A new battle for cellular airwaves is under way as governments around the world start to auction off spectrum for mobile coverage that could power near-instant video downloads and help run factories, control gadgets and navigate driverless cars.
Countries have long sold airwave rights for cellular service within their borders but places like Britain and Spain this year held their first major auctions for radio frequencies needed to make so-called 5G cellular networks, which could be much faster than today’s mobile networks,...