KT Corporation, originally known as Korea Telecom, is a South Korean telecommunications company established in 1981. The company, once entirely state-owned, was the first of its kind in South Korea and has been instrumental in the development of the nation's information technology sector. The National Pension Service of South Korea is currently the largest shareholder, holding 12.19% of shares, but it has no managerial control over the company. In 1994, KT divested its wireless affiliate, Korea Mobile Telecom, but reentered the wireless market in 1997 with the establishment of PCS carrier KTF. A decade later in 2009, KTF merged with KT, solidifying the company's footprint in both landline and cellular services. Despite this merger, KT maintains a balanced shareholder structure with no controlling shareholder.
Alias
KT Corporation, Korea Telecom
Country
South Korea
Type
Mobile Network Operator
KT Korea Telecom logo

3G Network

The company began its 2G GSM services in 1996 over the 1800 MHz band, and launched 3G UMTS over B1 (2100 MHz) in June 2006. 3G services were upgraded to HSPA+ in January 2012.

Network Frequency Band Status
B1 (2100 MHz)
Active
Date Event Subtype
Launch of 3G Network
Launch

4G Network

4G LTE was first launched under the Olleh LTE (올레 엘티이) banner in January 2012 following the refarming and deactivation of 1800 MHz 2G GSM services. VoLTE was implemented later in October 2012 to improve voice capacity. By September 2013 LTE bandwidth was extended to 20 MHz, permitting data rates up to 150 Mbps following the company securing additional spectrum in an August 2013 auction. Shortly after, KT introduced a B8 (900 MHz) carrier, implementing LTE-A 2C aggregation (CA_3A-8A) to provide higher peak data rates.

LTE-A was extended further in January 2015 with the addition of 10 MHz B1 (2100 MHz), providing 3C aggregation (300 Mbps peak data rates). In June 2015 announced its intention to deploy a "GIGA-LTE" network, comprising 3C aggregation and LTE-U LAA to provide peak data rates of 1.17 Gbps.

The company was an early adopter of the NB-IoT standard, demonstrating the technology in September 2016. The network was activated in April 2017, with national coverage achieved by July that year. The network, shared with LG U+, is understood to be using KT's B3 (1800 MHz) carrier. KT also provides an LTE-M network over its B3 (1800 MHz) network.

 

4G Frequency Bands
Network Frequency Band Max. Channel Bandwidth Status
B1 (2100 MHz)
10
Active
B3 (1800 MHz)
20
Active
B8 (900 MHz)
10
Active
Date Event Subtype
Launch of 4G Network
Launch

5G Network

KT became an early leader in the development of 5G NR, announcing its development in March 2015 and releasing draft specifications of the technology in mid-2016. By October 2016 the company had made its first data call over 5G. February 2017 saw a full end-to-end service completed, and October 2017 network handoff had been implemented.

KT showed the world’s first successful “5G network demo-service” at the PyeongChand 2018 Winter Olympic Games. The network implemented 252 sites outfitted with TDD n257 (28 GHz), Massive MIMO, hybrid-beamforming, and using intra-band 8CA of 100 MHz carriers (n257M).

South Korea held a 5G spectrum auction in March 2018, offering 300 MHz in the 3.5 GHz band, and 1 GHz in the 28 GHz mmWave band. KT secured 3500 to 3600 MHz, and the 26.5 to 27.3 GHz blocks.

Live network testing has been conducted in partnership with Samsung, most notably in March 2019 when KT achieved 1 Gbps over its n78 (3500 MHz) 5G network with a Samsung Galaxy S10. KT launched its 5G mobile network alongside competitors in April 2019, using a 100 MHz carrier in the n78 (3500 MHz) band.

The company completed implementation of its Standalone (SA) network in July 2021.

Network Frequency Band Max. Channel Bandwidth Status
n78 (3500 MHz)
100
Active
n257 (28 GHz)
400
Partial Use
Date Event Subtype
Launch of 5G Network
Launch