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Features of the Cisco Unified Wireless Network with CleanAir Technology 

Detection and identification of interference sources have always been very important, and they increase in 

importance as wireless networks increase in density (more clients, more access points, and more traffic). As a 

critical component of our High Density Experience (HDX) solution suite, Cisco CleanAir technology provides a lot of 
detailed information about interference. But to facilitate an “at a glance” understanding of where interference 

problems are impacting the network, it rolls up the detailed information into a high-level, easy-to- understand metric 

referred to as Air Quality (AQ). AQ is reported at a channel, floor, and system level and it supports AQ alerts, so 

that you can be automatically notified when AQ falls below a desired threshold. 

Air Quality is reported for both “classified” (that is, detected and identified) and ‘”unclassified” (that is, detected but 

unidentified) interference. Information about unclassified interference is included in the AQ report but is excluded 

from AQ Index calculations. For improved monitoring capabilities, when the severity of the unclassified category 

exceeds a user-defined threshold, an alarm is generated. 

In a CleanAir technology-enabled WLAN, devices that have been analyzed and detected are also integrated with 

the visual mapping displays provided by the Cisco Prime Network Control System (NCS) and Mobility Services 

Engine (MSE) management systems. In addition to seeing access points and clients on a map, you can track 

where interference devices exist on the same map. In terms of performance, the ability to see interference devices 

on the map (as well as their zone of impact) lets you determine what access points, clients, and areas of your floor 

space are impacted. 

From a security perspective, tracking devices on a map lets you know immediately where to dispatch your security 

personnel. 

In addition to displaying on a map any devices that affect security, you can customize alerts by location - for 

example, a specific floor of your building. This is a powerful feature since certain devices may be considered a 

threat in some areas of your building - for example, in the trading wing - but not in other areas, such as the 
building’s lobby. 

In addition to flexible deployment, Cisco CleanAir technology offers advanced automated response to interference. 

These automated responses include persistent device avoidance and event-driven RRM (EDRRM). 

Persistent device avoidance recognizes that certain devices tend to be static in location and frequency - for 

example, microwave ovens and wireless video cameras. For this reason, even when these devices are not 
currently being detected on a specific channel at a specific location, it’s known that they are likely to return at 

locations in which they have been detected previously. The system tracks these kinds of devices, and when 

channel selection is performed, tries to avoid channels at locations where persistent devices have been observed. 

Furthermore, an access point enabled with Cisco CleanAir technology will share (or propagate) information 

regarding the presence of persistent devices it has detected to neighboring Clean Air enabled access points. In this 

way, the system helps those access points avoid 

the possibility of “channel bouncing” (that is, doing dynamic 

channel assignment into a channel affected by a persistent interferer).