https://3c.yipee.cc/147157/opensignal-%e6%9c%80%e6%96%b0-4g-%e4%b8%8a%e7%b6%b2%e9%80%9f%e5%ba%a6%e8%aa%bf%e6%9f%a5%ef%bc%9a%e4%b8%ad%e8%8f%af%e4%b8%8b%e8%bc%89%e9%80%9f%e5%ba%a6%e9%a0%98%e5%85%88%ef%bc%8c%e4%bd%86%e5%8f%b0/