RINGS: Harnessing the Complexity of Modern Electromagnetic Environments for Resilient Wireless Communications

We have all come to expect faster and faster download speeds every year from our hand-held devices – a kind of Moore’s Law for wireless communications bandwidth. To maintain this relentless increase in data rates we need to harness every technological feature available to us, and utilize it to the maximum extent. A particular challenge is improving wireless communications in enclosed environments, like a room or building, where the signals reverberate in a chaotic manner and appear to be hopelessly scrambled, as compared to free space propagation.

One approach is to use a programmable wall or ceiling-mounted pixelated surface to literally mold the reverberating waves to increase the data transfer rates to targeted receivers. The science and technology of reliably improving the data rates is the subject of this work. This science is advanced through intelligent use of the random reverberant properties common to all enclosed spaces, combined with wave control enabled by our programmable pixelated surfaces.

The outcome is further improvement of wireless communication data rates even in situations where present-day technology is severely handicapped, or fails to operate altogether. This project provides enhanced infrastructure for research and education by developing a multi-institutional effort sharing the proven techniques and experiences of all partners, thus intertwining engineering culture and liberal arts culture.

The extraordinary complexity and sensitivity generated by multiple scattering and the consequent interference of many ray paths in spectrally crowded reverberant settings is typically considered anathema for resilient communications and spectrum management. This effort aims to invert this narrative, by developing novel reconfigurable intelligent surfaces (RIS) that take advantage of this complexity to harvest the enormous number of environmental degrees of freedom in order to actively modify, and control, the electromagnetic environment.

The developed RIS is able to manipulate, both spatially and temporally, the wavefronts reflected from them in order to create hot- or cold-spots in real space, and they enable frequency-shifting of signals to specific users for advanced spectrum management. They also rapidly adjust to disruptive events using stochastic algorithms together with machine learning techniques.

In addition, cells within the RIS are designed using RF and mixed signal circuits, antennas, and components to capture disruptive short pulse events that can occur randomly through the interaction of broadband signals, or due to a deliberate attack on the network, supporting adaptive and resilient communications. The outcome is a more robust and capable wireless communication network that fuels further innovations in wireless content and usage, resulting in increased satisfaction for the user.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.