A hyped miracle technology for 6G internet actually works no better than a standard metal lamppost in a real city.
Reconfigurable Intelligent Surfaces (RIS) are supposed to be smart mirrors that bounce 5G and 6G signals around corners to eliminate dead zones. Major tech companies have spent millions researching them, but new tests show they suffer massive performance drops in real environments. The natural scattering of radio waves off buildings and poles already does most of the work for free. When you account for the angle spread of signals in a real city, the smart surface provides almost no measurable benefit. This discovery suggests we might be over-complicating the future of wireless data. It means billions of dollars in research might be pointed at a solution that nobody actually needs.
Large Gain Degradation of Reflective Intelligent Surfaces in Realistic Environments
arXiv · 2605.04354
Reflective Intelligent Surfaces (RIS) are considered promising in improving coverage in Non-Line of Sight (NLOS) wireless links, especially at mm wave or higher frequency bands. Coverage provided by RIS is here compared to coverage from such ambient propagation mechanisms as scattering from street poles (e.g. lampposts), and corner diffraction. A simple formula for RIS gain degradation due to channel angle spread is derived. It is found an ideal 0.3 m x 0.3 m RIS at 28 GHz promises to deliver on