Centralized Scheduling Mechanism for Enhanced End-to-End Delay and QoS Support in Integrated Architecture of EPON and WiMAX

The integration of Ethernet Passive Optical Network (EPON) with IEEE 802.16 (WiMAX) is regarded as a promising access solution in realizing fixed mobile convergence (FMC) networks. The complementary features of EPON and WiMAX can bring not only wide bandwidth and mobility to subscriber stations (SS) but also economic efficiency to network providers. For successful convergence of EPON and WiMAX, there are some technical issues to resolve bandwidth allocation and QoS support in the MAC layer. Specifically, the independent scheduling (IS) mechanism to transmit data between EPON and WiMAX can cause performance degradation. For realizing EPON and WiMAX integration, this paper investigates three possible integrated architecture: independent ONU-BS (IOB), combined ONU-BS (COB), and hybrid ONU-BS (HOB). The emphasis on this paper is how to reduce the End-to-End (ETE) delay between EPON and WiMAX. For doing this, we propose a centralized scheduling (CS) mechanism that shortens the packet delay and the time of transmitting data upon requesting bandwidth for the SS. Simulation results witness that the proposed CS mechanism improves ETE delay, throughput, and QoS support compared to the IS when the cycle time of EPON and the frame size of WiMAX are 1 ms and 5 to 10 ms, as well as 2 ms and 5 ms, respectively.