https://qooah.com/2013/04/10/%e5%9b%a0-wifi%e3%80%81gps-%e5%95%8f%e9%a1%8c%ef%bc%8c%e8%8f%af%e7%a2%a9%e7%82%ba%e7%be%8e%e5%9c%8b%e7%94%a8%e5%ae%b6%e8%b3%a0%e5%84%9f-17-%e7%be%8e%e5%85%83/