Page 315 -

314 Part Two Information Technology Infrastructure

Review Summary

1. What are the principal components of telecommunications networks and key networking technologies?
A simple network consists of two or more connected computers. Basic network components include
computers, network interfaces, a connection medium, network operating system software, and either a
hub or a switch. The networking infrastructure for a large company includes the traditional telephone
system, mobile cellular communication, wireless local area networks, videoconferencing systems, a cor-
porate Web site, intranets, extranets, and an array of local and wide area networks, including the Internet.
Contemporary networks have been shaped by the rise of client/server computing, the use of packet
switching, and the adoption of Transmission Control Protocol/Internet Protocol (TCP/IP) as a universal
communications standard for linking disparate networks and computers, including the Internet.
Protocols provide a common set of rules that enable communication among diverse components in a
telecommunications network.
2. What are the different types of networks?
The principal physical transmission media are twisted copper telephone wire, coaxial copper cable,
fiber-optic cable, and wireless transmission.
Local area networks (LANs) connect PCs and other digital devices together within a 500-meter radius
and are used today for many corporate computing tasks. 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.

3. How do the Internet and Internet technology work, and how do they support communication and
e-business?
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. 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).
Major Internet services include e-mail, newsgroups, chatting, instant messaging, Telnet, FTP, and
the Web. Web pages are based on Hypertext Markup Language (HTML) and can display text, graphics,
video, and audio. Web site directories, search engines, and RSS technology help users locate the
information they need on the Web. RSS, blogs, social networking, and wikis are features of Web 2.0.
Firms are also starting to realize economies by using VoIP technology for voice transmission and by
using virtual private networks (VPNs) as low-cost alternatives to private WANs.

4. What are the principal technologies and standards for wireless networking, communication, and
Internet access?
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 Kbps
to more than 2 Mbps. 4G networks capable of transmission speeds that could reach 1 Gbps are starting
to be rolled out.
Major cellular standards include Code Division Multiple Access (CDMA), which is used primarily in
the United States, and Global System for Mobile Communications (GSM), which is the standard in
Europe and much of the rest of the world.
Standards for wireless computer networks include Bluetooth (802.15) for small personal area net-
works (PANs), Wi-Fi (802.11) for local area networks (LANs), and WiMax (802.16) for metropolitan area
networks (MANs).
5. Why are radio frequency identification (RFID) and wireless sensor networks valuable for business?
Radio frequency identification (RFID) systems provide a powerful technology for tracking the
movement of goods by using tiny tags with embedded data about an item and its location. RFID readers
read the radio signals transmitted by these tags and pass the data over a network to a computer for
processing. Wireless sensor networks (WSNs) are networks of interconnected wireless sensing and
transmitting devices that are embedded into the physical environment to provide measurements of
many points over large spaces.

MIS_13_Ch_07_Global.indd 314 1/17/2013 2:28:35 PM