Understanding data communications (7^th Ed.)

Langue : Anglais

Auteur : HELD Gilbert

Couverture de l’ouvrage Understanding data communications

Résumé
Sommaire

0672322161.ld

Understand the ins and outs of data communications.

Understanding Data Communications, Seventh Edition presents complex data communications concepts clearly and concisely within a tutorial format.
All of the concepts are modern and up-to-date, in sync with the current and future data communication market ranging from wireless communications to communication security.
The award-winning author is internationally recognized for his expertise in the field of communication.

Understanding Data Communications, Seventh Edition is the modern bible of data communications. It covers how data communications systems and their various hardware and software components work. In addition to this, the concepts covered allow the reader to access their current forms of data communication to determine systems best suit their current needs. Covering a vast range of topics from data networking to data communication security, this book focuses on the present and future of data communications. New material from the previous edition includes wireless technologies and security. The author provides a basis for understanding data communications in general, and provides expertise on setting up and securing types of communications systems. Organized like its highly successful 6th edition, this book can be tailored to the needs of both the computer professional and student. It approaches data communications in a tutorial format, challenging the reader with questions following every chapter to assess what has been learned. In addition to this, the author provides additional resources to the computer professional that wants a more in-depth account of specific concepts.

Gilbert Held in an internationally recognized author and lecturer who specializes in the applications of computer and communications technology. He is a frequent lecturer and conducts seminars on topics such as LAN/WAN internetworking, data compression, and PC hardware and software. Held is the author of more than 40 books on computers and communications technology, including the top selling Data Over Wireless Networks (McGraw-Hill Professional Publishing). He has won several awards for his technical excellence in writing.

Introduction.

Who This Book Is For.
This Books Approach to Data Communications.

1. An Overview of Data Communications.

The Importance of Data Communications.
The First Data Communications Systems.

Early Uses of Electricity.
The Telegraph.

Two-State Communications Systems.

Bits and Bytes.
Bytes and Octets.

Early Communications Codes.

Some Definitions.
Baudot Code.

Modern Codes.

A Note on the Standards Organizations.
EBCDIC.
ASCII.
The Escape Character.

Teleprinters.
Data Communications in Computing.

The 1950s.
The 1960s.
The 1970s.
The 1980s.
The 1990s.
Into the New Millennium.

Changes in the Industries.

The Portable Computer.
Communications Industry Revolution.
Emerging Technologies.

General Description of Data Communications Systems.

The Form and Content of Information.
The DTE-DCE Interface.
The Effect of Telecommunications Reform.

What You Have Learned.
Quiz for Chapter 1.

2. Terminal Devices.

Teleprinters.

Communications.
Terminals.

Teleprinters Versus CRT Terminals.
Serial Printers.

Impact Printers.
Nonimpact Printers.

CRT Terminals.

ASCII Terminals.
Non-ASCII Terminals.
Specialized Terminals.

Parts of a Terminal.

Ergonomics.
Keyboards.
Display Considerations.

PC Terminals.

PC Adapter Cards.

The Need for Speed.

Advantages of a PC as a Terminal.
The Ubiquitous Terminal.

Data Transmission.

Serial and Parallel Transmission.
Asynchronous Transmission.
Other Types of Transmission.

What You Have Learned.
Quiz for Chapter 2.

3. Messages and Transmission Channels.

Information as a Quantity.

Information Content of Symbols.
Using Redundancy in Communications.
Using Redundancy for Data Compression.

Bounded Medium.

Wire Pairs.
Coaxial Cable.
Waveguide.
Fiber-Optic Systems.
Building Cabling Standards.

Unbounded Medium.

High-Frequency Radiotelephone.
Microwave Radio.
Satellite Radiolink Systems.
Commercial Satellites.
LEOS Satellites.
Cellular Radio Systems.

Effects of Bandwidth on a Transmission Channel.

Handling Capacity of a Channel.
Intersymbol Interference.

Bandwidth Requirements for Signals.

Analog Signals.
Digital Signals.

Carrier Systems.

Using Frequency.
Using Time.
Using Pulse Code Modulation.

What You Have Learned.
Quiz for Chapter 3.

4. Asynchronous Modems and Interfaces.

Why Data Cant Be Transmitted Directly.
Solving the Problem with Modems.

Telephone Channel Restrictions on Modems.
Modem Interfaces.

Analog Modulation.

Sine Waves.
Low-Speed Modem Frequency Modulation Methods.
Frequency-Shift Keying.

V.21 Standard.

Bell System 212A and V.22 Modems.
V.22bis.

Modem Features.

Data Compression and the V.42bis Standard.
Bit Errors on Compressed Data.
Error Detection and Correction.
The MNP Protocol.
V.42 Recommendation.

Interface and Signaling Standards.

The RS-232 and V.24 Interface.
The Mechanical Interface.
Electrical and Functional Signals.
Subset of Signals.
Examples of RS-232 Connections.
Asynchronous Modem Control.
Nonstandard Use of the RS-232 Standard.
Limitations of RS-232.

Other Interfaces.

An Old Standby: The Current Loop.