 Internet Connection Sharing , supported on compatible devices , allows the phone to share its Internet connection with computers via USB and Bluetooth . Windows Mobile supports virtual private networking over PPTP protocol . Most devices with mobile connectivity also have a Radio Interface Layer . The Radio Interface Layer provides the system interface between the Cell Core layer within the Windows Mobile OS and the radio protocol stack used by the wireless modem hardware . This allows OEMs to integrate a variety of modems into their equipment . 
