OBS核心节点交换调度技术的研究

【作者】 吴强；

【导师】 李乐民；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2005， 硕士

【摘要】 因特网的快速发展和DWDM 在传输领域不可替代的优势,使得下一代互联网必然具有光分组传输和交换的特点。而在已知的几种光分组交换技术中, 光突发交换(OBS)以其灵活性(与OCS 相比)和可实现性(与OPS 相比)等特点而备受瞩目,成为国内外研究的热点。为了攻克和掌握这一关键技术,很多政府和研究机构开展了与OBS 相关的研究工作,我国863 重大计划也设立了重大项目“光突发交换关键技术和实验系统”,本文的工作正是该项目中的关键部分——核心节点控制系统。本文首先对光突发交换网络的基本概念和原理进行了描述,在此基础上介绍了OBS 实验系统的结构与工作流程,然后对实验系统中的重要组成部分——核心节点的结构、功能等做出祥述。并结合设计指标对几个关键参数进行了分析。然后本文对核心节点控制系统中的关键部件,即控制主板的设计方案进行了详尽的阐述,给出了设计原理图,并深入分析了各模块的功能和接口。最终采用多层PCB 和VHDL 编程实现了这部分功能。交换系统的性能很大程度上决定于交换调度算法,本文结合实际系统的光交换结构,分析了在控制主板中所采用的调度算法,对其进行了性能仿真,并对仿真结果作出了分析。最后,本文给出了利用该算法实现的核心节点交换调度器,分析并解决了硬件实现该调度算法的若干难点问题,如时标越界等。文中对核心调度器具体设计的描述,以各个子模块有限状态机的形式给出。本文设计在实验系统中得到验证,达到了系统设计指标要求。更多还原

【Abstract】 The fast development and un-replaceable advantage of DWDM in therealm of transmission make the optical packet transmission and switchingbecome a characteristic of next generation. OBS attracts much attention due toits flexibility(compared with ocs) and feasibility(compared with ops) ,andbecomes the focus of current study. To overcome and control this keytechnique, a lot of governments and institute do many related research work ofOBS. The national project 863 also established the important project "theoptical bust switching key technique and experiment system". The work of thispaper is one of the key parts of this project-the core node control system.First, this paper describes the basic concept and principles of the opticalburst switching network, and base on this the paper introduces the structureand flow process of the OBS experimental system. Then describe the importantpart of the experimental system-the structure of the core node, thefunction...etc. Combining the design index, the paper analyzes a few keyparameters also.Then the paper describes the key parts of the core node control system,which is the control panel and proposes the design principle diagram, analyzethe function and interface of each module. Finally multi-layer PCBs andVHDLs is used to carry out this part of functions.The importance of the switching system is the switching algorithm. Thispaper combines the structure of the practical optical switching system,analyzes the switching algorithm of the control main board, and simulates thefunction. Also the paper analyzes the method to improve the performance ofthe algorithm.更多还原