In order to have your Safari Browser access the internet, use App Store, or if you want to send and receive email, you have to turn on the Mobile Data Network on your device. If you have already used other iPhone in the past, the process seems to be easy. But if you are a newbie to the iOS 6 and you don't know how to switch it on, do the followings to know how:
1. First, tap the Home key to return to iPhone 5’s Home screen.
2. Next, select Settings.
3. Then tap on the General option.
4. Touch on the Mobile Data tab.
5. Here, switch the Mobile Data into ON mode.
6. Open the web browser and test to see if you could connect to the internet.
The above video may be a little different to the iOS 6.