QoS_GTE: A centralized QoS guaranteed throughput enhancement scheduling scheme for relay-assisted WiMAX networks

Abstract

A centralized QoS guaranteed throughput enhancement (QoS_GTE) scheduling scheme for downlink relay-assisted WiMAX networks is proposed. The QoS_GTE consists of a transmission time based path selection algorithm (TT_PSA), a service order based resource allocation algorithm (SO_RAA), and a transmission concurrency decision algorithm (TCDA). The TT_PSA selects the path with the minimal transmission time for packets, which takes path loss, shadow fading, and interference into consideration. The SO_RAA gives high priority to urgent users and maximizes throughput under QoS satisfaction. The TCDA carries out flexible resource reuse by deciding which relay station (RS) can transmit concurrently using the same frequency and time slots. Simulation results show that the proposed QoS_GTE outperforms the scheme of without relay by an amount of 63% and that of the LMP by an amount of 28%, in the system throughput. The QoS_GTE can also guarantee QoS requirements of real time services by 97%.