Information system ralph CH04

Fundamentals of Information
Systems, Fifth Edition
Chapter 4
Telecommunications, the Internet,
Intranets, and Extranets


Principles and Learning Objectives
• A telecommunications system has many
fundamental components that must be carefully
selected and work together effectively to enable
people to meet personal and organization
objectives
– Identify and describe the fundamental components
of a telecommunications system including media and
hardware devices

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Principles and Learning Objectives
(continued)
– Identify several network types and describe the uses
and limitations of each
– Name three basic processing alternatives for
organizations that require two or more computer
systems and discuss their fundamental features

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Principles and Learning Objectives
(continued)
• The Internet and the Web provide a wide range of
services, some of which are effective and practical for
use today, others are still evolving, and still others will
fade away from lack of use
– Briefly describe how the Internet works, including
alternatives for connecting to it and the role of Internet
service providers
– Describe how the World Wide Web works and the use
of Web browsers, search engines, and other Web tools
– Identify and briefly describe several applications
associated with the Internet and the Web
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Principles and Learning Objectives
(continued)
• Because use of the Internet and World Wide Web
is becoming universal in the business environment,
management, service and speed, privacy, and
security issues must continually be addressed and
resolved
– Outline a process and identify tools used to create

Web content
– Define the terms intranet and extranet and discuss
how organizations are using them
– Identify several issues associated with the use of
networks
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An Overview of Telecommunications
• Telecommunications
– The electronic transmission of signals for
communications

• Telecommunications medium
– Any material substance that carries an electronic
signal to support communications between a
sending and receiving device

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Channel Bandwidth
• The rate at which data is exchanged
• Broadband communications
– A telecommunications system that can exchange
data very quickly

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Communications Media
• Guided transmission media types
– Many utilities, cities, and organizations are
experimenting with broadband over power lines
(BPL)

• Wireless technologies
– Broadcast of communications in one of three
frequency ranges: microwave, radio, and infrared
– Near Field Communication (NFC)
– Bluetooth
– Ultra wideband (UWB)
– Wi-Fi
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Telecommunications Hardware
• Devices include:
– Modems, multiplexers, PBXs and front-end
processors that enable electronic communications to
occur or occur more efficiently

• Switches, bridges, routers and gateways
– Devices for sending packets of data through one or
more networks

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Services

• Digital subscriber line (DSL)
– Telecommunications service that delivers high-speed
Internet access to homes and small businesses over
the existing phone lines

• Asymmetric DSL (ADSL) line
– Does not require an additional phone line and yet
provides “always-on” Internet access

• Voice over Internet Protocol (VoIP)
– Enables voice conversations to be converted into
packets of data that can be sent over a data network
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Networks and Distributed Processing
• Computer network
– Communications media, devices, and software
needed to connect two or more computer systems
and/or devices

• Network nodes
– Computers and devices on the networks

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Network Types
• Personal area network (PAN)
– Wireless network that connects information technology
devices within a range of 33 feet or so

• Local area network (LAN)
– Connects computer systems and devices within a small
area, such as an office

• Metropolitan area network (MAN)
– Connects users and their computers in a geographical
area

• Wide area network (WAN)

– Connects large geographic regions
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Distributed Processing
• Centralized processing
– All processing occurs in a single location or facility

• Decentralized processing
– Processing devices are placed at various remote
locations

• Distributed processing
– Computers are placed at remote locations but
connected to each other via a network

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Client/Server Systems
• Multiple computer platforms are dedicated to

special functions, such as:
– Database management, printing, communications,
and program execution

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Communications Protocols
• Set of rules that govern the exchange of
information over a communications channel
• Protocols
– Govern several levels of a telecommunications
network

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Communications Software
• Network operating system (NOS)
– Systems software that controls the computer
systems and devices on a network and allows them
to communicate with each other

• Network management software
– Simplifies the process of updating files and programs
on computers on the network

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Use and Functioning of the Internet
• Internet
– Collection of interconnected networks, all freely
exchanging information

• ARPANET
– Ancestor of the Internet
– A project started by the U.S. Department of Defense
(DoD) in 1969

• Internet Protocol (IP)
– Enables traffic to be routed from one network to
another as needed
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