A Cross Layer Scheduling Scheme for Wimax

In this paper, we propose a novel scheduling scheme that will provide quality-of-service (QoS) support in the downlink (DL) of a WiMAX system. The proposed Subchannel mapping Scheduling Algorithm completely exploits the physical layer properties of the Orthogonal Frequency Division Multiple Access (OFDMA) in order to improve the throughput of the WiMAX network at the same time improving the QoS of the various services guaranteed by the network. The proposed scheduling scheme has three parts. The first stage of the scheduling shame is the optimized queuing model that will carry out effective mapping between the admitted service flows and the packet arrival statistics. The performance of the algorithm is improved further by the enhancement scheme which would further improve the performance of the proposed scheme through fuzzy logic design. At the last stage we have the slot allocation process which completes the process. The cross -layer approach followed in the scheduling scheme provides effective slot allocation under various channel conditions. It also offers more options for the network to cater delaysensitive multimedia traffic by reducing the delay in the network. Simulation results have demonstrated that the proposed scheduling scheme improves the throughput and also reduces the delay of the WiMAX network.