一种基于分时的LEO卫星网络无环路由算法

在分析传统卫星网络路由算法的基础上，提出一种基于分时的LEO卫星网络无环路由算法(DTRA)。针对卫星在各时间片之间进行路由表切换时可能出现的路由环问题，算法采用平滑路由表切换策略消除由于切换前后网络状态信息不一致而产生环路的可能性，保证分组在任何时刻都能够沿无环最短时延路径被转发。同时，DTRA也能够通过使用无环备份路径处理可能出现的链路拥塞、节点失败等突发情况。通过复杂性分析可知，算法只需较小的星上存储开销和星上处理开销，而无需星问通信开销。仿真实验结果也表明算法能够提供数据最优传送，具有较好的端到端时延性能。

Discrete time based loop-free routing algorithm for LEO satellite networks

Based on the analyses of traditional routing schemes proposed for satellite networks, a discrete time based loop-free routing algorithm (DTRA) for LEO satellite networks was developed. Focus on eliminating the possible loops caused by routing table transition between consecutive time intervals due to the inconsistent network information, a smooth routing table transition policy was introduced to guarantee that the packets would be forwarded on loop-free paths at any instant of time. At the same time, in case of link congestions and satellite failures, DTRA was also capable of routing the packets to the secondary next-hop on the backup paths. Results from the implementation complexity analysis demonstrate that the proposed algorithm had lower onboard computational, storage requirements, and no signaling overhead at all. The implementation complexity and communicational overhead were evaluated. The performance evaluation of DTRA was conducted by simulation. Furthermore, experimental results show that the new algorithm can provide optimal data transferring and has better end-to-end delay performance.