Activation Of Internal UMTS/3G Datacards

What to do if you got a brand-new ThinkPad X300, but the internal 3G data card (a SierraWireless device with the USB ID 1199:6813) simply refuses to find a network, and as a result cannot connect?
Well, maybe the card is just deactivated by default to save battery. You can enable it easily by sending:

at+cfun?
+CFUN: 0

OK
at+cfun=1
OK


to it (AT+CFUN? returns the current state, AT+CFUN=1 enables the device) with a terminal program of your choice (i always use "screen /dev/ttyUSB0" for such tasks). At least the card remembers this setting, so you don't have to repeat it every time. However, a setting somewhere in UMTSmon to automatically deactivate the card when the program exits would be cool to save some more battery power... I will have to look into that.