Transcript 8.15 Prof Jess Role @ UEAB 2010

8
TELECOMMUNICATIONS
AND NETWORKS
8.1
Prof Jess Role @ UEAB 2010
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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8.2
Prof Jess Role @ UEAB 2010
LEARNING OBJECTIVES
• COMPARE ALTERNATIVE
NETWORK SERVICES
• IDENTIFY APPLICATIONS FOR
SUPPORTING ELECTRONIC
COMMERCE, BUSINESS
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8.3
Prof Jess Role @ UEAB 2010
MANAGEMENT CHALLENGES
• TELECOMMUNICATIONS REVOLUTION
• COMPONENTS, FUNCTIONS OF
TELECOMMUNICATIONS SYSTEM
• COMMUNICATIONS NETWORKS
• ELECTRONIC COMMERCE &
ELECTRONIC BUSINESS TECHNOLOGIES
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8.4
Prof Jess Role @ UEAB 2010
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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8.5
Prof Jess Role @ UEAB 2010
TELECOMMUNICATIONS
COMMUNICATING INFORMATION
VIA ELECTRONIC MEANS
OVER SOME DISTANCE
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8.6
Prof Jess Role @ UEAB 2010
INFORMATION SUPERHIGHWAY
NATIONAL / WORLDWIDE
HIGH SPEED
DIGITAL TELECOMMUNICATIONS
ACCESSIBLE BY GENERAL PUBLIC
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8.7
Prof Jess Role @ UEAB 2010
SYSTEM COMPONENTS
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COMPUTERS
TERMINALS: Input / output devices
COMMUNICATIONS CHANNELS
PROCESSORS: Modems, multiplexers,
front-end processors
• COMMUNICATIONS
SOFTWARE
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8.8
Prof Jess Role @ UEAB 2010
PROTOCOL
RULES & PROCEDURES
TO GOVERN TRANSMISSION
BETWEEN COMPONENTS
IN A NETWORK
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8.9
Prof Jess Role @ UEAB 2010
ANALOG SIGNAL
• CONTINUOUS WAVEFORM
• PASSES THRU SYSTEM
• VOICE COMMUNICATIONS
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8.10
Prof Jess Role @ UEAB 2010
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
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001011101001110100101010111011110010001000010111101011010
8.11
Prof Jess Role @ UEAB 2010
COMMUNICATION CHANNELS
MEANS BY WHICH DATA ARE
TRANSMITTED:
• TWISTED WIRES: Copper Wires
• COAXIAL CABLE: Insulated Copper
Wires
• FIBER-OPTIC CABLE
• MICROWAVE
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8.12
Prof Jess Role @ UEAB 2010
FIBER OPTICS
• SUPER CLEAR GLASS STRANDS
• FAST, LIGHT, DURABLE
• TRILLIONS OF BITS PER SECOND, FULL
DUPLEX
• EXPENSIVE, HARDER TO INSTALL
• OFTEN USED AS BACKBONE OF
NETWORKS
PHOTO
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SIGNAL
LASER
CABLE
SIGNAL
DETECTOR
8.13
Prof Jess Role @ UEAB 2010
FIBER OPTICS
• 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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8.14
Prof Jess Role @ UEAB 2010
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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8.15
Prof Jess Role @ UEAB 2010
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
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8.16
Prof Jess Role @ UEAB 2010
ORBITING SATELLITES
MICROWAVE
TRANSMISSION
UPLINK
8.17
Prof Jess Role @ UEAB 2010
DOWNLINK
COMMUNICATIONS CHANNELS
• TRANSMISSION SPEED: Bits per
Second (BPS) or Baud
• BANDWIDTH: Capacity of Channel;
Difference between Highest & Lowest
Frequencies
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8.18
Prof Jess Role @ UEAB 2010
SPEEDS & COST OF MEDIA
MEDIUM
TWISTED WIRE
SPEED
300 BPS - 10 MBPS
MICROWAVE
256 KBPS - 100 MBPS
SATELLITE
256 KBPS - 100 MBPS
COAXIAL CABLE
56 KBPS - 200 MBPS
FIBER OPTICS
500 KBPS - 6.4 TBPS
BPS: BITS PER SECOND
KBPS: KILOBITS PS, MBPS: MEGABITS PS,
GBPS: GIGABITS PS, TBPS: TERABITS PS
8.19
Prof Jess Role @ UEAB 2010
COST
LOW
HIGH
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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8.20
Prof Jess Role @ UEAB 2010
NETWORK TOPOLOGIES
USER
USER
STAR
8.21
Prof Jess Role @ UEAB 2010
HOST
USER
USER
NETWORK TOPOLOGIES
USER
USER
USER
USER
USER
USER
BUS
8.22
Prof Jess Role @ UEAB 2010
NETWORK TOPOLOGIES
USER
USER
RING
8.23
Prof Jess Role @ UEAB 2010
USER
USER
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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8.24
Prof Jess Role @ UEAB 2010
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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8.25
Prof Jess Role @ UEAB 2010
WIDE - AREA NETWORK (WAN)
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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8.26
Prof Jess Role @ UEAB 2010
VALUE-ADDED NETWORK
(VAN)
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8.27
PRIVATE, MULTIPATH, DATA ONLY
3rd PARTY MANAGED
USED BY SEVERAL ORGANIZATIONS
SUBSCRIPTION BASIS
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Prof Jess Role @ UEAB 2010
NETWORK SERVICES
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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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8.28
Prof Jess Role @ UEAB 2010
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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8.29
Prof Jess Role @ UEAB 2010
FRAME RELAY
• PACKAGES DATA INTO BLOCKS
(FRAMES)
• HIGH-SPEED TRANSMISSION
• RELIABLE LINES
• NO ERROR-CORRECTION
ROUTINES
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8.30
Prof Jess Role @ UEAB 2010
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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8.31
Prof Jess Role @ UEAB 2010
INTEGRATED SERVICES DIGITAL
NETWORK (ISDN)
INTERNATIONAL STANDARD FOR
TRANSMITTING VOICE, VIDEO,
DATA
OVER PUBLIC TELEPHONE LINES
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8.32
Prof Jess Role @ UEAB 2010
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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8.33
Prof Jess Role @ UEAB 2010
OTHER SERVICES:
• BROADBAND: High-speed transmission,
multiple channels
• NETWORK CONVERGENCE: Enables
simultaneous transmission of voice, data,
video. Attractive for multimedia
applications: Video collaboration, voicedata call centers, distance learning,
unified messaging
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8.34
Prof Jess Role @ UEAB 2010
E-COMMERCE &
E-BUSINESS TECHNOLOGIES
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ELECTRONIC MAIL (e-mail)
GROUPWARE
VOICE MAIL
FACSIMILE MACHINES (fax)
TELECONFERENCING
DATACONFERENCING
VIDEOCONFERENCING
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8.35
Prof Jess Role @ UEAB 2010
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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8.36
Prof Jess Role @ UEAB 2010
COMMERCIAL DIGITAL INFORMATION
SERVICES
PROVIDER
8.37
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
Prof Jess Role @ UEAB 2010
ELECTRONIC DATA INTERCHANGE
(EDI)
COMPUTER - TO - COMPUTER
EXCHANGE BETWEEN TWO
ORGANIZATIONS
OF STANDARD BUSINESS
TRANSACTION DOCUMENTS
SELLER
CUSTOMER
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ORDERS, PAYMENTS
COMPUTER
SHIPPING NOTICES, PRICE
UPDATES, INVOICES
8.38
Prof Jess Role @ UEAB 2010
COMPUTER
TELECOMMUNICATIONS
AND NETWORKS
8.39
Prof Jess Role @ UEAB 2010