A slot allocation mechanism for diverse QoS types in OFDMA based IEEE 802.16e systems

In this paper, we investigate slot allocation for diverse quality of service (QoS) types in orthogonal frequency division multiple access (OFDMA) based IEEE 802.16e wireless MAN systems. For a downlink scenario, we propose flow metrics that dynamically capture the extent to which flows of diverse QoS types merit bandwidth allocation. Using these flow metrics, we propose a scheduling rule for a mixture of real-time, non real-time and best effort traffic. Our system model uses queues implemented as finite length buffers for each of the downlink flows. Simulation results are presented to compare the performance of the proposed rule with that of existing rules.