Itc20 Finals Mis8ch08

8/8/2019 Itc20 Finals Mis8ch08

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8.1 2004 by Prentice Hall

Management Information Systems 8/eManagement Information Systems 8/eChapter 8 Telecommunications and NetworksChapter 8 Telecommunications and Networks

88

TELECOMMUNICATIONSTELECOMMUNICATIONS

ANDAND

NETWORKSNETWORKS

Chapter


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What technologies are used inWhat technologies are used in

telecommunications systems?telecommunications systems?

What telecommunications transmissionWhat telecommunications transmission

media should our organization use?media should our organization use?

How should our organization design itsHow should our organization design itsnetworks?networks?

OBJECTIVES


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What alternative network services areWhat alternative network services are

available to our organization?available to our organization?

What telecommunications applicationsWhat telecommunications applications

can be used for electronic commerce andcan be used for electronic commerce and

electronic business?electronic business?

OBJECTIVES


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Managing LANsManaging LANs

Managing bandwidthManaging bandwidth

MANAGEMENT CHALLENGES


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COMPONENTS AND FUNCTIONS OF A TELECOMMUNICATIONS SYSTEM

Telecommunications:Telecommunications:

Communication of information byCommunication of information by

electronic meanselectronic means

Includes digital data transmissionIncludes digital data transmission

as well as voice transmissionas well as voice transmission


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Computers to process informationComputers to process information

Terminals or any input/output devicesTerminals or any input/output devicesthat send or receive datathat send or receive data

Communications processorsCommunications processors

Communications softwareCommunications software

Telecommunications System Components


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Components of a Telecommunications System

Figure 8-1


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Perform elementary processing ofPerform elementary processing of

informationinformation

Perform editorial tasks on dataPerform editorial tasks on data

Convert message speed or formatConvert message speed or format

Control flow of informationControl flow of information

Functions of Telecommunications Systems


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Digital signalDigital signal

Discrete waveformDiscrete waveform

Transmits data coded into twoTransmits data coded into twodiscrete states as 1discrete states as 1--bits and 0bits and 0--bitsbits

Used for data communicationsUsed for data communications

ModemModem Translates computers digitalTranslates computers digital

signals into analog and vice versasignals into analog and vice versa

Types of Signals: Analog and Digital


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Functions of the Modem

Figure 8-2


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Twisted wire:Twisted wire: Telephone systemsTelephone systems

Coaxial cable:Coaxial cable: Cable televisionCable television

Fiber optics and optical networks:Fiber optics and optical networks:

Dense wave division multiplexing (DWDM)Dense wave division multiplexing (DWDM)

Communications Channels


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Wireless transmission:Wireless transmission: Microwave,Microwave,Satellites, Paging systems, CellularSatellites, Paging systems, Cellulartelephones, Personal communicationtelephones, Personal communication

Services, Personal digital assistants,Services, Personal digital assistants,Mobile data networksMobile data networks

Transmission speed:Transmission speed: Baud,Baud,bandwidthbandwidth

Communications Channels


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Frequency Ranges for CommunicationsMedia and Devices

Figure 8-3


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Figure 8-4


Amocos Satellite Transmission System


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FrontFront--end processor:end processor: ManagesManagescommunications for the host computercommunications for the host computer

Concentrator:Concentrator: Collects and temporarilyCollects and temporarilystores messagesstores messages

Controller:Controller: Supervises communicationSupervises communicationtraffictraffic

Multiplexer:Multiplexer: Enables singleEnables singlecommunication channel to carry datacommunication channel to carry datatransmissionstransmissions

Communications Processors and Software


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COMMUNICATIONS NETWORKS

Star Network:Star Network: All computers and otherAll computers and otherdevices are connected to a central hostdevices are connected to a central hostcomputercomputer

Bus Network:Bus Network: Links a number ofLinks a number ofcomputers by a single circuitcomputers by a single circuit

Ring Network:Ring Network: All computers are linkedAll computers are linkedby a closed loopby a closed loop

Network Topologies


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A Star Network Topology


Figure 8-5


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A Bus Network Topology


Figure 8-6


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A Ring Network Topology


Figure 8-7


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Private Branch ExchangesPrivate Branch Exchanges

Central switching systemCentral switching system

Handle firms voice and digitalHandle firms voice and digital

communicationscommunications

Private Branch Exchanges, Local Area Networks (LANs),

and Wide Area Networks (WANs)



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Local Area NetworksLocal Area Networks

Require their own dedicated channelsRequire their own dedicated channels

Encompass a limited distanceEncompass a limited distance

Gateway, router, Network OperatingGateway, router, Network Operating

System (NOS), peerSystem (NOS), peer--toto--peerpeer





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A Local Area Network (LAN)

Figure 8-8


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Wireless LANsWireless LANs

WiWi--Fi (802.11b) standard: Up to 11Mbps,Fi (802.11b) standard: Up to 11Mbps,low cost, highlow cost, high--speed mobile Internetspeed mobile Internetaccess, links work groupsaccess, links work groups

Bluetooth standard: Up to 720 Kbps,Bluetooth standard: Up to 720 Kbps,small personal area networkssmall personal area networks





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Wide Area Networks (WANs)Wide Area Networks (WANs)

Span large geographical distanceSpan large geographical distance

Consist of variety of cable, satellite, andConsist of variety of cable, satellite, andmicrowave technologiesmicrowave technologies

Switched lines, dedicated linesSwitched lines, dedicated lines





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ValueValue--Added Networks (VANs)Added Networks (VANs)

Private, multipath, dataPrivate, multipath, data--only, thirdonly, third--partyparty--managedmanagednetworknetwork

Other Network ServicesOther Network Services

Packet switching, Frame Relay, AsynchronousPacket switching, Frame Relay, Asynchronoustransfer mode (ATM)transfer mode (ATM)

Integrated Services Digital Network (ISDN), DigitalIntegrated Services Digital Network (ISDN), Digitalsubscriber line (DSL), Cable modems, T1 linesubscriber line (DSL), Cable modems, T1 line --BroadbandBroadband

Network Services and Broadband Technologies



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Packed-Switched Networks and Packet

Communications

Figure 8-9



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Converged networkConverged network

Enables voice, video and data to runEnables voice, video and data to run

over a single networkover a single network

Unified messagingUnified messaging

System combining voice messages,System combining voice messages,

email, and faxemail, and fax

Network Convergence



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Electronic Mail and GroupwareElectronic Mail and Groupware

EE--mail:mail: Eliminates telephone tag andEliminates telephone tag andcostly longcostly long--distance telephone chargesdistance telephone charges

Groupware:Groupware: Enables work groups atEnables work groups atdifferent locations to participate indifferent locations to participate in

discussion forums and work on shareddiscussion forums and work on shared

documents and projectsdocuments and projects

Electronic Commerce and Electronic Business Technologies

ELECTRONIC COMMERCE AND ELECTRONIC BUSINESS TECHNOLOGIES


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Voice Mail and FaxVoice Mail and Fax

Voice mail:Voice mail: Digitizes spoken messageDigitizes spoken messageand transmits it over a networkand transmits it over a network

Fax:Fax: Digitizes and transmits documentsDigitizes and transmits documentsover telephone linesover telephone lines




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Digital information services, distanceDigital information services, distance

learning and Elearning and E--LearningLearning

Distance learning:Distance learning: Education or trainingEducation or trainingdelivered over a distance to individuals indelivered over a distance to individuals in

one or more locationsone or more locations

EE--learning:learning: Instruction delivered onlineInstruction delivered onlineusing the Internet or private networksusing the Internet or private networks




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Direct computerDirect computer--toto--computer exchangecomputer exchange

between two organizations of standardbetween two organizations of standard

business transaction documentsbusiness transaction documents

Electronic Data Interchange (EDI)



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Electronic Data Interchange (EDI)

Figure 8-10



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Management Information Systems 8/eManagement Information Systems 8/eChapter 8 Telecommunications and NetworksChapter 8 Telecommunications and Networks88

TELECOMMUNICATIONSTELECOMMUNICATIONS

ANDAND

NETWORKSNETWORKS

Chapter

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