Cisco Cisco Aironet 3700i Access Point 백서

 

 

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But with the advent of 802.11n (40 MHz channel widths) and 802.11ac (80 MHz channel widths today and 160 

MHz channel widths anticipated), Cisco realized that abandoning the entire operating channel was a highly 

inefficient solution. Why abandon the entire channel if radar is detected on only one 20 MHz segment? 

Furthermore, if the radar is detected only on a secondary channel, then why seek a new operating channel, if the 

primary operating channel can be automatically narrowed from 80 to 40 or 20? 

The answers to these questions are in Cisco’s patent-pending FlexDFS. In this case, radar energy can be 

accurately and reliably identified down to 1 MHz using the Cisco CleanAir subsystem in the custom ASIC in Cisco 

access points. This narrowband identification not only helps prevent false detection in the primary channel of 

operation, but also in the secondary channels of operation and in new channels to be considered (if necessary). 

Figure 6 shows an example of how FlexDFS works. 

Figure 6.    Cisco FlexDFS 

 

When coupled with the new DBS feature, the best channel width can be selected with confidence, and 

correspondingly, confidence can be established when operating at 80-MHz channel width. Keep in mind that a 

high-density deployment thrives on a large number of non-overlapping channels being available. Used in tandem, 

DBS and FlexDFS reinforce the usability of 5 GHz, not only by conserving spectrum, but also by reducing 

interruptions due to detecting and avoiding interference. 

Most significantly, FlexDFS does not require user enablement: it is merely an enhancement to our existing, 

industry-leading, always-on DFS solution. With FlexDFS, Cisco continuously improves functionality. 

Improved Mitigation of Wi-Fi Interference through Wi-Fi-Triggered Event-Driven Radio 
Resource Management (ED-RRM) 

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 access points 

and Wi-Fi Direct (client-to-client networking without requiring infrastructure) means th

at rogue devices don’t need to 

be connected to the infrastructure in order to create a potential for nuisance.