Although many users expected Apple to allow the use of FaceTime through a 3G connection of our iPhones, unfortunately the company from Cupertino still maintains the limitation that requires FaceTime to be used only through Wi-Fi networks. Of course, through jailbreak we can overcome this limitation and applications like My3G or 3G Unrestrictor allow us to use FaceTime via 3G, but I have for you a method that involves activating this function without jailbreak but only on iPhone 4.
I tried tutorial on a jailbroken iPhone 4 and it didn't work, everything stuck at the tethered startup process. You can also try the method on terminals without jailbreak and if it works, please leave a comment.
Step 1
Download iOS 5 available here and this version of redsn0w available here.
Step 2
Open redsn0w, choose the Extracts>Select ipsw menu and select the ipsw downloaded in step 1.
Step 3
Return to the main menu and then enter the terminal in DFU Mode.
Step 4
After you have entered the terminal in DFU Mode, press the Jailbreak button and from the following menu, uncheck Install Cydia and check only Enable FaceTime over 3G.
redsn0w should do its job and after the terminal restarts you should be able to make FaceTime calls via 3G. This method should not jailbreak, but use it at your own risk. Alternatively you can try this tutorial which requires jailbreak and works on Windows/Mac.
