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.

翻译：卫星网络设计中的一个重要选择是路由决策是在卫星上以分布式方式做出，还是在基于地面的控制器中以集中式方式做出。我们研究了大规模卫星网络中集中式与分布式路由之间的权衡。具体而言，我们考虑了一种能够获取全局但延迟的网络状态信息的集中式路由方案，以及一种能够获取局部但实时的网络状态信息的分布式路由方案。针对这两种路由方案，我们分析了在卫星上配备与不配备缓冲器的网络中，最短路径算法的吞吐量和延迟性能。我们证明，当网络链路状态的变化速率与固有的传播和传输延迟相当时，分布式路由优于集中式路由。具体来说，我们表明，在无缓冲器的高度动态网络中，分布式方案比集中式方案实现了更高的吞吐量。在配备缓冲器的网络中，分布式方案在相同吞吐量下实现了更低的延迟。