Re: Backoff algorithm

[Johannes Berg <johannes@sipsolutions.net>]

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On Thu, 2009-12-17 at 16:10 +0200, Andrey Lukyanenko wrote:
> Hello Everyone,
> 
> I wanted to find implementation of backoff protocols for different platforms.
> I tried to find it in various open-source drivers in linux-sources, madwifi and
> stlc45xx. Everywhere I could only find some initialization of CWmax, CWmin, ...
> but not the actual algorithm (something like, cw = min(cw<<1 + 1, cwmax) ),
> except ath_rate sample/mistrel where the operation is used for "best
> rate measurement"
> as I understood.
> Am I correct to assume that the protocol is implemented in firmwhere and there
> is no open source driver which I could use to "play" directly with it?

Yes, basically. It's not something you can really implement in any
driver anyway as it's very timing sensitive.

ar9170 even has this in hardware, afaik, although you can of course play
with it in b43 firmware and/or ar9170 by influencing the value you give
the hw.

johannes

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