UAV-Based Servicing of IoT Nodes: Assessment of Ecological Impact

Abstract

Internet of Things (IoT) nodes get deployed for a variety of applications and often need to operate on batteries. This restricts their autonomy and/or can have a major ecological impact. The core idea of this paper is to use a unmanned aerial vehicle (UAV) to provide energy to IoT nodes, and hence prolong their autonomy. In particular, the objective is to perform a comparison of the total energy consumption resulting from UAV-based recharging or battery replacement versus full provisioning at install time or remote RF-based wireless power transfer. To that end, an energy consumption model for a small license-free UAV is derived, and expressions for system efficiencies are formulated. An exploration of design and deployment parameters is performed. Our assessment shows that UAV-based servicing of IoT nodes is by far more beneficial in terms of energy efficiency when nodes at distances further than a few meters are serviced, with the gap increasing to orders of magnitude with the distance. Our numerical results also show that battery swapping from an energy perspective outperforms recharging in the field, as the latter increases hovering time and the energy consumption related to that considerably. The ecological aspects of the proposed methods are further evaluated, e.g., considering toxic materials and e-waste.

Erlang-U: Blocking Probability of UAV-Assisted Cellular Systems

“…In [12], the authors propose methods to recharge IoT nodes, and present a model for the energy consumption of the drones used to directly recharge nodes using different schemes. In [2] the authors also propose an energy consumption model focused on charging multiple UAVs according to a particular schedule.…”

“…There are many types of drones that can be used to assist the cellular system, such as the ones proposed in [12,15,16]. For drones in general, the service time, i.e., the dwelling time of the drone inside the region of interest, is determined by the energy drain of the battery.…”

“…The power required to perform these tasks is mainly related to the mass of the drone, vertical and horizontal speeds, and the thrust which is the required upward force. The energy consumption of the UAV can then be calculated according to the specific type of drone using the derived energy consumption models in the literature, such as the ones proposed in [2,12,15,16], among others. Also in [1], the authors propose an energy model for the energy consumption of the UAV that depends on the transmitting energy, the propulsion energy, and the hovering energy required in the operation of the system.…”

“…However, note that the energy consumption of the UAV is highly variable due to the environmental conditions and trajectories that the UAV must follow, which depend on the location of the traffic peak. Unlike [12], where the placement of nodes is known, in a cellular system, it is not predetermined the location where the traffic peak will occur, nor its duration. Also, these conditions may change during the UAV's flight at any point in time.…”

“…In modern telecommunicatiions systems, the use of drones is becoming more and more relevant due to the flexibility and ease of deployment. For instance, in cellular systems, drones can assist with additional channels [1][2][3][4][5][6][7][8][9][10][11], and also in the Internet of Things (IoT) to charge nodes or recollect data sensed by nodes in a region of interest [12]. For these cases, it is preferable to send drones to the region of interest with additional channels, in the case of cellular systems, in a temporary manner rather than setting new base stations, especially if traffic peaks also occur in this manner, i.e., temporarily.…”