Edge computing provides a powerful way to rapidly analyze data and process tasks at the edge of the network, closer to the end-user. Edge AI extends edge computing to enable AI on edge devices to make instantaneous intelligent decisions. In this talk, I will describe the vision of future Edge AI, called Ubiquitous AI, empowered by collaborative edge computing (CEC), which is a new-generation scalable edge computing infrastructure. With the computing power shared by collaborative edge nodes, edge AI models can be trained and seamlessly deployed jointly by the edge nodes that can be geographically distributed across a wide area. I will highlight the architecture and framework of CEC and how it enables ubiquitous AI demanded by advanced smart city applications like autonomous driving, industry 4.0 and metaverse.