7.1

CHAPTER 7. CHAPTER 7. TELECOMMUNICATIONSTELECOMMUNICATIONS

NETWORKS & THE NEW NETWORKS & THE NEW INFORMATION INFORMATION TECHNOLOGYTECHNOLOGY

7.2

LEARNING OBJECTIVESLEARNING OBJECTIVES

• DESCRIBE COMPONENTS OF DESCRIBE COMPONENTS OF TELECOMMUNICATIONS SYSTEMTELECOMMUNICATIONS SYSTEM

• CALCULATE CAPACITY OF CALCULATE CAPACITY OF TELECOMMUNICATIONS CHANNELS & TELECOMMUNICATIONS CHANNELS & EVALUATE TRANSMISSION MEDIAEVALUATE TRANSMISSION MEDIA

• COMPARE TYPES OF COMPARE TYPES OF NETWORKS & NETWORKS & NETWORK SERVICESNETWORK SERVICES

**

7.3

LEARNING OBJECTIVESLEARNING OBJECTIVES

• DESCRIBE INFRASTRUCTURE, DESCRIBE INFRASTRUCTURE, CONNECTIVITY STANDARDSCONNECTIVITY STANDARDS

• IDENTIFY APPLICATIONS FOR IDENTIFY APPLICATIONS FOR SUPPORTING ELECTRONIC SUPPORTING ELECTRONIC COMMERCE, BUSINESSCOMMERCE, BUSINESS

• ANALYZE MANAGEMENT PROBLEMS ANALYZE MANAGEMENT PROBLEMS OF OF NETWORKINGNETWORKING

**

7.4

MANAGEMENT CHALLENGESMANAGEMENT CHALLENGES

• TELECOMMUNICATIONS REVOLUTIONTELECOMMUNICATIONS REVOLUTION• COMPONENTS, FUNCTIONS OF COMPONENTS, FUNCTIONS OF

TELECOMMUNICATIONS SYSTEMTELECOMMUNICATIONS SYSTEM• COMMUNICATIONS NETWORKSCOMMUNICATIONS NETWORKS• NETWORK INFRASTUCTURENETWORK INFRASTUCTURE• MANAGEMENT ISSUES, DECISIONSMANAGEMENT ISSUES, DECISIONS

**

7.5

TELECOMMUNICATIONSTELECOMMUNICATIONS

COMMUNICATING INFORMATIONCOMMUNICATING INFORMATION

VIA ELECTRONIC MEANSVIA ELECTRONIC MEANS

OVER SOME DISTANCEOVER SOME DISTANCE

**

7.6

INFORMATION INFORMATION SUPERHIGHWAYSUPERHIGHWAY

NATIONAL / WORLDWIDENATIONAL / WORLDWIDE

HIGH SPEEDHIGH SPEED

DIGITAL TELECOMMUNICATIONSDIGITAL TELECOMMUNICATIONS

ACCESSIBLE BY GENERAL PUBLICACCESSIBLE BY GENERAL PUBLIC

**

7.7

SYSTEM COMPONENTSSYSTEM COMPONENTS

• COMPUTERSCOMPUTERS• TERMINALS (Input / output devices)TERMINALS (Input / output devices)• COMMUNICATIONS CHANNELSCOMMUNICATIONS CHANNELS• PROCESSORS (Modems; multiplexers; PROCESSORS (Modems; multiplexers;

front-end processors)front-end processors)• COMMUNICATIONSCOMMUNICATIONS SOFTWARE SOFTWARE

**

7.8

PROTOCOLPROTOCOL

RULES & PROCEDURESRULES & PROCEDURES

TO GOVERN TRANSMISSIONTO GOVERN TRANSMISSION

BETWEEN COMPONENTS BETWEEN COMPONENTS

IN A NETWORKIN A NETWORK

**

7.9

ANALOG SIGNALANALOG SIGNAL• CONTINUOUS WAVEFORMCONTINUOUS WAVEFORM

• PASSES THRU SYSTEMPASSES THRU SYSTEM

• VOICE COMMUNICATIONSVOICE COMMUNICATIONS

**

7.10

DIGITAL SIGNALDIGITAL SIGNAL• DISCRETE WAVEFORMDISCRETE WAVEFORM• TWO DISCRETE STATES:TWO DISCRETE STATES:

– 1-BIT & 0-BIT– ON / OFF PULSE

• DATA COMMUNICATIONDATA COMMUNICATION• USES MODEM TO TRANSLATE ANALOG USES MODEM TO TRANSLATE ANALOG

TO DIGITAL, DIGITAL TO ANALOGTO DIGITAL, DIGITAL TO ANALOG

**

0010111010011101001010101110111100100010000101111010110100111010010010110010101101100

7.11

COMMUNICATION COMMUNICATION CHANNELSCHANNELS

MEANS BY WHICH DATA ARE MEANS BY WHICH DATA ARE TRANSMITTED:TRANSMITTED:

• TWISTED WIRESTWISTED WIRES (Copper Wires)(Copper Wires)

• COAXIAL CABLE:COAXIAL CABLE: (Insulated Copper (Insulated Copper Wires)Wires)

• FIBER-OPTIC CABLEFIBER-OPTIC CABLE

• MICROWAVEMICROWAVE

**

7.12

• SUPER CLEAR GLASS STRANDSSUPER CLEAR GLASS STRANDS• FAST, LIGHT, DURABLEFAST, LIGHT, DURABLE• BILLIONS OF BITS PER SECOND, FULL BILLIONS OF BITS PER SECOND, FULL

DUPLEXDUPLEX• EXPENSIVE, HARDER TO INSTALLEXPENSIVE, HARDER TO INSTALL• OFTEN USED AS BACKBONE OF OFTEN USED AS BACKBONE OF

NETWORKSNETWORKS

**

FIBER OPTICSFIBER OPTICS

SIGNALSIGNAL LASERLASER CABLECABLE PHOTOPHOTODETECTORDETECTOR SIGNALSIGNAL

7.13

ORBITING SATELLITESORBITING SATELLITES

UPLINKUPLINK

MICROWAVE MICROWAVE TRANSMISSIONTRANSMISSION

DOWNLINKDOWNLINK

7.14

WIRELESS TRANSMISSION WIRELESS TRANSMISSION TECHNOLOGIESTECHNOLOGIES

• PAGING SYSTEM:PAGING SYSTEM: Small pager beeps Small pager beeps when receives short messagewhen receives short message

• CELLULAR TELEPHONE:CELLULAR TELEPHONE: Device uses Device uses radio waves to reach antennas within radio waves to reach antennas within areas called cellsareas called cells

• MOBILE DATA NETWORKS:MOBILE DATA NETWORKS: Radio - Radio - based data network using hand-held based data network using hand-held computers; cheap, efficientcomputers; cheap, efficient

**

7.15

WIRELESS TRANSMISSION WIRELESS TRANSMISSION TECHNOLOGIESTECHNOLOGIES

• PERSONAL COMMUNICATION SERVICE:PERSONAL COMMUNICATION SERVICE: Cellular; lower power; higher frequency. Cellular; lower power; higher frequency. Smaller phones not shielded by buildings, Smaller phones not shielded by buildings, tunnelstunnels

• PERSONAL DIGITAL ASSISTANT:PERSONAL DIGITAL ASSISTANT: Pen sized, hand-held, digital communicatorPen sized, hand-held, digital communicator

• SMART PHONE:SMART PHONE: Wireless, voice, text, Wireless, voice, text, InternetInternet

**

7.16

• TRANSMISSION SPEED:TRANSMISSION SPEED: Bits per Bits per Second (BPS) or BaudSecond (BPS) or Baud

• BANDWIDTH:BANDWIDTH: Capacity of Channel; Capacity of Channel; Difference between Highest & Difference between Highest & Lowest FrequenciesLowest Frequencies

**

COMMUNICATIONS COMMUNICATIONS CHANNELSCHANNELS

7.17

MEDIUMMEDIUM SPEEDSPEED COSTCOST TWISTED WIRETWISTED WIRE 300 BPS - 10 MBPS300 BPS - 10 MBPS LOWLOW

MICROWAVEMICROWAVE 256 KBPS - 100 MBPS256 KBPS - 100 MBPS

SATELLITESATELLITE 256 KBPS - 100 MBPS256 KBPS - 100 MBPS

COAXIAL CABLECOAXIAL CABLE 56 KBPS - 200 MBPS56 KBPS - 200 MBPS

FIBER OPTICSFIBER OPTICS 500 KBPS - 10 GBPS500 KBPS - 10 GBPS HIGHHIGH BPS: BITS PER SECONDBPS: BITS PER SECOND KBPS: KILOBITS PER SECONDKBPS: KILOBITS PER SECOND MBPS: MEGABITS PER SECONDMBPS: MEGABITS PER SECOND GBPS: GIGABITS PER SECONDGBPS: GIGABITS PER SECOND

SPEEDS & COST OF MEDIASPEEDS & COST OF MEDIA

7.18

COMMUNICATIONS COMMUNICATIONS PROCESSORSPROCESSORS

• FRONT- END PROCESSOR:FRONT- END PROCESSOR: minicomputer minicomputer manages communication for host computermanages communication for host computer

• CONCENTRATOR:CONCENTRATOR: computer collects computer collects messages for batch transmission to host messages for batch transmission to host computercomputer

• CONTROLLER:CONTROLLER: computer controls interface computer controls interface between CPU and peripheral devicesbetween CPU and peripheral devices

• MULTIPLEXER:MULTIPLEXER: allows channel to carry allows channel to carry multiple sources multiple sources simultaneouslysimultaneously

**

7.19

NETWORK TOPOLOGIESNETWORK TOPOLOGIES

HOSTHOST

USERUSER

USERUSER

USERUSER USERUSER

STAR

7.20

NETWORK TOPOLOGIESNETWORK TOPOLOGIES

BUS

USERUSER

USERUSER

USERUSER

USERUSER

USERUSER

USERUSER

7.21

NETWORK TOPOLOGIESNETWORK TOPOLOGIES

USERUSER

USERUSER

USERUSER

USERUSER

RING

7.22

LOCAL NETWORKSLOCAL NETWORKS

• PRIVATE BRANCH EXCHANGE (PBX):PRIVATE BRANCH EXCHANGE (PBX): firm’s central switching systemfirm’s central switching system

• LOCAL AREA NETWORK (LAN):LOCAL AREA NETWORK (LAN): dedicated dedicated channels; limited distance (less than 2000 channels; limited distance (less than 2000 foot radius); higher capacity than PBX. foot radius); higher capacity than PBX. Can share expensive hardware & softwareCan share expensive hardware & software

**

7.23

LOCAL AREA NETWORK LOCAL AREA NETWORK (LAN)(LAN)• GATEWAY:GATEWAY: Connection to other networksConnection to other networks

• ROUTER:ROUTER: Forwards data to other networks Forwards data to other networks

• NETWORK OPERATING SYSTEM (NOS):NETWORK OPERATING SYSTEM (NOS): Manages file server; routes communications Manages file server; routes communications on networkon network

• PEER - TO - PEER:PEER - TO - PEER: In some small networks all In some small networks all computers have equal powercomputers have equal power

**

7.24

Network spans large geographic distances. Network spans large geographic distances. Can include cable, satellite, microwaveCan include cable, satellite, microwave

• SWITCHED LINES:SWITCHED LINES: Route determined Route determined by by current trafficcurrent traffic

• DEDICATED LINES:DEDICATED LINES: Constantly available Constantly available for high-volume trafficfor high-volume traffic

**

WIDE - AREA NETWORK WIDE - AREA NETWORK (WAN)(WAN)

7.25

VALUE-ADDED VALUE-ADDED NETWORK (VAN)NETWORK (VAN)

• PRIVATE; MULTIPATH; DATA ONLYPRIVATE; MULTIPATH; DATA ONLY

• 3rd PARTY MANAGED3rd PARTY MANAGED

• USED BY SEVERAL ORGANIZATIONSUSED BY SEVERAL ORGANIZATIONS

• SUBSCRIPTION BASISSUBSCRIPTION BASIS

**

7.26

NETWORK SERVICESNETWORK SERVICES

• PACKET SWITCHINGPACKET SWITCHING• FRAME RELAYFRAME RELAY• ASYNCHRONOUS TRANSFER MODE ASYNCHRONOUS TRANSFER MODE (ATM)(ATM)• INTEGRATED SERVICES DIGITAL NETWORK INTEGRATED SERVICES DIGITAL NETWORK

(ISDN)(ISDN)• DIGITAL SUBSCRIBER LINEDIGITAL SUBSCRIBER LINE• CABLE MODEMCABLE MODEM• T1 LINET1 LINE

**

7.27

PACKET SWITCHINGPACKET SWITCHING (X.25)(X.25)::

• FORM OF FORM OF VValue alue AAdded dded NNetworketwork

• BREAKS DATA BLOCKS INTO BREAKS DATA BLOCKS INTO SMALL PACKETS (e.g.: 128 Bytes)SMALL PACKETS (e.g.: 128 Bytes)

• PACKETS ROUTED BY MOST PACKETS ROUTED BY MOST ECONOMICAL MEANSECONOMICAL MEANS

• REASSEMBLED AT DESTINATIONREASSEMBLED AT DESTINATION

**

7.28

ASYNCHRONOUS ASYNCHRONOUS TRANSFER MODETRANSFER MODE (ATM)(ATM)::• CELL:CELL: 53 Groups of 8 Bytes Each 53 Groups of 8 Bytes Each• USES FIBER OPTICS CABLEUSES FIBER OPTICS CABLE• INDEPENDENT OF VENDOR INDEPENDENT OF VENDOR

HARDWARE SPEEDSHARDWARE SPEEDS• CAN TIE LAN TO WANCAN TIE LAN TO WAN

**

7.29

INTEGRATED SERVICES INTEGRATED SERVICES DIGITAL NETWORKDIGITAL NETWORK (ISDN)(ISDN)::

INTERNATIONAL STANDARD FOR INTERNATIONAL STANDARD FOR TRANSMITTING VOICE, VIDEO, TRANSMITTING VOICE, VIDEO,

DATADATA

OVER PUBLIC TELEPHONE LINESOVER PUBLIC TELEPHONE LINES

**

7.30

OTHER SERVICES:OTHER SERVICES:

• DIGITAL SUBSCRIBER LINE (DSL):DIGITAL SUBSCRIBER LINE (DSL): enhancing capacity over copper enhancing capacity over copper telephone linestelephone lines

• CABLE MODEM:CABLE MODEM: modem for cable TV for modem for cable TV for high-speed access to Internethigh-speed access to Internet

• T1 LINE:T1 LINE: dedicated telephone connection, dedicated telephone connection, 24 channels @ 1.544 megabits per second24 channels @ 1.544 megabits per second

**

7.31

OTHER SERVICES:OTHER SERVICES:

• BROADBAND:BROADBAND: High-speed High-speed transmission, multiple channelstransmission, multiple channels

• CONVERGING NETWORK:CONVERGING NETWORK: Enables Enables simultaneous transmission of voice, simultaneous transmission of voice, datadata

**

7.32

• HARDWARE; SOFTWARE; HARDWARE; SOFTWARE; TELECOMMUNICATIONS, DATA TELECOMMUNICATIONS, DATA RESOURCESRESOURCES

• MORE COMPUTING POWER ON THE MORE COMPUTING POWER ON THE DESKTOPDESKTOP

• NETWORK LINKING SMALLER NETWORK LINKING SMALLER NETWORKSNETWORKS

**

ENTERPRISE NETWORKENTERPRISE NETWORK

7.33

INTERNETWORKINGINTERNETWORKING

LINK NETWORKSLINK NETWORKS

EACH RETAINS IDENTITYEACH RETAINS IDENTITY

INTO INTERCONNECTED NETWORKINTO INTERCONNECTED NETWORK

**

NETWORK A

NETWORK B

NETWORK C

7.34

CONNECTIVITYCONNECTIVITY

MEASURE OF ABILITY OF COMPUTING MEASURE OF ABILITY OF COMPUTING DEVICES TO PASS & SHARE DEVICES TO PASS & SHARE

INFORMATION WITHOUT HUMAN INFORMATION WITHOUT HUMAN INTERVENTIONINTERVENTION

OPEN SYSTEMS:OPEN SYSTEMS: Software able to Software able to function on different computer platforms. function on different computer platforms. Nonproprietary operating systems, Nonproprietary operating systems, applications, protocolsapplications, protocols

**

7.35

TRANSMISSION CONTROL TRANSMISSION CONTROL PROTOCOL / INTERNET PROTOCOL / INTERNET

PROTOCOL PROTOCOL (TCP / IP)(TCP / IP)REFERENCE MODEL DEVELOPED BY REFERENCE MODEL DEVELOPED BY

DEPARTMENT OF DEFENSE IN 1972DEPARTMENT OF DEFENSE IN 1972

1. APPLICATION:1. APPLICATION: Provides screen presentations Provides screen presentations

2. TRANSMISSION CONTROL PROTOCOL2. TRANSMISSION CONTROL PROTOCOL (TCP)(TCP):: Breaks data into datagramsBreaks data into datagrams

3. INTERNET PROTOCOL (IP):3. INTERNET PROTOCOL (IP): Breaks, sends Breaks, sends datagrams as smaller IP packets; can repeat datagrams as smaller IP packets; can repeat transmission to increase reliabilitytransmission to increase reliability

**

7.36

4. NETWORK INTERFACE:4. NETWORK INTERFACE: Handles Handles addressing and interface between addressing and interface between computer & networkcomputer & network

5. PHYSICAL NET:5. PHYSICAL NET: Defines electrical Defines electrical transmission characteristics for sending transmission characteristics for sending signal along networks to destinationsignal along networks to destination

**

TRANSMISSION CONTROL TRANSMISSION CONTROL PROTOCOL / INTERNET PROTOCOL / INTERNET

PROTOCOL PROTOCOL (TCP / IP)(TCP / IP)

7.37

OPEN SYSTEM OPEN SYSTEM INTERCONNECT INTERCONNECT (OSI)(OSI)

INTERNATIONAL REFERENCE INTERNATIONAL REFERENCE MODELMODEL

FOR LINKING DIFFERENT TYPES FOR LINKING DIFFERENT TYPES OFOF

COMPUTERS & NETWORKSCOMPUTERS & NETWORKS

**

7.38

E-COMMERCE & E-BUSINESS E-COMMERCE & E-BUSINESS TECHNOLOGIESTECHNOLOGIES

• ELECTRONIC MAIL (e-mail)ELECTRONIC MAIL (e-mail)• VOICE MAILVOICE MAIL• FACSIMILE MACHINES (fax)FACSIMILE MACHINES (fax)• TELECONFERENCINGTELECONFERENCING• DATACONFERENCINGDATACONFERENCING• VIDEOCONFERENCINGVIDEOCONFERENCING• GROUPWAREGROUPWARE

**

7.39

ELECTRONIC DATA ELECTRONIC DATA INTERCHANGE INTERCHANGE (EDI)(EDI)

COMPUTER - TO - COMPUTERCOMPUTER - TO - COMPUTER

EXCHANGE BETWEEN TWO EXCHANGE BETWEEN TWO ORGANIZATIONSORGANIZATIONS

OF STANDARD BUSINESS OF STANDARD BUSINESS TRANSACTION DOCUMENTSTRANSACTION DOCUMENTS

**

COMPUTER COMPUTER

SELLER CUSTOMER

ORDERS, PAYMENTS

SHIPPING NOTICES, PRICE

UPDATES, INVOICES

7.40

PROBLEMS POSED BY PROBLEMS POSED BY ENTERPRISE NETWORKINGENTERPRISE NETWORKING

• CONNECTIVITYCONNECTIVITY

• LOSS OF MANAGEMENT CONTROLLOSS OF MANAGEMENT CONTROL

• ORGANIZATIONAL CHANGE ORGANIZATIONAL CHANGE REQUIREMENTSREQUIREMENTS

• HIDDEN COSTS OF HIDDEN COSTS OF CLIENT/SERVER COMPUTINGCLIENT/SERVER COMPUTING

• RELIABILITY & SECURITYRELIABILITY & SECURITY

**

7.41

HIDDEN COSTS OF CLIENT / SERVER HIDDEN COSTS OF CLIENT / SERVER SYSTEMSSYSTEMS

• OPERATIONS & SUPPORTOPERATIONS & SUPPORT• APPLICATION DEVELOPMENTAPPLICATION DEVELOPMENT• HARDWARE, SOFTWARE, INSTALLATION, HARDWARE, SOFTWARE, INSTALLATION,

MAINTENANCEMAINTENANCE• EDUCATION & EDUCATION & TRAININGTRAINING

**

7.42

TELECOMMUNICATIONS PLAN:TELECOMMUNICATIONS PLAN:

• KNOW LONG-RANGE PLANSKNOW LONG-RANGE PLANS• AUDIT EXISTING CAPABILITIESAUDIT EXISTING CAPABILITIES• IDENTIFY, PRIORITIZE CRITICAL IDENTIFY, PRIORITIZE CRITICAL

IMPROVEMENTSIMPROVEMENTS• ENHANCE FIRM’S STRATEGIC POSITIONENHANCE FIRM’S STRATEGIC POSITION

IMPLEMENT PLANIMPLEMENT PLAN

**

7.43

IMPLEMENTATION FACTORSIMPLEMENTATION FACTORS• DISTANCEDISTANCE• RANGE OF SERVICESRANGE OF SERVICES• SECURITYSECURITY• MULTIPLE ACCESSMULTIPLE ACCESS• UTILIZATIONUTILIZATION• COSTCOST• INSTALLATIONINSTALLATION• CONNECTIVITYCONNECTIVITY

**

7.44

Connect to the INTERNETConnect to the INTERNETLaudon/Laudon Web site: http://www.prenhall.com/laudon

Additional Internet Resources related to this chapter:http://www.sap.comhttp://www.mysap.comhttp://www.peoplesoft.comhttp://www.oec.comhttp://www.novell.comhttp://www.microsoft.comhttp://samba.anu.edu.au/samba

http://www.wpine.com http://www.microsoft.com/netmeetinghttp://wwwhost.ots.utexas.edu/ethernet/

© 2001 Laudon & Laudon, Essentials of Management Information Systems 4/e

7.45

CHAPTER 7. CHAPTER 7. TELECOMMUNICATIONSTELECOMMUNICATIONS

NETWORKS & THE NEW NETWORKS & THE NEW INFORMATION INFORMATION TECHNOLOGYTECHNOLOGY