In the WCDMA system, the mobile UE connects with the fixed system network through a radio channel on the radio interface. Called Uu interface, this interface is one of the most important interfaces in the WCDMA system. The radio interface technology is the core one in the WCDMA system, which shows the core technologies and main differences of all kinds of 3G mobile communication systems.
By learning the WCDMA radio interface, we can understand the operating principle between the UE and the WCDMA network systems and get known to the communication procedures. Learning this chapter is also the precondition of the WCDMA radio network planning.