Everybody knows about the iPhone by now and all iPhone owners knows that it has built-in WiFi (wireless network). But when the iPhone arrived in China, it did so without the WiFi.
The Chinese government banned WiFi back in March, in an attempt to give an advantage to a Chinese-produced alternative for wireless communication. The ban was later removed but apparently it was still able to affect the first shipment of iPhones which just reached China.
Obviously the Chinese citizens are not happy about this and that could also be why China is importing more and more iPhones from the outside world. Those will need some modifications though, before they are able to run on cellular networks in China.