88TELECOMMUNICATIONSTELECOMMUNICATIONS

AND NETWORKSAND NETWORKS

LEARNING OBJECTIVES

DESCRIBE COMPONENTS OF TELECOMMUNICATIONS SYSTEM

CALCULATE CAPACITY OF TELECOMMUNICATIONS CHANNELS & EVALUATE TRANSMISSION MEDIA

COMPARE TYPES OF NETWORKS & NETWORK SERVICES

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LEARNING OBJECTIVES

COMPARE ALTERNATIVE NETWORK SERVICES

IDENTIFY APPLICATIONS FOR SUPPORTING ELECTRONIC COMMERCE, BUSINESS

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MANAGEMENT CHALLENGES

TELECOMMUNICATIONS REVOLUTION

COMPONENTS, FUNCTIONS OF TELECOMMUNICATIONS SYSTEM

COMMUNICATIONS NETWORKS ELECTRONIC COMMERCE &

ELECTRONIC BUSINESS TECHNOLOGIES

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MANAGEMENT CHALLENGES

1. MANAGING LOCAL AREA NETWORKS: Must be carefully administered, monitored, vulnerable to interruption, data loss, viruses

2. MANAGING BANDWIDTH: While costs per unit are dropping and capacity is growing, sudden demand can overwhelm system

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TELECOMMUNICATIONS

COMMUNICATING INFORMATIONVIA ELECTRONIC MEANSOVER SOME DISTANCE

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INFORMATION SUPERHIGHWAY

NATIONAL / WORLDWIDEHIGH SPEED

DIGITAL TELECOMMUNICATIONSACCESSIBLE BY GENERAL PUBLIC

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SYSTEM COMPONENTS

COMPUTERS TERMINALS: Input / output devices COMMUNICATIONS CHANNELS PROCESSORS: Modems, multiplexers,

front-end processors COMMUNICATIONS SOFTWARE Routers, Hubs and Switches

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PROTOCOL

RULES & PROCEDURESTO GOVERN TRANSMISSION

BETWEEN COMPONENTS IN A NETWORK

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ANALOG SIGNAL CONTINUOUS WAVEFORM PASSES THRU SYSTEM VOICE COMMUNICATIONS

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DIGITAL SIGNAL

DISCRETE WAVEFORM TWO DISCRETE STATES:

1-BIT & 0-BIT ON / OFF PULSE

DATA COMMUNICATION USES MODEM TO TRANSLATE

ANALOG TO DIGITAL, DIGITAL TO ANALOG

*0010111010011101001010101110111100100010000101111010110100111010010010110010101101100

COMMUNICATION CHANNELSMEANS BY WHICH DATA ARE

TRANSMITTED: TWISTED WIRES: Copper Wires COAXIAL CABLE: Insulated Copper Wires FIBER-OPTIC CABLE MICROWAVE Radio Frequency

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SUPER CLEAR GLASS STRANDS FAST, LIGHT, DURABLE TRILLIONS OF BITS PER SECOND, FULL

DUPLEX EXPENSIVE, HARDER TO INSTALL OFTEN USED AS BACKBONE OF

NETWORKS*

FIBER OPTICS

SIGNALSIGNAL LASERLASER CABLECABLE PHOTOPHOTODETECTORDETECTOR SIGNALSIGNAL

BACKBONE: Fiber optics cable carries light signals to distribution nodes, which use copper wires to user

DENSE WAVE DIVISION MULTIPLEXING (DWDM): Next-generation, uses many colors, (up to 160) each a channel, increases capacity of a fiber to 6.4 terabits per second

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FIBER OPTICS

WIRELESS TRANSMISSION TECHNOLOGIES PAGERS: Small pager beeps when

receives short message CELLULAR TELEPHONE: Device uses

radio waves to reach antennas within areas called cells

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

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WIRELESS TRANSMISSION TECHNOLOGIES

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

PERSONAL DIGITAL ASSISTANT: Pen sized, hand-held, digital

communicator SMART PHONE: Wireless, voice, text,

Internet*

ORBITING SATELLITES

UPLINKUPLINK

MICROWAVE MICROWAVE TRANSMISSIONTRANSMISSION

DOWNLINKDOWNLINK

TRANSMISSION SPEED: Bits per Second (BPS) or Baud

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

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COMMUNICATIONS CHANNELS

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 - 6.4 TBPS500 KBPS - 6.4 TBPS HIGHHIGH BPS: BITS PER SECONDBPS: BITS PER SECOND KBPS: KILOBITS PS, MBPS: MEGABITS PS,KBPS: KILOBITS PS, MBPS: MEGABITS PS, GBPS: GIGABITS PS, TBPS: TERABITS PSGBPS: GIGABITS PS, TBPS: TERABITS PS

SPEEDS & COST OF MEDIA

COMMUNICATIONS PROCESSORS

FRONT- END PROCESSOR: Minicomputer manages communication for host computer

CONCENTRATOR: Computer collects messages for batch transmission to host computer

CONTROLLER: Computer controls interface between CPU and peripheral devices

MULTIPLEXER: Allows channel to carry multiple sources simultaneously

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NETWORK TOPOLOGIES

HOSTHOST

USERUSER

USERUSER

USERUSER USERUSER

STARHost mainframe computers use this with terminals.

NETWORK TOPOLOGIES

BUSCollision detection is required for multiple devices to share the same bus. This creates some inefficiency.

USERUSER

USERUSER

USERUSER

USERUSER

USERUSER

USERUSER

Network devices may look like a

star configuration

NETWORK TOPOLOGIES

DeviceDevice

DeviceDevice

DeviceDevice

DeviceDevice

RINGA token is passed from device to device. Synchronizing access to the ring. Single rings exists in older systems. Newer double rings are more reliable.

LOCAL NETWORKS

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

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

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LOCAL AREA NETWORK (LAN)

GATEWAY: Connection to other networks ROUTER: Forwards data to other networks NETWORK OPERATING SYSTEM (NOS):

Manages file server; routes communications on network

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

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

SWITCHED LINES: Route determined by current traffic

DEDICATED LINES: Constantly available for high-volume traffic

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WIDE - AREA NETWORK (WAN)

VALUE-ADDED NETWORK (VAN) PRIVATE, MULTIPATH, DATA ONLY 3rd PARTY MANAGED USED BY SEVERAL ORGANIZATIONS SUBSCRIPTION BASIS

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NETWORK SERVICES

PACKET SWITCHING FRAME RELAY ASYNCHRONOUS TRANSFER MODE (ATM) INTEGRATED SERVICES DIGITAL

NETWORK (ISDN) SYMMETRIC DIGITAL SUBSCRIBER LINE CABLE MODEM T1 LINE

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PACKET SWITCHING (X.25) FORM OF Value Added Network BREAKS DATA BLOCKS INTO SMALL

PACKETS (e.g.: 128 Bytes) PACKETS ROUTED BY MOST

ECONOMICAL MEANS REASSEMBLED AT DESTINATION

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FRAME RELAY PACKAGES DATA INTO BLOCKS

(FRAMES) HIGH-SPEED TRANSMISSION RELIABLE LINES NO ERROR-CORRECTION

ROUTINES*

ASYNCHRONOUS TRANSFER MODE (ATM)

CELL: 53 Groups of 8 Bytes Each USES FIBER OPTICS CABLE INDEPENDENT OF VENDOR

HARDWARE SPEEDS CAN TIE LAN TO WAN

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INTEGRATED SERVICES DIGITAL NETWORK (ISDN)

INTERNATIONAL STANDARD FOR TRANSMITTING VOICE, VIDEO,

DATAOVER PUBLIC TELEPHONE LINES

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OTHER SERVICES:

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

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

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

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OTHER SERVICES:

BROADBAND: High-speed transmission, multiple channels

NETWORK CONVERGENCE: Enables simultaneous transmission of voice, data, video. Attractive for multimedia applications: Video collaboration, voice-data call centers, distance learning, unified messaging

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E-COMMERCE & E-BUSINESS TECHNOLOGIES

ELECTRONIC MAIL (e-mail) GROUPWARE VOICE MAIL FACSIMILE MACHINES (fax) TELECONFERENCING DATACONFERENCING VIDEOCONFERENCING

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E-COMMERCE & E-BUSINESS TECHNOLOGIES

DIGITAL INFORMATION SERVICES: Commercial service provides desired mix

DISTANCE LEARNING: Education, training delivered over a distance, can include printed material, teleconferencing, interactive multimedia, Web sites

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COMMERCIAL DIGITAL INFORMATION SERVICES

PROVIDER TYPE OF SERVICE

AMERICA ONLINE General interest / business information

PRODIGY General interest / business information

MICROSOFT NETWORK General interest / business information

DOW JONES NEWS RETRIEVAL Business / financial information

DIALOG Business / scientific / technical information

LEXIS Legal research

NEXIS News / business information

ELECTRONIC DATA INTERCHANGE (EDI)

COMPUTER - TO - COMPUTEREXCHANGE BETWEEN TWO

ORGANIZATIONSOF STANDARD BUSINESS TRANSACTION DOCUMENTS

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COMPUTER COMPUTER

SELLER CUSTOMER

ORDERS, PAYMENTS

SHIPPING NOTICES, PRICE

UPDATES, INVOICES

88TELECOMMUNICATIONSTELECOMMUNICATIONS

AND NETWORKSAND NETWORKS