应用MCDM的弹性光网络频谱碎片整理算法

Research on the spectrum defragmentation algorithm for the elastic optical network based on MCDM

针对弹性光网络频谱碎片导致业务请求阻塞率和带宽阻塞率增高的问题,对弹性光网络频谱碎片产生的原因进行了分析;根据光网络承载业务的特点,从提高频谱利用率的角度提出了基于多准则决策的弹性光网络碎片整理算法。该算法采用多准则决策方法对碎片整理过程中遇到的选择性问题,通过综合考虑各种评价指标做出决策,并进行频谱碎片的整理。在业务路由阶段,算法分为5个阶段,在每个阶段中根据光网络此时的状态,做出最佳决策来进行频谱碎片的整理。每个阶段都会用不同的标签标记不同类型的连接,并根据多准则决策方法所设置的权重对它们进行判断,最后采取最佳方案,使得碎片整理效果达到最佳。为验证这种算法的效果,通过具体实例进行了仿真验证。结果证明,所提算法具有较低的带宽阻塞率(高负载下阻塞率为36%)和较高的频谱利用率(高负载下频谱利用率可达65%),能有效地改善网络高负载情况下的网络请求阻塞率,为实际条件下弹性光网络频谱碎片处理提供了理论参考。

To solve the problem of the increased service request blocking rate and bandwidth blocking rate caused by the fragmentation of the elastic optical network spectrum,the causes of spectrum fragmentation is analyzed in detail.According to the characteristics of optical network carrying services,an elastic optical network fragmentation algorithm based on multi-criteria decision-making is proposed from the perspective of improving spectrum utilization.The algorithm uses the multi-criteria decision-making method to deal with the selectivity problems encountered in the process of defragmentation,and makes decisions by comprehensively considering various evaluation indexes,so as to defragment spectrum fragments.In the traffic routing stage,the algorithm is divided into five stages.In each stage,according to the current state of the optical network,the best decision is made to sort out the spectrum fragments.Each stage marks different types of connections with different labels,and judges them according to the weights set by the multi-criteria decision-making method.Finally,the best scheme is adopted to achieve the best defragmentation effect.Simulation verification is carried out through specific examples,with the results showing that the proposed algorithm has a lower bandwidth blocking rate(36%blocking rate under high load)and high spectrum utilization(up to 65%under high load),which can effectively improve the network request blocking rate under high network load conditions,and provide a theoretical reference for the processing of the spectrum fragmentation of the elastic optical network under actual conditions.