LG Uplus said on the 16th that it has completed building a railway integrated wireless network (LTE-R) across all sections of Seoul Subway Line 9.
LG Uplus, together with Seoul Metro Line9 and the Seoul Metro Line 9 operating institutional sector, began the LTE-R buildout in 2023. Following phase one (Gaehwa–Sinnonhyeon, 27 km, 25 stations), phases two and three (Eonju–Veterans Medical Center, 13 stations) were completed, connecting about 40 km across a total of 38 stations into a single communications network.
LTE-R is a next-generation wireless network designed for railway operations. It allows real-time exchange of voice, video, and operating data among train drivers, the integrated control center, and the safety management office. Compared with legacy communication technologies (TRS, VHF), it offers higher transmission speed and stability. With LTE-R, drivers can check platform conditions in advance from about 400 meters before a train enters a station. The integrated control center can monitor the operating status of multiple trains simultaneously and issue instructions.
More than 700,000 people use Line 9 daily on average. LG Uplus said, "With the LTE-R buildout, the speed of emergency response and the safety of operations are expected to be further strengthened," adding, "As the entire line has been consolidated into a single wireless network, communications quality and maintenance efficiency have also improved."
LG Uplus previously worked with Seoul Metro to complete LTE-R buildouts on multiple lines, including Seoul Subway Lines 1, 2, 3, 4, 5, 7, and 8; the Sillim Line light rail; and the Seohae Line (Sosa–Wonsi Line). On Seoul Subway Line 9, the company applied, for the first time in Korea, the "bidirectional radio access network (RAN) between LTE-Rs" technology to secure stable communications quality. The company said it fundamentally resolved radio interference issues in transfer sections by applying this technology. In particular, in the Gimpo Airport Station section, mutual base station sharing improved network operation efficiency. LG Uplus expects this to expand to resolve radio interference issues across LTE-R sections of urban railways nationwide.
Im Jang-hyeok, head of the corporate customer group (executive director) at LG Uplus, said, "It is significant that we can enhance the operational safety of Line 9, which serves as citizens' feet, together with the Seoul city government," adding, "We will continue to strengthen the safety of urban railways and public infrastructure based on our accumulated communications technology and operating experience."