Efficient Ray Description of the Field Scattered by Reflective Intelligent Surfaces

In recent years, there has been a continuous increase in the demand for widespread access to multimedia information, also due to the proliferation of numerous data-intensive applications. As a result, the Fifth Generation (5G) network is currently grappling with the challenge of increasing data speed, improving efficiency and reducing latency. Addressing these issues requires a revolutionary paradigm shift, especially at the physical layer. A novel concept, the Smart Radio Environment (SRE), has emerged as a possible solution to these needs. In SRE, the environment is jointly controlled and programmed with transmitters and receivers, rather than being something to compensate for. The fundamental technology supporting SREs relies on reflective intelligent surfaces (RiS). These artificial surfaces, or metasurfaces (MTSs), consist of electrically small elements whose electromagnetic behavior is electronically controlled. MTSs operate without the need for signal processing or amplification, resulting in extremely low power consumption. They can process electromagnetic signals at the speed of light, significantly reducing latency and complexity compared to fully digital solutions. © 2024 IEEE.