https://blog.wongcw.com/2020/11/19/fcc%e6%8a%95%e7%a5%a8%e6%b1%ba%e5%ae%9a%e9%96%8b%e6%94%be%e6%9b%b4%e5%a4%9awi-fi%e9%a0%bb%e8%ad%9c%e4%bd%8d%e6%96%bc5-9ghz%e9%99%84%e8%bf%91/