THE DFS PROJECT
'The DFS Project' is a vendor-agnostic web site created and supported by Nuts About Nets for the purpose of documenting how different APs respond to DFS radar events. In terms of DFS compliance, not all APs are created equal -- sometimes their response to a radar event is unexpected and/or incorrect. Most APs will jump when they detect the simulated radar pulse generated by WifiMETRIX. However, where their responses tend to differ concerns which channel(s) they jump to and how closely they conform to 802.11's DFS guidelines and recommendations. Sharing results will not only benefit the community as a whole but, hopefully, also encourage AP vendors to update their firmware and eliminate DFS errors and inconsistencies.
'The DFS Project' web site was inspired by Devin Akin and David Coleman -- renowned engineers and educators in the enterprise Wi-Fi world. Devin is the founder and Principal Wi-Fi Architect of Divergent Dynamics, a Wi-Fi Systems Integrator and Training organization. He specializes in innovative design, validation, and performance optimization solutions for healthcare, education, and stadium/arena markets. David is Director of Product Marketing at Extreme Networks and the author of multiple books about 802.11 Wi-Fi technology, including the most recent Wi-Fi "bible" -- CWNA Certified Wireless Network Administrator STUDY GUIDE.
Introduction by Devin Akin
In early 2018, The DFS Project was born out of a conversation around the Wi-Fi industry’s need to validate DFS functionality in the field. After over a year of research, testing, and on-going discussions, the WifiMETRIX device was born. Now you can create picture-perfect DFS events in the field, exactly as the regulatory bodies test the APs in a lab.
With WifiMETRIX you can answer questions like like:
- Does my AP detect DFS events of various types?
- If a DFS event is detected, does my AP move to a new channel? If so, how long does that take?
- Does my AP announce the Channel Switch Announcement (CSAs) in beacons, probe responses, and action frames? If so, for how long?
- If a DFS event happens, how does it affect application performance on my devices?
Combined with a channel scanner you can also answer the following questions:
- When my channel changes, where does it go?
- Does my AP return to the original channel? If so, after how long?
- After a channel change, what happens to the channels on the other APs in the area?
While validation of DFS functionality is the primary goal of the new DFS feature set in the WifiMETRIX, the same features can be used for other purposes (hint: automatic channel/power testing and DFS event sensitivity testing). Just because a vendor sends their AP through DFS testing (and receives a certification from the regulatory body) at one point in time does not mean that an AP will maintain the same level of DFS event recognition throughout its life because firmware and software change the AP’s functionality over time. Finally, the industry has a diagnostics platform that can fill the DFS testing gap and provide visibility into previously unexplored and unvalidated AP functionality.
Well done Nuts About Nets!
DAVID COLEMAN’S DFS PRESENTATION AT WLPC PRAGUE 2019
Everything you’ve ever wanted to know about DFS (dynamic frequency selection) — and more…
Thank you David Coleman and Wireless LAN Professionals.