宽带低轨卫星网高效组播中的部分网络编码算法

通过引入逻辑位置的概念，将宽带低轨卫星通信网的动态网络拓扑等效为多个静态拓扑的循环更替。针对静态网络的高效组播，提出部分网络编码算法。该算法只在有编码增益的节点处进行网络编码，其它节点直接路由转发。从等效的多个静态网络拓扑中提取连接关系不变的恒定网络拓扑，提出在恒定网络拓扑中采用部分网络编码实施组播。该方法能克服拓扑变化引起的路由和编码方案频繁变换问题，对应的吞吐量约为组播树路由的2倍，且优于多径路由，组播目的节点数越多，优势越明显。算法对于链路的失效具有较好的健壮性。研究成果对提高宽带低轨卫星通信网的组播吞吐量和健壮性具有一定的理论意义和实用价值。

A Partial Network Coding Algorithm for Highly Efficient Multicast in Broadband Low Earth Orbit Satellite Network

Logic locations are introduced to transform the dynamic topology into multiple static topologies in broadband low earth orbit (LEO) satellite communication network. To improve the multicast performance in a static network, a partial network coding algorithm is proposed. It uses network coding to combine data from upstream on those nodes with coding gain, while data is routed directly on the other nodes. The partial network coding is used in the invariable topology which is picked up from the dynamic topology of LEO network. It can avoid frequent change of the routing and network coding strategy caused by dynamic topology. The throughput of partial network coding is as twice as multicast tree routing and is also larger than multi-path routing. The more the multicasting destination nodes are, the larger gap of throughput between partial network coding and multi-path routing is. The partial network coding is also robust to link failure. The research is meaningful and valuable to improve the throughput and robustness of multicast communication in broadband LEO satellite communication network.