Abstract
In recent years, the utilization of sensors equipped with renewable energy sources has attracted the attention of many researchers. However, the unsteady nature of energy harvested from the environment imposes new challenges for resource management in sensors. In this research, we investigate the energy flow behaviour of mobile sensors modelled by coupled data and energy queues. Based on verified Markovian modelling, we derive the probabilities of battery depletion and data overflow of the sensors. In addition, we propose sufficient conditions in which model feasibility is guaranteed, and a closed-form solution for the optimal battery size for a node is obtained. Employing numerical study, we investigate the impact of different depletion and overflow rates on the battery size. We also use simulation to test the applicability of our mathematical model in a real-world scenario and estimate the data buffer size. These results offer useful insights to the optimal design of energy harvesting sensors.