Deploying Indoor Reconfigurable Intelligent Surfaces for Interference Reduction

Reconfigurable intelligent surfaces (RISs) have attracted a lot of interests with a focus on coverage extension. However, the capacity enhancement of indoor ultra dense networks (UDN) is hindered by interference, which can be addressed by RIS via interference reduction (IR). In this article, we introduce a promising use case for IR-oriented RIS (IR-RIS) to improve the indoor UDN capacity, highlighting its significant influence on the deployment of indoor wireless networks and the optimisation of interference management strategies. We first give an overview of IR-RIS design, and then investigate the impact of IR-RIS on the indoor UDN capacity. By proposing an innovative optimisation framework for IR-RIS deployment indoors based on the novel concept of interference path modelling, we quantify the indoor UDN capacity gain brought by IR-RIS with a comparison to signal-enhancing RIS in a case study. Finally, we present potential research directions for IR-RIS, aiming to inspire further exploration and innovation from both academic and industrial communities.