A novel dynamic bandwidth allocation algorithm for Ethernet PON
Creators: name: Peng, Zhiwen
Publisher: name: RMIT University
Year: 2024

description: Ethernet Passive Optical Network (EPON) is one of the most promising fiber based access techniques, which is expected to offer a cost-effective solution to broadband network access owing to the ubiquitous deployment of Ethernet-based network equipment. EPON can not only provide IP service access effortlessly, but also expand its ability to multi-services support and quality of service (QoS) guarantee, which means EPON will support integrative broadband access with multi-services such as voice, video and data in the future.<br><br>Upstream dynamic bandwidth allocation (DBA) is an active area of research for EPON. With further study on DBA strategy and cycle polling mechanisms, a fair DBA called KI-DBA based on minimizing idle time and bursty traffic prediction is proposed in this thesis. The key design goal of KI-DBA algorithm is that EPON can achieve high bandwidth utilization and support QoS fairly. Kolmogorov continuity theorem based prediction networks are introduced in traffic prediction for the first time in EPON together with the improved cycle polling including the strategy of bandwidth allocation based on the proportion of guaranteed bandwidth. The KI-DBA algorithm appears to be a practical method for upstream bandwidth allocation with higher bandwidth utilization, less packet delay, and improved QoS of lower priority service when in heavy traffic. The primary work and results are as follows:<br><br>(1) The thesis has designed a traffic prediction algorithm based on an idle time minimizing method and Kolmogorov continuity theorem which is optimized by adding error analysis to make the prediction algorithm converge faster and more accurately. The networks can adjust weight according to prediction error; as a result, the prediction is more accurate and adaptive.<br><br>(2) A burst sorting polling mechanism is proposed. The OLT adjusts the cycle polling order according to the burst traffic from each ONU during polling, and each ONU delays sending report message. As a result, the OLT can get newer information about the queues of ONUs. The new polling strategy can shorter the prediction range of bursty ONUs’ queues, so it improves the accuracy of traffic prediction further. Besides, the OLT allocates bandwidth and grants time slots more early. Thus the network can make full use of the idle time, so this mechanism enhances efficiency of the upstream bandwidth.<br><br>(3) A fair dynamic bandwidth allocation algorithm based on traffic prediction is proposed in the thesis. It allocates bandwidth among inter-ONUs and intra-ONUs according to the bandwidth requirement after prediction and the proportion of guarantee bandwidth. The scheme not only reduces packet delay, but also guarantees fairness.<br><br>(4) Finally, EPON simulation platform is established based on OPNET Modeler 16, in which the KI-DBA algorithm is verified. And results show that the prediction algorithm composed of the idle time and Kolmogorov continuity theorem networks perform better in convergence and accuracy. The system adopts the new KI-DBA to get higher bandwidth utilization and less packet delay. Furthermore, under the condition that the high priority services are ensured, the QoS of the low priority service is improved greatly when in heavy traffic.<br>