wdm环形网络的生存能力与波长分配问题分析.docx

WDM环形网络的生存能力与波长分配问题研究
摘要
波分复用(WDM)技术在未来的骨干网中扮演着极其重要的角色。在WDM光网络中,如何合理的规划蚓络的波长资源,足决定嘲络资源利用效率的关键问题,同u,3‘,光网络具有高速、大容量、多业务的特点, ,而不具有良好生存能力的网络是不能实际运营的。本文针对波K路由环形网络的两个关键问题一一路由和波长分配问题(Routing and WavelengthAssignment--RWA)和光网络的生存性问题进行』,研究,
主要工作及成果如下:
l、分析了WDM网络的RWA问题。图论中的相关数学理论是解决RWA问题的‘个有力工具。本文对小犁WDM环网的波长资源分配进行了深入分析,采用无阻塞站点接入方式可消除接入站对波长的限制,这为后一阶段的工作打下基础。
2、探讨r光网络的生存性问题即故障的保护和恢复。鉴丁I『叫步数字体系SDH环形l叫络结构的巨大成功,WDM环形网络必定首先实用化、商用化,本文着重对各种保护恢复机制的自愈环网进行J, 分析与比较。
3、针对WDM环网结构并应用顶点图着色方法,提出了一种启
发式波长分配算法——本文称为“改进的Greedy算法”。利用计算
机仿真与文献中常用算法进行了比较,证明了该算法用于WDM环网的静态波长分配能获得更高的波长利用率。然后本文利用该算法对各种不同保护结构WDM环网的波长配置需求进行了实验分析与比较,尤其对于大型网络,不同结构对波长的需求差别较大,这为建设网络时的综合考虑及权衡利弊提供了参考和帮助。同时,通过计算分析,得出了评价WDM环网波长分配算法的两个严格的波长下限,这可作为分析WDM网络资源利用率的依据。
关键词:波分复用,路由和波长分配,生存性,保护和恢复
图的顶点着色,自愈环
STUDY oN THE SURVIVABILlTY
AND RWA FoR WDM oPTICAL RINGS
ABSTRACT
Wavelength Division Multiplex(works will play an
important’role in future works。How to programming the wavelength reasonably in works is a key due to the specialty of high—speed,huge—capacity and multi—services of optical
networks,works without the nice survivability are not allowed to be the paper,these key technologies of wavelength routing works,the Routing and Wavelength Assignment(RWA)and the
survivability of WRN,is researched in detail
RWA is Theory is an effective tool for the discussed the problem of RWA for small WDM rings,and the restriction of Access Station to wavelength is avoided if we adopt
Non—blocking Access Station(NAS).These are groundwork for next
phases.
survivability of works, protection and restoration for failure,are the vast ess of works,it is WDM rings to be a fact kinds of WDM
self-healing rings are discussed pared
the method of vertices coloring,an initiatory arithmetic is proposed according to WDM rings,‘an improved Greedy algorithm Simulation puter is carried out pare this problem with a used