Link Reassignment based Snapshot Partition for Polar-orbit LEO Satellite Networks

Snapshot is a fundamental notion proposed for routing in mobile low earth orbit (LEO) satellite networks which is characterized with predictable topology dynamics. Its distribution has a great impact on the routing performance and on-board storage. Originally, the snapshot distribution is invariable by using the static snapshot partition method based on the mechanical steering antenna. Utilizing nowadays advanced phased-array antenna technology, we proposed a quasi-dynamic snapshot partition method based on the inter-satellite links (ISLs) reassignment for the polar-orbit LEO satellite networks. By steering the inter-satellite antennas when snapshot switches, we can reassign the ISLs and add available ISLs for a better following snapshot. Results show that our method can gain more stable routing performance by obtaining constant snapshot duration, constant ISL number and lower end to end delay. Especially for Iridium system, our method can gain not only longer merged snapshot duration, half of the snapshot number, but also higher utilization ratio of inter-plane ISLs. Potentially, our method could be very useful for the Iridium-next system.