Minimization of the Worst Case Average Energy Consumption in UAV-Assisted IoT Networks

• Published in: IEEE internet of things journal Vol. 9; no. 17; pp. 15827 - 15838
• Main Authors: Martinez Rosabal, Osmel, Lopez, Onel Luis Alcaraz, Perez, Dian Echevarria, Shehab, Mohammad, Hilleshein, Henrique, Alves, Hirley
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.09.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Antennas; Autonomous aerial vehicles; Energy consumption; Energy efficiency; Energy sources; geometric programming (GP); Hovering; Interference; Internet of Things; Internet of Things (IoT); Optimization; Power management; Quality of service; reconfigurable antennas; unmanned aerial vehicle (UAV); Unmanned aerial vehicles; Uplink; worst case average energy consumption
• ISSN: 2327-4662; 2327-4662
• DOI: 10.1109/JIOT.2022.3150419

The Internet of Things (IoT) brings connectivity to a massive number of devices that demand energy-efficient solutions to deal with limited battery capacities, uplink-dominant traffic, and channel impairments. In this work, we explore the use of unmanned aerial vehicles (UAVs) equipped with configurable antennas as a flexible solution for serving low-power IoT networks. We formulate an optimization problem to set the position and antenna beamwidth of the UAV, and the transmit power of the IoT devices subject to average-signal-to-average-interference-plus-noise ratio (<inline-formula> <tex-math notation="LaTeX">\bar {\text {S}}\overline {\text {IN}}\text {R} </tex-math></inline-formula>) Quality-of-Service (QoS) constraints. We minimize the worst case average energy consumption of the latter, thus targeting the fairest allocation of the energy resources. The problem is nonconvex and highly nonlinear; therefore, we reformulate it as a series of three geometric programs that can be solved iteratively. Results reveal the benefits of planning the network compared to a random deployment in terms of reducing the worst case average energy consumption. Furthermore, we show that the target <inline-formula> <tex-math notation="LaTeX">\bar {\text {S}}\overline {\text {IN}}\text {R} </tex-math></inline-formula> is limited by the number of IoT devices, and highlight the dominant impact of the UAV hovering height when serving wider areas. Our proposed algorithm outperforms other optimization benchmarks in terms of minimizing the average energy consumption at the most energy-demanding IoT device, and convergence time.