Sensor and gateway location optimization in body sensor networks

In body sensor networks (BSNs), energy-constrained sensors monitor the vital signs of human beings in healthcare applications. Energy consumption is a fundamental issue, since BSNs must operate properly and autonomously for long period of time without battery recharge or replacement. In addition, the human exposure to electromagnetic radiation must be limited. For all these reasons, the energy consumption in BSNs should be minimized. In this paper, sensor and gateway location optimization for BSNs has been analyzed. A mathematical model has been proposed to minimize the energy consumption of the BSN and the heating effects on human tissues. We distinguish between ‘in-body’ and ‘on-body’ sensors depending on their location inside or outside the human body, respectively. The theoretical analysis and the numerical results reveal that in in-BSNs the energy consumption can be significantly reduced when the optimal positions of the gateway or the sensors are computed. However, in on-BSNs the energy consumption is not affected by the devices’ location. With power control the interferences are minimized and the human exposure to electromagnetic radiation is reduced.