Cisco Raises The Stakes For Mission-Critical WLAN

Cisco Systems has rolled out its new CleanAir technology with an aim to thwart one of the biggest challenges to the enterprise WLAN, RF interference. Using CleanAir, the Cisco wireless network monitors the air quality within the environment, identifies sources of interference, and if necessary, moves affected access points to cleaner channels. This new level of airspace intelligence and proactive optimization is raising the bar for wireless networks and bringing the dream of self-healing, mission critical WiFi to the market.

Cisco's CleanAir technology has its roots in the Cognio spectrum analyzer tools, acquired by Cisco in late 2007.  Cognio's solution paid particular focus on not only visualizing what is going on in the airspace, but identifying the sources of interference, based on RF signatures.  But like nearly all of the spectrum analysis tools, the laptop-based application offered a reactive approach. The administrator had to physically go to the trouble spots in the building and hope to catch the interference while it was happening. After over two years of development work, Cisco has finally moved these spectrum analysis tools into the wireless infrastructure itself.

At the heart of the CleanAir system are the new Aironet 3500 series access points. The new APs feature a custom CleanAir ASIC that continually scans both the 2.4 and 5Ghz wireless spectrum for any signs of interference without requiring dedicated use of one of the access point's radios. Cisco notes that the new access points can detect and classify more than 20 different types of wireless interferences, distinguishing, for example, a cordless phone from a microwave oven or Bluetooth radio. 

Air quality data and location information of the interference is collected from all CleanAir equipped access points in the network, merged and collated within Cisco's Mobility Services Engine (MSE) appliance to build an Air Quality Index value for every part of the wireless network.  If this air quality value dips below a certain threshold, CleanAir takes corrective action, instructing the wireless controller's radio resource management to move affected access points to a new channel and at least temporarily marking the noisy channel as unusable. 

Administrators can also access this air quality data from Cisco's Wireless Control System (WCS) to not only get a real-time view of the air quality of their wireless infrastructure and use the location information to remove sources of interference, but also access the forensic history stored on the MSE to go back in time and identify trouble. This element is particularly useful to catching and identifying a moving target, such as a cordless phone, and with this level of history, an administrator can actually follow an interfering device as it moves through the building.Unfortunately, because the dedicated ASIC is currently available in the Aironet 3500 series access points, early adopters of Cisco's 802.11n products are left a bit in the lurch for embracing the CleanAir solution. While Cisco suggests that customers could deploy the new access points in a monitor mode as an overlay to their existing infrastructure, this approach limits the ability for the network to adapt to its environment. For new deployments and customers who have not yet transitioned to 802.11n, the benefits of CleanAir should be given serious consideration when evaluating the premium price point for the Aironet 3500 series access points.

The integration of spectrum analysis and building this intelligence into the infrastructure itself is a significant game changer for enterprises and could change their attitude and approach to wireless networks. A self-healing WLAN able to work around the various sources of interference is fast becoming a requirement as more mission-critical applications utilize the wireless networks and more end-users adopt WiFi as their primary connection to the enterprise network. Likewise, CleanAir has the ability to change how administrators support the infrastructure. 

The solution not only automates remediation of interference issues, but enables IT to resolve these issues throughout their organization, many times without putting boots on the ground.  The notion of service level agreements for the wireless network may have been laughable in the past, but with the level of technologies that CleanAir brings to bear on the biggest drawback to WiFi networks, a wireless SLA could be the norm going forward.