SKT is conducting research on 6G candidate frequency bands for 6G global standardization.

SKT announced on the 30th that it conducted field measurements and simulations on 6G candidate frequency bands in collaboration with the telecommunications industry to design the optimal network structure considering 6G frequency characteristics.

SKT has secured situational data on the impact of building structures and people's locations on communications in 6G candidate frequency bands through joint research between industry and academia. We also developed a graphical user interface (GUI)-based simulator that intuitively and efficiently designs 6G network architectures.

The 6G candidate frequency bands used in measurements and simulations are parts of the 4 GHz band, the 7–15 GHz band, and some high-frequency bands.

SKT plans to conduct specific research on 6G candidate frequency bands as the 6G frequency is confirmed at the World Radiocommunication Conference (WRC-27) in four years.

At the World Radiocommunication Conference (WRC-23) held in November last year, three out of four bands proposed by our government were ultimately adopted as 6G candidate frequency bands by regional organizations and countries: △4.4~4.8GHz △7.125~8.5GHz △14.8~15.35GHz.

The 4-10GHz band is the band that SKT presented as a candidate frequency for 6G in the 6G white paper published in August last year. SKT claimed that the band is “more advantageous than high-frequency bands in terms of coverage construction and securing base station capacity, and is a band where services can be provided from the early stages of 6G commercialization.”

■ 6G radio wave characteristics actual measurement… Verification of actual usage environment

SKT, together with Kyungpook National University, comprehensively measured the radio wave characteristics of the 6G candidate frequency bands, including path loss, building medium penetration characteristics, and human body loss.

The two sides said that through this study, they confirmed that “the propagation performance of candidate 6G frequency bands in a non-line-of-sight (NLOS) environment decreases as the band gets higher compared to the theoretical calculation value defined in the existing 5G.”

Also, experiments measuring radio wave transmission loss of building media such as glass, concrete, and wood revealed that transmission loss increases as frequency increases. In particular, in the high-frequency band, loss increased by 2.7 to 21.6 times (4.4 to 13.3 dB) when transmitting through 3 mm thick glass, and by 1,000 to 100,000 times (30 to 50 dB) when transmitting through 22 cm thick concrete walls, confirming a decrease in outdoor-to-indoor (O2I) coverage.

Both sides confirmed that signal quality deterioration occurs when the radio wave path is blocked by the human body in the 6G usage environment. When the radio wave path is interrupted by the human body, the signal is reduced by 30 to 160 times (14.8 to 22 dB) compared to when it is not interrupted.

SKT co-wrote a paper synthesizing the existing 6G white paper and the results of this study with Seoul National University and Kyungpook National University and submitted it to the SCI-level academic journal 'IEEE Communications Magazine'. The results of this study will also be contributed to global standardization organizations such as ITU-R and 3GPP to emphasize the need for 6G coverage enhancement technology for each frequency band.

■ Performance analysis by scenario using 6G simulator

SKT and Yonsei University have developed a '6G simulator' for performance analysis and optimal 6G network design by service scenario. The '6G simulator' predicts the performance of mobile communication systems by considering base stations, surrounding cells, and multiple users in a wireless communication environment. It can simulate performance related to data upload and download, coverage, etc. in mobile communication networks.

SKT and Yonsei University identified the optimal network structure based on the use of 6G candidate frequency bands in environments closely related to real life, such as dense urban areas, urban areas, and rural areas. In particular, it predicted the performance of 6G networks with UAM, satellite communications, Aerial Network, RIS (Reconfigurable Intelligent Surface), and AI-based base station performance enhancement technologies.

SKT announced that it plans to exhibit the results of its '6G Simulator' research at MWC 2024 and contribute to the IMT-2030 Technical Performance Requirement, which will be conducted by ITU-R starting this year.

Meanwhile, SKT is continuing its efforts to lead the global standardization of 6G and the establishment of a technology ecosystem. At the '6G Brooklyn Summit' and 'Telecom World Asia' held in November last year, SKT gave keynote speeches on '6G core technologies and requirements including AI-based 6G network evolution' and 'Securing killer services and low-frequency broadband frequencies for 6G'.

At the 3GPP Technology Plenary Meeting in December last year, we contributed to the 6G timeline and directionality, and through this meeting, we plan to proceed with wireless channel modeling of the new frequency bands approved, standardization of Integrated Sensing and Communication (ISAC), and related research.

Ryu Tak-ki, head of SK Telecom’s infrastructure technology division, said, “Through this research, we have confirmed the importance of early review of 6G candidate frequency bands and optimal network design,” and added, “We plan to continue active joint research between industry and academia and advanced technology development to help South Korea lead the global 6G technology ecosystem.”