-----Original Message-----
From: Pavel Roskin [mailto:proski@gnu.org]
Sent: Wed 9/9/2009 6:25 PM
To: Bryan Nielsen
Cc: madwifi-users@lists.sourceforge.net
Subject: Re: [Madwifi-users] unreliable radio signal

On Fri, 2009-08-21 at 10:58 -0600, Bryan Nielsen wrote:

> (script lines to bring wlan0 up)
> [root@wifitest tools]# more wifistart.sh
> #!/bin/bash
> sysctl -w dev.wifi0.diversity=0
> sysctl -w dev.wifi0.txantenna=2
> sysctl -w dev.wifi0.rxantenna=2
> iwpriv wlan0 mode 3 bgscan 0 bintval 200 pureg 1

This combining of settings doesn't work.  Please use separate commands:

iwpriv wlan0 mode 3
iwpriv wlan0 bgscan 0
iwpriv wlan0 bintval 200
iwpriv wlan0 pureg 1

> iwconfig wlan0 essid destiny channel 3
> ifconfig wlan0 up

I suggest that you try the defaults first.

It seems to me that "pureg" is broken.  Even after running the modified
script, I still see CCK rates in the scan results for the AP.  Moreover,
I was able to transmit data at 1Mbps.  Yet "get_pureg" gives 1.

Perhaps this breakage confuses the rate control algorithm on the client

Pavel Roskin

I've been confused on just what pureg does, as well.  It certainly doesn't drop the CCK rates, and my best guess is that clients that attempt to authenticate with the AP but only advertise support for the 802.11b rates don't receive authentication from a "pureg" AP.  802.11g clients and APs still support all the CCK rates, and I haven't found a way to rid myself of the CCK rates without hacking the rate tables (which works like a charm, by the way).

-Brian Prodoehl