Andrés Ambrois andresambrois at gmail.com
Wed Dec 2 11:45:10 EST 2009

On Wednesday 02 December 2009 10:49:38 am Martin Langhoff wrote:
> On Wed, Dec 2, 2009 at 1:32 PM, Daniel Drake <dsd at laptop.org> wrote:
> > Ok, and what about the documentation?
> Also - what does the firmware on the card do with that? Could it be
> overwritten by a DCW algorythm?

Are you sure that you're using a PHY mode with fixed bounds for the CW? The 
default values you suggest (31-1023) are for DCF. I think those are set by the 
AP in HCF. You could check if those values change in different environments 
(with an AP that properly supports those extensions) to test that.

Here's what 802.11-2007 says about the Hybrid Coordination Function:
>The contention window limits aCWmin and aCWmax, from which the random
> backoff is computed, are not fixed per PHY, as with DCF, but are variable
> (contained in the MIB attribute tables dot11QAPEDCACWmin and
> dot11QAPEDCACWmax for an AP and in the MIB attribute tables
> dot11EDCATableCWmin and dot11EDCATableCWmax for a non-AP STA) and assigned
> by a management entity or by an AP.

> m


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