Queue State Based Dynamical Routing for Non-geostationary Satellite Networks

The actual queuing delay in satellite networks is hard to get due to long propagation. So, most existing routing algorithms take the expected queuing delay as the routing metrics so that links with short-time light traffic are often chosen when setting up routing tables, which results in that more packets could be sent to the nodes with short-time light traffic. In this paper, we propose a Queue State based Dynamical Routing (QSDR) mechanism for NGEO satellite networks. Instead of expected queuing delay, we model effective queuing delay through filtering short-time light traffic based on the proposed forgotten factor, which considers not only the traffic load but also their duration. To balance traffic load, we propose a dynamical route updating algorithm based on real-time queue states with route state model, which ensures that each satellite sends out packets as soon as possible and avoids congestion at current node. We develop a NS2-based simulation system to evaluate our QSDR. The results demonstrate that our QSDR outperforms related TLR and ELB in terms of packet drop rate, throughput and end-to-end delay.