Abstract: For these problems such as redundancy control packet, not fully utilizing information of new paths to complete the follow-up paths, this paper proposes an efficient and low-delay LEO (low earth orbit) satellite network routing algorithm based on on-demand mechanism EIORA (efficient improved on-demand routing algorithm). The proposed algorithm reduces control overhead and increases the universality of routing update by making full use of the control groups of the source and target satellites. At the same time, the RREP (route reply) packet is designed to reduce the network control overhead by discarding the RREQ (route request) packet when corresponding RREQ packet is received after intermediate satellite receiving the RREP packet. And the time of building the path is shortened by increasing the probability of intermediate satellite instead of target satellite to answer the response. Simulation results show that the proposed algorithm can reduce the control overhead and the end-to-end delay, as well as improve the transmission efficiency compared with the LAOR (lightweight ad hoc on-demand routing) algorithm.

Key words: LEO satellite, packet navigation, feedback response, on-demand routing

摘要： 针对按需LEO（low earth orbit）卫星网络路由算法存在冗余控制开销，未充分利用新建路径有效信息完成后续路径建立等问题，提出了基于按需机制的高效低时延LEO卫星网络路由算法EIORA（efficient improved on-demand routing algorithm）。该算法充分利用源卫星与目的卫星发送的控制分组，减少寻路的控制开销，增加路由更新的广泛性；采用RREP（route reply）分组免疫机制，中间卫星收到RREP分组后若收到对应的RREQ（route request）分组，则丢弃该RREQ分组，以减小网络控制开销；增加中间卫星代替目的卫星回复应答的几率，缩短路径建立时间。仿真结果表明，与LAOR算法相比，该算法在减缓星地之间的控制开销与端到端时延，以及提升传输效率上有明显的改善。

关键词: LEO卫星, 分组导航, 反馈应答, 按需寻路