KT claimed it was the first in South Korea to reach terabit transmission rates in pilot tests on its backbone network, aiming to achieve similar speeds on medium- and long-distance segments of its commercial infrastructure in the first half of 2025.

In statement, the operator confirmed data was stably transmitted and received at a speed of 1.2Tb/s on the long-distance section (530km) between Seoul and Busan, and 1.6Tb/s on the medium-distance section (110km) between Seoul and Cheonan.

KT noted it used advanced technologies to support large-capacity transmission on its backbone network during the demonstration, including coherent technology and the flex-grid wavelength transmission method.

Once the backbone is upgraded, the data transmission rate between metropolitan data centres is forecast to rise by about 2.6-times and the nationwide network by about two-times.

Director of network strategy Kwon Hye-jin added the company plans to continue to invest in network advancements to “proactively respond to the increasing demand for large-capacity traffic in the AI ​​era”.