Robust Topology Design in Time-Evolving and Predictable Spacecraft Network with Node Efficiency

In spacecraft network, each nodes move in a predictable trajectory and the communication opportunities between them are often very short, therefore, network topology changes frequent and predictable. However, with the expansion of spacecraft network, how to maintain efficient and dynamic topology becomes increasingly crucial. In this paper, the topology design problem is studied in a spacecraft network where the dynamic topology and node efficiency can be predicted. First, a directed space-time graph that includes both spatial and temporal information is modeled for the spacecraft network. In order to reduce the impact of node congestion on the network performance, a new robust topology design problem which aims to balance the network load and minimize the total cost of the sparse structure while still maintaining the network connectivity over time is proposed. Second, two topology design algorithms which can significantly reduce the total cost of topology and maintain a space-time path connecting with robustness higher than the required threshold are proposed for this optimization problem. Finally, simulations results from random time-evolving and predicted spacecraft network demonstrate the efficiency of the proposed methods.