Openwrt修改频点法律法规

常用的命令

  1. 获取国家码对应的频点信息：iw reg get

    global
country US: DFS-FCC
        (902 - 904 @ 2), (N/A, 30), (N/A)
        (904 - 920 @ 16), (N/A, 30), (N/A)
        (920 - 928 @ 8), (N/A, 30), (N/A)
        (2400 - 2472 @ 40), (N/A, 30), (N/A)
        (5150 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
        (5250 - 5350 @ 80), (N/A, 24), (0 ms), DFS, AUTO-BW
        (5470 - 5730 @ 160), (N/A, 24), (N/A), AUTO-BW
        (5730 - 5850 @ 80), (N/A, 30), (N/A), AUTO-BW
        (5850 - 5895 @ 40), (N/A, 27), (N/A), NO-OUTDOOR, AUTO-BW, PASSIVE-SCAN
        (5925 - 7125 @ 320), (N/A, 12), (N/A), NO-OUTDOOR, PASSIVE-SCAN
        (57240 - 71000 @ 2160), (N/A, 40), (N/A)

phy#1
country US: DFS-FCC
        (902 - 904 @ 2), (N/A, 30), (N/A)
        (904 - 920 @ 16), (N/A, 30), (N/A)
        (920 - 928 @ 8), (N/A, 30), (N/A)
        (2400 - 2472 @ 40), (N/A, 30), (N/A)
        (5150 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
        (5250 - 5350 @ 80), (N/A, 24), (0 ms), DFS, AUTO-BW
        (5470 - 5730 @ 160), (N/A, 24), (N/A), AUTO-BW
        (5730 - 5850 @ 80), (N/A, 30), (N/A), AUTO-BW
        (5850 - 5895 @ 40), (N/A, 27), (N/A), NO-OUTDOOR, AUTO-BW, PASSIVE-SCAN
        (5925 - 7125 @ 320), (N/A, 12), (N/A), NO-OUTDOOR, PASSIVE-SCAN
        (57240 - 71000 @ 2160), (N/A, 40), (N/A)

    解释：

    (5250 - 5350 @ 80), (N/A, 24), (0 ms), DFS, AUTO-BW
# 5250 - 5350	：频段：5250–5350 MHz
# @ 80			：频宽80M
# (N/A, 24)		：N/A：最大天线增益:  24：最大EIRP
# (0 ms), DFS,	：(0 ms)：DFS 检测的强制等待时间为0 通俗点：检测到雷达后无需等待，立马切换频点
# AUTO-BW		：自动带宽选择，比如检测到80M干扰比较严重，就改变频宽40M

  2. 设置国家码命令：iw reg set US

  3. 获取当前频宽 频点：iw dev wifi0 info

    图上显示：

    • channel：120 对应频点5600

    • 频宽80MH

    • 中心频率5610M

修改国家码对应的法律法规

打开文件：build_dir/target-powerpc_8540_musl/wireless-regdb-2022.08.12/db.txt

以US为例说明：

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), (30), 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)

解释上述配置：

  • 示例1：(5470 - 5730 @ 160), (24), DFS

    频率范围在5470 - 5730， @ 160 指的是支持160M频宽 最大功率为24 强制要求DFS支持(radar detection)

    如果检测到雷达信号，自己就会跳频

  • 示例2：(5850 - 5895 @ 40), (27), NO-OUTDOOR, AUTO-BW, NO-IR

    频率范围在5850 - 5895 ， @ 40指的是支持40M频宽 最大功率为27

    NO-OUTDOOR：不能在户外使用，AUTO-BW：自动频宽，如果检测到有干扰会改变自己的频宽

上述配置比如(5250 - 5350 @ 80), (24), DFS, AUTO-BW和(5470 - 5730 @ 160), (24), DFS 中，强制DFS，设备运行后使用iw list 命令可以看到下面的截图：

image-20250520145801679

现在我们把这些DFS去掉：修改后的

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

  • (5470 - 5730 @ 160), (24)

修改后完整的如下：

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
	# 修改的地方 去掉DFS
	(5250 - 5350 @ 80), (24), 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.
	# 修改的地方 去掉DFS
	(5470 - 5730 @ 160), (24)
	(5730 - 5850 @ 80), (30), 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)

设备运行的表现如下：可以看到没有