No sensibility info

Pavel Roskin proski
Tue Apr 20 09:41:12 PDT 2004

On Wed, 21 Apr 2004, Ryan Verner wrote:

> Pavel Roskin wrote:
> > You can use iwspy to collect information for specific stations.
> Is there a recommended firmware/wireless-tools/hostap to use together so
> iwspy (? - isn't this iwlist <dev> scanning) gives accurate values?

iwlist scanning returns a list of access points.  It returns signal and
noise levels for the probe response.

iwspy gives average data for packets received from a certain node.

> I normally see values such as 229/90 or something.  I'd give an example,
> but the machine that I was going to use is playing funny buggers currently.

You have found a serious bug!  __prism2_translate_scan() doesn't set
iwe.u.qual.qual, so it contains leftovers from the previous operation,
perhaps some bytes from the frequency.

Wireless tools require "quality" to be set in the scan results, but the
Prism firmware doesn't provide it.  It only provides quality for
established links (in managed mode).

The driver should set iwe.u.qual.qual to something that reflects the
signal to noise ratio.  I'll post a patch once I can test it.

In the meantime please look at "signal" and "noise" and ignore "quality"
in the scan results.  If you still see data beyond the range please report
them with the firmware and hostap versions.

Pavel Roskin

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