Topology Optimization for FSO-Based Fronthaul/Backhaul in 5G+ Wireless Networks

Free space optical (FSO) communication has been emerging as a promising solution for mobile fronthaul/backhaul frameworks in 5G+ wireless networks. Owing to the dynamic of traffic demands among different small cells, reconfigurable topologies of FSO-based mobile fronthaul/backhaul frameworks are required to meet the small cells networks. However, the limited node degree and the fragile links make the efficient topology reconfiguration of FSO networks remain to be an open challenge. In this paper, we investigate a periodic reconfiguration method that generates the optimal topology for the given traffic demand during a period. In particular, we formulate a multi-objective optimization program that jointly optimizes the network throughput and power consumption of FSO networks. As for large-scale networks, we propose a greedy matching based topology formation algorithm to derive the optimal topology of FSO networks. We compared the performance of the designed algorithm in terms of network throughput and power consumption. Simulation results demonstrate that the derived optimal topology can optimize the throughput and network cost simultaneously.