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HDX Blog Series #1: Why Spectrum Intelligence Still Matters

- January 8, 2014 - 0 Comments

Editor’s Note: This is the first of a four-part deep dive series into High Density Experience (HDX), Cisco’s latest solution suite designed for high density environments and next-generation wireless technologies. For more on Cisco HDX, visit

CleanAir for 802.11ac:  Why Spectrum Intelligence Still Matters

In wireless networking and communications, as with life, nothing good comes for free. It’s well known that the primary feature of the new IEEE 802.11ac amendment is support for an 80 MHz-wide channel. The benefit of an 80 MHz channel is the potential to double usable throughput in comparison to that of 802.11n using a 40 MHz wide channel.

However, what is less well known is that a wider RF channel is also more susceptible to interference. In other words, 802.11ac devices “hear more” than 802.11n devices, primarily due to the wider channel support. It should be noted that this is not a flaw in the 802.11ac amendment, it’s simply basic communications theory.

Nevertheless, there is far more to building an 802.11ac access point than simply meeting the standard. Not all 802.11ac access points perform equally without interference. But more importantly, not all 802.11ac access points perform well in the presence of interference.

Furthermore, there is far more to deploying High Density wireless LANs than only considering the performance of individual access points. It should not be a surprise that not all networks perform well in the presence of interference. As the number of clients per access point continues to increase, and the number of access points in a given wireless network continues to increase, and the number of wireless networks themselves continues to increase, wireless network operators and administrators are increasingly challenged to maintain performance in the presence of interference.

In brief, for high performance and high density environments, Spectrum Intelligence continues to matter. When interference can be detected and identified, it can also be mitigated.

For these reasons, Cisco CleanAir technology will be one of several key features in our High Density Experience (HDX) solution.

The fundamental features and benefits provided by Cisco CleanAir technology are directly extensible to 802.11ac and to High Density environments. For example, in the new Aironet 3700 Series access point, the CleanAir subsystem will 1) monitor the entire 80 MHz channel 2) will report interferers detected within the full 80 MHz channel and 3) will create AQ (Air Quality) reports for each of the four 20-MHz channels that form the 80-MHz channel.

CleanAir support for monitoring the entire 80-MHz channel helps to 1) provide superior 802.11ac network quality management 2) improve visualization of how the RF spectrum is being used, and 3) enable EDRRM (Event Driven Radio Resource Management) across the entire 80 MHz channel.

In summary, because of the increased channel bandwidth for 802.11ac networks, and the increasing density of wireless networks, CleanAir is essential to help assure that no significant degradation or suboptimal performance results from the migration to 802.11ac and concurrent growth of high density deployments.

For more on Cisco’s approach to 802.11ac and high density environments, visit


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