Reaearch On Dynamic Bandwidth Allocation Algorithm Based On EPON Network

EPON technology combines Ethernet technology and passive optical network technology,which is compatible with the current large-scale application Ethernet equipment and the best choice to solve the last mile access network bandwidth bottlenecks.In the EPON system,the dynamic bandwidth allocation algorithm determines the uplink bandwidth allocation of the system and also has a crucial impact on the system performance.How efficiently allocates bandwidth is an important issue of EPON,and also it becomes the focus of attention.In this paper,the key technology and principle of EPON system and the dynamic bandwidth allocation algorithm are studied.On this basis,an improved dynamic bandwidth allocation algorithm is proposed.The main work and achievements of the paper are as follows:(1)The network structure and basic principle of EPON are analyzed,and the channel communication mode and TDM core principle are studied.(2)This paper studies the principle and structure of EPON,the key technology of EPON.(3)The design idea and realization process of IPACT algorithm are studied.(4)In order to solve the problems of light load penalty,bandwidth utilization and QoS,an improved DBA algorithm is proposed.The algorithm uses the method of setting the minimum transmission window and the maximum transmission threshold,and makes reasonable use of the remaining bandwidth of the uplink channel to eliminate the light load penalty phenomenon and improve the bandwidth utilization of the system.By changing the priority class classification of IEEE802.1P protocol,the priority queue of ONU side is effectively guaranteed to ensure the service quality of the system.(5)The improved DBA algorithm,the classical DBA algorithm and the distribution method of three kinds of service bandwidth are simulated by OPNET Modeler network simulation software.The simulation results show that the improved algorithm can greatly improve the bandwidth utilization of the system compared with the other two algorithms,and effectively guarantee the quality of the system.