I am using Gnome 3.8 desktop. as a previous Gnome 2 user i know that to enable mobile broadband by entering the context menu with Alt + right click.
However with Gnome 3 i am unable to do so .
Please note that my usb modem works with sakis3g and wvdial and i have modemmanager installed. and mobile broadband works well with them i need to configure the networkmanager applet in Gnome 3 to work with my 3g USB modem