Introduction to Telecommunications

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Chapter 1

• Introduction to Telecommunications

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Communication

• 1. Process that allows information to pass
  between a sender and receiver
• - or -
• 2. Transfer of meaningful information between two
  locations
• Meaningful implies perception

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Telecommunications

• Tele means far off or distant
• Telecommunications today means communication by
  electrical or electromagnetic means, usually over
  a distance

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Data Communications

• Subset of telecommunications excluding analog
  signals
• Non much analog these days

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Data vs. Information

• Data - representation of facts, concepts, etc.
  suitable for communication
• Information - meaning associated with data

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Telecommunications Elements

• May have multiple transmitters in a system
• Form networks
• Rules or protocols
• Example establishing communications requires
• Initiation
• Identification of sender and receiver
• Order of communication

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Basic Telecom System Elements
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Telecom and Business

• Business must move data and voice information
  within locations and between locations
• Timing
• Information must be available when needed
• Telecom advances are revolutionizing information
  transfer
• Competitive business must maximize use of
  information for marketing and productivity
  enhancement
• Transactions
• Airline reservations, banking, marketing
• Used for availability, location, shipping
  accounting
• Online business E-commerce

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Telecom and Business

• Reduces effect of geography
• Link remote branches with voice/data/video
• Mobile communications
• Telecommuting

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Telecom Examples
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Telecom Examples
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Telecom Examples
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Telecom Examples
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Telecom Examples
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Telecom Examples
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Telecom System Requirements (Data System)

• Availability
• System ready and operating when needed
• Reliability
• System trouble free and error free
• Real time or real-enough time
• Response time
• System does not hinder user by introducing too
  much delay
• Ease of use
• Ergonomics
• Flexibility and scalability
• System easy to change to meet future needs

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Availability

• Variable requirements
• Some applications need round-the-clock
  availability
• Some businesses operate 8am to 5pm
• Time zone effects
• Must take into account working hours in other
  locations you must communicate with, nationally
  and internationally

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Reliability

• MTBF - mean time between failure
• MTTR - Mean time to repair
• How long does it take to repair system?
• Reduce effects of failure with redundant (backup)
  components

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Reliability Example 1

• Overall reliability in a cascaded system is
  always lower than the least reliable component

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Reliability Example 2
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Telecommunications Timeline
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Key Telecom Events

• 1847 - Telegraph
• 1877 - Telephone
• 1885 - American Telephone and Telegraph Company
  (ATT) formed
• 1895 - Radio
• 1934 - Communications Act of 1934 (FCC)
• 1939 - Television
• 1947 - Microwave communications
• 1956 - First transatlantic telephone cable TAT-1
• 1957 - Satellite
• 1960s Computer/Terminal communications

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Key Telecom Events

• 1969 - ARPANET
• An experimental data network
• 1970 - Fiber optics
• 1970s - Dial-up computer communications
• 1978 - Cellular phone
• 1981 - IBM PC
• 1984 - ATT Divestiture
• 1980s - LAN
• 1990 - World Wide Web (WWW)
• 1996 - Telecommunications Act of 1996
• 1990s - Intranet, Extranet, E-Commerce, growth of
  wireless
• Late 1990s - media convergence

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Internet Timeline
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Key Internet Events

• 1961 - Leonard Kleinrock publishes paper on
  packet switching
• 1969 - ARPANET test
• 1970 - Network Control Protocol (NCP) implemented
  on ARPANET
• 1971 - E-mail
• 1974 - Kahn and Cerf publish paper on TCP/IP
• 1974 - 62 hosts on ARPANET
• 1979 - USENET newsgroup network

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Key Internet Events

• 1983 - Internet Activity Board (IAB) created to
  oversee protocol development
• 1983 - TCP/IP version 4 adopted for ARPANET
• 1983 - 500 hosts
• 1984 - Domain Name System (DNS)
• 1986 - National Science Foundation Network
  (NSFNET)
• 1988 - Worm virus
• 1988 - Computer Emergency Response Team (CERT)
• 1990 - ARPANET retired

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Key Internet Events

• 1991 - Gopher menu-driven Intenet interface
• 1991 - Tim Berners-Lee develops World Wide Web
• 1992 - 1,000,000 hosts
• 1993 - Mosaic graphical WWW interface
• 1993 - Internet Network Information Center
  (InterNIC)
• 1993 - 2,000,000 hosts
• 1995 - NSF stops supporting NSFNET
• Internet goes commercial
• Internet Service Providers (ISPs)

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Key Internet Events

• 1995 - NSF starts supporting Very-High-Speed
  Backbone Network Service (vBNS)
• 1996 - Telecommunications Act of 1996
• 1996 - 10,000,000 hosts
• 1997 to present - E-commerce, distance learning,
  Voice-Over-IP, Virtual Private Networks, etc.

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Major Internet Components

• Backbone
• Main infrastructure of Internet
• Main nodes connected by T1, T3, OC3, OC12 links
• Backbone routers
• Packet switches route data
• A DSU/CSU (Data Service Unit / Channel Service
  Unit) interfaces router to backbone
• Internet Service Provider (ISP)
• Company that links many users to backbone

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Major Internet Components

• Concentrator
• Interfaces several network technologies in a
  single chassis
• Similar to a router
• Site Router
• Also known as an Access Router or Premise Router
• Connects a customer-s computers to the ISP

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Major Internet Components

• T. Fallon, The Internet Today, Upper Saddle
  River, NJ, Prentice Hall, 2000

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Case Study - Dow Corning

• Headquarters in Midland Michigan
• Business
• Develop, manufacture, and market silicones and
  related products
• Business structure requires close coordination
  between marketing, manufacturing, etc.
• Telecom at Dow Corning
• Responsibility lies within corporate Information
  Technology (IT) department
• Data and voice responsibilities brought under
  same group in 1982

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Case Study - Dow Corning

• Data and voice responsibilities brought under
  same group in 1982
• 1991 - emphasis on interaction between CIS
  department and telecom people in manufacturing
  areas
• Network (in 1999)
• 11,000 personal computers and terminals
• 5,800 in U.S.
• Goal to provide rapid response time for most
  transactions

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Case Study - Dow Corning
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Case Study - Dow Corning