A distributed dual-ascent approach for power control of wireless power transfer networks

Deployment of networks composed of several radio frequency (RF) based wireless power transfer nodes will be a indispensable component of future Internet of Things (IoTs). The natural objective of such networks, so called the wireless power transfer networks (WPTNs), is to charge energy receiver (ER) devices wirelessly as quickly as possible; i.e., maximizing the transmitted power. However, a safe-charging WPTN must also comply with the RF exposure regulations and keep electromagnetic radiation (EMR) under a predefined threshold. In this paper we consider the problem of maximizing the transmitted wireless power to ERs subject to the safety constraints. We introduce a dual ascent-like distributed charging algorithm where energy transmitters communicate only with the sensors in their power transmission range to obtain their measurements, perform simple computation steps to adjust their power levels and, in turn, to satisfy safety constraints without global information.