Chapter 6: Business Networks and

Telecommunications

Management Information Systems, Oz

 Learning objectives

• What are advantages of Business networks and

telecommunications
• What are components of Networks
• Types of Topologies, Types of Networks (Geo)
• Media Types
 Telecommunications in Business

• Telecommunications: transmission of data and

information
– Allows communications over large distances
• Network technologies bring about several
improvements to business process

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 Telecommunications in Business
(continued)
• Advantages of telecommunications
– Better business communication
– Geographical distance irrelevant
– Greater efficiency
– Information becomes immediately available
– Better distribution of data

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 Telecommunications in Business
(continued)
• Advantages of telecommunications
– Instant transactions
– Flexible and mobile workforce
– Alternative channels
• Disadvantage
– Network security is risk

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 Telecommunications in Daily Use:
Cellular Phones
• Name 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

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 Videoconferencing

• Videoconferencing: transmitted images and

speech
• Brings conference rooms thousands of miles
apart together
• Save on multiple costs
– Travel
– Lodging
– Time

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 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

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 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

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 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

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 Web-Empowered Commerce
• Increasingly fast communication allows
businesses options
– Research
– Market
– Educate
– Train
– Shop
• Entire industries created by Web
– Online exchanges and auctions

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 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

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 Bandwidth (continued)

Figure 6.1: Transmission speed measurement units

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 Media

• Several types of communications media

• Tangible or intangible
– Tangible
• Twisted pair cable
• Coaxial cable
• Optical fiber
• Intangible media
– Microwave radio technologies

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 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 fiber: uses light to represent bits
– Not susceptible to interference

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 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

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 Media (continued)

Figure 6.2: Networking media

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 Networks

• Network: combination of devices (nodes)

connected through communication channels
• Any compatible device can transmit and
receive on a network

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 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

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 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

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 Types of Networks (continued)

• Value-added networks (VANs): networks with

enhanced services
– Reliability
– Management
– Maintenance
• Internet service providers (ISPs): preferred
method of conducting commerce

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 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 meters

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 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

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 Networking Hardware (continued)

• 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

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 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

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 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

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 Switching Techniques (continued)

Figure 6.3: A packet

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 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

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 TCP/IP
• TCP/IP: Transmission Control Protocol/Internet
Protocol
– Ensures packets arrive accurately
– Ensures delivery of packets from node to node,
respectively
• Internet backbone: highest speed channels
• Host: computer connect directly to backbone
• IP number: unique identification for device
• DNS: Domain Name Service maintains
character-based names of IP numbers

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 TCP/IP (continued)

• Static IP number: permanent number assigned

to device
• Dynamic IP number: temporary IP number
assigned for duration of connection

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 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

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 Wireless Protocols
• IEEE 802.11: known as Wi-Fi
– Supports wireless communication within 100
meters 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 meters
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 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

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 Wireless Protocols (continued)

Figure 6.6: Wireless networking protocols

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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

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 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

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 Internet Networking Services
(continued)

Figure 6.6: Wireless networking protocols

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 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

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 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

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 T1 and T3 Lines

• T1 and T3 lines: point-to-point dedicated digital

circuits
– T3 lines made of 24 channels of 64 Kbps
– T1 line made of 672 channels of 64 Kbps
– Expensive
– Used in universities

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 Satellite

• Satellite services use microwaves

• Service provider installs dish antenna, used as
communications satellite
• Speeds up to 45 Mbps
• GPS free satellite service

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 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

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 Optical Carrier

• Optical carrier
– Expensive
– High connection speeds
• Uses basic unit of 51.84 Mbps
• Used by
– ISPs
– Search engines
– Content-rich Web sites

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 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

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 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 911

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 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

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 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

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 Summary

• Telecommunications is communication over

distance
• Different media have different bandwidths
• Networks are classified according to reach and
complexity
• Network can be turned into a virtual private
network (VPN)
• Two ways to switch a communication line:
packet switching and circuit switching

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 Summary (continued)

• 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
• As Internet links become faster, Internet
telephoning is gaining in popularity

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 Summary (continued)

• Wireless technologies support the increasingly

popular RFID technologies
• Much like hardware, telecommunications
technologies are merging
• Increasing numbers of employees now
telecommute

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