智能光网络中新模型下波长缓存拥塞控制问题研究

发布时间：2019-02-15 05:26

【摘要】：由于数据业务的爆炸式增长而倍增的带宽需求以及WDM技术带来的新型的光带宽资源的复用,智能光网络应运而生并得到飞速发展。网络阻塞率的高低是衡量网络性能的一个非常重要的指标,如何最大程度地减少智能光网络的阻塞率,提高网络的资源利用率是研究智能光网络的核心问题之一。部分稀疏有限范围波长变换网络模型能够降低网络的阻塞率,同时最小化网络的代价。本文主要研究智能光网络中基于部分稀疏有限范围波长变换网络模型的拥塞控制问题并提出了一些创新性的设计。智能光网络拥塞产生的原因可以分为有限的波长资源、波长连续性限制和链路的级联效应三大类。首先,为了消除网络的波长连续性限制,在波长转换代价和网络阻塞率之间取得折中,论文设计了基于部分稀疏有限范围波长变换网络模型的波长变换器配置算法；其次,为了降低网络的时间不均衡性,论文在基于部分稀疏有限范围波长变换网络模型的波长变换器配置算法的基础上加入波长缓存策略,设计了基于波长缓存的拥塞控制路由算法。同时设计了阻塞率分解法解决波长缓存策略中的计算网络阻塞率关键问题。再次,为了解决网络拓扑与业务传输请求的空间分布不均衡而造成网络资源的不充分利用,论文将波长缓存策略与软抢占策略相结合,设计了基于波长缓存和软抢占策略的拥塞控制路由算法,并通过负载加权法和交换路由法分别解决了软抢占策略中的拥塞定位和重路由计算两大关键问题。该算法更好地保护已有业务的服务质量,当且仅当被抢占业务找到新路径进行传输时,才会中断该业务传输请求并释放其资源给新的业务使用。论文最后对设计的三种拥塞控制算法进行了仿真实现,对不同选路方案的性能进行了对比分析。仿真结果表明：基于部分稀疏有限范围波长变换网络模型的波长变换器的配置算法可以在很大程度上提高网络性能改善度,较之基于稀疏部分波长变换网络模型的波长变换器配置算法网络性能改善度提高了大约20%；基于波长缓存的拥塞控制路由算法以及基于波长缓存和软抢占的拥塞控制路由算法都可以有效减少网络阻塞率,提高网络资源利用率,较之没有波长缓存策略和软抢占的拥塞控制算法,网络阻塞率分别降低了13%和10%。
[Abstract]:Due to the explosive growth of data services and the multiplication of bandwidth requirements and the reuse of new optical bandwidth resources brought by WDM technology, intelligent optical networks emerge as the times require and develop rapidly. The network blocking rate is a very important index to measure the network performance. How to reduce the blocking rate of the intelligent optical network to the greatest extent and improve the network resource utilization is one of the core problems in the research of the intelligent optical network. The partially sparse finite range wavelength conversion network model can reduce the blocking rate of the network and minimize the network cost. In this paper, the problem of congestion control based on partially sparse finite range wavelength conversion network model in intelligent optical networks is studied and some innovative designs are proposed. The causes of congestion in intelligent optical networks can be divided into three categories: limited wavelength resource, wavelength continuity limitation and cascading effect of link. Firstly, in order to eliminate the limitation of wavelength continuity and make a compromise between wavelength conversion cost and network blocking rate, a wavelength converter configuration algorithm based on partially sparse finite range wavelength conversion network model is designed. Secondly, in order to reduce the time imbalance of the network, this paper adds the wavelength buffer strategy to the wavelength converter configuration algorithm based on the partially sparse finite range wavelength conversion network model. A congestion control routing algorithm based on wavelength buffer is designed. At the same time, the blocking rate decomposition method is designed to solve the critical problem of computing the network blocking rate in the wavelength buffer strategy. Thirdly, in order to solve the problem of uneven spatial distribution of network topology and traffic request, this paper combines wavelength cache policy with soft preemption strategy. A congestion control routing algorithm based on wavelength cache and soft preemption strategy is designed, and two key problems of congestion location and rerouting calculation in soft preemption strategy are solved by load weighting method and switching routing method, respectively. The proposed algorithm can better protect the quality of service of the existing service. If and only if the preemptive service finds a new path for transmission, it will interrupt the traffic request and release its resources to the new service. Finally, three congestion control algorithms are simulated, and the performance of different routing schemes is compared and analyzed. The simulation results show that the configuration algorithm of wavelength converter based on partially sparse finite range wavelength conversion network model can greatly improve the performance of the network. Compared with the wavelength converter configuration algorithm based on sparse partial wavelength conversion network model, the network performance is improved by about 20%. The congestion control routing algorithm based on wavelength buffer and congestion control routing algorithm based on wavelength cache and soft preemption can effectively reduce the congestion rate and improve the utilization of network resources. Compared with the congestion control algorithm without wavelength buffer and soft preemption, the blocking rate of the network is reduced by 13% and 10%, respectively.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1

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