On Wed Oct 18, 2023 at 9:58 PM CEST, Remi Pommarel wrote:
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Also, this seems to assume that time slices are divided equally. That's probably only be true for WiFi drivers that have airtime fairness changes integrated? So only recent versions of mt76, ath9k and ath10k? Has anyone verified that this works fine not only in AP but also in 11s mode?
I don't know how that would behave on setup that does not have airtime fairness changes integrated, if you think the current dividing by two approach is better maybe this can be made a configurable option but that could be tricky ?
It seems to me that airtime fairness is something that most current drivers aim at doing. Even the mac80211 scheduler is going this route with the itxq work. So I feel like we should assume that with time, most drivers will be. And devices that do not respect airtime fairness will probably not match the current TP/2 rule either.
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And a third concern, but we'd probably have this issue with both our current and your suggestion: Would we be off again 802.11be and its "Multi-Link Operation" in the future?
This, I have hard time figuring out how MLO would play along with B.A.T.M.A.N-Adv integration. Unfortunately right now I have no way to experiment that yet. IIUC the link would be a mix between half and full duplex, and this would probably complicate things a bit.
Thanks a lot for your review.
For me MLO is hard to take into account. Depending on the drivers (and probably on the firmwares mostly) we do not know if it is/will be used as a real aggregation mechanism or as a way to have 'free' roaming between multiple bands.
Moreover, currently all the path throughput estimation is based on the expected throuput that the 80211 stack gives us for individual sta. I beleive that very few drivers actually provide a value for it.
So IMHO we should do our best to have a good path estimation based on the sta estimated throughput, and it should be the mac80211 drivers job to provide us with an accurate estimated throughput for each sta on a link. And yes in the MLO case it will be a hard job indeed...