I saw a good video recently on YouTube on how you can skip the Wifi and use 3G to download Additional data files for your game or app.
EVEN AFTER INSTALLING SD DATA OF GAMES,IT STILL ASK FOR ADDITIONAL DATA WHICH CAN BE DOWNLOADED ONLY THROUGH WiFi. MINE IS SAMSUNG GALAXY S2.
SIMPLE STEPS.
1-ANDROID ROOTED MOBILE (IT WORKS WITH UNROOTED PHONE)
2-OPEN A NEW TEXT FILE & WRITE (FALSE) & RENAME THE TEXT FILE AS (qaWifiOnlyMode).
3-INSTALL THIS TEXT FILE IN THE ROOT OF ANDROID MOBILE & HERE YOU ARE FREE TO DOWNLOAD THROUGH YOUR MOBILE INTERNET.
USED "SCREENCAST" APP TO RECORD THE VIDEO ON MOBILE
Source: Youtube.com