https://blog.wongcw.com/2020/12/02/iphone-12%e7%9a%844g-5g%e4%bf%a1%e8%99%9f%e5%8f%88%e7%bf%bb%e8%bb%8a%ef%bc%9a%e7%b6%b2%e7%b5%a1%e6%9c%8d%e5%8b%99%e6%84%8f%e5%a4%96%e6%8e%89%e7%b7%9a/