【作者】 李青波；

【导师】 王亚民；

【作者基本信息】 西安科技大学 ， 通信与信息系统， 2008， 硕士

【摘要】 近年来,随着互联网飞速发展与数据业务的急剧增长,连接骨干网与用户间的接入网成为整个网络的瓶颈。而光纤到户(FTTH)作为接入网发展的最终目标,被广泛认为是一种理想的综合接入方案。在各种光接入技术中,吉比特无源光网络(GPON)技术由于其高速率、高效率、全业务的QoS保证以及充分考虑运营商的意见等优势,成为解决带宽瓶颈的最佳选择。因此研究GPON技术,特别是研究GPON的关键技术具有非常重要的地位。论文首先讨论了GPON技术的研究背景、发展现状,分析了GPON的优势所在;然后介绍了GPON系统,分析了该系统的结构、网络要求及关键技术;其次,密切结合ITU-T的G.984系列协议标准,分析了GPON系统的协议栈和TC分层结构以及关键概念。研究TC层的上、下行帧结构,并讨论了帧中各个字段的含义及作用。本文围绕GPON技术的动态带宽分配(DBA)算法这个核心问题,讨论了现有的DBA算法研究现状,并通过性能分析且考虑目前的技术实现条件,对一些有代表性的算法进行了优缺点的比较。对比已有的算法,提出了一种基于T-CONT的GPON的上行动态带宽分配算法。采用仿真软件,建立了一个仿真模型,并在此平台上对该DBA算法性能进行仿真。通过理论分析与仿真实验,表明这种算法在时延、时延抖动方面有较好表现,且符合规范的要求,可以实现一种满足全业务服务等级要求的动态带宽分配方案。更多还原

【Abstract】 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.更多还原