This book discusses various emerging concepts/technologies/ architectures in the domain of next generation SatComs and integrated satellite-terrestrial systems. The chapters included in this book are presented in the logical sequence of 5G SatCom scenarios and services/networking (Chapters 1-4), channel and propagation aspects (Chapters 5 and 6), physical-and system-level techniques (Chapters 7-10), optical technology-based satellite systems (Chapters 11-12), onboard processing (OBP) systems and techniques (Chapters 13 and 14), advanced collision/interference mitigation, spectrum sharing and latency reduction techniques (Chapters 15-18).