This book gathers key advances in various areas related to using wireless Internet and wireless connectivity to achieve a more connected world. The world is now highly dependent on Internet connectivity. Even though some parts of the globe remain isolated, the smoothly running world all around us relies on Internet services for countless businesses and activities. During the COVID-19 pandemic, we have seen that exclusively relying on wired Internet would leave out a large part of our tech-savvy world. Hence, wireless connectivity is essential to anywhere, anytime connectivity. Further, in the event of a new pandemic or other disaster of global scale, wireless Internet offers a reliable way to keep us all connected.  The contributors to this book, hailing from academia, industrial and research laboratories, report on the latest solutions, trends and technologies with the potential to make wireless Internet more reliable and secure for the years to come.