Cisco Cisco Aironet 3500p Access Point Libro blanco
Copyright © 2010 Miercom
Cisco CleanAir Competitive
Page 17
With the video camera at 100 feet from the access point, only the farthest client was affected.
Noise level reading was -66dBm. After one half hour, the access point did not change channels.
Our attempt to force ACS to switch channels manually was unsuccessful.
Noise level reading was -66dBm. After one half hour, the access point did not change channels.
Our attempt to force ACS to switch channels manually was unsuccessful.
Meru Equipment:
Meru’s AP320 uses the Proactive Spectrum Manager feature. It displays the level of “goodness”
of each channel. When we sent video streams over a clean channel, PSM reported the channel
as “bad” due to the high utilization, but when the channel was jammed by the video camera,
resulting in no utilization, PSM reported a 100% “goodness” score for the channel.
of each channel. When we sent video streams over a clean channel, PSM reported the channel
as “bad” due to the high utilization, but when the channel was jammed by the video camera,
resulting in no utilization, PSM reported a 100% “goodness” score for the channel.
This 802.11n access point essentially does not support auto channel as the 802.11 a/b/g
models do, nor does it appear to support self-healing. PSM does evaluate the channel every
user-defined number of seconds, and then moves stations to a clear channel. The only
threshold which is used to trigger this change is the presence of rogues.
models do, nor does it appear to support self-healing. PSM does evaluate the channel every
user-defined number of seconds, and then moves stations to a clear channel. The only
threshold which is used to trigger this change is the presence of rogues.
Screenshot taken while the video camera was completely jamming the channel. Meru reports a
100% “goodness” score for the channel, because the jamming interference means that Wi-Fi
channel utilization is in fact 0%, from Meru rating of channel quality. Meru would not change
channels even if the channel is completely jammed and unusable by Wi-Fi.
We measured the relative noise levels on the Meru access point to determine their accuracy.
Meru measured a noise level of -82dBm as a baseline on a clean channel. With our video
camera 50 feet away, the noise floor read -85dBm. With the video camera at a distance of
100 feet, the noise floor reading was -71dBm. See
100% “goodness” score for the channel, because the jamming interference means that Wi-Fi
channel utilization is in fact 0%, from Meru rating of channel quality. Meru would not change
channels even if the channel is completely jammed and unusable by Wi-Fi.
We measured the relative noise levels on the Meru access point to determine their accuracy.
Meru measured a noise level of -82dBm as a baseline on a clean channel. With our video
camera 50 feet away, the noise floor read -85dBm. With the video camera at a distance of
100 feet, the noise floor reading was -71dBm. See
Figure 4
on page 18 for a summary
of the results.