"The current terrestrial network consolidates only 14% of Earth's surface with mobile networks. The remaining roughly 85% gap will be filled by a space satellite network based on 6G." (Professor Lee Moon-gyu, School of Electrical, Electronic and Computer Engineering, University of Seoul)
"As a latecomer in satellites, Korea's shortcut to competitiveness is to extend artificial intelligence (AI) services of terrestrial networks to space." (Professor Choi Ji-hwan, Department of Aerospace Engineering, KAIST)
The Korean Academy of Science and Technology (KAST) held the 248th KAST roundtable discussion on the 23rd at The Plaza Hotel in Jung-gu, Seoul, under the theme "Mobile communications in the Starlink era: Korea's response strategy toward the era of satellite–terrestrial network coexistence." With the recent spread of low Earth orbit satellite communication services, including Starlink by SpaceX, the mobile communication environment is shifting to a coexistence system of satellite and terrestrial networks. At the discussion, experts actively debated Korea's response strategy in line with the global shift in communication paradigms.
Professor Lee Moon-gyu of the School of Electrical, Electronic and Computer Engineering at the University of Seoul gave a presentation on "The technological reality of direct-to-cell (a method in which smartphones communicate directly with satellites) and non-terrestrial networks (NTN): what is possible and what is still difficult." He said, "SpaceX's Starlink is putting 15,000 base stations into satellites via a direct-to-cell method, and some are concerned that Starlink could monopolize the global direct-to-cell market," adding, "But that concern is overstated."
He said, "The direct-to-cell method allows for a strategic approach akin to 'roaming,' in which users in areas outside existing networks use the facilities of a satellite operator," adding, "In the end, non-terrestrial networks will play a supplementary role to mobile networks, leading satellite communication operators and terrestrial carriers to maintain a cooperative relationship."
Professor Choi Ji-hwan of the Department of Aerospace Engineering at KAIST presented on "Korea's options: future response plans for satellite–terrestrial network coexistence," saying, "As a latecomer, Korea needs a strategy that leverages external satellite networks. We should focus on extending all core terrestrial technologies—AI, semiconductors, Edge Computing, data centers, and power grids—into space."
Last year in Korea, KT and SK Telink launched services in the B2B (business-to-business) sector, while Starlink Korea began official service for individual users. The United States has completed a space economy model led by the private sector centered on Starlink, and Europe is pursuing a dual-track strategy of building its own satellite networks while using Starlink. In Japan, SoftBank and Starlink serve the B2B sector, while for general individual users, in addition to Starlink, domestic operators Rakuten and NTT are offering direct-to-cell services. China, led by the state, has deployed 13,000 satellites to build space infrastructure to counter the United States.
Kim Seung-jo, emeritus professor in the Department of Aerospace Engineering at Seoul National University, also presented on "The current state of the Starlink system and what comes next," stressing, "For Korea to realize a space economy, existing large industrial sectors must converge with space technologies to create a new, large market."
Kim said, "Satellite communication centered on low Earth orbit will capture the world," adding, "The key is solving power and cooling problems in space, and how to address radiation is crucial." He added, "In the space economy, Korea should respond by leveraging AI technologies."
◇ "In the Starlink era, the game is not 'launch speed' but 'standards and ecosystem'"
In the discussion that followed the presentations, participants weighed the opportunities that low Earth orbit satellite communications will bring and the technological, standards-related, and business hurdles that must be cleared to implement them reliably as commercial services. Experts agreed that the key in the era of satellite–terrestrial network coexistence is not only "who can launch satellites faster," but also securing first-mover advantage in standards, obtaining essential technologies, and building the ecosystem starting with markets and services favorable to Korea.
Professor Shim Byung-hyo of the Department of Electrical and Computer Engineering at Seoul National University noted that satellite communication over distances of several hundred kilometers or more presents clear technical challenges. He said, "Because signals weaken over longer distances (path loss), it is difficult to secure communication quality, and even though radio waves travel at the speed of light, the sheer distance creates latency," adding, "Also, because satellites move quickly, consolidation in a situation where the communication counterpart keeps changing—through seamless handover—is essential." He emphasized that solving this requires simultaneous advances in high-performance antennas and satellite power and antenna design.
In particular, Shim said that as the method of connecting satellites directly to relay data mid-route (inter-satellite links) spreads, satellite-to-satellite routing (technology that determines the optimal path for data), which reduces inefficient detours, becomes more important. He said, "The later you enter, the more critical the network-oriented technological edge becomes," adding, "In the direct-to-cell method, where smartphones communicate directly with satellites, the battery and antenna size limitations of handsets ultimately shift the burden to satellites. Satellite power output and antenna requirements are bound to grow rapidly."
Lee Moon-sik, head of the Satellite Communications Research Division at the Electronics and Telecommunications Research Institute (ETRI), proposed Korea's response direction from the viewpoint that standards equate to competitiveness. Lee said, "As non-terrestrial network (NTN) standardization accelerates around the global mobile communication standards body 3GPP, Korea must secure leadership," adding, "If standard-based capabilities accumulate, the domestic industrial ecosystem can expand globally."
He added, "Future axes of competition include AI-based intelligent satellite communications, services that combine communications with precise positioning, navigation and timing (PNT), and integration of sensing and communications," adding, "If you build systems on standards, satellite sharing and international cooperation between countries and institutions become easier, and export opportunities open up."
From a carrier's perspective, Lee Jong-sik, head of KT's Future Network Research Institute, said, "Although Starlink has moved toward commercialization with satellite internet and direct-to-cell, when you consider real-world speeds, capacity, and price burdens, the immediate impact that could upend the market is limited," adding, "For satellite networks to have a big impact, expense must come down further."
He added, "It is not easy to build an independent satellite network and turn a profit on private demand alone," adding, "We need to find additional revenue sources, such as data centers, add-on functions, and supplementing subsea cables, where expansion burdens are heavy due to rising AI data."