OBS核心节点控制模块BHP调度处理设计与实现

【作者】 张翔；

【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】 光突发交换(Optical Burst Switching-OBS)技术是目前光网络研究方面的一个热点,它融合了光链路交换和光分组交换两种光交换技术的优点,成为目前非常有发展前景的一种光交换技术。但是,当前对OBS 的研究仍然以理论研究居多,实践研究较少,因此OBS 交换技术还很不成熟,没有实际投入使用。基于此,本文在研究了OBS 核心节点及调度算法理论方案的基础上,结合实验网络的8Х4Х4 交换结构特点,从实践的角度出发,重点研究了OBS 核心节点控制模块的调度处理功能,设计实现了用于BHP(Burst Header Packet)调度的DSP 协处理模块电路方案,以及OBS 调度算法LAUC(Latest Available Unscheduled Channel)和LAUC-VF(Latest Available Unscheduled Channel-Void Filling)在实验系统交换结构上的具体实现流程。首先,本文概述了OBS 技术的原理和OBS 网络系统的结构,然后对项目中搭建的实验系统的具体模型进行分析,明确了各个功能模块的作用,以及系统中OBS 控制信号BHP 的处理流程,并描述了系统期望达到的性能指标,简要分析了影响性能指标的因素。其次,本文详细描述了核心节点控制模块DSP 协处理电路的硬件设计方案,并给出了DSP 协处理模块与用于核心节点控制的FPGA 模块的接口,实现了模块之间的连接交互。采用FPGA 外接DSP 电路的设计方法,把复杂的调度运算功能交给运算速率高的DSP 芯片来处理,可以大大节省FPGA 的硬件资源开销,减轻硬件处理的负担,从而改善调度性能。最后,本文阐述了两种OBS 调度算法LAUC 和LAUC-VF 在实验系统交换结构上的实现方案,明确了BHP、路由表、资源表、状态表、控制命令字等的定义和数据结构,分析了两个算法之间的差异,给出了两个算法的具体流程。并针对系统交换结构对LAUC-VF 算法进行了仿真,分析指令的运行周期以优化系统性能。本文分别从硬件和调度算法两方面对OBS 核心节点的交换调度功能进行了实践性研究,取得了一定的经验。更多还原

【Abstract】 OBS( Optical Burst Switching) is a hotspot of the optical network research. It syncretizes the advantages of OCS( Optical Circuit Switching) and OPS(Optical Packet Switching) and becomes an optical switching technique bright future. But the theory research to the OBS is more than practice research. So without practical usage, OBS is not mature. According to this, base on the studies of numerous theories projects, combining the characteristics of the switching structure that is built in the experiment network, from the practical point of view, this paper mainly studies the switching function of core node control module, proposes the DSP circuit board of mold design project that is uesd in BHP( the Burst Header Packet) ,and the flow of implementing process in the experimental switching structure of the classic switching algorithmses of OBS--the LAUC( the Latest Available Unscheduled Channel) and LAUC-VF( the Latest Available Unscheduled Channel-Void Filling). First, this paper summarizes the technical principle and the network system structure of OBS, then analyzes the concrete model built in the experiment system, explicit the function of the each mold and the processing flow of control signal BHP of the OBS system, and described the function index sign that the system expect to attain, the briefly analyzeds the factor which influences the function. Second, this paper describes the hardware design project of a DSP core node control mold in detail( can pay respects to the electric circuit in the appendix principle diagram), and proposes the interface of DSP mold and the core node control FPGA mold, realizes the conjunction between the molds. Adopt the design method that the FPGA acrosses to the DSP electric circuit ,it can adjust one complicated operation function to hand over to the high-performance DSP chip ,thus can mostly save the hardware resources of the FPGA to lighten the burden of the hardware processing, System function will be highly improved . Finally, this paper describes implement project of two kinds of classic OBS switching algorithmses--LAUC and LAUC-VF in switching structure built in experimental system, proposes BHP, road form and the data structures of the form, resources form, appearance form, the control order word...etc., describes the concrete process of two algorithms, and analyzes the difference更多还原