[Ground-station] Experimental Channels

[Michelle Thompson]

It is not impossibly hard to do this. There are existing models.

It doesn’t change the downlink at all.

I’m not green lighting anything that endangers the digital multiplexed
design. Unless and until it’s proven to be dangerous, we consider things
that help serve the community.

It will be thoroughly tested on the ground. That’s where it may stay if it
doesn’t meet our standards

Similar arguments lead to flex radio offering a SmartSDR Waveform API for
their radios.

The following are rhetorical questions.
How many amateurs have taken advantage of this API?
Did having this API satisfy an entire class of critics?

We can and should take a good hard run at this, document everything, and
make it as easy to use as possible - by design.

It’s not scary, we have the expertise, and if it works reliably, then we
will provide it.  If it can’t work reliably, we drop it, and nothing breaks.

Let’s talk about exactly what is needed to reserve an uplink channel and
have that channel sampled and multiplexed, so that arbitrary modulations
can be accomplished. What precisely needs to happen?

Uplink is 4-ary minimum shift keying. There’s discussion and justification
in the archive. It helps achieve several design goals. That’s the (default)
expected uplink modulation.

>From there, what must happen if I want my kitbashed C4FM signal to pass
through and those samples appear in my downlink payload stream? Or my
hybrid wideband LoRa? Or my special sauce white noise?

>From a purely technical point of view, what must happen? Assume that the
operator authenticates, and then can reserve their channel for experimental
use.

-Michelle W5NYV


On Thu, Feb 13, 2020 at 19:56 Phil Karn via Ground-Station
<ground-station at lists.openresearch.institute> wrote:

> On 2/12/20 16:18, Bruce Perens wrote:
> > Let us all be aware of the fallacy of making our satellite all things
> > to all people. If it's not a good experimental platform for new
> > modulations, and it's not a good platform for FM communications, we
> > should console ourselves in the fact that it is not actually the last
> > Amateur satellite to be launched. Opportunities for us to launch
> > experimental satellites are increasing.
>
> I actually agree with this pretty strongly. I'd do this experimental
> mode only if it's easy and doesn't significantly impair the primary
> operating mode.
>
> My boss at Qualcomm, Franklin Antonio N6NKF, said that way back in
> Linkabit they had a saying: "Modes kill modems". This has become
> somewhat less so over time, but it's still not completely false.
>
> Phil
>
>
>
> --
-Michelle W5NYV

"Potestatem obscuri lateris nescis."
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