Smart Electromagnetic Skin Assisted Multicasting: Moving to 6G Intelligent Communications

The increasing demand for mobile data traffic has driven the standardization of millimeter-wave (mmWave) frequencies to address this challenge. Smart electromagnetic skins (SES) are a passive and cost-effective solution based on reflectarray or metasurface panels, which enhance mmWave coverage in blind spots. Additionally, by sharing radio resources, multicasting has recently garnered significant attention as a physical-layer solution for efficiently serving multiple users with identical service demands. This paper presents the design and performance analysis of a low-cost, broadened-beam SES-assisted multicast solution for mmWave communications. The results show that the proposed broadened-beam SES enables a base station (BS) to cover both a line-of-sight (LOS) region and a non-line-of-sight (NLOS) region for multicast users with a single beam. We analyze the impact of SES placement on the coverage area in both LOS and NLOS conditions. An exhaustive evaluation of the broadened-beam SES highlights its ability to deliver multicast services to a large group of users within the coverage area, ensuring the required bitrate for all users.