A key technology that can expand the indoor millimeter wave communication range by attaching it to building glass has been developed, raising expectations that in the future, indoor millimeter wave band mobile communication will be possible without repeaters.

The Electronics and Telecommunications Research Institute (ETRI) announced on the 20th that it has developed a new technology that can smoothly support indoor millimeter wave band mobile communications without repeaters.

This achievement is attracting attention as an innovative technology that will overcome the difficulties of high-frequency communication and dramatically improve indoor communication quality.

ETRI has unveiled Intelligent Reconfigurable Antenna (RIS) technology with high penetration, wideband, and wide-angle characteristics in the millimeter wave (mmWave) band. This technology effectively transmits high-frequency signals indoors by attaching a film-type ultra-small array antenna to a building window or wall, and solves the high cost problem required for installing existing repeaters. In particular, by utilizing the microscopic patterns formed on glass to increase the transmittance of radio waves, radio wave loss can be reduced and communication quality can be significantly improved.

The high-penetration, wide-band, wide-angle RIS developed by ETRI has a bandwidth approximately 10 times wider than existing technologies, and can support 5G, connected 5G, and future 6G services simultaneously with a single RIS.

In addition, it is expected to contribute to eliminating indoor shadow areas and improving data speeds by maintaining consistent high-transmittance characteristics even at a transmission angle of 80 degrees or more.

The research team said that they have established the technological foundation to dramatically expand indoor communication coverage simply by attaching RIS film to building windows without additional repeaters.

ETRI is also conducting research on 'scattering RIS technology' to expand the indoor communication area. This technology expands the communication area by re-propagating high-frequency signals transmitted indoors over a wide range, and is evaluated as an energy-efficient future radio technology because it does not require a separate power source.

Currently, the ETRI research team has achieved a level of transmission loss improvement approximately four times that of ordinary glass, and plans to continue development to increase this to six times so that it can exhibit optimal performance even in coated and heat-blocking glass. The research team plans to transfer the technology to an antenna material component company and move on to the practical application stage with the goal of commercialization within the next three years.

Dr. Lee Jeong-nam of ETRI’s Radio Environment Monitoring Lab said, “This technology will contribute to innovatively improving indoor communication quality by overcoming the limitations of high-frequency communications,” and added, “We will continue to work to expand the scope of our country’s radio technology.”

This research was conducted with the support of the Ministry of Science and ICT and the National IT Industry Promotion Agency, and CleverLogic Co., Ltd. and Deoksan Nepcore Co., Ltd. participated as joint research institutions.