Abstract: Dynamic Bandwidth Allocation（DBA） is a key technology of EPON. The paper proposes an improved polling algorithm, adjusts the order of ONU authorization time slot according to the data traffic flow burst characteristics, constructs a neural network prediction model in Particle Swarm Optimization（PSO）, enhances the ONU added data prediction precision in the polling cycle, and thus guarantees bandwidth allocation fairness. The simulation proves that the algorithm performs better in the improvement of bandwidth utilization and has a smaller average packet delay compared with traditional DBA.

Key words: Ethernet Passive Optical Network（EPON）, Dynamic Bandwidth Allocation（DBA）, fairness, Artificial Neural Network（ANN）, Particle Swarm Optimization（PSO）

摘要： 动态带宽分配（DBA）是EPON的关键技术，根据数据业务流量的突发性调整了ONU授权时隙的顺序，提出了一种改进的轮询算法，构造了微粒群（PSO）优化的神经网络预测模型，提高了轮询周期内ONU新增数据的预测精度，从而保证了带宽分配公平性。仿真结果表明，该算法在优化带宽资源分配、降低平均数据时延方面均优于传统DBA算法。

关键词: 以太网无源光网络（EPON）, 动态带宽分配, 公平性, 人工神经网络, 微粒群