Practical Challenges for Reliable RIS Deployment in Heterogeneous Multi-Operator Multi-Band Networks

TL;DR

This paper explores the practical challenges of deploying reconfigurable intelligent surfaces (RISs) in complex multi-operator, multi-band wireless networks, highlighting issues of unintended interference and proposing ultra-narrowband metasurfaces as a mitigation approach.

Contribution

It identifies key deployment challenges of RISs in heterogeneous networks and discusses potential mitigation strategies like ultra-narrowband metasurfaces.

Findings

RIS deployments can cause unintended interference among users.

Ultra-narrowband metasurfaces may mitigate deployment challenges.

Simulation highlights practical issues in shared environments.

Abstract

Reconfigurable intelligent surfaces (RISs) have been introduced as arrays of nearly passive elements with software-tunable electromagnetic properties to dynamically manipulate the reflection/transmission of radio signals. Research works in this area are focused on two applications, namely {\it user-assist} RIS aiming at tuning the RIS to enhance the quality-of-service (QoS) of target users, and the {\it malicious} RIS aiming for an attacker to degrade the QoS at victim receivers through generating {\it intended} destructive interference. While both user-assist and malicious RIS applications have been explored extensively, the impact of RIS deployments on imposing {\it unintended} interference on various wireless user-equipments (EUs) remains underexplored. This paper investigates the challenges of integrating RISs into multi-carrier, multi-user, and multi-operator networks. We discuss how RIS deployments intended to benefit specific users can negatively impact other users served at various carrier frequencies through different network operators. While not an ideal solution, we discuss how ultra-narrowband metasurfaces can be incorporated into the manufacturing of RISs to mitigate some challenges of RIS deployment in wireless networks. We also present a simulation scenario to illuminate some practical challenges associated with the deployment of RISs in shared public environments.