Anyone who has watched their phone hunt for signal in the shadow of skyscrapers or inside a dense office complex knows the frustration. The cause is simple: high-frequency signals lose strength when they hit concrete walls and building facades.

Turkey's 6G research is now taking an unusual approach to the problem. Rather than trying to push signals through obstacles, Turkcell and TÜBİTAK have developed smart surfaces that change the signal's route. The prototypes were tested for the first time in real field conditions at Turkcell's Kartal Plaza and the TÜBİTAK Gebze Campus.

Walls become signal routers

These smart surfaces can reflect a signal, steer it toward another desired direction, or pass it through to the other side of a window. The result: the wall or facade that once blocked the connection becomes a tool that directs it. The space stays the same; only the path the signal follows changes.

In trials conducted in real building environments, the surfaces were observed to improve signal quality. Tests ran at two different frequencies: 3.7 GHz, which is also used in 5G, and the 26 GHz band, which promises high data speeds. This allowed the technology's performance to be measured across different frequencies and in real-world conditions.

Centrally controlled RIS panels also in the field

The system isn't limited to fixed panels. Reconfigurable Intelligent Surfaces (RIS) were also tested in the field. Because these panels can be controlled from a central point, the direction of the signal can be adjusted and access can be provided to poorly connected areas.

That capability matters greatly for stadiums, concert venues and shopping malls, where thousands of people connect to the network at the same time. Being able to reorganize signal direction according to demand offers a new way to improve connection quality in crowded spaces.

Redirecting signals without extra power

Another notable detail concerns energy. The fixed reflective surfaces and the panels that allow transmission through glass consume no additional electricity while steering signals. That means the building facades and glass surfaces that cut off connections today could become components that strengthen coverage tomorrow.