Campus lan and Wireless lan solution Design Guide

Cisco CleanAir 
Cisco CleanAir is a purpose-built spectrum intelligence solution designed to proactively manage the non-Wi-Fi 
interference in the 2.4 and 5 GHz spectrums. Many consumer devices use the same frequencies that are used 
for 802.11 Wi-Fi—Bluetooth headsets, microwave ovens, and many new IOT devices use different protocols but 
occupy the same frequencies required for operation of the WLAN. 
Cisco CleanAir is an innovation available in Cisco Catalyst 9120AX and 9130AX APs, which include the Cisco RF 
ASIC. CleanAir is dedicated to detecting and identifying sources of interference that otherwise would simply 
appear as noise to a Wi-Fi chipset. 
Cisco CleanAir technology was released in 2010 and has continuously adapted to keep pace with the market 
and changing nature of the WLAN spectrum. CleanAir monitors the full channel bandwidth capability of a 
CleanAir-capable AP regardless of the deployment requirements, and as a result, it monitors the range of 20 
MHz-160 MHz channels. 
CleanAir can report analysis and findings through the WLAN controller. You can use certain Cisco DNA Spaces 
implementations and Cisco Prime to map both the interference and the impact of the interference for easy 
analysis and troubleshooting.
At the controller level, you can use two mitigation strategies to help maintain your network and prevent outages 
associated with common non-Wi-Fi interference sources: 
● 
Persistent Interference Avoidance
—Allows the WLC to track and report non-Wi-Fi interferers to DCA.
For instance, there may be a microwave oven that becomes quite active around lunchtime every day.
Persistent Interference Avoidance remembers this device and instructs DCA to pick channels for the 
affected APs that will not be interfered with by this periodic interference source. 
● 
ED-RRM
—Helps mitigate disruptions from interference sources (perhaps a video camera) that use 100% 
of the available airtime when enabled. Because this interference is not recognizable as anything other 
than noise to the 802.11 chipset, all clients and APs typically wait for the channel to become less busy.
ED-RRM provides a safety net by doing two things:
◦
Recognizing that something is not noise but instead is intentionally transmitting and interfering with the 
network operations. 
◦
Forcing the AP away from the problematic channel to a channel where operations can resume. The 
resolution is very fast acting (30 seconds or less), and the information about the interference is 
incorporated into RRM through DCA, alerting DCA about interference disruptions related to the channel 
just abandoned. 
As a best practice, you should enable CleanAir, Persistent Device Avoidance, and ED-RRM. 

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For additional details, visit cisco.com and 
search for the Cisco CleanAir Technology: Intelligence in Action White 
Papers
.