Up in the Air, Split on the Ground: STAR-RIS vs. RIS in 3D Networks
The upgrade is not the answer; the angle is Hardware upgrades are comforting because they sound linear. A faster chip is faster. A bigger antenna array has more elements. A surface that can both transmit and reflect sounds strictly better than one that only reflects. Wireless geometry is less polite. The paper behind this article compares aerial RIS and aerial STAR-RIS in three-dimensional wireless environments.1 The obvious story would be simple: conventional RIS reflects signals on one side; STAR-RIS can simultaneously transmit and reflect; therefore STAR-RIS should win. The paper’s actual story is more useful. STAR-RIS often wins, especially at lower altitudes and farther deployment positions. But conventional RIS can outperform it near the base station at higher altitude. STAR-RIS is also highly sensitive to orientation. ...