how to get raspberry pi to automatically connect to 3g network on every boot up?

I tried to follow this guide http://www.sakis3g.org/versions/latest/guruplug/guruplug.html

but no luck 🙁 it seems that my modem does not get into proper mode first, but if I run sakis3g it switches automaticaly and it connects, however with /etc/udev/rules.d/ files it does not...