if you want to use the sms function of the internal 3G modem follow this steps.
"sudo aptitude install wammu gammu gcom"
If the sim card is inserted under the battery, fire up a terminal and enter "gcom -d /dev/ttyUSB0" Few seconds later gcom should ask for the pin, then give network feedback.
Fire up wammu, create a "guided connection". Use "not known" for the handy type, "/dev/ttyUSB0" as interface, "AT" as protocol. Wammu should find a "huawei unknown device" and the configuration is ready. After "connect" you can send and receive sms with internal huawei.