Re: signal strength problem for multiple ap's w/ the same essid

[Dan Williams <dcbw redhat com>]

On Mon, 2005-01-31 at 17:04 -0500, Sven wrote:
> checked out the CVS. sorry to report that: a few restarts of NM produced
> 2 bars, 43%, and 39%, while everything else says ~80%... the applet
> seems not to change the %, ever... unless i restart NM, so it seems. i
> guess it's fair to say that it shows the signal quality correctly "most
> of the time" ;-) also, locking the card to a certain AP, staying
> connected etc, does not change the % either...

I just tried with my 5212 card, and I get only about 75% quality when
right next to the AP and at 36MB/s.

This is _completely_ a driver problem, please file a bug with Madwifi, I
can't do anything about it in NetworkManager.  For example, when right
next to the access point, 'iwconfig' reports a quality value of "75/94".
This is current qual / max qual, as directly reported by the driver.
NetworkManager takes these two values and divides them to obtain a total
"quality" percentage.  If the driver reports either quality or
max_quality as 0, then NM tries to use the Signal and Noise levels to
obtain quality through Signal-to-Noise ratio.

The Madwifi driver sources hardcode the max quality:
(net80211/ieee80211_wireless.c):

range->max_qual.qual = 0xff - 161

This value is wrong for both our chipsets, and needs to be fixed in the
driver.  If driver's cannot provide clear & correct values for their
supported hardware or don't follow the WEXT API, there's not much I can
do about it in NetworkManager.

Dan