Re: adaptive rate algorithms and Atheros adaptive radio

On Thu, 2010-03-04 at 11:46 +0530, MOHAN.R. wrote:

> 1. It is my understanding that the adaptive rate algorithm ( sample,
> minstrel, etc..) is enabled only when the rate is set to auto using
> the iwconfig command. If an explicit rate such as 36M is set, then the
> adaptive rate algorithm is disabled. Is my understanding correct?

That's true.  I know that from the code.  Just search for iv_fixed_rate
under ath_rate to see for yourself.

> 2. Both adaptive rate algorithms as well as Atheros adaptive radio do
> the same job of selecting the best possible data rate over air.

I don't see any references to "adaptive radio" in the code.  If you mean
AMMR (Adaptive Multi Rate Retry), that's just another rate control
algorithm, like sample and minstrel.

> If both are enabled (rate set to auto using iwconfig and ar set to 1 /
> enabled using the iwpriv) will there be a conflict of interests
> between these?

The "ar" parameter ultimately leads to the IEEE80211_ATHC_AR bit, which
is described in net80211/ieee80211.h:

#define IEEE80211_ATHC_AR       0x0010          /* Advanced Radar support */

Apart from the above comment, this is completely undocumented, as far as
I can tell.

-- 
Regards,
Pavel Roskin

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