The Research On EPON Upstream Access Bandwidth Allocation Algorithm

Along with the rapid development of communication technology, the requirements of users for bandwidth become higher and higher. The Ethernet Passive Optical Network (Ethernet PON) based on mature Ethernet technology uses point-to-multipoint structure, passive optical transmission, and is able to provide a wide range of business on the Ethernet. It combines the advantages of passive optical network technology and Ethernet technology. It has characteristics as follows: low-cost, compatibility, maturity, easy to maintain, operational flexibility and so on. It becomes one of the best schemes of the next generation broadband access network.As EPON special point-to-multipoint network topology, all Optical Network Units should share channel bandwidth at upstream direction and use TDMA to send data. It needs bandwidth allocation technology to harmonize the various Optical Network Units sending upstream data and to avoid conflicts. It is of great significance for bandwidth allocation technology to improve service quality of system, delay of system and network throughput. It is one of the core key technologies of EPON system. This paper mainly research on the EPON system upstream access bandwidth allocation algorithm.On the platform of OPNET, referring to the basic framework of EPON system, the paper has established the upstream channel simulation model of EPON system. Use this model to verify several network performance indicators of static bandwidth assignment algorithm and a typical dynamic bandwidth assignment algorithm (IPACT algorithm).The simulation results show that the network performance of dynamic bandwidth assignment algorithm is superior to static bandwidth assignment algorithm.The paper has proposed a modified version of a dynamic bandwidth allocation algorithm. It effectively guarantees the QoS and the fairness of bandwidth allocation for all of EPON network. It is better to meet the current network requirements of multi-services and multi-priorities. And using constructed EPON system simulation model simulates the algorithm. The simulation results show that the improved algorithm has effectively enhanced the bandwidth utilization of uplink channel, and reduced the delay jitter of EF class business. This algorithm has good time characteristics. It is provided the reference for EPON upstream access bandwidth allocation standards of the multi-service QoS.