This book discusses the architecture of future wireless networks, reliable communications between different nodes, and energy-efficient resource allocations for achieving sustainable wireless communications. To meet the increasing demands of wireless communication networks and achieve sustainable wireless communications, various promising technologies in this book have been investigated and developed. This book is to present cutting-edge research results on achieving sustainable wireless communications. In particular, the sustainable ultra-dense heterogeneous networks and the sustainability issues of non-orthogonal multiple access are investigated, the performances of cooperative networks with space-time network coding under different scenarios are evaluated, the dynamic estimation for a unified laser telemetry, tracking, and command system is discussed, and the energy-efficient resource allocation schemes are developed for future wireless communication networks. Webelieve that the results in this book can provide useful insights for the design of future wireless communication networks and achieving sustainable wireless communications. Graduate students, researchers, and engineers in the field of wireless communications can benefit from the book.