中文摘要：

突发竞争是引起光突发交换（OBS）网络丢包的主要因素之一，而作为一种有效的突发竞争解决方法的偏射路由，因其对光缓存器的性能和数量要求较低而备受关注。然而，现有偏射路由算法忽略了偏射业务对偏射路径上原有业务的影响以及业务被偏射后自身的成功传输率，同时也忽略由偏射引起的偏置时间不够的问题，致使OBS网络整体丢包率较高。为此，本文提出了一种支持业务均衡的分布式回退偏射路由算法（DBDF-LB），基本思路在于：从全网业务均衡出发，根据网络状态信息分布式的为偏射业务选择一条丢包率最小、跳数最短的路径；然后通过回退机制，利用网络资源来缓存突发包，从而补偿由偏射引起的额外偏置时间。与典型的最短路径偏射算法（SPDF）相比，DBDF-LB能有效降低丢包率约23～50％，而成功传输突发包所经历的平均跳数增加不到1跳。

英文摘要：

Burst contention can cause the burst loss in the optical burst switching （OILS） networks. Therefore, various contention resolution schemes have been proposed. Among them, the deflection routing is more attractive due to its low requirement for optical buffer in capability and quantity. However, the existing algorithms do not consider the deflected traffic＇s impact on the original traffic of the deflection path or the successful transmission probability of deflection traffic. Meanwhile, the offset-time deficit caused by deflection is ignored. Thus, in order to reduce the burst loss probability in OBS networks, a distributed backoff-channel deflection algorithm with load balancing （DBDF-LB） is proposed. It consists of two parts,i, e. ,the deflection with load balancing and the backoff-channel buffering. Firstly,from the perspective of the network-wide load balancing, the optimal deflection path, on which the contention-failure burst is deflected with the minimum hops and the least burst loss probability, is selected. Secondly, the extra offset-time for the deflected burst is provided through the backoff-channel buffering scheme. Finally,by numerical simulations, compared with the classical shortest path deflection algorithm （SPDF） ,the DBDF-LB can obviously reduce the burst loss probability by about 23% -50% ,and with a extra transport overhead less than one hop.