(Telecompaper) Mobile data roaming will bring in USD 50 billion in revenues by 2019, contributing as much as 56 percent to global roaming revenues, according to new research by Ovum. Europe will account for 46 percent of global roaming revenues this year, boosted by revenue growth coming from the EU. The revenue contribution from Asia is also increasing, particularly from Central & Southern Asia, which is expected to grow at a compound average growth rate (CAGR) of 12 percent by 2019. Mobile data will experience the fastest revenue growth over the next five years, and is expected to drive growth of roaming revenues as voice revenues begin to stagnate. The increasing penetration of smartphones and Sim-enabled tablets, along with the deployment of LTE networks, is driving the growth of mobile data usage. The report noted that roaming growth was still impeded by the cost of roaming services and the legacy of "bill shock".