Automatically connect Mobile Broadband in Linux

Do you use Mobile Broadband in Ubuntu?
Does it get disconnected often(I use DOCOMO and it is disconnected every hour) ?
disconnection is headache when you want to sleep and leave your laptop for downloading all night but when you wake up and come to know that download was stopped after an hour or half after you sleep !!! :-(
I had same problem and decided to overcome. I've written a bash script which will help you get rid of this.
Put this script in Start-Up programs.