[Battlemesh] Questions for a weather radar specialist?

[freifunk at yanosz.net]

Hello,


Am 04/11/2019 um 11.32 schrieb Linus Lüssing:
> Oh, what a coincidence I was in Vienna this weekend and
> my train back to Germany leaves in 1.5 hours :D.
> 
> 
> Questions I'd have would basically be related to the DFS related
> topics and discussions we regularly had at the Battlemesh:
> 
> * Are they aware that we would like to use those 5GHz frequencies
>   for meshing but that on-demand channel switching triggered by
>   DFS will break our connectivity/networks? And with only using the 2.4GHz
>   band for adhoc-meshing we are kind of limited in the quality and
>   throughput we can achieve. And the 5GHz point-to-(multi-)point
>   links with stock firmwares workaround is not really satisfactory
>   for an adhoc, on-demand, dynamic meshing goal. Do they have any idea
>   on how this could be solved in the future?

I'm aware of some DFS-stuff presented by Simon Wunderlich a few years
ago (at battlemesh?)- but I don't know what made it into 802.11s or
open80211s. Unfortunalty, I don't find this slides, atm.
@Simon: Was it you? Do you have the slides, still?

I haven't found a comprehensive full-stack guide for 802.11s (many
comprehensive guids seem to cover draft versions), yet. Most literature
on 802.11 (i.e. Perahia) skip 802.11s. References welcome ;-).

For open80211s there's a ticket
https://github.com/o11s/open80211s/issues/31 that hasn't been touched
for 5 years or so. I don't know, if open80211s issue are tracked on
github, still. At least, meshing with ath10k is possible, altough
there's a ticket https://github.com/o11s/open80211s/issues/81. For
whatever reason, channel switching is supported, while DFS is not
https://github.com/o11s/open80211s/wiki/Mesh-Channel-Switching.

I have no clue about the situation for batman-adv using 802.11s frames
(OpenWRT: option forwarding "no"). I guess, that DFS message wont' be
forwarded, too.

> * What are their thoughts on enforcing regulatory demands via
>   locked-down, signed firmwares? Are they aware of the
>   difficulties with this for community networks?

who is "their"? Rumors suggest, that functions such as radar detection
are handled in firmware-blogs nowadays (ath10k), due to their real-time
requirements.

> * Do they have any ideas on how we could improve the open-source
>   DFS implementation in the Linux kernel? Not just from a
>   technical perspective, but maybe even organizational point of
>   view, between regulators, weather radar operators and Linux
>   kernel developers.

Is it in the kernel, still? (see above).

Greetz, yanosz
-- 
There's a ripped off cord
To my TV screen
With a note saying:
"Im not afraid to dream"
-- Donkey Boy, Crazy Something Normal