As one of the fastest growing technologies in our culture today, data communications and networking presents a unique challenge for instructors. As both the number and types of students are increasing, it is essential to have a textbook that provides coverage of the latest advances, while presenting the material in a way that is accessible to students with little or no background in the field. Using a bottom-up approach,
Data communications and networking are changing the way we do business and the way
we live. Business decisions have to be made ever more quickly, and the decision makers
require immediate access to accurate information. Why wait a week for that report
from Germany to arrive by mail when it could appear almost instantaneously through
computer networks? Businesses today rely on computer networks and internetworks.
(BQ) Data Communications and Computer Networks: A Business User's Approach will give you the thorough understanding you need of basic features, operations, and limitations of ifferent types of computer networks. This book offers full coverage of wireless technologies, industry convergence, compression techniques, network security, LAN technologies, VoIP, and error detection and correction.
Data Communications and Networking, 3/e provides a comprehensive and current introduction to networking technologies. The book is accessible to students from all backgrounds and uses hundreds of figures to visually represent concepts. The new edition has been completely updated to reflect the constantly changing world of network technologies. Enhanced coverage of bluetooth, wireless, satellites, as well as four new chapters on security have been added. The third edition has transitioned from using the 7-layer OSI model to the 5-layer Internet Model.
This chapter addresses four issues: data communications, networks, the internet, and protocols and standards. First we give a broad definition of data communications. Then we define networks as a highway on which data can travel. The internet is discussed as a good example of an internetwork. Finally, we discuss different types of protocols, the difference between protocols and standards, and the organizations that set those standards.
The two dominant networking models are the Open Systems Interconnection (OSI) and the Internet model (TCP/IP).The first is a theoretical framework; the second is the actual model used in today's data communications. In Chapter 2, we first discuss the OSI model to give a general background. We then concentrate on the Internet model, which is the foundation for the rest of the lecture.
One of the major functions of the physical layer is to move data in the form of electromagnetic signals across a transmission medium. Whether you are collecting numerical statistics from another computer, sending animated pictures from a design workstation, or causing a bell to ring at a distant control center, you are working with the transmission of data across network connections. Chapter 3 discusses the relationship between data, which are created by a device, and electromagnetic signals, which are transmitted over a medium.
A computer network is designed to send information from one point to another. This information needs to be converted to either a digital signal or an analog signal for transmission. In this chapter, we discuss the first choice, conversion to digital signals.
Converting digital data to a bandpass analog signal.is traditionally called digitalto-analog conversion. Converting a low-pass analog signal to a bandpass analog signal is traditionally called analog-to-analog conversion. In this chapter, we discuss these two types of conversions.
Chapter 6 - Bandwidth utilization: Multiplexing and spreading. In this chapter we will show how we can use the available bandwidth efficiently. We discuss two separate, but related topics, multiplexing and spreading.
After explaining some ideas about data and signals and how we can use them efficiently, we discuss the characteristics of transmission media, both guided and unguided, in this chapter. Although transmission media operates under the physical layer, they are controlled by the physical layer.
Chapter 9 - Using telephoneand cable networks for data transmission. This chapter shows how the issues discussed in the previous chapters can be used in actual networks. In this chapter, we first discuss the telephone network as designed to carry voice. We then show how it can be used to carry data. Second, we discuss the cable network as a television network. We then show how it can also be used to carry data.
Chapter 10 - Error detection and correction. This chapter discusses error detection and correction. Although the quality of devices and media have been improved during the last decade, we still need to check for errors and correct them in most applications.
Chapter 11 is named data link control, which involves flow and error control. It discusses some protocols that are designed to handle the services required from the data link layer in relation to the network layer.
Chapter 12 is devoted to access control, the duties of the data link layer that are related to the use of the physical layer. The main contents of this chapter include all of the following: Random access, controlled access, channelization.
Chapter 13 introduces you to wired LANs: Ethernet. This chapter introduces wired local area networks. A wired LAN, viewed as a link, is mostly involved in the physical and data link layers. We have devoted the chapter to the discussion of Ethernet and its evolution, a dominant technology today.
This chapter introduces wireless local area networks. The wireless LAN is a growing technology in the Internet. We devote one chapter to this topic. The main contents of this chapter include all of the following: IEEE 802.11, bluetooth.
LANs do not normally operate in isolation. They are connected to one another or to the Internet. To connect LANs, or segments ofLANs, we use connecting devices. Connecting devices can operate in different layers of the Internet model. In this chapter, we discuss only those that operate in the physical and data link layers.
We discussed wireless LANs in chapter 14. Wireless technology is also used in cellular telephony and satellite networks. We discuss the former in this chapter as well as examples of channelization access methods (see Chapter 12). We also briefly discuss satellite networks, a technology that eventually will be linked to cellular telephony to access the Internet directly.
In this chapter, we introduce a wide area network (WAN), SONET, that is used as a transport network to carry loads from other WANs. We first discuss SONET as a protocol, and we then show how SONET networks can be constructed from the standards defined in the protocol.