Simulation of Call Admission Control in Multi-Traffics WCDMA System

Wideband Code Division Multiple Access (WCDMA) is the multiple access technique used in the third generation of mobile telecommunication (3G) systems. Capacity of this technique does not have an exact limit. The maximum capacity of WCDMA depends on current interference in the system. However, high interference causes the system a degradation of quality-of-service (QoS). Therefore, a mechanism to suppress the interference is vital. Call Admission Control (CAC) is a mechanism capable for maintaining the interference below a threshold. This report presents a basic simulation description necessary for demonstrating a simulation of a simple WCDMA system with CAC. The report includes some fundamental theories about a WCDMA system, traffic modeling, and CAC algorithms. Some simulation results are also given. The simulation results show that the blocking probability depends on the average number of users and thresholds. The results also show that much data traffic is blocked although the capacity is still available. This leads us to realize the importance of a mechanism to handle data traffic in the multi-traffics WCDMA system.