def open_device(self):
        MobileDevice.open_device(self)
        
        res = self.send_at_command("AT^PORTSEL=1")
        if res[2] != "OK" :
            print "error opening huawei device"

        res = self.send_at_command("AT+COPS=3,0")
        if res[2] != "OK" :
            print "error opening huawei device"