Topology Optimizing in FSO-based UAVs Relay Networks for Resilience Enhancement

Applying free space optical (FSO) in unmanned aerial vehicles (UAVs) relay networks has emerged as a promising technology due to high throughput, long transmission range, and the negligible interference incurred by FSO communications. However, FSO links are vulnerable in free space because of atmospheric turbulence, thus significantly reducing the reliability of the network. Thus, how to construct the FSO-based UAVs relay network topology to achieve a high network reliability is critical. This paper studies the network topology formation problem by considering the network resilience, where the resilience is referred to the ability of a network topology to defend against link failures. The network topology formation problem is formulated as a mixed integer nonlinear programming problem with the objective of maximizing network resilience. To solve this problem, two network resilience aware topology formation (NRATF) methods, i.e., centralized-NRATF and distributed-NRATF, are investigated to solve the topology designing problem efficiently. The performance of the proposed algorithms are evaluated via extensive simulations.