https://blog.wongcw.com/2020/04/06/fcc%e6%8e%a8%e9%80%b26ghz-wi-fi%e8%a8%88%e5%8a%83%e9%81%ad%e9%81%8b%e7%87%9f%e5%95%86%e5%bc%b7%e7%83%88%e5%8f%8d%e5%b0%8d/