With South Korean carriers LG U+ and SK Telecom already on the LTE bandwagon, KT had been the only remaining holdout — until now. The company today officially flipped the switch on its Olleh 4G LTE service, bringing with it launch devices that include Samsung's Galaxy S II LTE and its HD LTE sibling. Tiered data plans are in full effect here, starting at 34,000 Korean won (rough $30 USD). The rollout comes more than a month after initially anticipated, though the carrier maintains its plan to blanket the entire nation in LTE coverage by April, equaling SK Telecom's footprint. Such an ambitious goal doesn't come without sacrifices, which in this case is 2G connectivity. KT obtained final approval from a court last week to shut off its 2G CDMA signal, much to the chagrin of the 1,000-plus customers that filed a class action lawsuit hoping to keep service alive. The freed up 1.8GHz band will now be dedicated entirely to LTE deployment.

This is a big deal for South Korea, as it becomes the first nation with LTE offered by each of its mobile carriers and ubiquitous access to 4G coverage inside its borders. Unfortunately, a massive appetite for data — the country ranks first in overall usage — makes unlimited plans simply unrealistic, according to KT CEO Lee Suk-chae. Still, the company is taking measures to help customers avoid overage fees, which becomes significantly easier to do with 4G speeds. It provides users with a buffer of 20 percent additional data for the first three months, and offers the option of cutting off access upon hitting the tiered ceiling. Finally, KT touts its continued investment in a consistent and reliable network, most recently with the development of Warp, described as a virtual station comprised of 144 cell cites that can dynamically shift resources to account for congestion.