【作者】 钱敬；

【导师】 毛培法； 沈梁；

【作者基本信息】 浙江工业大学 ， 通信与信息系统， 2003， 硕士

【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，如何合理的规划网络的波长资源，是决定网络资源利用效率的关键问题，同时，光网络具有高速、大容量、多业务的特点，一旦发生故障将给用户带来巨大的损失，而不具有良好生存能力的网络是不能实际运营的。本文针对波长路由环形网络的两个关键问题——路由和波长分配问题(Routing and Wavelength Assignment—RWA)和光网络的生存性问题进行了研究，主要工作及成果如下： 1、分析了WDM网络的RWA问题。图论中的相关数学理论是解决RWA问题的一个有力工具。本文对小型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、探讨了光网络的生存性问题即故障的保护和恢复。鉴于同步数字体系SDH环形网络结构的巨大成功，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了分析与比较。 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。更多还原

【Abstract】 Wavelength Division Multiplex (WDM) networks will play an important "role in future backbone networks. How to programming the wavelength reasonably in the networks is a key issue. And due to the specialty of high-speed, huge-capacity and multi-services of optical networks, the networks without the nice survivability are not allowed to be employed. In the paper, these key technologies of wavelength routing ring networks, the Routing and Wavelength Assignment (RWA) and the survivability of WRN, is researched in detail.1. The RWA is analyzed. Graph Theory is an effective tool for the problem. We 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.2. The survivability of Optical networks, i.e. the protection and restoration for failure, are discussed. Whereas the vast success of SDH networks, it is WDM rings to be a fact firstly. Some kinds of WDMself-healing rings are discussed and compared.3.Utilized the method of vertices coloring, an initiatory arithmetic is proposed according to WDM rings, ’an improved Greedy algorithm’. Simulation on computer is carried out to compare this problem with a used one, the new algorithm acquires the higher wavelength efficiency. Then the algorithm is used to compare the demand of some different rings. The result show there is obvious difference for these rings especially for big networks. It offers the consult and the gist for the building of WDM networks. Two strict wavelength lower limits are achieved to estimating the RWA algorithm for WDM rings. It can be used as the criterion of the utilizing rate of WDM network resource.更多还原