Active scheduling algorithm for intra-ONU Dynamic Bandwidth Allocation in ethernet passive optical networks

An EPON DBA algorithm can be separated into inter-ONU scheduling and intra-ONU scheduling. Intra-ONU scheduling may not predict the bandwidth allocation result from inter-ONU scheduling and waste the allocated bandwidth due to the unused slot remainder (USR) problem. In this study, we propose an active intra-ONU scheduling to make the result from the inter-ONU scheduling predictable, thus completely preventing USR. When combining with WRR-based inter-ONU scheduling, the simulation results show that compared to the previously proposed method, the bandwidth utilization is improved, the average packet delay is decreased, the optimal fairness is maintained, and differentiated QoS is supported.