The Analysis And Simulation Of Call Admission Control Algorithms In WCDMA System

The Radio Resource Management algorithm guarantees the QoS of system through the allocation and application of the air interface resource, so as to obtain the planned coverage region and increase the system's capability. The Radio Resource Management algorithm comprises of Power Control, Handover, Call Admission Control, Load Control, Packet Scheduling, etc. The Call Admission Control algorithm is an important component of the Radio Resource Management algorithm, and it is of great theoretical significance as well as practical value to carry deep research.The classic Call Admission Control algorithm, which bases on throughput, works as follows: First, the algorithm estimates the load factor adding the request, then compares it with the threshold value of load factor that is permitted in the system, and approves the request if it is below the threshold and rejects otherwise. Such an algorithm fail to consider the different priorities among individual QoS services of the WCDMA system, nor does it take the handover call's precedence over the new call into account. In this paper, the author provides a new Call Admission Control algorithm on the basis of the classic one, which applies preemption and queuing strategies to real-time voice service and non-real-time data services and to new calls and handover calls, called the improved Call Admission Control algorithm based on throughput. Furthermore, in order to demonstrate the validity and effectiveness of the improved algorithm, it is actually simulated using OPNET network simulation software with WCDMA simulation library, including detailed design and coding. According to the record of simulation, the new algorithm is correct, feasible, and highly valuable for the future implementation of Call Admission Control algorithm.