If you're looking for hot 4G LTE action, look no further than the South Korean peninsula.

SK Telecom (Nasdaq: SKM), which already boasts more than 12 million LTE users and a small but growing base of LTE-Advanced subscribers, has been utilizing carrier aggregation techniques to push the maximum downlink speed of its LTE-Advanced service to 225 Mbit/s, a 50% gain on the maximum speed of regular LTE. (See SK Telecom Demos 225Mbit/s LTE-Advanced and SKT's LTE-Advanced Subs Growing Fast.)

The operator says it aggregated 20MHz of capacity in the 1.8GHz band and 10MHz of capacity in the 800MHz band for a demonstration in the South Korean capital of Seoul. A commercial service offering is expected in the second half of 2014, as the smartphone chipsets required to support such a high-speed service are still being developed.

According to SK Telecom, an 800MB video file could be downloaded in just 28 seconds if a connection of 225 Mbit/s was achieved: The same download, over maximum speeds, would take 7 minutes and 24 seconds over 3G, 1 minute and 25 seconds over regular LTE, and 43 seconds across a current LTE-Advanced connection.

And that's not the end of the journey. Not content with aggregating two carriers, SK Telecom is now working towards aggregating three chunks of capacity in different bands to achieve maximum downlink speeds of 300 Mbit/s over a mobile broadband connection.

For more on SK Telecom and LTE-Advanced developments:

— Ray Le Maistre, Editor-in-Chief, Light Reading