Jim Moy

Of course, our 802.11b connections are too much of a good thing, you knew someone had to start. (From one of my favorite 802.11b resources.)

The new antenna location is working great. It appears to solve the weird behavior I was seeing before, and even stand up to some accumulation of snow and ice with headroom to spare. Over the past few days we’ve had a snowstorm that caused a half-inch of snow and ice to accumulate on the antenna overnight. You can see the signal strength effect on the MRTG graph shown here.

The accumulation begins a little before midnight, and by the time I got started at work the next morning the signal strength had dropped a good ten points. The new location has greater fade margin, so I never noticed the difference. I would typically see the full “11Mbps” 802.11b speed if my signal strength was greater than 30. These are Linux Aironet driver numbers, which have been discussed, but I’m still not exactly sure what relation, if any, these are to dBm, although the 2nd technique described here gives numbers that are consistent with my experiences with an OmniSky CDPD modem, to compare apples and oranges.