Based On Opnet Epon Mac Layer Algorithm Optimization

EPON is one of the feasible settlements for the problem of "the last mile", and the emergence of the standard of IEEE 802.3ah prepares the basis for the popularization of EPON. But there are some important technologies that have not been defined by this standard, for example, the algorithm of the MAC layer. The algorithm of the MAC layer of EPON mainly based on the protocol of MPCP can be classified as registering and timeslot assigning process as a whole. In this ariticle, the platform of MPCP protocol is constructed based on the network simulation tool of OPNET, and then the registering and timeslot assigning process are also carried out on this platform. In the registering process, a new registering algorithm based on the maximum distance is introduced. This algorithm can mostly minimize the adverse effect the registering process posed on the utilization of the entire resource. In the timeslot assigning process, mutilple algorithms such as the static algorithm, two scheduling algorithms of interleaved polling with adaptive cycle time (IPACT), the algorithm of proportioning, two novel algorithms of token switching and double scheduling are also carried out on this platform, and the simlulation results of these algorithms are compared and analyzed. And from these results, we can see that the algorithm of token switching can assure the qulity of different services, and also have priorities on link utilization and the justice of different ONUs in the statistical opinion, and the algorithm of double scheduling can furthestly minimize the delay and delay variation of real time packets.