SK Telecom has launched commercial five-band Carrier Aggregation (CA) and 4X4 MIMO, which are key technologies of LTE-A Pro. Five-band CA is a core LTE-A Pro technology that enhances data transmission speed and performance by aggregating five component carriers. 

According to SK Telecom it’s five-band CA LTE-A Pro service supports up to 700Mbps data rates, enabling users to download an HD movie (2GB) within 23 seconds. The five-band CA LTE-A Pro service currently covers 53 cities in Korea, including Seoul, Busan and Daegu. SK Telecom's bandwidth resources as of February 2017 are: 10MHz bandwidth in the 800MHz band, 20MHz bandwidth in the 1.8GHz band, 10MHz bandwidth in the 2.1GHz band, 10MHz + 20 MHz bandwidths in the 2.6Ghz band.

Moreover, the company has also launched the 900Mbps LTE-A Pro service by combining three-band/ four-band CA and 4X4 MIMO. The 900Mbps LTE-A Pro service currently covers main areas of six major cities namely Seoul, Busan, Daegu, Gwangju, Daejeon and Ulsan.

Samsung Galaxy S8 users will be able to get these LTE-A Pro services via an over-the-air firmware upgrade. The company projects that the to-be-launched premium smartphones will support LTE-A Pro services.

Going forward, SK Telecom plans to aggressively expand the coverage of its LTE-A Pro services: It expects that the five-band CA LTE-A Pro service and 900Mbps LTE-A Pro service, when combined, will cover more than 50 percent of the Korean population by the end of this year.

By combining five-band CA or four-band CA with other key LTE-A Pro technologies like 4X4 MIMO, SK Telecom plans to launch 1 Gbps LTE-A Pro service in the first half of 2018. To this end, the company is applying key LTE-A Pro technologies, including five-band CA, 4X4 MIMO, and 256 QAM, to its base stations nationwide.