The articles in this special section focus on artificial intelligence-driven fog radio access networks. To satisfy the explosively increasing demands of highspeed data applications and access requirements from a massive number of Internet-of-Things (IoT) devices, a paradigm of fog computing-based radio access network (F-RAN) has emerged as a promising evolution path for the fifth generation (5G) radio access networks. By taking full advantage of distributed caching and centralized processing, F-RANs provide great flexibility to satisfy the quality-of-service requirements of various 5G services. With the rapid deployment of 5G communication networks, the application of F-RANs to the envisioned sixth-generation (6G) mobile network has attracted extensive attention from academia, industry, and government agencies. The 6G network progress in enhanced mobile broadband, massive machine-type communications and ultra-reliable and low-latency communications will lead to the fast development of new applications, including augmented reality (AR), virtual reality (VR), holographic communications, vehicle-to-everything (V2X), self-driving cars, massive sensors connective on the ground and several tens of thousands of satellites connective in the sky.