Uplink and downlink scheduling for point to multipoint WiMAX Networks

IEEE 802.16 standard lacks a Media Access Control (MAC) scheduling architecture to enforce Quality of Service (QoS) requirements of different services classes. In this paper, we propose an opportunistic and optimized scheduler that meets connections’ QoS requirements while it pledges fairness among admitted connections. Our approach involves separating the scheduling problem into two sub-problems. In the first sub-problem, which addresses interclass time-slots allocation, the proposed scheduler calculates the optimum number of time-slots in each time frame corresponding to the service classes with the objective of minimizing the blocking probability of each class. In the second sub-problem, the intraclass slot allocation problem, time-slots for each class are allocated using an integrated cross-layer priority functions (PFs) that provide proportional fairness among a class connections. The simulation results reveal that the proposed scheduler realizes our objectives, and provides efficient QoS scheduling without starving the connections of the BE class. Copyright © 2008 John Wiley & Sons, Ltd.