USB modem doesn't get connected

Question

I'm using the 3.5G Hsdpa modem, it has been detected as an usb modem. But when I try to connect, it always disconnected. I've tried to use Wvdial & Sakis3G but it still can't connect.

I don't think this is a signal or a device problem since it it connects normally with Windows even when the signal is very low.

Answer 1

Try Sakis3G with some switches:

--pppd 
--nostorage
--nofix
--nohal

One of these may solve your problem. If not, try --interactive to manually configure your modem.