Samsung Electronics will sell a faster version of its flagship Galaxy S4 smartphone that will support the LTE Advanced (LTE-A), the next generation of superfast mobile data, although is is not sure mobile carriers will be able to support it. J.K. Shin, head of Samsung mobile business, said on Monday said the phone would be sold in South Korea as early as this month, according to ta Reuters report.

LTE-Advanced 4G technology is an upgrade from 4G LTE. LTE-Advanced offers data transmission at up to twice the normal 4G speed. The phones will be powered by Qualcomm chips.

LTE-A has has theoretical peak rates of around 3Gbps download and 1.5Gbps upload, but real-world networks will be far slower. Russian carriers Yota has already launched LTE-A.

In the U.S., AT&T plans to begin offering LTE Advanced in the second half of this year, and Verizon plans to add LTE-A to its network through a small-cell AWS network soon. T-Mobile has not yet unveilled an LTE-A plan.

In China, China Mobile, China Unicom and China Telecom all plan to spend high amounts this year on network upgrades.

The S4 sold 10 million sets in just one month of its debut in late April, outperforming its predecessor, the S3.