[youtube]http://www.youtube.com/watch?v=bg7BgW2aafE[/youtube]
FaceTime is one of the main functions of the iPhone 4 because it allows making video calls between 2 iPhone 4 terminals at a video quality clearly superior to that offered by other smartphones on the market. The fact that FaceTime offers such good video quality is mainly due to the fact that the calls are made on WiFi networks instead of 3G, so the stream is made through a network that, theoretically, has a higher speed than that offered by operators via 3G. MuscleNerd said that being able to use FaceTime over a 3G network will be one of the main reasons iPhone 4 users should jailbreak, and the Dev Team is working on modifying iOS to allow FaceTime calls over the network 3G.
In theory, FaceTime should also work on 3G, but would the video quality be the same? Looking at the video clip above, I can say that using the FaceTime function via 3G would be a waste of data traffic from your subscription. The above test was done by Laptop Mag magazine which used an HTC EVO 4G, connected to Verizon's 3G data network, as a WiFi Hotspot to connect an iPhone 4 to the WiFi network provided by the EVO 4G. Considering that the HTC used as a hotspot offered connectivity at 3G speed, it is clear why the call quality is so poor. It can be seen that the terminal connected to the 3G network is not capable of quality video streaming, and even worse, the sound is not even synchronized.
I don't know what the Dev Team is planning to do, but it is possible that this function will work just as badly on any other 3G network due to the low upload speeds that the operators offer.
