改进的OBS长度自适应门限组装算法

现有OBS长度自适应组装算法的突发数据长度门限的选择虽然随着业务流的变化而变化,克服了固定长度门限算法输出的突发数据的突发性,但仍然没有考虑业务流的自相似特性,因此不能有效降低输出突发数据的自相似程度和分组阻塞率。针对这一问题,该文提出了一种改进的OBS长度自适应门限组装算法,能根据到达的网络业务流的自相似特性自适应地调整长度门限值。仿真结果表明:在相同的调度算法下,更能降低业务流的自相似性,分组阻塞率降低一个数量级。

A Modified OBS Adaptive Assembly Algorithm Based on Length Threshold

The OBS length adaptive assembly algorithm can select length thresholds adaptively depending on the input traffic, and make output data bursts length change more slowly than the given length threshold algorithm. But the length thresholds can not be changed by the input self-similar traffic, then it can not depress the self-similarity and packet blocking rate largely. Based on this algorithm, a modified algorithm based on length-changeable thresholds is proposed. The new algorithm can reduce the self-similarity more effectively and adjust the length thresholds according to the properties of the input network traffic stream more adaptively than the length adaptive assembly algorithm. The simulation results show that the packet block rate of the modified adaptive assembly algorithm is only about one tenth of that of adaptive assembly algorithm.