Radio signal propagation via metamaterial-based intelligent surfaces has emerged recently as an attractive and smart solution to replace power-hungry active components. Such smart radio environments, that have the ability of transmitting data without generating new radio waves but reusing the same radio waves, can be implemented with the aid of reflective surfaces. This novel concept utilizes electromagnetically controllable metamaterial-based surfaces that can be integrated into the existing infrastructure, for example, along the walls of buildings. Such a surface is frequently referred to as Reconfigurable Intelligent Surface (RIS), Large Intelligent Surface (LIS) or Intelligent Reflective Surface (IRS). Its tunable and reconfigurable reflectors are made of passive or almost passive electromagnetic devices which exhibit a negligible energy consumption compared to the active elements or nodes. In this talk, we will highlight the state-of-the art of metasurface-based communications, basic communication theory, and promising applications in 6G wireless networks. Finally, a new a novel paradigm of metasurface shells able to increase the energy efficiency, energy harvesting and physical layer security will be presented.

Theodoros A. Tsiftsis was born in Lamia, Greece, in 1970. He received the BSc degree in physics from the Aristotle University of Thessaloniki, Greece, in 1993, the MSc degree in digital systems engineering from the Heriot-Watt University, Edinburgh, U.K., in 1995, the MSc degree in decision sciences from the Athens University of Economics and Business, in 2000, and the PhD degree in electrical engineering from the University of Patras, Greece, in 2006. He is a Professor in the School of Intelligent Systems Science & Engineering at Jinan University, China, also affiliated with the University of Thessaly, Greece, and Honorary Professor at Shandong Jiaotong University, Jinan, China. His research interests fall into the broad areas of communication theory and wireless communications with emphasis on energy efficient communications, smart surfaces, ultra-reliable and low-latency communication, and physical layer security.
Dr. Tsiftsis has served in the Editorial Boards of the IEEE Transactions on Communications, IEEE Transactions on Vehicular Technology, and IEEE Communications Letters. He is currently an Editor of the IEEE Transactions on Wireless Communications and IEEE Transactions on Mobile Computing. Prof. Tsiftsis has been appointed as an IEEE Vehicular Technology Society Distinguished Lecturer (IEEE VTS DL).