Multicast Source Routing based on Bloomed Link Identifiers for LEO Satellite Network

The low earth orbit (LEO) satellite network has the potential to provide low-latency transmission for global Internet services. Due to the mobility of LEO satellites, the frequent handover between a ground station (GS) and satellites will significantly affect the quality of content delivery. To overcome this challenge, we propose a multicast source routing mechanism for large-scale LEO satellite networks. This mechanism enables the source satellite to flexibly select the routes towards multiple satellites covering the same GS, thus ensures seamless satellite handover. Different from IP-based multicast, our approach assigns link identifiers for each unidirectional inter-satellite link, which can enable us to achieve reliable and efficient packet forwarding. Specifically, we design the equivalent virtual links based on the link identifiers, which can mitigate the impact of occasional link failures by forwarding the packets via the alternative route. Moreover, we use two bloom filters to encode the route (i.e., physical and virtual link identifiers) into the packet header. This way, the intermediate satellites could efficiently forward the packet according to its link identifier table. We evaluate the performance of the proposed mechanism via packetlevel simulation on OMNeT++. Results show that our proposed method outperforms IP-based routing in terms of end-to-end delay and delivery ratio.