Cisco’s CleanAir Spectrum Analysis: Review

Cisco CleanAir — based on the networking giant’s newest Aironet 3500 series access points and the 7.0 version of the Unified Wireless Network software — provides outstanding RF visibility combined with reporting, tracking and assessment tools that help wireless administrators build stable wireless networks ready to host mission-critical systems and applications.

For providing a premium and distinct solution (even at a premium price) in an increasingly commoditised marketplace trending toward lower prices and similar feature sets, Cisco and CleanAir earn eWEEK’s Analyst’s Choice.

With many wireless LAN vendors now touting spectrum analysis detection features, Cisco stands alone as the only vendor providing that capability via integrated, purpose-built hardware. Leveraging its 2007 acquisition of Cognio, Cisco added a customised chip set to the new Aironet 3500 series AP (access points) that works in concert with the standard Wi-Fi implementation to provide reporting, assessment and actions based on visibility into raw spectrum energy and Wi-Fi-related sources.

Testing

I tested CleanAir using six Aironet 3502i dual-band 802.11n access points deployed throughout eWEEK’s San Francisco offices, connected to a 5508 WLC (Wireless Controller) running version 7.0.98 of its Unified Wireless Network software. To the testbed, I added a Cisco WCS (Wireless Control System) installed on a Windows XP-based laptop and a 3300 series MSE (Mobility Services Engine).

Prices for the 3500 series Aironet APs start at $1,095 (£702) each for the 2.4 GHz-only 3501i with internal antennae, and go up to $1495 (£959)  for the dual-band 3502e with external antenna connectors. Our 3502i is right in the middle at $1295 (£830) apiece.  According to Cisco representatives, a network that comprises 250 Aironet APs, a single 5508 WLC, WCS software and wireless-management licenses, and a 3300 MSE with Context Aware licenses would cost $414,225 (£265,699) when using Aironet 3502i APs.

Aironet 3500 APs and a 2100, 4400 or 5500 series WLC with 7.0 software are the only required elements for CleanAir. The MSE and WCS are optional, but they do add mapping, systemwide air-quality data aggregation and storage, and an analysis of historical data that are not otherwise available.

CleanAir APs generate a couple of distinct pieces of information that are transmitted to the WLC to provide the RF perspective. The first, the IDR (Interference Device Report), generates a unique device identifier for detected interferers, while reporting the interferer classification along with affected radio band and channel. The IDR also reports an interferer’s severity index, based on its relative transmit power and its duty cycle.