SK Telecom develops reconfigurable surface tech for 6G transmission

SK Telecom Co. on Thursday said it developed the world's first reconfigurable intelligent surface (RIS) technology that transmits 6G candidate frequencies.

RIS is a technology that reflects or transmits radio waves by adjusting transmission power based on the waves' characteristics.

Through its research cooperation with chemical materials company Dongwoo Fine-Chem, SK Telecom has developed technology that transmits high-frequency band frequencies by applying RIS technology to low-E glass, which is widely used in building exteriors.

Made by coating a thin silver film on one side of glass, Low-E glass transmits most of the sun's visible light and reflects much of its solar heat rays. Though widely used as a building external material due to its excellent insulating properties, the material has the disadvantage of transmitting mobile communication frequencies by blocking radio waves.

Through its research, SK Telecom measured the transmission traits of the upper-mid band of 7-24 GHz and sub-terahertz band of 92-300 GHz, which are being considered as new frequency bands among several candidates for 6G, and ran comparison tests with 5G commercial frequencies.

Its findings showed that transmission loss occurred compared with 5G commercial frequencies, but the application of RIS improved performance by about 40%, the company said.

SK Telecom said this technology will enable the production of 6G RIS glass that transmits light and radio waves but with no loss of insulation performance.

As such, the commercial application of such glass is also expected to improve wireless communication quality, which could include expanded indoor 6G coverage.

"Development of this 6G RIS technology is a meaningful outcome stemming from technology's natural evolution to 6G, secured through 5G and LTE," said Yu Tak-ki, SK Telecom vice president and head of infrastructure technology. "This will be a benchmark in preparation for 5G's advancement and the 6G era."

Write to Seung-Woo Lee at leeswoo@hankyung.com