Chap06 Telecommunications and Networks

Management Information Systems, 4th Edition

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Chapter 6

Information Technology in

Business: Telecommunications

and Networks


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Learning Objectives

• Explain why successful managers must be familiar

with telecommunications concepts and

terminology

• Describe the principles of communication within

a computer system and among computers

• Identify the major media and devices used in

telecommunications


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Learning Objectives (Cont.)

• List and explain the functions of different

network layouts and the concept of protocols

• Explain how telecommunications can improve

operations in organizations

• Cite the latest developments in

telecommunications media and transmission speed


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Telecommunications in Business • Transmittal of data from one computer to another

over a distance

• Telecommunications has improved business in three

main ways:

– Better communication

– Higher efficiency

– Better distribution of data


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Telecommunications in Daily Use

• Cellular Phones

• Videoconferences

• Voice Mail

• Facsimile/Fax

• Information Kiosks

• Pay at the Pump


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• Easy Passing

• Web-Based Electronic Commerce

• Worldwide Peer-to-Peer File Sharing

– With directory

– Without directory


(Cont.)


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(Cont.)


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Data Communications

• Any transfer of data within a computer, between a

computer and another device, or between two

computers

• Parallel and Serial Data Communications


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Data Communications (Cont.)


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• Simplex

– One-way in one direction

• Half-Duplex

– One-way in two directions

• Full-Duplex

– Two-way in two directions

Communication Direction


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Communication Direction (Cont.)


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• Parity Check

– Error detection method

– Checks that no bits are added or deleted during

transmission

– Odd Parity Check looks for an odd number of ones

– Even Parity Check looks for even number of ones

Error Detection


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• Communications medium

– Physical medium through which data can be communicated

– Telephone lines, television cables

• Capacity

– Speed at which data are communicated

– Also called the transmission rate

– It is often called “bandwidth”

• Bandwidth is measured in bits per second (bps)

– The greater the capacity, the faster the transmission

Bandwidth and Media


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Bandwidth and Media (Cont.)


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• Bandwidth

– Narrowband is low speed

– Broadband has greater capacity

• Media

– A medium is any means by which data can be

transmitted

Bandwidth and Media (Cont.)


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• A medium’s capacity is determined by the range

of bits per second at which it can operate

• Baud is the number of signals per minute

• Repeater receives and strengthens signals before

sending them on

Transmission speed


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Transmission Speed (Cont.)


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• Telephone line made of a pair

of copper wires twisted to

reduce electromagnetic

interference (EMI)

Twisted Pair


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Coaxial Cable

• Commonly used for cable

television transmission

– More expensive than twisted pair

– Greater transmission rate than

twisted pair

– Much less susceptible to EMI

(Electronic Magnetic Interference )


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• High-frequency, short radio-frequency (RF) waves

– Terrestrial microwave

– Satellite microwave

Microwaves


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Optical Fiber

• Fiber-optic technology uses light instead of

electricity to transmit data


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Characteristics of Media


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Modulation

• Modification of a digital signal into an analog

signal

• Demodulation

– Modification of an analog signal into a digital

signal


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• Analog vs. Digital

– Analog: A continuous series of waves

– Digital: A series of discrete bits

Modulation (Cont.)


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Modulation (Cont.)


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Modulation (Cont.)

• Amplitude Modulation (AM)

• Frequency Modulation (FM)

• Phase Modulation

• Modems

– Devices that modulate and demodulate signals


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Modulation (Cont.)

Figure 6.9 Multiplexing


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Networks

• LANs (Local Area Networks)

– Networks within a building, or within a group of

adjacent buildings

• WANs (Wide Area Networks)

– Networks that cross organizational boundaries or

reach outside the company

• Value-added networks (VANs)

• Wireless communication


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Network Topology

• Physical layout of the nodes in a network

– Star

– Ring

– Bus

– Tree


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Network Topology


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Networking Hardware

• Network Interface Card

• Hub

• Switch

• Bridge (connect different networks)

• Router ("traffic directing" functions on the

Internet)


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Virtual Private Network

• A combination of private and public lines

• A link between a private network and the Internet

• “Virtual” refers to the illusion that the use is

accessing a private network directly

• https://vpn2.stut.edu.tw

https://vpn2.stut.edu.tw/


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Protocols

• Communication protocols

– Rules governing the communication between

computers or between computers and other

computer-related devices

• Network protocols

– Rules governing a network of devices


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Protocols (Cont.)

• LAN Protocols

– Polling

– Contention

– Token passing

• WAN Protocols

– OSI (Open Systems Interconnection)

• Standard protocol model


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Switching Techniques

• Circuit Switching

– Message is communicated in its entirety from the

transmitting computers to the receiving computers

• Packet Switching

– Message is divided into packets of bytes and

transmitted via several nodes

– TCP/IP


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Switching Techniques (Cont.)


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The Changing Business

Environment

• Cellular Phones

• Teleconferencing

• Voice Mail

• Facsimile/Fax

• What else in mobile device?


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A Variety of Services

• Cable

• Digital Subscriber Line (DSL)

• T1 and T3 Lines

• Satellite

• Fixed Wireless

• Gigabit Ethernet

• Optical Carrier


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A Wireless Revolution

• Popular Wireless Technologies

• Would You Like Wi-Fi?

• Combining Technologies


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Wireless Technologies (Cont.)


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Summary

• Telecommunications concepts and terminology

• Communication within a computer system and

among computers

• Telecommunications media and devices

• Network layouts and protocols

• Telecommunications impact on operations

• Telecommunications developments and speed

Chap06 Telecommunications and Networks

Business

Transcript of Chap06 Telecommunications and Networks