From: Vladimir Ivaschenko (hazard_at_hazard.maks.net)
Date: 2002-04-11 12:06:01 UTC
Hi,
I have checked the stats with the spectrum analyzer. Jordi's formulas are correct, he did a good work unlike me. :) Formulas from wvlan_cs are way off, and his second formula seems to give more accurate result than the first one. Still a few db off, but that's ok, considering that cards are not calibrated like spectrum analyzers.
I attach a patch with the second formula.
Mon, Apr 08, 2002 at 04:47:31PM +0200 Jordi Murgo wrote about Re: Signal quality statistics
> On Mon, 2002-04-08 at 14:09, Vladimir Ivaschenko wrote:
>
> > > Vladimir Ivaschenko wrote:
>
> > > Murgo, my name is Jordi Murgo, not Jodi Morgo :)
> >
> > Oops, sorry. You can misspell my name in exchange. ;-)
>
> Misspelling your name are really easy, for sure :)
>
> > > I have played again with my prism2 and hermes cards ...
> > > Assuming hermes statistics are ok, I think my formulas are more acurate
> > > than wvlan_cs ones.
> >
> > You surely seem to have done a lot of investigation. My decisions were
> > much simpler basing that wvlan_cs has right assumption about max quality
> > level. :-)
>
> Not a lot ... only a bit of hacking at home. My house have 4 floor. I
> have tested the values returned by
>
> cat /proc/net/prism2/wlan0/rids | grep QUAL
>
> then, I have removed prism2 card, and inserted hermes/orinoco (OEM
> Lucent Technologies card), ussing hermes, orinoco and orinoco_cs
> modules, from pcmcia-cs.
>
> iwconfig eth0 | grep Quality
>
> These steps are done for each position, laptop powered with batteries.
>
> Isn't a lab test, but is enough to have an idea ...
>
> > I will bring a WLAN spectrum analyzer to my home today and will check your
> > formulas.
>
> Great.
>
> By the way, my ranges are:
>
> range.max_qual.qual = 100;
> range.max_qual.level = 0x100 - 100 -1;
> range.max_qual.noise = 0x100 - 100 -1;
>
> You can add the same formulas to fill the values of prism2_ap.c used by
> "iwspy"
>
> Salut, <jordi />
>
> --
> Jordi Murg? i Ambou
> Internet Web Serveis, S.L.
> Lleida / Catalonia / Spain
> Tfn: +34-973234106
>
>
-- Best Regards Vladimir Ivaschenko http://www.hazard.maks.net/~hazard