Outdoor to indoor coverage enhancement with transmissive metasurface.

Indoor coverage remains a major hurdle for millimeter wave (mmWave) communication, an emerging technology for next generation wireless networks. While mmWave technology delivers impressive data speeds and low latency, its deployment in indoor environments present a major challenge due to severe signal attenuation. To tackle this problem, reconfigurable intelligent surfaces (RIS), i.e metasurface, offers a promising solution. These innovative surfaces can control and redirect electromagnetic waves, helping to overcome signal losses and improve coverage in complex indoor environments. In this study, ray tracing simulations are used to create a detailed representation of a room with hole, windows, frames and other obstructions for understanding signal propagation behaviour i.e. reflections, diffractions, and scattering effects. To further enhance coverage, the potential of transmissive metasurface is explored into these simulations evaluating its ability to improve signal strength. This study examines multiple scenarios, comparing room setup with and without windows and hole, as well as setups with and without metasurface. The results highlight the effectiveness of metasurface in addressing mmWave limitations and possibility of significantly improving signal strength to ensure reliable coverage even in challenging conditions. By positioning the metasurface several centimeters outside the external wall, focusing signal power through the hole inside the room. This approach leverages existing architectural features, such as ventilation holes commonly found in Southern European buildings and provides a possible cost-effective and energy-efficient framework for designing solutions for beyond 5G (B5G) and 6G networks. This approach is a critical step toward achieving seamless outdoor-to-indoor (O2I) connectivity, which will be essential for the smart wireless environments of the future.