icbnet

This work examines the technique of fractional frequency reuse for the downlink of multi-cellular WiMAX networks. Different frequency-reuse deployment scenarios are presented. Three schemes for the reuse zone selection are evaluated, namely, the distance-based and SINR-based approaches, as well as a new scheme, which is based on load-balancing between different reuse zones. The proposed load-balancing scheme overcomes the main weakness of the SINR-based approach, which is its inability to efficiently manage the available resources of both reuse zones as their size varies. The evaluation of the different schemes is based on simulations that employ a ray-tracing propagation model, thus estimating the propagation phenomena as closely to reality as possible. The simulation results demonstrated clearly better performance of the proposed algorithm compared to the distance-based and SINR-based approaches. It is shown that the use of fractional frequency reuse with the proposed load-balancing approach improves the performance of WiMAX networks in terms of a variety of metrics, such as blocking ratio and offered bit rate.