical" 
Amateur radio. I guess one could count them as Amateur radio, since they 
are amateur and they use radio, but for the purposes of your survey 
probably they're best counted as "radio experimentation".

> 3. Do you think GNU radio and applications using it solve some specific problem
> for amateur operators which is not solved by other free software DSP
> libraries, or, on the contrary, do you think it should implement a solution
> that already exists elsewhere?

I think that one specific feature that GNU Radio gives to Amateur 
operators is the ability to build something custom out of a set of 
blocks that they can use as a black box. This is not so different from 
building a microwave transceiver out of modules and there are people who 
like this approach.

> 4. What would you consider strong and weak points in GNU radio when related to
> amateur radio usage?

The strong points would be my answer to the previous question and the 
fact that it is very flexible, so it is possible to start doing 
experimentation and new development rather easily.

On the other hand, this is also sort of its weak point, since GNU Radio 
is a very general framework and not particularly intended for typical 
Amateur usage. For example, if you want to use HF digital modes, you're 
probably better off using fldigi than trying to replicate or rebuild all 
of that into GNU Radio. However, if you're experimenting with building 
new digital mode...

I think one important point is that GNU Radio is a framework rather than 
a tool. Most of the tools we use for Amateur radio are not based on GNU 
Radio but rather on custom DSP. The only very popular tool using GNU 
Radio that I can think of (and forgive me if I'm missing someone's great 
project) is GQRX. However, GQRX doesn't expose very much the fact that 
it's GNU Radio under the hood, so the ability to quickly modify GNU 
Radio based designs is somehow lost with GQRX.

If there was an Amateur radio tool that was based on GNU Radio but also 
exposed its inner workings in a flexible/transparent manner, then it 
should be possible to start using that tool (in order not to reinvent 
the wheel) and modify/extend it as needed.

> 5. Is your local amateur radio community generally aware of the existence of
> GNU radio?

I think yes, but they usually see it as something too difficult or not 
very practical for what they do.

> 6. If you have any authored / co-authored published papers, talk slides,
> seminars etc. related to the topic of this survey, can you provide a short
> description and a link if available?

Yes. The lists of articles and talks are here:

https://destevez.net/articles/
https://destevez.net/talks/

I'm not sure I can highlight any that are specially relevant for your 
survey. Reviewing them, it seems to me that the more "typical Amateur 
radio" ones use GNU Radio very lightly or not at all, while the ones 
that have important usage of GNU Radio could be considered "experimental 
radio".

> 7. Are you involved in research projects which use amateur radio crowd-sourced
> data, and if so, can you provide a short description of the project?

No.

> 8. Do you have any suggestions for raising general amateur radio public
> awareness of free software in general and specifically GNU radio?

Regarding free software in general, I think we're doing pretty well. A 
large fraction of the popular software for Amateur radio is open source. 
I think we still need to continue promoting free software and open 
standards on our bands on the basis that this is the only way to satisfy 
the self-training and educational intentions of Amateur radio without 
any licensing barriers.

Regarding GNU Radio, I'm not particularly sure what to do, but I think 
we should realize where it shines and promote that: it allows people to 
learn how things work, build their own, etc. (again, self-training and 
education). We should also realize where it is perhaps not the best 
tool: trying to build yet another GQRX replacement, for instance. So we 
shouldn't expect, try or insist that people try to use GNU Radio for 
replacing existing tools in Amateur radio. The other tools are probably 
better suited for the task.

Best,

Daniel.

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