A State-Aware and Load-Balanced Routing Model for LEO Satellite Networks

Arbitrary flow arrival and satellite communication hot spot cause uneven traffic distribution, which breaks load balancing even results in congestion in partial nodes. In this paper, we propose a State-Aware and Load-Balanced (SALB) routing model for LEO (low earth orbit) satellite networks. We firstly propose a mechanism to quantitatively estimate link states and dynamically adjust the weight of queuing delay. SALB divides the occupancy rate of each queue into n levels and each level corresponds to a link state. Then, we develop the SALB model that considers various situations including load change, and link and node failure and recovery. Routing tables are reset up at the beginning of each handover and are dynamically updated through an efficient shortest path tree algorithm between two successive handovers, which significantly lower routing overhead. We evaluate our SALB model through a NS2-based system. The results demonstrate that our SALB outperforms related proposals in terms of system throughput, end-to-end delay, and packet drop rate.