LEO 卫星网络路径选择策略研究

路由算法在选择路径时，主要考虑传输延迟和跳数这两个因素，分别选取最短延迟路径(Least Delay Path, LDP)或最少跳数路径( Least Hops Path, LHP)。在卫星网络中，基于LHP选径策略实现更加简单，但其应用在LEO卫星网络中合理性的研究成果不多。本文对极轨道LEO卫星网络中，LDP和LHP之间关系进行详细的理论分析，验证了LHP选径策略的合理性。并在此基础上，提出一种基于横向传输优先级（Horizontal Transmitting Priority, HTP）的LHP最短路径选择策略，利用横向链路长短特性简化路径决策流程。通过仿真，该方法能够快速寻找到最短LHP路径，为LEO卫星网络路由算法提供一定的研究基础。

Research on Path Selecting Strategy in LEO Satellite Network

The transmission delay and the number of hops in path are the two main factors which should be considered when designing a routing algorithm for a specific network. The paths generated by the different routing strategy are called least delay path (LDP) and least hop path (LHP). In satellite network, the algorithm for LHP is much simpler, but there is limited research achievements for the rationality of LHP. In this paper, we have a detailed theoretical analysis for the differences between LDP and LHP in polar circular LEO satellite network. Basing on the results of our analysis, we propose a simplified LHP path selecting strategy with an idea of horizontal transmitting priority (HTP) by using the features of horizontal link length. The simulation results prove that our path selecting strategy can quickly find out the shortest path among all the LHP between every two nodes. It provides a foundation for the research of routing algorithms in LEO satellite network.