https://blog.wongcw.com/2019/03/11/%e4%b8%ad%e5%9c%8b%e7%a7%bb%e5%8b%95td-scdma%e5%b7%b2%e9%96%8b%e5%a7%8b%e9%80%80%e7%b6%b2%e6%88%962020%e5%b9%b4%e5%ae%8c%e6%88%90%e9%80%80%e7%b6%b2%e5%b7%a5%e4%bd%9c/