Enhancing HDX: Improved Mitigation of Wi-Fi Interference through Wi-Fi-Triggered Event-Driven Radio Resource Management …

Cisco Systems is announcing a new set of features that enhance its HDX (High Density Experience) suite. This blog is the fourth in a series that explains the new features that comprise the enhancements to HDX.

The first three blogs in the Enhancing HDX series are here and here and here.

The rapid and massive adoption of Wi-Fi into handheld devices has created new challenges for managing a wireless network.

As a consequence, the traditional view of a rogue Access Point has to change. The advent of mobile APs and Wi-Fi Direct (client to client networking without requiring infrastructure) means that rogue devices don’t need to be “connected” to the infrastructure in order to create a potential for nuisance.

Effectively these capabilities mean that “Bring Your Own Device” (BYOD) may also mean “Bring Your Own AP” or “Bring Your Own Network” and therefore “Bring Your Own Interferer”. Thus the threat from a rogue becomes less about security and more about consuming excessive air time (a so-called “spectrum hog”) thus degrading performance in the WLAN. This can be especially troublesome in high density pubic venues but can also be problematic in enterprises.

So in addition to Cisco CleanAir (which mitigates and reports on non Wi-Fi interference) and RRM (which primarily prevents self induced neighboring AP interference via DCA and TPC for the entire WLAN) Cisco is effectively merging aspects of both of these solutions in order to provide improved mitigation of Wi-Fi that is not affiliated with the production WLAN.

Accounting for rogue Wi-Fi interference is accomplished by configuring a trigger threshold for ED-RRM. This is effectively a severity indicator so that the affected access point that has ED-RRM is additionally triggered by Wi-Fi interference.

Since rogue severity is now added to the ED-RRM metrics, this provides the capability of a faster channel change than the typical DCA cycle. In other words, if a rogue is interfering with airspace, then instead of waiting until the next DCA cycle to elapse, change the channel as quickly as possible. This is the same behavior as for mitigating non-Wi-Fi interferers with Cisco CleanAir technology.

Since Wi-Fi interference is becoming more prevalent, rogue APs that are serving traffic to clients (e.g., mobile APs) or client devices creating networks in real time means that air quality will be affected. Wi-Fi needs to be prevented from becoming a problem by reacting to the presence of client devices that are legitimately acting as independent, unaffiliated networks.