Towards more Realistic Models for Wireless Power Transfer Algorithm Design

We elaborate on two fundamental models for the emerging technology of Wireless Power Transfer in ad hoc communication networks. The first model is scalar, basically assuming that the received power by multiple transmitters is additive. The second model is vectorial, highlighting the detailed interference between RF waves of different power sources, thus, it is more precise (especially in the far field regions of dense charging systems) and allows addressing interesting superadditive (constructive) and cancellation (destructive) phenomena on the received power. Under these models, we present selected state of the art algorithms for key problems, such as how to deploy and configure the wireless chargers and how to achieve good trade-offs between efficient charging and electromagnetic radiation. We conclude with some future trends and directions in this fascinating topic.