A standard interface for interfacing a wireless modem assembly with a host device comprises a primary serial interface, a secondary serial interface, and a differential serial interface for supporting communication between the wireless modem assembly and the host device. The standard interface can be implemented in a standardized connector, such as a 70-pin connector having unused pins for future feature expansion. The standard interface also provides for other interfaces including, for example, power, modem status, audio, voice, general purpose input/output, and subscriber identification.