China Wireless Technologies, a leading maker of cellphones, is to step up development of media tablets and produce more low-cost 3G handsets after posting hefty gains last year. The Shenzhen-based company said yesterday its net profit last year doubled to HK$480.27 million from HK$240.01 million in 2009, mainly because of strong sales of its Coolpad smart phones and accessories. Sales of Coolpad phones, including 2G models, rose 132.3 per cent to 5.04 million units, while revenue grew 76.3 per cent to HK$4.59 billion.