This book delves into the burgeoning field of space-ground integrated networks (SGINs), focusing on the evolution, architecture and application scenarios of large satellite constellations. As global communication demands surge, the next-generation SGINs are transitioning towards large-scale, hyperscale, and hierarchical constellations to address diverse user needs, such as ultra-long-haul, high-speed and instantaneous communications. Through an in-depth exploration of network working princ...