Android USB Tethering

Tethering means sharing the Internet connection of an Internet-capable mobile phone with other devices. This sharing can be offered over a wireless LAN (Wi-Fi), or over Bluetooth, or by physical connection using a cable (Tethering).

Our focus in this article will be the USB tethering.
Your Android mobile phone can behave as an external network interface usbN, connected via the USB infrastructure. The usbN interface is in turn connected to the mobile phone LAN, providing dhcp server, DNS server, gateway and so on.
That's how your mobile phone can provide an Internet connection to another device.

Android phones are already equipped to provide this functionality. Simply connect the USB cable and go to Settings -> Wireless settings -> Tethering -> Tethering USB.

What you need is some kernel and network configuration on the other side (e.g. your laptop).

原文地址：http://wiki.gentoo.org/wiki/Android_USB_Tethering