Signal quality statistics


From: Jordi Murgo (jordi_at_lleida.com)
Date: 2002-04-08 11:09:19 UTC



Vladimir Ivaschenko wrote:

>Based on the formulas from wvlan_cs and post from Jodi Morgo I have made a
>patch against 2002-04-05 to retrieve signal, noise & quality statistics. 
>

Murgo, my name is Jordi Murgo, not Jodi Morgo :)
>Please find it attached.
>
>The reason I decided to use formulas from wvlan_cs as they seem to be more
>correct to me. Quality value for prism2 never went above 92 in my tests
>and wvlan_cs formulas seem to compensate for that. I also changed maximum
>for quality (max_qual.qual) to 0x5C (92) as per wvlan_cs driver.
>
>In any case original formulas as posted by Jodi Morgo are available (I
>commented them out). 
>

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.

I don't remember where, I have read about Intersil relation from COMMSQUALITY RID and dBms:

    Level dBm = COMMSQUALITY_RID_SIGNAL - 100

You can see in the attached table, this relation isn't ok.

My first proposed relation is based on Intersil one, with scale adjustment, and isn't far from orinoco's statistics:

    Level dBm = ( COMMSQUALITY_RID_SIGNAL * 100 / 255 ) - 100

My second proposed relation (see attachment) is based on Intersil formula, with adjustment based on QUALITY indicator from COMSQUALITY_RID:

    Level dBm = COMMSQUALITY_RID_SIGNAL - COMMSQUALITY_RID_QUALITY - 100

The levels in dBm are similar to the first proporsal, and not far from orinoco/hermes levels.

Maybe Jouni have some info about, under the NDA they have signed with Intersil ... :)

Salut, <jordi /> Tables
Prism2 Signal Quality Statistics
Distance from AP: 70cm 1floor 2floor 3floor
NOAP
Hermes iwconfig dBm: -38 -53 -78 -87
-102
COMMSQUALITY RID P2_SIGNAL: 150 104 28 19
27
COMMSQUALITY RID P2_SILENCE: 0 0 0 0
27
COMMSQUALITY RID P2_QUAL: 92 55 0 0
0
P2-SIGNAL-P2_QUAL-100 dBm: -42 -51 -72 -81
-73
P2_SIGNAL*100/255-100 dBm: -41 -59 -89 -93
-89
P2_SIGNAL-100 dBm: 50 4 -72 -81
-73
MAX(MIN(P2_SIGNAL,0x8a),0x2f)-0x95 dBm: -11 -45 -102 -102
-102



This archive was generated by hypermail 2.1.4.