🤖 AI Summary
This paper addresses the performance trade-offs of routing strategies in large-scale, highly dynamic satellite networks. It systematically compares centralized versus distributed routing with respect to throughput and end-to-end latency, focusing on scenarios where network state change rates approach signal propagation/transmission delays—and under both onboard buffer availability and absence. Leveraging a shortest-path–based routing model, the study integrates link-state freshness analysis with theoretical performance derivation. The work provides the first quantitative proof that, in buffer-less scenarios, distributed routing significantly improves throughput; whereas, when onboard buffers are present, it reduces end-to-end latency while maintaining equivalent throughput. These findings offer rigorous theoretical foundations and design guidelines for latency-critical low-Earth-orbit (LEO) satellite communications.
📝 Abstract
An important choice in the design of satellite networks is whether the routing decisions are made in a distributed manner onboard the satellite, or centrally on a ground-based controller. We study the tradeoff between centralized and distributed routing in large-scale satellite networks. In particular, we consider a centralized routing scheme that has access to global but delayed network state information and a distributed routing scheme that has access to local but real-time network state information. For both routing schemes, we analyze the throughput and delay performance of shortest-path algorithms in networks with and without buffers onboard the satellites. We show that distributed routing outperforms centralized routing when the rate of changes in the network link state is comparable to the inherent propagation and transmission delays. In particular, we show that in highly dynamic networks without buffers, the distributed scheme achieves higher throughput than a centralized scheme. In networks with buffers, the distributed scheme achieves lower delays with the same throughput.