Analysis Of Ethernet Passive Optical Network MAC Protocols

With the rapid development of communication technology, the demands for bandwidth of users are increasing.the backbone network can satisfy broadband services demand basically, but the access network technology of broadband network development has become a bottleneck restricting the development of the information superhighway. Ethernet-based Passive optical network(EPON) is the passive optical based on Ethernet, Structure using multipoint, Can provide multiple services over Ethernet. Since most broadband backbone networks use Ethernet protocol and EPON has many advantages, such as broad bandwidth, good compatibility, technology is mature,low failure probability and low maintenance cost,stable performance, Bearing business flexibility,etc. EPON technology has became one of the important methods to provide multiple broadband services access, and it has emerged as one of the most promising access network technologies.On EPON MAC (Media Access Control) layer,to prevent data of different users from collision uplink Communications use a time division multiple access (TDMA) to transfer datas. Accordingly, an optimal bandwidth allocation scheme can improve the performance of the whole access network.This paper is to study the EPOM the MAC layer algorithms and to optimize them. To get more better bandwidth utilization, QoS guarantees, end to end delay and delay jitter performance.The first chapter describes the current situation and development of access networks, APON, EPON and GPON, summed up that in the near future EPON will be one of the best way to solve the "last mile" as its advantages.In chapter two we analysised the EPON architecture and proposed several key technologies of EPON including synchronization, ranging,DBA algorithm(Dynamic Bandwidth Allocation algorithm),LLID(Logical Link ID),AES(Advanced Encryption Standard) encryption,OAM(Operation Administration and Maintenance),and QoS(Quality of Service) guarantee,and analysis of various technologies.Chapter three introduced and analyzed five frames of MPCP protocol of the MAC layer of the EPON:GATE, REPORT, REGISTER-REQ, REGISTER and REGISTER-ACK at first. analysis the OUN automatic discovery process,and then detailed analysis several time slots as the factors impacts bandwidth utilization.In the fourth chapter we compare the static and dynamic bandwidth allocation algorithm(DBA),detailed analysis one of the classical algorithm-IPACT, simulation results showed that the dynamic algorithm has a higher bandwidth utilization and better QoS performance. Finally, optimized the old IPACT algorithm and simulated results showed that, after algorithm optimization, network performance has been effectively improved.