Transcript Database Principles & Design By Colin Ritchie

Management
Information Systems
By Effy Oz & Andy Jones
Chapter 5: Business Networks and
Telecommunications
www.cengage.co.uk/oz
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Objectives
• Describe business and home applications of
digital telecommunications
• Identify the major media and devices used in
telecommunications
• Explain the concept of protocols
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Objectives (continued)
• Compare and contrast various networking and
Internet services
• List networking technologies and trends that
are likely to have an impact on businesses and
information management in the near future
• Discuss the pros and cons of telecommuting
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Telecommunications in Business
• Telecommunications: transmittal of data and
information
– Allows communications over large distances
• Network technologies bring about several
improvements to business process
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Telecommunications in Business
(continued)
• Advantages of telecommunications
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–
–
Better business communication
Geographical distance irrelevant
Greater efficiency
Information becomes immediately available
Better distribution of data
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Telecommunications in Business
(continued)
• Advantages of telecommunications
– Instant transactions
– Flexible and mobile workforce
– Alternative channels
• However network security is risk
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Telecommunications in Daily
Use: Mobile Phones
• American term of “cellular phone” is derived from areas
of service called cells
• Use computerized transceiver
– Transmits and receives signals
• Transmit and receive calls almost anywhere
• Other uses
– E-mail and faxing
– GPS
– Digital cameras
• Major advantage is mobility
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Videoconferencing
• Videoconferencing: transmitted images and
speech
• Brings conference rooms thousands of miles
apart together
• Save on multiple costs
– Travel
– Lodging
– Time
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Fax
• Fax: Transmission and reception of images over
telephone line
• Fax machine digitizes image and transmits
representative bits to other fax machine
• Can be sent through Internet
– Uses special software
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Wireless Payments and
Warehousing
• Radio frequency identification (RFID) technology
enables quick transactions and payments
• Used in gas stations and wireless toll plazas
– Facilitates payments
• Used in warehouses
– Check availability
– Locate items to be picked up and stored
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Peer-to-Peer File Sharing
• Peer-to-Peer file sharing: locate and download
files from online computer through Internet
– LimeWire
– KaZaa
– Morpheus
• Exchange music and video files
• Raises many issues with copyright violation
• BitTorrent: Download segments of files from
multiple sources
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Web-Empowered Commerce
• Increasingly fast communication allows
businesses options
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Research
Market
Educate
Train
Shop
• Entire industries created by Web
– Online exchanges and auctions
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Bandwidth and Media
• Bandwidth: speed at which data are
communicated
• Bits per second: unit of measure for bandwidth
• Baseband: carry only one transmission at a time
• Broadband: carry multiple transmissions
simultaneously
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Bandwidth (continued)
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Media
• Several types of communications media
• Tangible or intangible
– Tangible
• Twisted pair cable
• Coaxial cable
• Optical fibre
– Intangible media
• Microwave radio technologies
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Media (continued)
• Twisted pair cable: pairs of insulated copper
wires twisted together
– Twisting reduces electromagnetic interference
– Low cost
– Used in networking devices
• Coaxial cable: for cable television transmission
– Used for Internet
• Optical fibre: uses light to represent bits
– Not susceptible to interference
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Media (continued)
• Microwaves: high-frequency radio waves that
can carry signals over long distances
• Used in radio-frequency technologies
• Signals transmitted by satellite links
• Geostationary satellites are farther away from
the Earth
• Electrical power lines: electrical power grid
used for telecommunication
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Media (continued)
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Networks
• Network: combination of devices (nodes)
connected through communication channels
• Any compatible device can transmit and
receive on a network
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Types of Networks
• Three basic types of networks
– Local area network (LAN): established by single
organization and shared among employees
– Server: single computer often used as central
repository of programs and files for all computers
– Peer-to-peer LAN: no central device controls
communications
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Types of Networks (continued)
• Wireless LANs (WLANs): easier installation
and more scalable
– Scalability: ease of expanding system
– Wireless networks less secure
• Metropolitan area network (MAN): links
multiple LANs within large city
• Wide area network (WAN): far-reaching
system of networks composed of LANs or
MANs
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Types of Networks (continued)
• Value-added networks (VANs): networks with
enhanced services
– Reliability
– Management
– Maintenance
• Internet service providers (ISPs): preferred
method of conducting commerce
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
PANs
• Personal area network (PAN): wireless
network designed for handheld and portable
devices
– Used by one or two people
– Transmission speed slower
– Maximum distance 10 metres
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Networking Hardware
• Networks use variety of devices to connect
computers and peripheral devices
• Network interface card: connects through
cable or wireless antenna to middle device
• Middle device connects to LAN or WAN
– Hub: central location to connect computers
– Switch: controls direction of communications
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Networking Hardware
(continued)
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•
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Bridge: connects two networks
Router: routes data packets to next node
Repeater: amplifies or regenerates signals
Modem: translates communication signals
form analog to digital and vice versa
• Dial-up connection: slower type of connection
through modem
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Virtual Private Networks
• Virtual private network (VPN): alternative to
creating LAN
• Does not require leasing of lines
• Utilizes Internet, a public network to simulate
a private network
• Enables intranets and extranets
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Switching Techniques
• Circuit switching: dedicated channel established
for duration of transmission
• Packet switching: message broken into packets
• Packet: group of bits transmitted together
• Frame relay: high-speed packet-switching
protocol used in WANs
– Variable-sized packets routed quickly
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Switching Techniques
(continued)
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Protocols
• Protocol: set of rules governing communication
between computers
• Protocol is like human language and basic
understanding
• Some protocols designed for WANs, LANs, and
wireless communications
• Most important set of protocols called TCP/IP
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
TCP/IP
• TCP/IP: Transmission Control Protocol/Internet
Protocol
– Ensures packets arrive accurately
– Ensures delivery of packets from node to node,
respectively
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Internet backbone: highest speed channels
Host: computer connect directly to backbone
IP number: unique identification for device
DNS: Domain Name Service maintains characterbased names of IP numbers
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
TCP/IP (continued)
• Static IP number: permanent number assigned to
device
• Dynamic IP number: temporary IP number
assigned for duration of connection
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Ethernet
• Ethernet: LAN protocol using coaxial cable
• Gigabit Ethernet: faster Ethernet connections
• Devices on network contend with other devices
for transmission time
• CSMA/CD protocol ensures no collisions in
transmission
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Wireless Protocols
• IEEE 802.11: known as Wi-Fi
– Supports wireless communication within 100 metres of
router
– Max speed 11 Mbps
• Access point (hotspot): allows Internet access
within range of equipment
• Encryption: ability to scramble and code
messages
– Use keys shared between sender and receiver
• Bluetooth: allows devices to communicate within
10 metres
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Wireless Protocols (continued)
• Worldwide Interoperability for Microwave
Access (WIMAX): increases range and speed of
wireless communication
– Works with metropolitan area networks
• Mobile Broadband Wireless Access (MBWA):
similar to cell phone communications
– Compatible with IP services
– Compatible with Wi-Fi and Bluetooth
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Wireless Protocols (continued)
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Generations in Mobile
Communications
• Networking professionals refer to generations
of mobile communication technologies
• First generation analog
• Second generation used digital voice encoding
• Third generation stepped up speeds
• Fourth Generation digital
– Packet switching
– Higher security
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Internet Networking Services
• Variety of options to choose from when
subscribing to network services
• Downstream: speed of receiving from
network
• Upstream: speed of transmitting to network
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Cable
• Internet links provided by television cable
firms
• Cable connected to Internet server
• At residence, cable split into TV set and
computer
• Cable shared by all subscribers
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Digital Subscriber Line (DSL)
• Digital subscriber line (DSL): data remains
digital through entire transmission
• Uses telephone lines connected to DSL bridge
• Several types of DSL
– Asymmetric allows different upstream and
downstream rates
• Transmission rates closely related to distance
from telephone company
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Satellite
• Satellite services use microwaves
• Service provider installs dish antenna, used as
communications satellite
• Speeds up to 45 Mbps
• GPS free satellite service
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Fixed Wireless
• Fixed wireless: point-to-point transmission
between two stationary devices
• Wireless Internet service provider (WISP)
– Provides fixed wireless service
• Highly modular and scalable
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Optical Carrier
• Optical carrier
– Expensive
– High connection speeds
• Uses basic unit of 51.84 Mbps
• Used by
– ISPs
– Search engines
– Content-rich Web sites
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Broadband over Power Lines
(BPL)
• Broadband over Power Lines (BPL): uses
electric power lines to carry digital signals
• Used by utility companies
– Monitor power consumption
– Detect power failure
– Track power outages
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
The Future of Networking
Technologies: Broadband
Telephoning
• Voice over Internet Protocol: uses Internet
connection to conduct telephone conversations
• Free of charge
• Different quality of sound from traditional
telephone services
• Does not allow calls to emergency numbers
such as 999
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Radio Frequency Identification
• RFID tags tiny and need little power
• Objects are embedded with tags that contain
radio transceiver
• Tags encoded with electronic product code
• Readers decode data stored in tag’s memory
and data passed to host computer
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Future Uses of RFID
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Converging Technologies
•
•
•
•
Convergence occurs in networking technology
Cell phones can act as Web phones
Television sets connect to Internet
Wireless technologies combined in same
device enhance functionality
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Summary
• Telecommunications is communication over
distance
• Telecommunications technology has changed the
business environment
• Different media have different bandwidths
• Networks are classified according to reach and
complexity
• Network can be turned into a virtual private
network (VPN)
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Summary (continued)
• Two ways to switch a communication line: packet
switching and circuit switching
• Network protocols are sets of rules to which all
devices on network must adhere
• The Internet adheres to the TCP/IP protocol
• Wireless technologies make it easy and affordable
to create wireless LANs
• Organizations and individuals have variety of
choices when subscribing to networking services
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning
Summary (continued)
• As Internet links become faster, Internet
telephoning is gaining in popularity
• Wireless technologies support the increasingly
popular RFID technologies
• Much like hardware, telecommunications
technologies are merging
• Increasing numbers of employees now
telecommute
Use with Management Information Systems 1e
By Effy Oz & Andy Jones ISBN 9781844807581
© 2008 Cengage Learning