Efficient Dynamic Bandwidth Allocation for Epon

Ethernet Passive Optical Network (EPON) has emerged as the solution of choice for the access network. In EPON, the data transfer channel is shared among users in the upstream direction. Therefore, it requires an arbitration method to allow ONUs to share the upstream bandwidth. There are many research papers on bandwidth arbitration schemes. Most of the Dynamic Bandwidth Allocation (DBA) schemes in the literatures do not consider the overall network condition to globally optimize their algorithm. Furthermore, they do not consider the ONU MAC frame boundary when granting bandwidth to an ONU. This causes mismatch between granted bandwidth and ONU frame boundary. Since fragmentation of Ethernet frame to fit the remaining ONU slot is not allowed, it causes unused ONU slot bandwidth (ONU slot remainder). In addition, number of them require DBA calculation time when no upstream traffic is allowed (idle cycle time). In this paper, we propose a DBA scheme that eliminates ONU slot remainder and idle cycle time and reuses all unused cycle bandwidth in a globally optimized fashion to maximize the upstream bandwidth utilization. Improved utilization will result in minimization of packet delay, packet loss ratio and ONU buffer occupancy. Simulation was done to demonstrate the advantages of the proposed DBA.