By Stefan Nicola and Joe Mayes Mobile World Congress, the wireless industry's biggest conference, begins next week in Barcelona, where more than 100,000 people are set to see the latest smartphones, artificial intelligence devices and autonomous drones exhibited by roughly 2,300 companies. The event is also the industry's largest networking opportunity for executives, bankers, analysts and the like to talk shop -- and potential deals. Here are the big themes likely to dominate the event: Samsung to Sony in device battle MWC has long been a venue for companies to show off their latest mobile devices and vie for consumer attention. This year, Samsung is back to unveil its latest flagship phone, widely expected to be the Galaxy S9. Sony created buzz when it posted a video on Twitter last Sunday for what looks like it could be a new Xperia device with curves, and gadget blogs such as Wired have speculated whether foldable phones will make their debut this year.