Gpon System And Simulation, Dynamic Bandwidth Allocation Algorithm Based On All The T-cont Type

In recent years, with copper wire being replaced by optical fiber and rapid development of technology of FTTx, Gigabit Passive Optical Network(GPON) has been one of the hottest topics in the research of access network as a typical optical access technology. GPON has high efficiency and capability to support Full Service Access. GPON is designed to apply to higher data transmission efficiency and a higher level of service, to efficiently support the multimedia service. To improve the utilization of bandwidth and reduce the delay of grouping, assuring the user's QoS, it is very necessary to use DBA mechanism in GPON system. The research on GPON DBA has very important significance to the realization of all-optical networking.Firstly, the development of PON, the market status and the development direction of FTTx were studied. The standardization process of GPON, the protocol model and the function configuration of GPON were introduced. The significance and direction of GPON DBA research were analyzed.Secondly, key conceptions and principles of GPON DBA were studied deep; the basic technology of DBA was introduced. The PON DBA arithmetics that already exists were summarized, and the characteristics of arithmetics that could be use for reference were analyzed. An improved DBA arithmetic based on all types of T-CONTs was described.Finally, the models of key nodes such like OLTs, ONUs, and optical splitters were built in OPNET Modeler. With different combinations of service source, performance of DBA arithmetic was imitated. Subscribers with different subscription rate could be treated differently, the fairness was considered and QoS of different services were assured, all of these were proved by the results. The basic logical functional block diagram was drawn.