How do the Internet and Internet technology work, and how do they support communication and e-business?
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The Internet is a worldwide network of networks
that uses the client/server model of computing and the TCP/IP network reference
model. Every computer on the Internet is assigned a unique numeric IP address.
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The domain name system (DNS) converts IP
addresses to more user-friendly domain names. Worldwide Internet policies are
established by organizations and government bodies, such as the Internet Architecture
Board (IAB) and the World Wide Web Consortium (W3C).
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Major Internet services include e-mail,
newsgroups, chatting, instant messaging, Telnet, file transfer protocol (FTP),
and the Web. Web pages are based on Hypertext Markup Language (HTML) and can
display text, graphics, video, and audio.
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Web site directories, search engines, and RSS
(Really Simple Syndication) technology help users locate the information they
need on the Web. RSS, blogs, social networking, and wikis are features of Web
2.0.
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Firms are also starting to realize economies by
using Voice-over Internet Protocol (VoIP) technology for voice transmission and
by using virtual private networks (VPNs) as low-cost alternatives to private
WANs.
2. What are the principal technologies and
standards for wireless networking, communication, and Internet access?
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Cellular networks are evolving toward high-speed,
high-bandwidth, digital packet-switched transmission. Broadband 3G networks are
capable of transmitting data at speeds ranging from 144 kilobits per second
(kbps) to more than 2 Mbps.
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4G networks capable of transmission speeds that
could reach 1 gigabits per second (Gbps) are starting to be rolled out.
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Major cellular standards include Code Division
Multiple Access (CDMA), which is used primarily in North America, and Global
System for Mobile Communications (GSM), which is the standard in much of the
rest of the world. Standards for wireless computer networks include Bluetooth
(802.15) for small personal area networks (PANs), Wi-Fi (802.11) for local area
networks (LANs), and WiMax (802.16) for metropolitan area networks (MANs).
3. What are the main telecommunications transmission
media and types of networks?
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The principal physical transmission media are
twisted copper telephone wire, coaxial copper cable, fibre-optic cable, and
wireless transmission.
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Twisted wire enables companies to use existing
wiring for telephone systems for digital communication, although it is
relatively slow.
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Fibre-optic and coaxial cable are used for
high-volume transmission but are expensive to install. Microwave and
communications satellites are used for wireless communication over long
distances.
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Local area networks (LANs) connect personal
computers (PCs) and other digital devices together within a 500-metre radius
and are used today for many corporate computing tasks. Network components may
be connected together using a star, bus, or ring topology.
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Wide area networks (WANs) span broad
geographical distances, ranging from several miles to continents, and are
private networks that are independently managed. Metropolitan area networks
(MANs) span a single urban area. Digital subscriber line (DSL) technologies,
cable Internet connections, and T1 lines are often used for high-capacity
Internet connections.
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Cable Internet connections provide high-speed
access to the Web or corporate intranets at speeds of up to 10 megabits per
second (Mbps). A T1 line supports a data transmission rate of 1.544 Mbps.
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