OBS网络中一种基于突发包优先级分割的可控重传方案  

A controllable retransmission scheme based on prioritized burst segmentation in OBS networks

作　　者：何婷婷[1] 许建真[1] 侯睿[2] 

机构地区：[1]南京邮电大学计算机学院,江苏南京210046 [2]中南民族大学计算机科学学院,湖北武汉430074

出　　处：《光电子．激光》2013年第5期912-916,共5页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(60841001);湖北省自然科学基金(2011CDB412);国家民委自然科学基金(12ZNZ010);武汉市青年科技晨光计划(201150431076);武汉市科技攻关(2013010501010125)资助项目

摘　　要：在光突发交换(OBS)网络中,突发包会由于竞争OBS核心节点输出端口的有限波长资源而发生冲突。突发包重传能够在一定程度上减少由于突发包在核心节点冲突而导致的数据损失,但重传次数的增加可能会加重网络负荷,反而增加数据丢失率。并且,在多业务存在的OBS网络中,重传方案需要能够实现区分服务以保证网络的服务质量(QoS)。据此,本文提出一种基于突发包优先级分割的可控重传方案,在实施优先级分割的同时,根据网络负荷赋予每次重传不同的概率,并对重传次数加以控制。最后,仿真分析了路径阻塞率和不同优先级业务的字节丢失率(ByLP,byte loss probability)性能。In optical burst switching （OBS） networks, contentions may occur at the output port of an OBS core node when the incoming bursts contend the limited wavelength resources. Burst retransmission can reduce data loss due to the burst contention in OBS core nodes. But uncontrolled retransmission may increase network load and data loss probability significantl. In addition, in a priority traffic existing OBS network,retransmission mechanisms should realize different services to support the quality-of-service （QoS） of the network. According to this,in this paper,we develop a controllable retransmission scheme based on prioritized burst segmentation. Different from previous works in the literature, we apply the prioritized burst segmentation and set a different value to retransmission probability at each contention and control the total transmission times referred to the network load condition. In addition,we apply the proposed retransmission scheme to the prioritized burst segmentation for QoS support. We take the load at each link due to both the fresh and the retransmitted traffic into account. At last, we calculate the path blocking probability and the byte loss probability （ByLP） for different priority bursts to evaluate the network performance. The results have some theoretical significance for the designing of an OBS network.

关 键 词：光突发交换(OBS)网络 重传 分割 多优先级业务 服务质量(QoS) 

分 类 号：TN929.11[电子电信—通信与信息系统]