# 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` ![](media/image-20250520100213700.png) 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](media/image-20250520145801679.png) 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 ![](media/image-20250520150241410.png)