Optimal positioning of communication relay unmanned aerial vehicles in urban environments

This paper proposes a method of finding the optimal position of unmanned aerial vehicles (UAVs) functioning as a communication relay node to improve the network connectivity and communication performance of a team of ground nodes/vehicles. A three-dimensional complex urban environment containing many buildings is considered where the line-of-sight between ground nodes is often blocked. The particle swarm optimisation is used to find the optimal UAV position using three different communication performance metrics depending on the requirement. Numerical simulations are performed to show the advantage of using relay UAVs and the specific metric in sample scenarios. An indoor proof-of-concept experiment is also performed to show the feasibility of the proposed approach in a real time.