Setting up Ubuntu 14.10 to detect 3g Modem

1. Make sure your modem listed here. (example :Alcatel OT-X220D
   )
2. Need to install library usb_modeswitch. Refer section 'How to Install' in given link
3. Before installing above library you need to make sure 'tcl' and libusb-1.x libraries need to be installed.
4. Install those libraries using;
1. sudo apt-get install tcl (this is already available with ubuntu)
2. sudo apt-get install libusb-1.X-X-dev (X-X => use latest version of library).
5.  Now install lib usb_modeswitch

Alternatively, you can try direct installation with - sudo apt-get install usb-modeswitch.

Also this is another alternative method called sakis3g. But it seems bit outdated.

To understand as to why your modem may not detected by ubuntu//linux, see here