Optimal source rate allocation in Body Sensor Networks with energy harvesting

Body Sensor Networks (BSNs) are promising in pervasive health monitoring applications. One of the major challenges in BSNs is the sustainable power supply since each body sensor has limited battery capacity. In this paper, we optimize the source rate of the sensor to provide an uninterrupted service for BSNs with energy harvesting. First, we employ a discrete-time Markov chain to model the energy harvesting process at each sensor, and then theoretically analyze the relationship between the source rate and the uninterrupted lifetime of the sensor. Second, we formulate a steady-rate optimization problem, which minimizes the rate fluctuation with respect to the average sustainable rate via optimal source rate allocation at each sensor, under the requirement of the uninterrupted service. We propose an analytical solution to solve the optimization problem. In the simulations, we demonstrate that the proposed optimal solution enables the BSN to maintain an uninterrupted service with a steady output rate at each sensor.