Abstract: Wireless networks composed of nodes that can harvest energy from the environment represent the green future of communications. Utilizing the harvested ambient energy improves the environmental impact of wireless devices in the global scale, while extending the network lifetime indefinitely and making the devices truly mobile. Energy harvesting (EH) brings new dimensions to system design in the form of randomness and intermittency of available energy, as well as additional system issues such as energy storage capacity and processing complexity. Additionally, the deployment of EH wireless networks calls for novel techniques for resource and interference management, cooperation among EH nodes, as well as cross-layer optimization of the network. 

The research focuses on a new set of challenges brought about by wireless networks composed of EH nodes. The research directions are divided into four major thrusts.

• (1) The first challenge is to understand the fundamental limit of EH communications in the information theoretic setting, accounting for random and intermittent supply of available energy, finite battery capacity with storage and withdrawal efficiencies. The special cases for low-power and high-power regimes are of particular interest.
• (2) In order to make efficient use of the available resources, joint energy scheduling and spectral and/or spatial resource allocation in EH networks exploiting the inherent structure of the resource allocation problems becomes an important problem.
• (3) Different EH nodes in the network can share their harvested energy either through the presence of power line between them, or through wireless charging. The research studies previous thrusts with energy and data cooperation.
• (4) The research investigates efficient distributed cross-layer solutions to maximize the total system utility subject to data and energy queuing stability constraints.