Fourth generation (4G) smartphones are gaining a foothold in Thailand's mobile handset market, as evidenced by a strong increase in unit sales in the first quarter. 4G mobile phones accounted for a 17%market share of the total 4.3 million units of first-quarter handset sales, said Prisana Ratanasuwanasri, senior vice-president for postpaid operations at Total Access Communication (DTAC). Of the 4.3 million units sold, 76.5% were smartphones.