SK Telecom (SKT), the largest mobile operator in South Korea, launched an LTE-Advanced Pro (LTE-A Pro) service using five-band carrier aggregation (CA) to deliver peak download speeds of 700Mb/s in 53 cities across the country.

Its LTE-A Pro network, which also uses 4×4 multiple-input multiple-output (MIMO) technology, enables users to download an HD movie (2GB) within 23 seconds, it said in a statement.

The operator also said it rolled out an LTE-A Pro network combining three-band and four-band CA to achieve peak downlink rates of 900Mb/s in parts of six cities.

It expects to combine the five-band CA service and the 900Mb/s LTE-A Pro service to reach 50 per cent of the Korean population by end-2017.

Only the Samsung Galaxy S8 is compatible with SKT’s LTE-A Pro service, and even then requires an over-the-air firmware upgrade. However, the operator said it expects new premium smartphones to be compatible with the technology.

Choi Seung-won, SVP and head of infrastructure strategy at SKT, said it plans to launch 1Gb/s LTE-A Pro service in the first half of 2018: “The LTE-A Pro services represent an early application of 5G technologies that support Gb/s-level data speeds and massive network capacity,” he said.

SKT’s bandwidth resources comprise 10MHz in the 800MHz band, 20MHz in the 1.8GHz band, 10MHz in the 2.1GHz band, and 10MHz + 20MHz in the 2.6GHz band.