Project Title: SWIFT: SMALL: Enabling Seamless Coexistence between Passive and Active Networks using Reconfigurable Reflecting Surfaces

Funding Agency: National Science Foundation (Division of Electrical, Communications and Cyber Systems)

Award Number: ECCS-2030215 (Virginia Tech), ECCS-2030068 (Duke University and Arizona State University)

Project Summary:

Harmonious coexistence between multiple wireless technologies is necessary for efficient utilization of the radio spectrum. However, enabling this in practice is known to be challenging because of the random and uncontrollable nature of the wireless channels, which makes it difficult to limit interference among co-existing wireless systems. This challenge is exacerbated by the fact that many wireless technologies, such as radio astronomy, rely on passive receivers whose performance can be disrupted by the slightest levels of interference. However, recent advances in metamaterials have made it possible to develop reconfigurable reflective surfaces (RRSs), which are electromagnetically active surfaces (e.g., a wall with wireless capabilities) that can be used to control the wireless propagation environment. Thus, RRSs can potentially help mitigate the challenge of interference among co-existing wireless technologies. The goal of this research is, thus, to develop a novel framework that will enable seamless co-existence among multiple passive and active wireless systems, by developing the fundamental science and technology needed to practically exploit the RRS concept to suppress interference at the wireless receivers. By achieving this goal, the proposed research will pave the way towards a seamless co-existence among a broad range of wireless technologies and applications. Improving these critical technologies will have tangible societal and economic impacts. The research is complemented by a comprehensive educational plan that includes spectrum-centric courses as well as the involvement of graduate and undergraduate students through diverse activities on spectrum sharing. Concrete broadening participation events, including seminars and participation in science fairs and outreach activities, are planned to engage under-represented K-12 students in spectrum research.

This research will develop foundational analytical and experimental approaches for holistic and cross-layer design, analysis, deployment, and optimization of RRS-enhanced spectrum co-existence networks. This includes several novel contributions: 1) A holistic statistical model that captures the effect of RRS deployment on the wireless propagation environment in spectrum sharing scenarios and creates RRS-inspired performance metrics tailored to spectrum co-existence use cases, 2) A systematic approach for network planning that can be used to determine how many RRSs to deploy, where, and with what surface and orientation so as to facilitate seamless communication, 3) A novel online optimization framework for performing distributed spectrum sharing while dynamically leveraging RRS reconfigurability, and 4) Design and fabrication of an RRS that offers near-continuous beam steering capability, as well as an experimental demonstration of RRS-enhanced spectrum co-existence in practical settings.