This book constitutes the refereed post-conference proceedings of the 6th International Conference on Future Access Enablers for Ubiquitous and Intelligent Infrastructures, FABULOUS 2022, held in May 2022. Due to COVID-19 pandemic the conference was held virtually. The 18 revised full papers were carefully reviewed and selected from 70 submissions. The papers are organized in thematic sessions on: Future access networks; Internet of Things and smart city/smart environment applications; Information and communications technology; Sustainable communications and computing infrastructures.