An Evaluation Model for Call Admission Control Scheme in CDMA System

Call admission control (CAC) is a key factor in quality of service (QoS) provisioning for different services. In this paper, a Quasi-birth-and-death (QBD) process model is developed for the purpose of evaluating the CAC schemes of the cellular systems, where exist several types of traffics with different arrival rates. The CAC controller seeks to optimize the throughput and minimize the blocking probability. We obtain the theoretical expressions of several parameters that indicate the performance of the system, such as connection blocking probability, channel utilization, and normalized throughput, by analyzing the complete sharing CAC scheme. Simulations are implemented and the results show that the simulated outcomes coincide with the theoretical results got from the expressions. This verifies that the modeling is proper to evaluate the performance of CAC scheme.