KT has extended smartphone battery life by up to 45%. KT's battery saving technology (hereinafter, C-DRX) is a technology that utilizes the network rather than physical battery capacity.

While connected to LTE data, the smartphone periodically switches its communication functions to low-power mode to reduce battery consumption.

In existing network environments, the system maintained uninterrupted communication between the modem and the base station while the communication was turned on. The C-DRX environment reduces unnecessary battery consumption by turning off communication functions when no transmission or reception is taking place.

When watching real-time video, data is received periodically rather than through continuous communication with the base station, ensuring uninterrupted connectivity while reducing usage. It is a method similar to ISG (Idle Stop & Go) in luxury sedans, which reduces fuel consumption by stopping unnecessary engine operation when the vehicle is stopped.

Looking at the battery consumption comparison graph, the orange line with C-DRX applied is low,
You can see that the unapplied blue color appears high.

KT Marketing Division Head Kang Kuk-hyun answering questions at a press conference themed 'People, Technology'.

KT applied battery-saving technology to its nationwide commercial LTE network on April 1. As a result, KT LTE subscribers can now enjoy extended battery life without the need for a separate device upgrade.

The degree of battery saving varies depending on various variables such as the smartphone model, battery degradation level, wireless environment, and the number of installed apps, but under identical conditions, the effect is clearly evident.


The Korea Information and Communications Technology Association (TTA) conducted a C-DRX test on eight Galaxy S8 and Galaxy 7 Edge devices for three days. The method involved continuously using YouTube videos to record in the same environment. As a result, the maximum usage time of the Galaxy S8 was found to be 10 hours and 36 minutes when C-DRX was not operating, and 14 hours and 24 minutes when it was operating.

The maximum usage time of the Galaxy S7 Edge was 12 hours and 36 minutes when C-DRX was not active and 16 hours and 24 minutes when active. The maximum usage time of the Galaxy S8 increased by 45%.

At a press conference held at KT's Gwanghwamun branch on the 12th, Kim Young-sik, Head of KT Network Research & Technology, explained the nationwide measurement chart and related data regarding the application of C-DRX, repeatedly emphasizing that "KT is the first in Korea to introduce C-DRX technology."

KT Marketing Division Head Kang Kuk-hyun stated, “Although the tangible impact on customers may not be significant, we will realize differentiated customer satisfaction through warm, people-oriented innovative technology.”