Nokia's smartphone with android OS Nokia XL (L), Nokia X (C) and Nokia X+ are displayed at the Mobile World Congress (MWC) in Barcelona, Spain, on Feb. 24, 2014. The MWC kicked off Monday in the city of Barcelona with the presence of 75,000 delegates from 200 countries and regions as well as 1,800 companies from the mobile telecommunications sector. (Xinhua/Xie Haining)