光突发交换网络中基于优先级的可控重传方案  

A Prioritized Controlled Burst Retransmission Scheme in Optical Burst Switching Networks

作　　者：何婷婷[1] 许建真[1] 

机构地区：[1]南京邮电大学计算机学院,南京210046

出　　处：《光子学报》2013年第10期1193-1196,共4页Acta Photonica Sinica

基　　金：江苏省研究生科研创新计划项目(No.CXLX13-69)资助

摘　　要：在光突发交换网络中,突发包重传能够在一定程度上减少由于突发包冲突而产生的数据损失,但重传次数的增加会加重网络负荷,从而增加数据丢失率.本文提出一种基于优先级的可控重传方案,根据网络负荷赋予不同优先级突发包每次重传不同的概率,并对重传次数加以控制,当重传次数达到4次时,便不再进行重传而将产生冲突的突发包丢弃,以此来均衡网络负荷.利用路径阻塞率和突发包丢失率来衡量模型性能,并进行仿真分析,仿真结果表明重传次数的增多以及重传概率的增大虽然会在不同程度上减少包丢失率,却也同时增大了路径阻塞率,因此必须对重传次数及重传概率加以控制;所得结果对光突发交换网络试验床设计有一定理论指导意义.In optical burst switching networks,burst retransmission can reduce data loss which is arising from the burst contention in optical burst switching core nodes,but uncontrolled burst retransmission may increase network load and data loss probability.A quality-of-service-supported controlled retransmission scheme was developed in optical burst switching networks.In this scheme,different values to retransmission probability were set at each contention and the total transmission times were controlled referred to the network load condition.In order to reach a balanced network load,the conflict bursts would no longer be retransmitted but be discarded when the number of burst retransmission reached our times.The path blocking probability and the burst loss probability for different priority bursts were calculated to evaluate the performance of the proposed scheme.From the simulation,with the retransmission probability and the number of retransmission increasing,it can be seen that burst loss probability is reducing while the path block probability is reducing.So it is necessary to control the retransmission probability and the number of retransmission.This result has some theoretical significance for the designing of an optical burst switching network test bed.

关 键 词：光通信 光突发交换 重传 突发包冲突 优先级 数据丢失率 服务质量 

分 类 号：TN929.11[电子电信—通信与信息系统]