(Telecompaper) Thai mobile operator DTAC's total revenues for the first quarter increased by 1.9 percent to THB 22.8 billion, mainly boosted by handset sales and mobile data revenue growth, offset by a decline in voice revenue, the company said. Service revenue decreased 3.6 percent year-on-year to THB 16.7 billion. Handset and starter kit sales rose by 35 percent year-on-year, while voice revenue amounted to THB 7.7 billion, which represents a decrease of 18 percent in the period. Data revenue reached THB 7.4 billion, increasing by 13 percent from the first quarter of 2014.