Cisco Cisco Aironet 3500p Access Point Libro blanco

 

 

© 2014 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public Information. 

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The primary new feature of the new 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 channel. 

Of course, a wider channel is also more susceptible 
to interference. For example, 802.11ac devices “hear 
more” than 802.11n devices, primarily due to the 
wider channel support. 

Figure 5 shows why there is 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. 

Figure 5. 

802.11ac Throughput With and Without 

 

5-GHz Interference on Secondary 40 

 

 

Source: Miercom 

 

The fundamental features and benefits provided by 

Cisco CleanAir technology are directly extensible to 

emerging Wi-Fi technologies. For example, when the 

802.11ac module is installed and enabled in an Aironet 

3600 Series access point, the CleanAir subsystem will 

monitor the entire 80-MHz channel (that is, the 5-GHz 

802.11n radio native to the Aironet 3600 monitors the 

full channel bandwidth being used by the 802.11ac 

module instead of monitoring only its own 40-MHz-wide 

channel). 

Furthermore, this same proven functionality is provided 

in the new Aironet 3700 Series access points. As with 

the Aironet 3600 plus 802.11ac module, the CleanAir 

subsystem within the Aironet 3700 will report interferers 

detected within the full 80-MHz channel in addition to 

creating AQ reports for each of the four 20-MHz 

channels that form the 80-MHz channel. 

In summary, CleanAir continues to detect and report 

upon interference sources and AQ despite the increased 

channel bandwidth. Therefore, no degradation or 

suboptimal performance results from the migration to 

802.11ac. CleanAir support for monitoring the entire 80-

MHz channel provides superior 802.11ac network 

quality management, helps improved visualization of 

how the RF spectrum is being used, and enables 

EDRRM for the full 80-MHz channel. 

Conclusions 

Because Wi-Fi operates in a shared unlicensed band, integrated spectrum intelligence and spectrum management 
are a “must haves” to enable a high level of performance, security, and reliability in your Wi-Fi network. Spectrum 

management is critical for providing a rich and dependable 

 experience to end users with business-critical 

wireless applications. 

Because the limited RF visibility capabilities of commercial Wi-Fi chipsets are not sufficient, Cisco has integrated 

patented spectrum processing hardware and software specially designed for analyzing interference, and created a 

true enterprise-class Wi-Fi chipset. With this underlying silicon capability, Cisco CleanAir technology classifies and 

locates individual sources of interference and tells you how it impacts the performance or security of your network. 

While SI can be acquired in the form of tools like Spectrum Expert that are useful in the predeployment phase, the 

best option is to have SI technology integrated directly within the infrastructure. Cisco CleanAir technology provides 

powerful spectrum management features such as 24/7 proactive monitoring of interference, spectrum security and 

performance alerts, remote management, and interference device location. Most importantly, integrated SI enables 

a new level of automated spectrum management that is able to understand and intelligently mitigate the impacts of 

interference.