Suppliers focusing on 2.5G technology performed best in the digital baseband semiconductor market during the first quarter of the year, according to figures from iSuppli. Global revenue from sales of 2.5G baseband chips rose 4.2 percent sequentially, while 3G baseband revenue slid 3.4 percent, the research firm said. Leading baseband supplier Qualcomm suffered from a slump in 3G chip sales, with its baseband revenue down 4.5 percent. However, iSuppli expects 3G to regain its momentum later in the year as sales in developed areas increase.