**Preface XI**


Preface

cryption to subscribers.

The demand for advance telecommunication services has increased dramatically over the last few years. This has led to technological changes with revolutionized engineering strat‐ egies to optimize network construction and operation. Telecommunication networks inte‐ grate with a wide range of technologies, including optical amplifiers, software architectures for network control and management, abstract algebra required to design error correction codes, and network modeling. This book presents research contributions towards new tech‐ niques, concepts, analysis of the telecom market's evolving trends, and infrastructure to pro‐ vide integrated voice, data, and video communications services that are critical to the

operation and competitiveness of companies, governments, and other organizations.

and the high social significance of the telecommunications industry.

ware development projects from telecom products.

of the signal, which is transmitted to the communication channel.

*Chapter 1* presents the structure and dynamics of the main indicators of the Russian tele‐ communication services market for the growth of telecommunication companies. It takes in‐ to account its strong state protectionism, which is conditioned by the strategic importance

*Chapter 2* describes the design challenges in optimizing a hybrid quantum-classical network and the initial results, based on experimental and numerical analysis, to characterize and evaluate the distribution of secure data to the subscribers using the Quantum-to-the-Home (QTTH) transmission model. The presented results provide a solid base to enhance the exist‐ ing telecommunication infrastructure and modules to deliver end-to-end optical data en‐

*Chapter 3* explores BRACE—a cloud-based, integrated, one-stop center for software reliabil‐ ity modeling, testing, and defect analysis. Each of these is provided as-a-service to develop‐ ment teams. Initial implementation of BRACE includes a software reliability growth modeling algorithm, which provides defect prediction for both early and late stages of the software development cycle. To illustrate and validate the tool and algorithm, the authors also discuss key use cases, including actual defect and outage data from two large-scale soft‐

*Chapter 4* presents a concept of chaos-based physical layer protocol for secure communica‐ tion and hidden data transmission over an open network channel. The protocol is based on spectral keying of chaotic signals generated by nonlinear dynamical systems with delayed feedback. In this technique, the modulating information sequence controls the parameter of nonlinear elements, so that it switches the chaotic modes and changes the spectral structure

*Chapter 5* provides an overview of optical amplifiers. The optical amplifier is an important element in optical communication networks. Tremendous progress has been made recently
