As the International Telecommunication Union (ITU), an organization under the United Nations, focuses on standardizing satellite communications, the integrated development of terrestrial and satellite networks is increasingly being emphasized.

On the 12th, the Satellite Communication Forum, ETRI, the Korean Institute of Communications and Information Sciences, the Korean Institute of Electromagnetic Engineering and Science, and the Satellite Information and Communications Society co-hosted the 6G Satellite Communication Conference at the Yongsan Dragon City Hotel. In the presentations that day, experts from academia, industry, and research discussed 6G satellite communication policies and trends, and 6G satellite communication standard activities.

Kim Hee-wook, head of the Satellite Communication Research Division of the ETRI Stereoscopic Communication Research Institute, said in a presentation on satellite communication standardization trends by the International Telecommunication Union (ITU-R), an international standardization organization, that “there were attempts to establish the role of satellite communications in the past, but commercialization was not possible due to a lack of competitiveness compared to terrestrial communications.” He continued, “This time, the outlook is bright as satellite operators are building an ecosystem by integrating with terrestrial systems rather than establishing their own satellite systems.”

ITU is a standards organization that develops technical standards in the field of telecommunications. In fact, the detailed technical standards proposed by 3GPP, a standardization organization, are evaluated and the final international standard is adopted.

Standardization organizations are divided into official standardization and factual standardization. Official standardization organizations are internationally recognized organizations, and factual standardization organizations are formed by consortia of companies. Kim said, “Official standardization organizations are often delayed due to time-based cooperation between countries,” and “Currently, factual standardization organizations and official standardization organizations are structured to cooperate with each other rather than compete.”

The ITU-R's 'SG (Study Group) 4', which is currently in charge of radio communications, is standardizing satellite 5G communications (IMT-2020). The results of this standardization are expected to be an extension of satellite IMT-2030, which is 6G communications.

After 3GPP's process of proposing candidate technologies runs through December, the ITU is expected to include the IMT-2020 satellite standards in its report in mid-2025.

Kim said that compared to the past, terrestrial mobile operators and terminal vendors are now focusing on configuring systems that complement each other with satellite operators and reducing development and launch costs to increase competitiveness. In addition, the situation where mobile carriers are looking for new market opportunities due to terrestrial service saturation was also evaluated positively.

■ NTN aims to provide broadband services to remote areas A key focus of the satellite IMT-2020 vision is to provide seamless services using terrestrial and satellite communication links.

LG Electronics Managing Director Yoon Young-woo said in a presentation on the latest wireless communication technology related to 3GPP NTN that they are defining satellites in the NTN (Non-Terrestrial Network) field within 3GPP and are working on standardization, and are proposing IMT-2020 candidate technologies.

NTN refers to a technology that provides broadband services to terminals using non-terrestrial networks including UAVs, and aims to supplement areas outside of terrestrial network facilities in preparation for remote areas or disasters based on low-orbit satellites.

Samsung Electronics verified the technology by integrating the NTN modem into the 'Exynos 5300' chip in February. Samsung Electronics also announced that it will develop NB-IoT-based satellite communication standard technology and apply it to the next-generation Exynos modem.

Since the first publication of the standard in Rel-17, performance improvements are underway to combine TN-NTN with minimal modifications to the terrestrial network standard in Rel-18.

Satellite IMT-2020 must be developed taking into account differences in standards development from terrestrial systems. For example, the definition of eMBB-s with an s added to eMBB, which is a feature of TN, indicates that the service and technology itself are different.

Satellite IMT-2020 completed the development of a report on vision, requirements, and evaluation guidelines in September last year. Key participants include Qualcomm, Ericsson, Apple, and Samsung.

■ '6G Satellite Communication' 3D Hyper-Space Stereoscopic Communication

3GPP NTN standardization work for 5G satellite communications is evolving into 6G NTN.

6G satellite communications are expected to expand to a scale of over 200 trillion won by 2028. 6G will implement a 3D ubiquitous network by combining TN and NTN into one.

Global low-orbit satellite communications operators SpaceX and OneWeb plan to provide regional services to ensure full global service coverage.

Starlink is available in 45 countries around the world and is emerging with the characteristics of being faster than other satellite internet services and providing unlimited data. OneWeb will run services worldwide, including Korea, in the fourth quarter of 2023. In Korea, KT SAT is building an edge cloud and using the satellite itself as a backhaul.

LG Electronics Managing Director Yoon Young-woo said, "6G will be a network composed of nodes distributed in various layers in 3D by integrating TN and NTN, and will implement service coverage that can be accessed anywhere by combining terrestrial and satellite networks."