China Unicom, which holds the only license for the WCDMA 3g technology compatible with the iPhone, is China's second-largest carrier.

With the users 'gradual increase of China Unicom CDMA network, the single carrier CDMA wireless network can not meet the need for the traffic growth and types of business increase.

China Unicom GPRS network gradually opened and put into commercial application, as its special feature, the radio resource optimization of the GPRS network become very important.