Improvement And Simulation Of Dynamic Call Admission Control Algorithm In WiMAX System

As we all know, wireless resource is very valuable. For operators, they expect to create higher operating earnings through limited resources; and for users, they expect to have the quality assurance communication service continuously and stable. The two are contradictory. In this thesis, the algorithm is to achieve the good compromise between the operating revenue and user satisfaction.This thesis first introduces you the relevant organizations, the network model and key technologies of WiMAX systems. Then, this thesis research into the algorithm that used to improve the system of WiMAX wireless management techniques. Finally, the paper specially designed and discussed a dynamic Call admission control algorithm that suitable to the WiMAX system, and also executed a performance simulation analysis to WiMAX system.Improved algorithm proposed in this thesis is under the condition of switch connect application's priority higher than the ordinary connect applications. It divided system resources into dedicated resources and public resources. In dedicated system resources, reserved bandwidth resources is for the switch connection usage, that is, when this system resources have been used more than the size of public resources, the common connection applications can not be permitted to access the system; on the opposite, when system resources is no more than the size of the total resources, the switch connect application will have the opportunity to access the system. To rationally allocated the proportion of dedicated resources and the public resources, this algorithm based on the usage situation of system resources to dynamically adjust the size of reserved channels. Compare this algorithm to the traditional fixed Reserved channel mechanism, not only did it reduces the system call dropped rate, but also effectively controls the system call blocked rate. In addition, the algorithm added connecting income factor to the priority function that makes it possible to bring more revenue to apply for priority accessing to the network, thus it helps to increase the overall system average revenue value. Finally, it used MATLAB simulation tool to comparatively analyze the algorithm proposed in this thesis, algorithm of fixed reserved channel mechanism and the traditional priority mechanism. It approved that the new algorithm indeed increased the system average earnings under the condition of user-satisfaction.