How Do I Go on Playstation Network with My Ps3?

My internet is not fast enough to go on playstation network. I want to know how I can go on PlayStation Network without using my internet. Sonic the HedgeHog 4 is coming out this fall and I want to be able to download the game so I can play! Plz tell me how to do this.

Suggestion:

you can't , playstation network is an online network so obviously requires an internet connection to use

your only option is to upgrade your internet service to broadband so you have fast enough service

as far as I know sonic 4 will be available on disc .
you could always take your ps3 to a friends and connect online temporarily , sign up for playstation network and download some stuff . you can sign up on a pc too at http://us.playstation.com and use this account later on your ps3