A Dynamic Hierarchical CAC Mechanism for IEEE 802.16d System

In the paper, we propose a dynamic hierarchical call admission control mechanism in IEEE 802.16d WiMAX system. The mechanism is built upon hierarchical user nodes priorities and service classes priorities. And it uses a dynamic bandwidth algorithm to maximize the bandwidth allocation efficiently at the base station. In this paper, we use average polling delay and scheduling efficiency as the performance measurements. Our simulation is performed for comparisons of the proposed CAC mechanism with a conventional bandwidth-based CAC. The simulation results show that our CAC algorithm guarantees that the average polling delay is smaller and the scheduling efficiency is higher when we comparison it with the conventional bandwidth-based CAC.