Given that Samsung swallowed its pride, and strapped a Snapdragon 800 onto a Galaxy S4 to create the Galaxy S4 LTE-A; being one of the first smartphone makers to take advantage of Korea's new LTE-Advanced network is a high-stakes game. Apple is interested in creating a variant of its next-generation smartphone, the iPhone 5S (working title), which can take advantage of LTE-Advanced. Since no other country has an LTE-Advanced network to speak of, this variant could be a Korea-exclusive for some time.
Apple is reportedly in talks with SK Telecom, which is piloting an LTE-Advanced network, and has Samsung's Galaxy S4 LTE-A onboard; as well as other Korean carriers with LTE-Advanced networks under development, to launch the variant.
Given that Apple largely designs its own SoCs, the company is talking to Qualcomm to supply an LTE-Advanced soft-modem chip, rather than a full-fledged SoC. This chip would work in tandem with Apple's next-generation A7 chip.
An LTE-Advanced network gives devices Internet bandwidths as high as 150 Mbps, along with carrier aggregation.