Toward a Global Power Manager in Energy Harvesting Wireless Sensor Networks

Wireless Sensor Networks (WSNs) bring a great attention in recent years due to their potential monitoring applications in remote areas, where wire connections are impractical to deploy. Moreover, energy harvesting capability is considered as a promising solution to extend the lifetime of the network. As ambient energy can be scavenged as long as desired, the lifetime of the network can be theoretically infinite. To achieve that, a Power Manager (PM) in a WSN node is required to balance between the consumed energy and the harvested energy to reach the Energy Neutral Operation (ENO) state. However, due to the limited resources in the WSN nodes, the localized PMs must be low complexity and thus less intelligent. In this paper, we propose a Global Power Manager (GPM) that is implemented at a base station to control adaptations of the WSN nodes' power in the network. This solution inaugurates a new paradigm to design an efficient PM as the base station has less constrained on memory, computational capability and particularly energy resources than the WSN nodes. Moreover, a survey of state-of-the-art localized PM techniques is presented. It provides fundamental operations of these techniques to achieve satisfactory performances within a given energy budget.