一种多级别OBS中评估阻塞概率的精确模型

提出了一种应用于多级别光突发交换(OBS)网络中评估每一种级别业务的阻塞概率的分析模型。该模型可以评估OBS网络中任意突发长度分布和任意偏置时间情形下的阻塞概率,也包括每一级别的平均突发长度不同的OBS系统。这样的OBS系统并不遵从守恒律,因此,不能应用已知的OBS模型进行分析。对一个两级别的OBS系统,业务负载为10-3,高优先级与低优先级业务的比率为1:5时,本模型可以为每一级别精确预测阻塞概率。假定守恒条件下,已知的分析模型所给出的预测结果比仿真结果低将近75%。

Study of an Accurate Model of Evaluation Blocking Probability in Multi-class OBS Systems

This paper presents an analytical model that can be used to evaluate the blocking probability of each service class in a multi-class optical burst-switching network.The model allows,for the first time,the evaluation of blocking probabilities in optical burst switching(OBS) systems with arbitrary burst-length distributions and arbitrary offsets,including OBS systems in which all classes are different in mean burst length.Such systems do not follow the conservation law and cannot,therefore,be analyzed using previously published OBS models.For an OBS system with two classes,an offset load of 10-3,and a 1 : 5 ratio of high-priority to low-priority traffic,this shows that the model accurately predicts the blocking probability for each class,whereas predictions from previously published models that assume conservation disagree with the simulation results by as much as 75%.