Fundamentals of Optical Networks and Components

Partha Pratim Sahu

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9781000060638
• Edition: 1
• Topic: Informatica
• Subtopic: Reti di computer

This book is intended as an undergraduate/postgraduate level textbook for courses on high-speed optical networks as well as computer networks. Nine chapters cover the basic principles of the technology and different devices for optical networks, as well as processing of integrated waveguide devices of optical networks using different technologies. It provides students, researchers and practicing engineers with an expert guide to the fundamental concepts, issues and state-of-the-art developments in optical networks. It includes examples throughout all the chapters of the book to aid understanding of basic problems and solutions.

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• Presents basics of the optical network devices and discusses latest developments

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• Includes examples and exercises throughout all the chapters of the book to aid understanding of basic problems and solutions for undergraduate and postgraduate students

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• Discusses different optical network node architectures and their components

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• Includes basic theories and latest developments of hardware devices with their fabrication technologies (such as optical switch, wavelength router, wavelength division multiplexer/demultiplexer and add/drop multiplexer), helpful for researchers to initiate research on this field and to develop research problem-solving capability

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• Reviews fiber-optic networks without WDM and single-hop and multi-hop WDM optical networks

P. P. Sahu received his M.Tech. degree from the Indian Institute of Technology Delhi and his Ph.D. degree in engineering from Jadavpur University, India. In 1991, he joined Haryana State Electronics Development Corporation Limited, where he has been engaged in R&D works related to optical fiber components and telecommunication instruments. In 1996, he joined Northeastern Regional Institute of Science and Technology as a faculty member. At present, he is working as a professor in the Department of Electronics and Communication Engineering, Tezpur Central University, India. His field of interest is integrated optic and electronic circuits, wireless and optical communication, clinical instrumentation, green energy, etc. He has received an INSA teacher award (instituted by the highest academic body Indian National Science Academy) for high level of teaching and research. He has published more than 90 papers in peer-reviewed international journals, 60 papers in international conference, and has written five books published by Springer Nature, McGraw-Hill. Dr Sahu is a Fellow of the Optical Society of India, Life Member of Indian Society for Technical Education and Senior Member of the IEEE.

1 Introductory Concept

Due to the skyrocketed increase of internet users and services, high-speed communication is required to to fulfill enormous demand of bandwidth. In this direction, all optical networks with wavelength divisional multiplexing (WDM) technology have become essential to develop such high-speed communication. This book deals with the principles and fabrication of optical network devices such as wavelength router [1–6], WDM [7–11], add/drop multiplexer (ADM) [12–17], photonic switch [18–23], Erbium-doped fiber amplifier (EDFA) [24–26], and EDFA gain equalizer [27–30].

1.1 Basic Communication Model

Before discussing optical networks, one should know the basic communication model. Figure 1.1 shows the general block diagram of a communication system having a source system, destination system and transmission media. The source system has a source device that generates raw signals such as data, voice/video and information, and a transmitter that transforms and encodes raw signals in such a way as to produce electromagnetic signals that can be transmitted through a transmission system, which is a complex network connecting source and destination. The destination system has a receiver that receives signal from a transmission system and converts it into a raw signal, and from the raw signal, the information/message is recovered. In this section, we provide an overview of different communication networks.

FIGURE 1.1 Transport of data under OSI environment.

1.1.1 Local Area Network

Local area network is a communication network that covers a small geographical area (typically a building or a cluster of buildings) and provides a means for information exchange among the devices/nodes attached to it. The communication between different nodes of the network is mainly based on open system interconnection (OSI) model or transport control protocol/internet protocol (TCP/IP).

1.1.1.1 OSI Model

Since the origin of communication, its operation varies from vendor to vendor. So standards are needed to promote interoperability among vendor equipment and to encourage economics of scale. Because of the complexity of communication tasks, no single standard will be sufficient. It is better to form a framework for standardization rather than breaking the operation into manageable parts. In 1977, the International Standard Organization (ISO) had started to establish a subcommittee for developing the architecture of the framework. As a result, OSI has been developed [31,32]. The OSI model is a seven-layer architecture in which each layer performs definite functions, namely physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer.

1. Physical layer: It permits interconnection with different control procedures such as V.24 and V.25 for various physical media.
2. Data link layer: It controls data transmission through the system having high error rate (i.e., an error rate not acceptable for a great majority of applications). It works in the framework of high-level data link control (HDLC). It is just above the physical layer.
3. Network layer: It selects a connection path or provides a rout (where the intermediate nodes may be present) for data transmission from one node to the other.
4. Transport layer: It controls successful transportation of data from the source to the destination node. It provides totality of transmission service and ensures that data are delivered error-free, in sequences with no loss and delicacy.
5. Session layer: It provides synchronization or organization dialog between the source and the destination before data transmission. It does function above the transport layer. It provides a mechanism for recovery and permits backup.
6. Presentation layer: It does general interest functions related to representation and manipulation of structured data just before the application layer. It defines the format of the data to be exchanged between different applications.
7. Application layer: It performs management functions and generally useful mechanisms that support distributed applications.

Figure 1.1 shows how data are transmitted in an OSI architecture with the use of a protocol data unit (PDU). When user A has a message to send to user B, it transfers these data to the application layer, where a header is added to the data making it A-PDU. Then, it is passed to the presentation layer. In the same way, these PDU goes through the layers as per the figure (by using HDLC format) to a data link layer. The data link layer unit, also called as a frame, is then passed to a communication path/link in the network by using a physical link. When the frame is received in the destination node/target node, a reverse process occurs. As the PDU ascends, each layer strips off the outermost header, acts on the protocol information contained therein, and passes the remainder up to the next layer.

1.1.1.2 TCP/IP Protocol

Since 1990, TCP/IP has become more popular than the OSI model because of its simplicity and interoperability over different networks, thus providing different services through its IP layer. In an OSI model, protocols at the same level of hierarchy have certain features in common. In this direction, TCP/IP architecture is better than that of the OSI model. The TCP/IP has five layers [33,34] – physical layer, network access layer, internet layer, transport layer and application layer.

1. Physical layer: It defines the characteristics of transmission medium, signaling rate and encoding scheme.
2. Network access layer: It makes a logical interface between an end system and a subnetwork where a connection path is selected.
3. Internet layer: It does the function of routing data from the source node to the destination host through one or more networks connected by routers.
4. Host-to-host transport layer.
5. Application layer.

Figure 1.2 shows the transport layer through different layers in TCP/IP protocol [34]. When user A has a message to send to user B via different applications, as given in F...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• Acknowledgements
• Author
• Chapter 1 Introductory Concept
• Chapter 2 Different Optical Network Node
• Chapter 3 Devices in Optical Network Node
• Chapter 4 Processing of Integrated Waveguide Devices for Optical Network Using Different Technologies
• Chapter 5 Data Link Control for Optical Network
• Chapter 6 Data Communication Networks Having No Optical Transmission
• Chapter 7 Fiber-Optic Network without WDM
• Chapter 8 Single-Hop and Multihop WDM Optical Networks
• Chapter 9 Optical Access Architecture
• Index