Link Quality Aware Dynamic Frame Partition Method for WiMAX Mesh Networks

Abstract

IEEE 802.16 networks deployed in the mesh mode help to extend the coverage areas of the base stations (BSs). Two types of scheduling methods can be used in these networks: centralized and distributed scheduling. It is also possible to use these two scheduling methods together by partitioning the frames between the centralized and distributed flows. As link qualities in the network change, the bandwidth requirements of the nodes change. To support the quality of service (QoS) requirements of the centralized flows that run between the BSs and the subscriber stations and for efficient bandwidth utilization, the partition sizes should be adjusted dynamically according to the changing bandwidth requirements of nodes. To handle this issue, the present paper proposes a dynamic partition size selection method for IEEE 802.16 mesh networks. With this method, nodes change the partition sizes locally according to the changing bandwidth requirements of the centralized flows that are induced by the varying link qualities in the network. The partition sizes are changed network-wide when most of the nodes in the network are affected by the local partition size adjustments. Simulations are performed to compare the performance of the proposed method with the partition method proposed in the IEEE 802.16 standard. It is observed that, in the environments where link qualities vary, the proposed method fulfills the QoS requirements of flows in a better way, compared to the partition method.