RIS-assisted grant-free massive access scenario (IMAGE) Tsinghua University Press Caption Illustration of an RIS-assisted grant-free massive access in a smart factory, where a cluster of RIS subarrays working in the refraction mode are deployed on the wall of the factory. Credit Intelligent and Converged Networks Usage Restrictions News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.