The Worldwide Interoperability for Microwave Access

Abstract- IEEE 802.16 standard was designed to support the bandwidth demanding applications with quality of service (QoS).Bandwidth is reserved for each application to ensure the QoS. For variable bit rate (VBR) applications, however, it is difficult for the subscriber station (SS) to predict the amount of incoming data. To ensure the QoS guaranteed services, the SS may calculate more bandwidth. In this paper, we propose a scheme, named Bandwidth Calculation, to calculate the bandwidth without changing the existing unused calculates bandwidth. The idea of the proposed scheme is to allow other SSs to calculate the bandwidth when it is available. Thus, the system through put can be improved while maintaining the same QoS guaranteed services. Mathematical analysis and simulation are used to evaluate the proposed scheme..Simulation and analysis results confirm that the proposed scheme can calculate on average. By analyzing factors affecting the calculating performance, scheduling algorithms are proposed to improve the overall throughput. The simulation results show that our proposed algorithm improves the overall throughput by 40 % in a steady network