Hybrid scheduling For QoS in WiMAX

Abstract

WiMAX (IEEE 802.16) is one of the most emerging broadband wireless technologies and is viable alternative to traditional wired broadband techniques due to its cost efficiency. WiMAX supports various multimedia applications such as voice over Internet protocol (VoIP), video conferencing and online gaming. These applications are diverse in nature and they have diverse requirement to be satisfied. To satisfy these types of requirements it is necessary to take into consideration Quality of Service (QoS). The QoS, an accepted criteria for measuring the performance of a network is provided through both classification and scheduling of the four different types of traffic classes defined by the standard. Each class has it own bandwidth requirements as well as its level of QoS, which has to be maintained. Many traffic scheduling algorithms are available for wireless networks, e.g. Round Robin, Proportional Fairness (PF) scheme and Cross-layer scheduling. Among these conventional schemes, some cannot differentiate services, while some can fulfill the service differentiation with a high-complexity implementation. Therefore, an effective scheduling is a must for WiMAX. In the presented work, an analysis of various available scheduling algorithms based on QoS criteria is carried out. Based upon the analysis, a new algorithm is proposed, by implying some credits to the Round Robin algorithm and is termed as - “Credit Base Round Robin Algorithm”. Our simulation results show that the proposed algorithm overcomes the limitations inherent in a single scheduling algorithm thus resulting in an efficient utilization of resources for better QoS.