While the 5th Generation (5G) system is being widely deployed across the globe, the research and consensus building for the 6th generation (6G) are already well underway with high expectations toward the merger of digital, physical and human worlds. The main goal of this book is to introduce the upcoming 6G technologies and outline the foreseen challenges, enablers, and architectural design trends that will be instrumental in realizing a Sustainable and Trustworthy 6G system in the coming years. The envisioned 6G system promises to offer a more advanced and comprehensive user experience...