This book focuses on practical implementation details, telecommunication techniques, security and technology challenges and approaches to implementing quantum technology in modern telecommunication systems. The authors use their extensive practical academic and industrial experience in network technologies and provide details from international projects in quantum cryptography in which they actively participate. Using a variety of examples, analogies, illustrations, tables, and features from practical quantum network realizations, the authors provide a unique view of quantum technology from an engineering telecommunication standpoint, allowing the reader to identify the advantages and challenges of quantum technology. This book also addresses challenges posed by quantum technology such as network organization, passive and active eavesdropping, and future trends in QKD such as Software Defined Networking (SDN) with QKD and application QKD in 5G networks. It is conceived through eight chapters by treating the following thematic units separately: Fundamentals of Quantum Key Distribution, QoS architecture/mode, QoS MAC layer, QoS signaling techniques for key management and session negotiation purpose and QoS routing protocols that minimize the consumption of key material through the equitable utilization of network resources when finding an optimal path. Through numerous information on practical solutions, simulation examples, illustrations, and analysis, readers can easily distinguish the specificity of quantum technology and understand the challenges and methods of practical implementation of quantum cryptography in common telecommunications standards. Researchers working in quantum technology and applied networking security as well as advanced-level students studying computer science and electrical engineering will benefit from this book. Professionals working within these related fields will also benefit from this book.