STOCKHOLM, June 3 The number of subscriptions for smartphones globally will nearly quadruple by 2018, driving a huge increase in data on mobile networks, Ericsson said the on Monday. Ericsson, the world's biggest supplier of mobile network equipment, said it expected 4.5 billion smartphone subscriptions globally by 2018, up from 1.2 billion in 2012 and higher than the 3.3 billion it forecast at the end of last year.