Re: [Make-wifi-fast] Bayesian rate control

[Dave Taht <dave.taht@gmail.com>]

Dear Bjorn:

I took a quick look at your patches in
http://www.openias.org/bayesian-wifi-materials-and-methods

sampling minstrel at such a high rate is going to hurt you, I think,
on a lower end architecture, especially. We have a sampler that can
run at about 20ms intervals (tops) on limited hardware, that can grab
mcs rates, in flent, if that helps.

To me, key to fixing rate control is first the other stuff for queue
management, then doing "smart things" fast when a station pops up to
grab a web page and then goes silent. Right now I've seen minstrel
take a minute or more to find the right rate, an ideal one would be
closer to 100ms.



On Sat, Oct 29, 2016 at 1:50 PM, Björn Smedman <bjorn@openias.org> wrote:
> Thomas, Dave, Adrian, Johannes,
>
> Thanks for comments and encouragement. I bought the TP-Link TL-WA901ND
> access point and TP-Link TL-WDN4800 PCIe card. Had no problem getting
> them talking to each other with ath9k, and the rate table contains 52
> entries, so plenty to start out with.
>
> I've written a follow-up post about it if anybody's interested:
> http://www.openias.org/bayesian-wifi-materials-and-methods
>
> Cheers,
>
> Björn
>
> On Wed, Oct 26, 2016 at 7:56 AM, Johannes Berg
> <johannes@sipsolutions.net> wrote:
>>
>>> The intel 7260 and later parts also allow user controllable rate
>>> control and provide transmit completion feedback, but I don't know
>>> whether it's enough for your needs.
>>
>> Perhaps. However, existing rate control is *very* tightly coupled to
>> the driver, and it'd be fairly pointless to disentangle just for the
>> sake of playing with a rate control algorithm.
>>
>> Also, the device doesn't support per-frame control nor any kind of
>> sampling-with-table-fallback, only the rate table that you give to the
>> device and update.
>>
>> Btw, mac80211_hwsim with wmediumd doing some medium simulation might
>> also be something to look at for just extending to VHT.
>>
>> And come to think of it, there's this new driver Felix et al have been
>> working on, mt7601u, which also should support proper rate control
>> APIs.
>>
>> johannes



-- 
Dave Täht
Let's go make home routers and wifi faster! With better software!
http://blog.cerowrt.org