
The HSDPA standard allows W-CDMA mobile phones to transfer data at rates above 10Mbps. In normal use, data rates of 1Mbps to 3.5Mbps are common.
HSDPA is among the mobile technologies sometimes classed as 3.5G because they enable features not found in traditional 3G phones.
Korea's new HSDPA phones offer features like high-speed web surfing and video calls.
KTF, the country's leading HSDPA mobile provider, has more than one million subscribers, or 71 per cent of the market, according to research firm Ovum. The operator expects to exceed 1.8 million users by the end of the year.
However, the company's initial advantage has come in part from its early rollout of HSDPA support on its mobile network.
"It is likely that KTF's early dominance in next-generation subscriber acquisition will be eroded," said Ovum senior analyst Suran Seong.
"To capitalise on its first-mover advantage, KTF needs to clearly differentiate its products to reduce the chance of customer churn.
"It must also enhance its distribution channels to quickly expand its subscriber base, translating its first-mover advantage into economies of scale. "
KTF has used new low-priced handsets as a way to promote HSDPA use. The handsets do not support full wireless internet services, but rely on HSDPA mainly for video calling.