Load Balancing Routing Based on Agent for Polar-orbit LEO Satellite Networks ⋆

A novel load balancing routing scheme is proposed for Polar-orbit Low Earth Orbit satellite networks. This scheme employs mobile agents to gather related routing information by migrating autonomously. And, stationary agents estimate Inter-satellite Link (ISL) cost, routing path cost and update routing items on satellites. In the proposed scheme, ISL queueing delay is estimated using M/M/1 queueing model. Moreover, ISL cost is calculated as the sum of propagation and queueing delays. Furthermore, ISL Cost Modification Factor (ICMF) is designed considering the characteristic of Polar-orbit satellite constellation as well as the traffic distribution on the earth. Finally, path cost is evaluated based on ICMF and ISL cost. Simulation results on an Iridium-like system show that the novel scheme can achieve better load balancing, throughput and end-to-end delay than the existing method. Besides, the impact of ICMF on the observed performance is thoroughly investigated.