Autorun may automatically use the Media sync (MTP) mode in certain circumstances.
Autorun automatically switches to Internet connection mode if the connection fails while syncing or connecting.
You can share your phone’s internet connection with your PC using a USB Cable. After connecting with a USB Cable, set the USB connection mode to Internet connection. Then select either Ethernet or Modem.
Ethernet This mode changes the phone to USB tethering mode from the PC. From the Home screen, tap . Return to the Settings screen and tap More... (under the WIRELESS & NETWORKS section) > USB tethering > Mobile Broadband Connect checkbox.
This mode can only be used by a user registered to a tethering plan.
Modem This mode changes the phone to Modem mode from the PC.