A surge in mobile-data demand worldwide has more and more people asking when they’ll get that speedy next-generation 5G mobile service. Companies are wondering, too, since 5G has the potential to revolutionize everything from self-driving cars to robotic surgery. Mobile providers are racing to patent technologies that will form the industry standards and build working networks. Yet not all nations are embracing the push with equal vigor. And concerns about China’s ability to use 5G equipment to spy on other nations may limit its manufacturers’ ability to profit from the world’s next mobile upgrade.