Toward Self-Sustainable Airborne Communication Networks: Comprehensive Modeling and Analysis of Energy Consumption and Harvesting

Airborne networks build upon the use of unmanned aerial vehicles (UAVs) and high-altitude platform stations (HAPSs) for wireless access and backhauling and are expected to be instrumental in providing global coverage and ubiquitous connectivity. They can offer a range of benefits, including lower latency and higher data rate capacity per unit area, making them an attractive alternative or complementary solution to low-earth orbit satellites in future non-terrestrial networks. The practical deployment of airborne nodes is restricted by onboard energy limitations, motivating the use of energy harvesting techniques. In this paper, we present an in-depth examination of the power consumption of HAPSs and rotary-wing UAVs. We delve into consumption patterns across various flight phases, shedding light on the multifaceted impact of diverse system and operational parameters on overall energy utilization. We then present a thorough analysis of energy harvesting methods. First, we examine solar energy harvesting and demonstrate its dependence on factors such as operational altitude, geographical location, climate conditions, and daylight duration. Subsequently, we introduce laser power beaming as a more predictable and controllable energy source. Thereafter, we discuss the feasibility of self-sustainable airborne networks based on these energy harvesting techniques and typical energy consumption patterns.