Energy Efficiency Maximization of Relay Aerial Robotic Networks

This paper proposes a new method of maximising the energy efficiency of Aerial Robotic (AR) networks in order to prolong AR battery life. An AR network is composed of an unmanned aircraft (drone) fitted with a wireless relay network. The AR network provides a connection server between two spread ground nodes. It is able to hover at any point of its flight path, which enables the AR network to function as a Mobile Base Station (MBS). An MBS can increase the range and flexibility of a communication network, but this ability increases the AR's energy consumption, which in turn increases drone battery drain. Therefore, it is essential to select the optimal MBS location so that the drone battery drain is minimised. In this paper we propose a method for evaluating the MBS's energy consumption at any point on the drone's flight path and thus select the hovering location of minimum energy consumption as the optimal MBS location. The proposed method optimises the source and relay power allocations on the drone's flight path. The power allocations are then combined at each MBS location to maximize the energy efficiency metric. Since the power allocations can also influence positively the AR throughput, this enables the AR throughput to be enhanced as well as the energy efficiency. The proposed analytical results are verified by using the MATLAB source code. It is shown that the proposed method can considerably improve both of AR network energy efficiency and throughput compared with conventional designs.