  The recent upsurge of diversified mobile applications, especially those
supported by Artificial Intelligence (AI), is spurring heated discussions on
the future evolution of wireless communications. While 5G is being deployed
around the world, efforts from industry and academia have started to look
beyond 5G and conceptualize 6G. We envision 6G to undergo an unprecedented
transformation that will make it substantially different from the previous
generations of wireless cellular systems. In particular, 6G will go beyond
mobile Internet and will be required to support ubiquitous AI services from the
core to the end devices of the network. Meanwhile, AI will play a critical role
in designing and optimizing 6G architectures, protocols, and operations. In
this article, we discuss potential technologies for 6G to enable mobile AI
applications, as well as AI-enabled methodologies for 6G network design and
optimization. Key trends in the evolution to 6G will also be discussed.
