WCDMA technology. The Iu interface establishes the communications between the RNC and the CN. The Iu divides the system into radio-specific UTRAN and CN which handles switching, routing and service control. The Iu is logically divided into two different instances: Iu- CS (Iu-Circuit Switched) for connecting UTRAN to the CN circuit switched domain and Iu-PS (Iu-Packet Switched) for connecting UTRAN to the CN packet switched domain. All these interfaces defined in the 3GPP specification are open interfaces, this ensure the compatibility between equipment of different manufacturers and allows multivendor scenarios in the network configuration. A Node B is handling transmission and reception in one or several cells. It is logically correspond to the Base Transceiver Station (BTS) in GSM. In contrast to GSM base station, Node B uses WCDMA as the air transport technology. The Node B converts the radio frames received from the radio interface into a data stream and then forwards it to the RNC via the transport channels over the lub interface. In the opposite direction, the Node B prepares incoming data for transport over the radio interface and transmits them to the UE. Traditionally, the Node B has minimum functionality and is mainly controlled by an RNC. However, this is changing with the emergence of HSPA (HSDPA/HSUPA), where some control and resource management functions are handled by the Node B to achieve lower system latency. The RNC is the central controlling element in UTRAN responsible for the control of the radio resources of UMTS. It connects the CN and also terminates the Radio Resource Control (RRC) protocol that defines the messages and procedures between UE and UTRAN. The RNC is essentially in responsible for call setup, quality of service handling, and management of the radio resources in the cells for which it is responsible by performing the Radio Resource Management (RRM) functions like admission control, power control, code allocation, radio bearer setup and release, handover, etc. The RNC usually c