Analysis And Design Of Dynamic Bandwidth Allocation Algorithm For Ethernet Passive Optical

While in recent years backbone bandwidth has experienced substantial growth, little has changed in the access network. "Last mile" still remains the bottleneck between a high capacity LAN or home network and the backbone. Recently, Ethernet Passive Optical Network (EPON) seems to be ready for commercial deployment in access networks due to the maturity of a number of enabling technologies, long distance and reduced maintenance.At first, we introduce EPON access networks and multipoint control protocol (MPCP), defined within the IEEE 802.3ah Task Force, which is used to arbitrate the bandwidth. Then we present different bandwidth allocation algorithms, such as static bandwidth assignment, Interleaved Polling with Adaptive Cycle Time (IPACT), and dynamic bandwidth allocation algorithm for multimedia services.IPACT algorithm doesn't do well in bandwidth utilization and low-load penalty under some conditions. Moreover, IPACT algorithm pays little attention to QoS and isn't suitable to transfer real-time data. We make some modifications on the algorithm, such as making use of the remnant window in every cycle and setting a minimum transfer window. After the modification, we do better in bandwidth efficiency, low-load penalty and QoS in specific conditions. Besides we take simulations with OPNET Modeler to test the performance of the improved algorithm.We are recently developing Optical Line Terminal (OLT) device for a compony and implementing vendor extension Dynamic Bandwidth Allocation (DBA) algorithms is part of the job. So we also lay foundations for developing DBA algorithms in the specific framework.