management information systems, 4 th edition 1 chapter 6 information technology in business:...
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Management Information Systems, 4th Edition 1
Chapter 6Information Technology in
Business: Telecommunications and Networks
Management Information Systems, 4th Edition 2
Learning Objectives
• Explain why successful managers must be familiar with telecommunications concepts and terminology
• Describe the principles of communication within a computer system and among computers
• Identify the major media and devices used in telecommunications
Management Information Systems, 4th Edition 3
Learning Objectives (Cont.)
• List and explain the functions of different network layouts and the concept of protocols
• Explain how telecommunications can improve operations in organizations
• Cite the latest developments in telecommunications media and transmission speed
Management Information Systems, 4th Edition 4
Telecommunications in Business• Transmittal of data from one computer to another
over a distance
• Telecommunications has improved business in three main ways:
– Better communication
– Higher efficiency
– Better distribution of data
Management Information Systems, 4th Edition 5
Telecommunications in Daily Use
• Cellular Phones
• Videoconferences
• Voice Mail
• Facsimile
• Information Kiosks
• Pay at the Pump
Management Information Systems, 4th Edition 6
• Easy Passing
• Web-Based Electronic Commerce
• Worldwide Peer-to-Peer File Sharing
– Napster, Gnutella, BearShare, Morpheus
– With directory
– Without directory
Telecommunications in Daily Use (Cont.)
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Data Communications
• Any transfer of data within a computer, between a computer and another device, or between two computers
• Parallel and Serial Data Communications
Management Information Systems, 4th Edition 10
• Simplex
– One-way in one direction
• Half-Duplex
– One-way in two directions
• Full-Duplex
– Two-way in two directions
Communication Direction
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• Parity Check
– Error detection method
– Checks that no bits are added or deleted during transmission
– Odd Parity Check looks for an odd number of ones
– Even Parity Check looks for even number of ones
Error Detection
Management Information Systems, 4th Edition 13
• Communications medium – Physical medium through which data can be
communicated– Telephone lines, television cables
• Capacity– Speed at which data are communicated– Also called the transmission rate– It is often called “bandwidth”
• Bandwidth is measured in bits per second (bps)– The greater the capacity, the faster the transmission
Bandwidth and Media
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• Bandwidth
– Narrowband is low speed
– Broadband has greater capacity
• Media
– A medium is any means by which data can be transmitted
Bandwidth and Media (Cont.)
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• A medium’s capacity is determined by the range of bits per second at which it can operate
• Baud is the number of signals per minute
• Repeater receives and strengthens signals before sending them on
Transmission speed
Management Information Systems, 4th Edition 18
• Telephone line made of a pair of copper wires twisted to reduce electromagnetic interference (EMI)
Twisted Pair
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Coaxial Cable
• Commonly used for cable television transmission
– More expensive than twisted pair
– Greater transmission rate than twisted pair
– Much less susceptible to EMI
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• High-frequency, short radio-frequency (RF) waves
– Terrestrial microwave
– Satellite microwave
Microwaves
Management Information Systems, 4th Edition 21
Optical Fiber
• Fiber-optic technology uses light instead of electricity to transmit data
Management Information Systems, 4th Edition 23
Modulation
• Modification of a digital signal into an analog signal
• Demodulation
– Modification of an analog signal into a digital signal
Management Information Systems, 4th Edition 24
• Analog vs. Digital
– Analog: A continuous series of waves
– Digital: A series of discrete bits
Modulation (Cont.)
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Modulation (Cont.)
• Amplitude Modulation (AM)
• Frequency Modulation (FM)
• Phase Modulation
• Modems
– Devices that modulate and demodulate signals
Management Information Systems, 4th Edition 28
Networks• LANs (Local Area Networks)
– Networks within a building, or within a group of adjacent buildings
• WANs (Wide Area Networks)
– Networks that cross organizational boundaries or reach outside the company
• Value-added networks (VANs)
• Wireless communication
Management Information Systems, 4th Edition 29
Network Topology
• Physical layout of the nodes in a network
– Star
– Ring
– Bus
– Tree
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Networking Hardware
• Network Interface Card
• Hub
• Switch
• Bridge
• Router
Management Information Systems, 4th Edition 32
Virtual Private Network
• A combination of private and public lines
• A link between a private network and the Internet
• “Virtual” refers to the illusion that the use is accessing a private network directly
Management Information Systems, 4th Edition 33
Protocols
• Communication protocols
– Rules governing the communication between computers or between computers and other computer-related devices
• Network protocols
– Rules governing a network of devices
Management Information Systems, 4th Edition 34
Protocols (Cont.)
• LAN Protocols– Polling
– Contention
– Token passing
• WAN Protocols– OSI (Open Systems Interconnection)
• Standard protocol model
• Seven layers
Management Information Systems, 4th Edition 36
Switching Techniques• Circuit Switching
– Message is communicated in its entirety from the transmitting computer to the receiving computer
• Packet Switching
– Message is divided into packets of bytes and transmitted via several nodes
– TCP/IP
Management Information Systems, 4th Edition 38
The Changing Business Environment
• Cellular Phones
• Teleconferencing
• Voice Mail
• Facsimile
Management Information Systems, 4th Edition 39
A Variety of Services• Cable
• Digital Subscriber Line (DSL)
• T1 and T3 Lines
• Satellite
• Fixed Wireless
• Gigabit Ethernet
• Optical Carrier
Management Information Systems, 4th Edition 41
A Wireless Revolution
• Popular Wireless Technologies
• Would You Like Wi-Fi With That?
• Combining Technologies
Management Information Systems, 4th Edition 44
Ethical and Societal IssuesTelecommuting: Pros and Cons
• Pros
– Saves travel cost and time
– Decreases pollution
– May reduce unemployment.
– Productivity higher among telecommuters
Management Information Systems, 4th Edition 45
Ethical and Societal IssuesTelecommuting: Pros and Cons
• Cons
– Employers tend to pressure telecommuters to work harder than workers in the office.
– No office to foster new social ties and camaraderie.
– May negatively impact some segments of the economy
• Restaurants
• Downtown business and industries
Management Information Systems, 4th Edition 46
Summary• Telecommunications concepts and terminology
• Communication within a computer system and among computers
• Telecommunications media and devices
• Network layouts and protocols
• Telecommunications impact on operations
• Telecommunications developments and speed
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