中文摘要：

为了降低光组播路由的光域网络编码代价和提高达到理论最大光组播容量的概率,提出一种基于共享链路和网络编码的优化光组播容量方法。首先设计一种从多条源-宿最短路径中选择能达到最大光组播容量的最短路径簇,然后在最短路径簇中计算路径的共享度,选择共享度高的组播路径传输网络编码信息,构造网络编码次数最少的光组播编码子图,解决传统的网络编码组播路由和最大共享度链路组播路由中存在的网络编码次数过多和达到最大光组播容量概率过低的问题。仿真结果表明：本文提出的方法具有最低的网络编码代价,能以最大的概率达到光组播理论最大容量。

英文摘要：

For reducing the network coding cost in optical field and improving the probability of realizing optical multicast theoretical maximum capacity in optical multicast routing,a multicast method based on shared links and network coding is proposed to optimize the optical multicast capacity in this paper.In the proposed method,a strategy is designed firstly to choose the multiple shortest paths from source node to each destination node,respectively.These shortest paths make up the shortest path cluster for the multicast.Then,the link shared degree of each path is calculated in the shortest path cluster.The paths with high link shared degree are selected to transmit the encoded multicast information.The multicast sub-graph is constructed by the link needing fewest number of network coding operations to optimize network coding cost.The proposed method can solve two routing problems：one is too many times of network coding operations in the traditional network coding multicast routing,and the other is too low probability of reach multicast maximal capacity for the multicast routing based on maximal shared degree links.Compared with the above two multicast routing methods,the simulation results show that the proposed multicast routing method can get the lowest network coding cost,the maximum probability of achieving optical multicast theoretical maximum capacity and appropriate multicast average routing cost.