Re: [patch] don't display very-low-strength APs

[Bill Moss <bmoss clemson edu>]

The ipw2200 driver coverts signal level in dbm to signal quality in 
percent using a quadratic model which I developed. This model and a 
simpler linear model are discussed in the article 
http://www.ces.clemson.edu/linux/dbm-rssi.shtml. The ipw2200 driver 
computes link quality (as reported by iwconfig) as a min of signal 
quality, transmit quality, receiver quality, beacon quality, and rate 
quality, but for many drivers, link quality is the same as signal 
quality, that is, the signal level in dbm converted to a percentage.

At this time, there is no standard for conversion of signal level in dbm 
to signal quality as a percentage. In the above article, I suggested 
using 20% for the disassociation link quality which would put the clear 
channel link quality in the range of 1-10%.

Until the wireless driver maintainers agree on some standard approach to 
conversion from dbm to percent, any use of link quality to change the 
behaviour of NM is not advised.

--
Bill Moss
Professor, Mathematical Sciences
Clemson University