Reconfiguration Penalty-Aware Topology Control in Optical Communication Satellite Networks

Optical communication satellite networks (OC-SN s) are promising candidates for the next-generation high-throughput space networks, and are driven by free space optical (FSO) communication technology. While FSO has a great advantage of efficient data transmission using a collimated narrow beam, it requires accurate pointing, acquisition and tracking that lead to long topology-reconfiguration time. In particular, from practical networking viewpoint, it is essential to discuss the impact of such topology-reconfiguration penalty on throughput, however, this problem has not yet been considered in the design of OCSNs. Therefore, this paper proposes a recon-figuration frequency-controllable dynamic-topology model and investigated the relationship between topology-reconfiguration and network throughput. The results indicate that properly suppressing reconfiguration improves throughput by about 10% compared with the conventional model. It was also found that too much reconfiguration suppression leads to a significant loss in important topological features and, conversely, to throughput degradation. These results provide important insight into the nature of the system: The dynamic topology control of OCSNs is not a trivial problem of simply suppressing reconfiguration, but rather a problem of finding the optimal point where important topology characteristics and reconfiguration frequency are well balanced.