【作者】 朱永华；

【导师】 林如俭；

【作者基本信息】 上海大学 ， 通信与信息系统， 2006， 博士

【摘要】 随着网络业务量的爆炸性增长以及低成本、高性能的光网络设备的出现,基于波分复用和波长路由技术的波分复用光网络被认为是下一代高速广域骨干网和城域网的最有力竞争者。它不仅提供了巨大的带宽容量,而且能实现对不同传输码率、数据格式和调制方式的透明传输。波分复用光网络具有可重构性,可根据通信业务量的需求来改变网络的逻辑结构,网络资源利用率高;特别是它还具有良好的生存能力,能够在很短的时间内从失效故障中自动恢复所携带的业务。本文对波分复用光网络的生存性和对低速业务的疏导问题进行了深入的研究。包括动态业务下波分复用光网络的动态路由和波长分配问题、动态业务下光网络的生存性问题、基于共享风险链路组限制的网状网的生存性问题和光网络中的业务量疏导问题。这些问题的合理解决不仅可以提高网络资源的利用率,在满足不同粒度的业务需求的同时,使网络资源得到最优化配置,而且可以提高网络的抗毁能力,使网络在发生故障时性能仍保持在较高的水平,确保服务质量。本文的第一章是绪论,所做工作集中在第二章至第五章,主要包括以下内容:第二章研究了多光纤波分复用光网络的动态资源分配问题,提出了基于分层图模型的启发式动态路由和波长分配算法,有效降低了算法复杂度。在本章中的另一贡献是,在提出的动态选路策略中,首次引入了优选路径与随机路径相结合的方案,这种方案主要考虑到实际运行网络的业务请求的并发性,兼顾了业务响应时间与降低阻塞率两者因素。并对所提出的各种方案在波长路由网状网中进行了仿真测试,数值结果表明本文的启发式算法在提高业务响应时间和降低阻塞率之间能达到较好的平衡。第三章对网状网光网络中的生存性机制进行了深入的分析和研究。我们提出了一种新的可应用在光网络中的保护方法----基于工作路径与备份路径复用技术的算法,并提出了一种新的链路因子用于路径的选择,以达到负载平衡的目的。此外,我们还建立了针对几种重要生存性机制的网状网光网络生存性策略的性能评估体系,包括专用/共享通道保护方案阻塞概率模型和单链路故障情况下通道保护方案的恢复概率模型,并对相应的性能模型进行了仿真分析。数据证明了所提算法在降低网络阻塞率方面的表现出很好的性能。引入链路因子后的算法,可以充分挖掘网络资源的共享能力。在第四章中,对基于共享风险链路组的波分复用网状网的生存性问题进行了研究,首次在连接请求中引入了服务等级协议,包括多种保护要求和路径长度要求的限制。我们将问题分解成收益最大化和容量最小化的两个子问题。在本章中,我们推出了这两个子问题的整数线性规划公式。为解决整数线性规划公式的计算更多还原

【Abstract】 Wavelength Division Multiplexing (WDM) optical networks, based on wavelength division multiplexing and wavelength-routed technology, are one of the most competitive candidates for next generation high speed WAN backbone and MAN. It features not only on the huge bandwidth, but also on the transparency of different transport code rates, data formats and modulations. WDM optical networks can be reconfigured to improve the resource efficiency. Its logical topology can be changed to meet the demand of traffic. WDM optical networks can recover infected traffic from failure in a short time. Good survivability is its favorable merit.The thesis focuses on the investigation of network survivability and low-rate traffic grooming problem in WDM optical networks, including four sub-problems of dynamic routing and wavelength assignment, dynamic survivable routing of dynamic traffic, survivability of mesh networks based on the Shared Risk Link Groups (SRLG) and traffic grooming. By solving these problems in a proper way, network resources can be best configured. Further, optimization of these problems can obtain the greatest network performance, and even if the some failure takes place, the network performance can still maintain in a high level and provide the kinds of quality of service.The introduction is given in the first chapter. Most of work is described from chapter 2 to 5. The main work in this thesis is dated as follows.The second chapter discusses the dynamic resource allocation problem of multi-fiber WDM optical networks. Aiming to reduce the ILP calculating complexity, a new and efficient heuristic algorithm based on the layered-graph is presented. Considering the concurrency of connection requests and the speed of responding in the real network, a new policy of choosing the alternate path is introduced, that is both the best path and a random one are selected. Numerical results show that the heuristics perform well in term of both the calculating cost and blocking probability.In chapter three, many suitable mesh protection/restoration schemes are investigated. A new protection scheme is proposed based on the primary-backup multiplexing technique. Considering the load balancing problem, a new link metrics is introduced. Also a kind of performance evaluation system of survivability policies is established in mesh optical network which includes network blocking probability models of dedicate/share path-based protection schemes and restoration efficiency更多还原