But mobile phone operators face “saturation point” across the world – forcing them to develop new services and business models, according to research. An extra ONE BILLION people will become mobile subscribers over the next five years, bringing the total to 5.6 billion – equivalent to 72 per cent of the expected global population by this point. It comes after rapid growth of 1.4 billion new subscribers between 2010 and 2015, with 4.7 billion unique mobile subscribers worldwide at the end of 2015 – 63…