Pulse Code Modulation Techniques


Book Description

Pulse Code Modulation Techniques brings together the theory and practice of PCM at the physical layer, where the "bits meet the silicon", so to speak. The key topics of symbol encoding, detection and synchronization are discussed, in detail, both from a theoretical and a practical standpoint. Topics which have been largely absent in text books, such as multiplexing, formatting and format synchronization, are also considered. Although PCM evolved as a communication technology, it has become an important technology in data recording. In a sense, magnetic or optical media are just specialized communication media and the key technologies discussed in this book are just as important to recording applications as to communications. PCM codes used for magnetic recording applications are discussed along with traditional communication codes. The design, analysis and implementation of a PCM system requires knowledge of very specific techniques associated with detection, synchronization and coding. The techniques have evolved from both ad hoc methods and complex theory. One of the goals of this book is to bridge the gap between theory and practice in the key techniques. Matched filters are not only discussed theoretically, but means for implementing them are also considered. The same is true with symbol synchronization.




Digital Telephony and Network Integration


Book Description

What is "digital telephony"? To the authors, the term digital telephony de notes the technology used to provide a completely digital point-to-point voice communication system from end to end. This implies the use of digital technol ogy from one end instrument through the transmission facilities and switching centers to another end instrument. Digital telephony has become possible only because of the recent and ongoing surge of semiconductor developments allowing microminiaturization and high reliability along with reduced costs. This book deals with both the future and the present. Thus, the first chapter is entitled, "A Network in Transition." As baselines, Chapters 2, 3, and 10 provide the reader with the present status of telephone technology in terms of voice digitization as well as switching principles. The book is an outgrowth of the authors' continuing engineering education course, "Digital Telephony," which they have taught since January, 1980, to attendees from business, industry, government, common carriers, and tele phony equipment manufacturers. These attendees come from a wide variety of educational backgrounds. but generally have the equivalent of at least a bachelor's degree in electrical engineering. The book has been written to provide both the engineering student and the practicing engineer a working knowledge of the principles of present and future voice communication systems based upon the use of the public switched network. Problems or discussion questions have been included at the ends of the chapters to facilitate the book's use as a senior level or first year graduate level course text.



















Digital Transmission Systems: From PCM to OTN


Book Description

Digital transmission systems are the backbone of modern communication networks, enabling the exchange of information across various media, such as copper wires, optical fibers, radio waves, and satellites. These systems use digital signals to encode, transmit, and decode data, such as voice, video, text, and images. Digital transmission systems have many advantages over analog systems, such as higher capacity, better quality, lower cost, and more flexibility. However, designing and implementing digital transmission systems is not a trivial task. It requires a solid understanding of the fundamental principles, techniques, and standards that govern the operation and performance of these systems. It also requires a familiarity with the various technologies and components that are used to realize these systems, such as modulation, multiplexing, coding, switching, amplification, and synchronization. This book aims to provide a comprehensive and up-to-date introduction to the fundamentals of digital transmission systems, covering both theoretical and practical aspects. It is intended for students, engineers, and researchers who want to learn the basics of digital transmission systems, as well as for professionals who want to refresh or update their knowledge in this field. The book is also important for communication engineers and operators who are involved in the planning, design, installation, operation, maintenance, and troubleshooting of digital transmission systems and networks. The book covers the most common and widely used standards and technologies in digital transmission, such as PCM, PDH, SDH, OTN, WDM, ADSL, GPON, and radio waves. The book also provides the latest information on the evolution and trends of digital transmission, such as liquid OTN, fiber-optic transmission systems, and digital transmission networks. The book helps communication engineers and operators to understand the principles, advantages, limitations, and challenges of digital transmission systems and to apply them to their specific needs and scenarios. The book is organized into eight chapters, each covering a major topic in digital transmission systems. The chapters are as follows: Chapter 1 introduces the importance, motivations, and overview of digital transmission systems, and provides a conclusion and some questions for review. Chapter 2 explains the fundamentals of pulse code modulation (PCM), which is the most common technique for converting analog signals into digital signals. It also describes the structure and signaling of the 2 Mbit/s (E1) frame, which is the basic unit of transmission in many digital systems. Chapter 3 discusses the plesiochronous digital hierarchy (PDH), which is a legacy standard for multiplexing and transporting digital signals over copper wires or optical fibers. It also covers the frame structure, synchronization, signaling, error detection and correction, network architecture, and limitations of PDH. Chapter 4 introduces the synchronous digital hierarchy (SDH), which is a more advanced and widely adopted standard for multiplexing and transporting digital signals over optical fibers. It also covers the general and specific frame structures, multiplexing hierarchy, network and management, network protections, and synchronization of SDH. Chapter 5 presents optical fiber technology, which is the main medium for transmitting digital signals over long distances and at high speeds. It also covers the technical overview, physics of light, and design and protection of fiber optic cables. Chapter 6 explores the wavelength division multiplexing (WDM) technology, which is a technique for increasing the capacity and efficiency of optical fiber networks by using multiple wavelengths of light. It also covers the WDM and optical fiber structure, active and passive optical components, optical amplification, noise calculation, fiber-optic transmission systems, and fiber-optic networks. Chapter 7 describes the optical transport network (OTN), which is a standard for multiplexing and transporting various types of digital signals over optical fibers using a common format. It also covers the OTN fundamentals, multiplexing overview, frame structure, evolution to liquid OTN, and important topics in OTN. Chapter 8 reviews the ADSL modems, GPON fundamentals, and radio waves propagations, which are some of the technologies and phenomena that are related to digital transmission systems. The book also includes two appendices that provide some supplementary information on BIP, SDH Synchronization, OTN protection and more. The book assumes that the reader has some basic knowledge of mathematics, physics, and electronics, as well as some familiarity with communication systems and networks. The book provides clear explanations, examples, figures, tables, and equations to illustrate the concepts and methods of digital transmission systems. The book also provides questions at the end of each chapter to test the reader’s understanding and to stimulate further exploration. The book is written by who is a Doctor of Electrical Engineering, Egypt. Ayman Elmassarawy has a PhD in communication systems and has over 20 years of research and practical experience in the field of digital transmission systems in the field of digital transmission systems. The book is a valuable resource for anyone who wants to learn the fundamentals of digital transmission systems and to gain a deeper insight into the current and emerging technologies and standards in this field. The book is also a useful reference for anyone who is involved in the design, implementation, operation, or maintenance of digital transmission systems and networks.




Fundamentals of Digital Transmission Systems


Book Description

Due to the competitions between the telecommunication service providers, the required capacities are increasing all the time. It is important for these providers to develop a network that can transfer more data bytes from one place to another. In addition, the mobile traffic and the internet services need more capacities in the telecommunication networks. Therefore, it is mandatory for the networks to handle large amounts of data in a fast and a reliable way. Of course, one possibility would be Ethernet traffic, but in cellular transmission networks there are a strict requirement for delay, data loss and synchronization and this is why the Ethernet is not yet supported.The Synchronous Digital Hierarchy (SDH) is one answer for increasing the network data traffic. For example, if we need to transfer 63 × 2.048 Mb/s (E1) signals from one place to another a huge amount of wires will be needed, on the other hand the SDH needs only two fibers to do the same operation. Many vendors have a product called STM1 multiplexer and its functionality to add and drop 63 × 2.048 Mbit/s into 155.52 Mbit/s (STM-1). The bit rates of the basic signals in the SDH are derived from the same clock source, which means that the SDH is completely synchronous transmission system. SDH has many different hierarchy levels starting from 155.52 Mbit/s to 10 Gbit/s and the STM-1 with a bit rate of 155.52 Mbit/s is the basic module of the SDH system. The SDH signal is terminated to E1 (2.048 Mbit/s) signals by using terminal multiplexer.Before the SDH multiplexer operates in the telecommunication market, there is a huge amount of work to put the requirements specifications, by studying the reality of the market needs. Many chip manufacturers have SDH chips in their product catalog, so one has to make a decision which manufacturer's chip to use. In addition, one must decide how to handle overhead bytes and how to implement all this in network manager software. After all these decisions, we have a huge amount of data and the last thing to do is to decide which features are implemented and which are not. Because of time-to-market pressures, the implementation has to be phased and the first phase must contain only the necessary functionality and nothing more to reduce the development time to minimum.The Synchronous Digital Hierarchy (SDH) multiplexers form the core part of the backbone telecommunication networks, and the effective design, reliability analysis and training are essential to managing SDH network effectively. Today and shortly, the demands to transfer a tremendous mass of data among the various applications in many fields inside the country become an exclusive responsibility particularly with the significant developments of the clouding policies in the different forms such the data centers and the implementations of many smart applications of the 5G in the various areas of the information technologies. The current design of the core communication network consists of 3 independent zones, the 1'st zone is layer 1 and layer 2 which recognized as the physical layer of the core optical network such Optical Transport Network (OTN), the 2'nd band is layer 3 which viewed as IP core network, and the last zone is the access and the application layers such 4G network. The challenge in the current communication model is no associations among these 3 zones of the communication network to optimize the capacities and the needed resources which are required to carry the data among any of them. Now the optical transport network (OTN) represents the critical point of carrying a tremendous amount of data for the mobile network such 4G between the different sites.