Dynamic Frequency Selection | David Coleman | WLPC Prague 2019

The rules for 802.11 radios to transmit on the DFS channels might vary by region; however, the goal is to avoid inference with radar. DFS regulations protect many radar systems, including radar on boats, weather radar, and military radar. As a result, many enterprises WLANs never even deploy the DFS channels. This presentation will discuss how DFS actually works and why you should not afraid of the technology. We will also discuss 5 GHz channel reuse best practices with the availability of DFS channels.

Chapters:
00:00 - Start
01:15 - Channel Reuse
01:33 - Co-Channel Interference (CCI)
02:23 - 5 GHz Channel Reuse Preventing CCI
03:09 - 5 GHZ Channel Reuse - DFS Channels
03:17 - Dynamic Frequency Selection (DFS)
05:01 - History of DFS - Regulations
06:05 - History Of DFS - 802.11h 2003
06:38 - Transmit Power Control (TPC)
09:19 - DFS - Regulatory Certification - Europe
10:00 - DFS - Regulatory Certification - USA
14:13 - DFS Mechanisms
15:47 - DFS - Channel Availability Check (CAC)
16:58 - Pulse Radar Waveforms
18:07 - DFS - Radar Waveform
21:48 - DFS - Radar Detected
22:29 - DFS - Channel Move Time
23:00 - Channel Switch Announcement (CSA) Information Element
24:03 - CSA - Channel Switch Mode
25:39 - In-Service Monitoring
26:25 - Off-Channel CAC Time
27:36 - Off-Channel CAC - Switch Between DFS Channels
28:22 - DFS - Non-Occupancy Time
28:45 - Return to DFS Channel
29:29 - Zero-Wait-DFS
32:28 - Radio Resource Management (RRM) Protocols And DFS
33:44 - 40 MHz and DFS
35:15 - 40 MHz Channel Switch
38:44 - DFS Fallback Channel
39:20 - DFS and Dual 5 GHz APs
41:01 - DFS and Voice - 802.11k
41:39 - Outdoor APs And DFS
43:02 - DFS - AP Vendor Problems
47:02 - WiFiMetrix Channel Analyzer
47:55 - DFS - Examples
51:51 - Observations
53:31 - DFS Monitoring - ExtremeCloud IQ
54:04 - DFS - Machine Learning and AI