Optimizing LTE wireless access networks towards power consumption and electromagnetic exposure of human beings

When developing future wireless access networks, it is important to focus not only on optimizing the power consumption, but also the electromagnetic field exposure for human beings. However, optimizing towards these two parameters results in conflicting requirements on the network. In this paper, a deployment tool for future green wireless access networks is proposed, allowing four different levels of optimizations: towards power consumption, towards human exposure, towards power consumption while satisfying a certain exposure limit, and towards both power consumption and human exposure. The proposed deployment tool is capacity-based, meaning that it responds to the instantaneous bit rate required by the users in the considered area by switching base stations dynamically on and off. The tool is applied on a realistic suburban case in Ghent, Belgium to compare the four different levels of optimizations. A first compromise between optimizing towards power consumption and human exposure is obtained by optimizing towards power consumption while satisfying an exposure limit (at 2.6 GHz). However, there is still room for improvement especially when considering the human exposure. A better trade-off is achieved by the optimization towards power consumption and human exposure at the same time. Furthermore, the influence of the most important parameters such as the weighting factors of the fitness function, the distance between base station and general public, and between the grid points for evaluating the exposure is investigated.