JEE_V5_N1_RP6 V. Jeyalakshmi G. Indumathi Journal on Electrical Engineering 2230 – 7176 5 1 41 48 WIMAX Network, MAC, Quality of Service Providing quality of service (QoS) to different service classes with integrated real-time and non-real-time traffic is an important issue in broadband wireless access networks. Opportunistic MAC (OMAC) is a novel view of communication over spatio temporally varying wireless link where by the multi-user diversity is exploited rather than combated to maximize bandwidth efficiency or system throughput. It combines cross-layer design features and opportunistic scheduling scheme to achieve high utilization while providing QoS support to various applications. Channel characteristics, traffic characteristics and queue characteristics are the essential factors in the design of opportunistic scheduling algorithms. The authors propose a cross-layer MAC scheduling framework in WiMAX point-to multipoint (PMP) systems and a corresponding opportunistic scheduling algorithm to provide QoS support to the heterogeneous traffic. Extensive Simulation experiments have been carried out to evaluate the performance of our proposal. This can improve the performance of the WiMAX PMP systems in terms of packet loss rate, packet delay and system throughput. The proposed scheduling scheme effectively support rtps traffic to make rtps packets meeting their delay bounds. July - September 2011 Copyright © 2011 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1561