Client-side · Regulatory Data

DFS Channel Checker

5 GHz DFS channel availability by regulatory region. Understand CAC timers, TDWR restrictions and permitted power levels.

Available Channels

Non-DFS (preferred)

DFS Channels

Worked example

Deploying an outdoor AP for a US warehouse a few miles from an airport? Channels 120, 124 and 128 sit next to the Terminal Doppler Weather Radar band, so before the AP can even start using them it must sit silently and listen for 600 seconds (10 minutes) — ten times the standard 60-second CAC every other DFS channel needs. Any radar hit afterwards, on any DFS channel, forces a further 30-minute Non-Occupancy Period on that channel while the AP hops to another one. For a link that can’t tolerate that startup delay or an occasional mid-day channel change, pick a non-DFS channel instead — 36–48 or 149–165 above — and reserve the TDWR-adjacent range for capacity, not the primary path. Try: switch the region above to EU and compare — ETSI blocks 149–165 entirely, so a European deployment has no non-DFS option past channel 64.

United States (FCC)

→FCC Part 15.407

→CAC: 60s standard, 600s for TDWR adjacent channels (120,124,128)

→CAC (Channel Availability Check): minimum 60s

Channel Details

Channel	Frequency	DFS	Available	Max TX Power	Notes
36	5180 MHz	No	✓	23 dBm	—
40	5200 MHz	No	✓	23 dBm	—
44	5220 MHz	No	✓	23 dBm	—
48	5240 MHz	No	✓	23 dBm	—
52	5260 MHz	DFS	✓	23 dBm	—
56	5280 MHz	DFS	✓	23 dBm	—
60	5300 MHz	DFS	✓	23 dBm	—
64	5320 MHz	DFS	✓	23 dBm	—
100	5500 MHz	DFS	✓	23 dBm	—
104	5520 MHz	DFS	✓	23 dBm	—
108	5540 MHz	DFS	✓	23 dBm	—
112	5560 MHz	DFS	✓	23 dBm	—
116	5580 MHz	DFS	✓	23 dBm	—
120	5600 MHz	DFS	✓	23 dBm	Near TDWR — avoid near airports
124	5620 MHz	DFS	✓	23 dBm	Near TDWR — avoid near airports
128	5640 MHz	DFS	✓	23 dBm	Near TDWR — avoid near airports
132	5660 MHz	DFS	✓	23 dBm	—
136	5680 MHz	DFS	✓	23 dBm	—
140	5700 MHz	DFS	✓	23 dBm	—
144	5720 MHz	DFS	✓	23 dBm	—
149	5745 MHz	No	✓	30 dBm	—
153	5765 MHz	No	✓	30 dBm	—
157	5785 MHz	No	✓	30 dBm	—
161	5805 MHz	No	✓	30 dBm	—
165	5825 MHz	No	✓	30 dBm	—