  While the fifth generation (5G) is bringing an innovative fabric of
breakthrough technologies, enabling smart factories, cities, and
Internet-of-Things (IoT), the unprecedented strain on communication networks
put by these applications, in terms of highly cognitive, agile architectures
and the support of massive connectivity, energy efficiency, and extreme
ultralow latency, is pushing 5G to their limits. As such, the focus of academic
and industrial efforts has shifted toward beyond 5G (B5G) and the
conceptualization of sixth generation (6G) systems. This article discusses four
main digital and societal use cases (UCs) that will drive the need to reconcile
a new breed of network requirements. Based on this, we provide our vision of
the fundamental architectural ingredients that will enable the promise of 6G
networks of bringing the unification of experiences across the digital,
physical, and human worlds. We outline key disruptive technological paradigms
that will support 6G materialize a bouquet of unique expectations and redefine
how we live and protect our planet. Finally, we adopt the recently envisaged
ecosystem of the Internet-of-Musical Things (IoMusT) to depict how the
discussed UCs and technological paradigms may be exploited to realize this
ecosystem.
