OpenWRT Boot Times Affected by WiFi

OpenWRT Regulatory Database Flag Summary

This section summarizes common Linux/OpenWRT wireless regulatory database flags used after a frequency range entry.

Typical rule format:

(freq_start - freq_end @ max_channel_width), (max_power), optional_flags

Example:

(5250 - 5350 @ 80), (24), DFS, AUTO-BW

Item	Meaning																																						Practical Interpretation The regulatory database affects the final usable wireless settings through this path: regulatory.db ↓ kernel cfg80211 regulatory rules ↓ iw reg get / iw phy ↓ hostapd channel validation ↓ radio starts, waits for DFS, falls back, or fails For boot-time testing, the most important flags are: DFS NO-IR AUTO-BW The DFS flag is the primary item associated with radar scanning and delayed AP availability. Removing or changing power alone is not a direct test of DFS behavior. A direct test compares the same frequency range with and without the DFS flag. United States Regulatory Insert country US: DFS-FCC # S1G Channel 1-3 (902 - 904 @ 2), (30) # S1G Channel 5-35 (904 - 920 @ 16), (30) # S1G Channel 37-51 (920 - 928 @ 8), (30) (2400 - 2472 @ 40), (30) # 5.15 ~ 5.25 GHz: 30 dBm for master mode, 23 dBm for clients (5150 - 5250 @ 80), (23), AUTO-BW (5250 - 5350 @ 80), (24), DFS, AUTO-BW # This range ends at 5725 MHz, but channel 144 extends to 5730 MHz. # Since 5725 ~ 5730 MHz belongs to the next range which has looser # requirements, we can extend the range by 5 MHz to make the kernel # happy and be able to use channel 144. (5470 - 5730 @ 160), (24), DFS (5730 - 5850 @ 80), (31), AUTO-BW # https://www.federalregister.gov/documents/2021/05/03/2021-08802/use-of-the-5850-5925-ghz-band # max. 33 dBm AP @ 20MHz, 36 dBm AP @ 40Mhz+, 6 dB less for clients (5850 - 5895 @ 40), (27), NO-OUTDOOR, AUTO-BW, NO-IR # 6g band # https://www.federalregister.gov/documents/2020/05/26/2020-11236/unlicensed-use-of-the-6ghz-band (5925 - 7125 @ 320), (12), NO-OUTDOOR, NO-IR # 60g band # reference: section IV-D https://docs.fcc.gov/public/attachments/FCC-16-89A1.pdf # channels 1-6 EIRP=40dBm(43dBm peak) (57240 - 71000 @ 2160), (40) Notes Channel 116 is inside the normal 5 GHz DFS block. If DFS is removed from the applicable range and AP startup becomes faster, that supports DFS/radar handling as a startup-delay factor. A channel selected by automatic channel selection should not be assumed to be the objectively least congested channel. It only means the channel was selected by the available scan/survey data and the active regulatory/driver/hostapd rules. A scan table showing fewer visible APs on a channel supports that the channel is cleaner from a visible Wi-Fi Basic Service Set perspective, but does not prove lowest total RF noise or lowest airtime utilization.