what exactly means the signal quality (in rapport with SNR) ?

Sorin PAUN Laurentiu-Sorin.Paun at imag.fr
Thu Jun 12 13:20:56 EDT 2003


I would like to ask you more details about what exactly means the signal 
quality and how it is computed.

Is it effectively the radio signal quality, the signal "clearness", the 
fact that there are or not interferences?

Or it is a higher level concept, indicator computed un function of 
number or rate of packet losses, retransmissions, reception or lack of 
beacon frames, etc...  It is also in function of SNR, or the correlation 
is just the normal one (evidently you loss more packets if the SNR is 
lower). Does it take into account also the presence or lack of beacons?

Second, why the signal quality is important? Apparently, the firmware 
initiate the scanning procedure if the signal quality goes lower than a 
(configurable, with iwconfig wlan0 sens 1|2|3 )threshold. It is true? 
What are the values of these theresholds?

Also, there is a way to block the automatical initiation of these scans? 
We know that in host roaming mode, the decision of choosing the new AP 
is done by the driver, but the fw still can initiate the scan. There is 
no a more powerful mode where all is at the charge of the driver?

There is another role the sig. quality plays? By example, in changinig 
up and down the transmittion rate?

Thanks, and I know ùy questions are not related particullarely to 
HostAP, but I think there are some guys on the list who could help me...

Sorin PAUN                           mailto:Laurentiu-Sorin.Paun at imag.fr

Doctorant INPG                             http://drakkar.imag.fr/~lpaun

Laboratoire LSR-IMAG, Equipe Drakkar
681, rue de la Passerelle - BP 72          phone: (+33) (0)4 76 82 72 12
38402 St Martin d'Hères Cedex - France       fax: (+33) (0)4 76 82 72 87

More information about the HostAP mailing list