Acing Versatility of RIS Partitioning: An Experimental Proof-of-Concept Campaign

Reconfigurable Intelligent Surfaces (RIS) have emerged as an innovative technology for enhancing signal reception by manipulating the channel state and enabling passive beamforming toward targeted directions. Nonetheless, the effective deployment of RIS relies on precise phase shift optimization, a challenge exacerbated by restricted computational resources and the need for accurate channel state information. In this context, predefined codebooks and RIS partitioning deployment offer strategic solutions, enabling the RIS to serve multiple users simultaneously by assigning different partitions to various tasks and selecting the optimal codeword for specific objectives. As efforts to standardize RIS, this article presents an experimental testbed developed to assess the impact of RIS partitioning in the millimeter-wave band across several scenarios, including enhancing data rates in grant-free non-orthogonal multiple access, managing interference in heterogeneous networks, and maximizing secrecy capacity in physical layer security contexts. By investigating these case studies, this article provides empirical insights into the versatility and effectiveness of RIS partitioning across various communication environments. The research concludes by discussing the crucial challenges in RIS hardware design and implementation, emphasizing innovative pathways for advancing RIS technology in wireless infrastructures.