Telecommunications

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Telecommunications Networks
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Structure of the Internet

• IP address (Internet Protocol)
• Packet
• Router
• TCP/IP Video

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Communications Media

• Communications medium
• The hardware that connects computers and other
  digital equipment
• Bandwidth
• Indicates how much data can be transferred
  through the medium in a fixed amount of time
• Usually measured in bits per second (bps)

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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

00101110100111010010101011101111001000100001011110
10110100111010010010110010101101100
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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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FIBER OPTICS

• SUPER CLEAR GLASS STRANDS
• FAST, LIGHT, DURABLE
• BILLIONS OF BITS PER SECOND, FULL DUPLEX
• EXPENSIVE, HARDER TO INSTALL
• OFTEN USED AS BACKBONE OF NETWORKS

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5.3.2 Communications Media

• Fiber-optic cable
• Composed of flexible glass fiber, is thinner and
  lighter than traditional copper wire, yet has
  much wider bandwidth
• Uses short bursts of light to represent bits
• Optical modem
• Modem stands for modulator and demodulator
• Translates digital signals from computers into
  light through a process called modulation
• Opto chip
• Converts the most basic particle of light, the
  photon, into an electric current
• Allows tremendous amounts of data to be sent over
  fiber-optic networks through particles 100 times
  smaller than the diameter of a human hair

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ORBITING SATELLITES
MICROWAVE TRANSMISSION
UPLINK
DOWNLINK
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WIRELESS TRANSMISSION TECHNOLOGIES

• PAGING SYSTEM 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

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SPEEDS COST OF MEDIA
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Connecting to the Internet

• Most home users subscribe to an Internet Service
  Provider (ISP) to connect to the Internet
• Analog modem
• Takes digital signals from the computer and turns
  them into analog signals
• A modem at the ISP then converts the sound back
  into a digital signal that can be transmitted
  over the Internet

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Integrated Services Digital Network (ISDN)

• Provides high-speed connections to the Internet
  over both digital and standard telephone lines
• Limited service
• Costly connection

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Digital Subscriber Lines

• Digital Subscriber Lines (DSL)
• Offers high-bandwidth Internet access over
  existing copper telephone lines
• Splits your phone line into three
  information-carrying channels
• DSL connections require special hardware at the
  local telephone companys central office and at
  the users location

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Digital Subscriber Lines

• IAD (integrated access device)
• High-speed Internet access, and for multiple
  voice lines
• ADSL (asymmetric DSL)
• Speed for sending data (upstream) is slower than
  for receiving (downstream)
• VoDSL (voice over DSL)
• Voice services and high-speed data access over a
  single telephone line
• SDSL (symmetric DSL)
• Same speed both upstream and downstream

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T-1 and T-3 Lines

• T-1 line
• A dedicated connection that supports data rates
  of 1.544 Mb per second
• Made up of 24 channels
• T-3 line
• Supports data rates of 43Mbps and is made up of
  672 channels that each support 64Kbps
• T-1 and T-3 lines can be used for both voice and
  data communication

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Technology Speed
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Broadband

• A category of high-bandwidth Internet service
• Can handle voice, data and video information
• Enables videoconferencing, real-time voice and
  streaming-media applications

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Internet2

• Consortium developing next generation of the
  Internet
• Abeline - A high-speed network able to transfer
  2.4 gigabits of data per second
• Teleimmersion - Allows users to share information
  in real timeeven 3D images
• Virtual laboratory - Enable researchers worldwide
  to collaborate on projects
• Digital libraries - Storage of audio and video
  files enabling a search capabilities.

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Metromedia Fiber Network
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Software

• Application Service Providers
• Databases

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Application Service Provider

• Provide customized business software applications
  over the Internet
• Maintains and updates the application as
  necessary
• Companies can eliminate the costs associated with
  developing and maintaining business applications
• Virtual private networks (VPNs) using the
  point-to-point tunneling protocol (PPTP)

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Databases

• Database management system (DBMS)
• Provides mechanisms for storing and organizing
  data in a manner that facilitates satisfying
  sophisticated queries and data manipulations
• Structured Query Language (SQL
• Almost universally used with relational database
  systems to make queries (i.e., to request
  information that satisfies given criteria) and
  manipulate data

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Databases

• Relational database model
• A logical representation of the data that allows
  the relationships between the data to be
  considered independently of the physical
  implementation of the data structures
• Popular enterprise-level relational database
  systems Microsoft SQL Server, Oracle , Sybase ,
  DB2

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Enhancing Business Communication

• Intranets Extranets
• Streaming audio and video
• Internet telephony - Makes PC-to-PC and
  PC-to-phone calls possible, dramatically reducing
  the cost of communication
• Web casting
• Virtual conferencing
• Wireless technology

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Intranets and Extranets

• Intranet
• An organizations internal network that uses
  TCP/IP protocols of the Internet
• Only authorized parties have access to an
  organizations intranet
• Used to store internal information
• Extranet
• An intranet that is accessible by authorized
  external parties who are not employees of the
  organization
• Employees might have unrestricted access to
  information on the extranet, whereas customers or
  vendors might have access to a limited subset of
  that information

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Webcasting and Web Conferencing

• Webcasting
• Broadcasting over the Web
• Businesses can stream seminars, conferences,
  shows, sales presentations and more though their
  Web sites
• Live or prerecorded
• Web conferencing
• Allows businesses to meet and collaborate online,
  in real time from anywhere in the world

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NETWORK TOPOLOGIES
STAR
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NETWORK TOPOLOGIES
BUS
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NETWORK TOPOLOGIES
RING
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LOCAL AREA NETWORKS

• Limited distance (less than 2000 foot radius
• Share expensive hardware software
• 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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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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VALUE-ADDED NETWORK (VAN)

• PRIVATE MULTIPATH DATA ONLY
• 3rd PARTY MANAGED
• USED BY SEVERAL ORGANIZATIONS
• SUBSCRIPTION BASIS

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TELECOMMUNICATIONS PLAN

• KNOW LONG-RANGE PLANS
• AUDIT EXISTING CAPABILITIES
• IDENTIFY, PRIORITIZE CRITICAL IMPROVEMENTS
• ENHANCE FIRMS STRATEGIC POSITION
• IMPLEMENT PLAN

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IMPLEMENTATION FACTORS

• DISTANCE
• RANGE OF SERVICES
• SECURITY
• MULTIPLE ACCESS
• UTILIZATION
• COST
• INSTALLATION
• CONNECTIVITY

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Getting a Technology Job

• http//www.techjobsonline.com