[Make-wifi-fast] Thoughts on tackling airtime fairness

[David Lang]

On Wed, 11 May 2016, Toke Høiland-Jørgensen wrote:

>> Ten years ago I played with SFQ and madwifi for 802.11g to get max-min
>> time fairness (and so proportional rate fairness) with excellent
>> results. The hacking I made was based on using time quanta instead of
>> bytes. Which required me to get the current PHY rates (AP to all
>> STAtions) and dynamically compute/update SFQ time quanta.
>
> Do you happen to recall what precision you achieved or how much the
> precision was really important? Several papers seem to assume that very
> high precision is not terribly important since it all evens out in the
> end, and I can see how that could be true; but would like to have it
> confirmed :)

I think the point here is that perfect is the enemy of good enough. Right now 
the only attempt at fairness is packet counts. Anything that improved this would 
be a win. We can probably get several orders of magnatude improvement from even 
the most crude measurements.

So start simple/cheap and see how much improvement there is, only go to more 
precision (more expensive) if you find there's a need to.

for that matter, retries may be something that you start off ignoring, just like 
multicast

David Lang