| With the growth of Internet and data service, the access network that connects backbone and users is becoming the bottleneck of whole network in recent years. FTTH(Fiber to the Home) becomes the objective of access networks and is accepted as a kind of excellent integrated solution for access network. Among kinds of optical access network techniques, GPON supports high speed rate, high efficiency, full-services QoS, and considers the suggestions of SPs(service providers) at the same time. GPON is regarded as an optimal choice of solution for bottleneck of access bandwidth in the future. So it is very important to research GPON and its key technologies especially.Firstly, this paper discusses about the technique background of GPON, GPON development actuality and advantages of GPON. Then, it introduces GPON optical access network system, analyzes the structure, optical network requirements, and key techniques of system. Thirdly, according to the GPON G.984.x recommendation, it analyses protocol stack of GPON system, TC(Transmission Convergence) layered model and introduces the key conception of TC layer. Based on studying up on structure of the upstream and downstream frame, the meaning and function of various fields contained in frame is discussed.This paper focuses on the issue of DBA algorithm in the GPON technology, discusses DBA algorithms which have been put forward, and point out their advantage and disadvantage. By comparing DBA algorithm which have been put forward, a new DBA algorithm that base on the T-CONT is presented. The model for this algorithm is used for test the algorithm performance, which built and implemented in OPNET. According to theoretical research and simulation experiment, the simulation result shows this algorithm has well performance at packet delay and delay variation. And also, this algorithm can satisfy with its all services level over GPON and it follows the request of standard. |
