中文摘要：

由低轨LEO（Low Earth Orbit）和中轨MEO（Medium Earth Orbit）卫星构成的双层卫星网络具有较好的组网通信性能．利用MEO和LEO卫星在长、短距通信中的优势，提出一种分层、分布式的双层卫星网动态路由算法．通过控制链路状态信息的洪泛，LEO卫星只需掌握局部拓扑即可完成短距业务通信，长距通信业务则由MEO卫星承载。将星间链路的剩余生存时间因素引入路径权重中，路由计算的路径是综合考虑了时延与持续时间双重因素的最优路径。仿真结果表明该算法在时延、路由开销、网络业务流分布等方面都具有较好的性能，并且易于系统实现。

英文摘要：

Double-Layered satellite networks consisting of LEO （ low earth orbit） and MEO （ medium earth orbit） satellites have advantages on networking and communication performances. Based on the advantages of MEO and LEO satellites in long-distance and short-distance communications respectively, a hierarchical and distributed dynamic routing algorithm named DLRA （double-layered satellite-network routing algorithm） was proposed. By controlling flood of link state information, LEO satellites could acquire local topology information to route the short-distance traffics. The long-distance traffics were routed in MEO layer. The residual lifetime of the ISL （inter-satellite link） was considered in the path weight calculation in this algorithm. The selected path was optimal in path delay and duration. The simulation results show that DLRA has better performances in end-to-end delay, routing overhead and traffic flow distribution, and is easy to be applied.