Vietnam 's oldest mobile operator MobiFone has said it has increased its network capacity by 50 percent in order to meet the rising demand of data-based services. The upgrade, mainly of core transmission lines, wireless GSM network (System for Mobile Communications) and 3G (Third Generation network), focused o­n the central and southern regions, the company said. "While the higher capacity of core transmission will help us serve the rising number of subscribers, an upgraded wireless network and data bandwidth will better serve our Smartphone users" said MobiFone's deputy director Nguyen Dang Nguyen. MobiFone said the upgrade is technically backed by international network solutions firm Nokia Siemens Networks. According to Tanat Techatanabaht, general director of Nokia Siemens Networks Vietnam, the project will help MobiFone solidify its position in the fiercely competitive market while raising the company's revenue from the value added services. MobiFone, a subsidiary of Vietnam 's largest telecom service provider Vietnam Post and Telecommunication Group (VNPT), currently accounts for some 29 percent of the country's total 120 million mobile subscribers. New mobile subscriptions in Vietnam have skyrocketed in recent years with 19 million in 2006, 25 million in 2007, 74 million in 2008, 98 million in 2009 and 120 million in 2012.