Download Chapter 1 Introduction to Telecommunications

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
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Meaningful implies perception
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Telecommunications
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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
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Subset of telecommunications excluding
analog signals
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Non much analog these days
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Data vs. Information
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Data - representation of facts, concepts, etc.
suitable for communication
Information - meaning associated with data
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Telecommunications Elements
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May have multiple transmitters in a system
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Form networks
Rules or protocols
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Example: establishing communications requires
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Initiation
Identification of sender and receiver
Order of communication
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Basic Telecom System
Elements
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Telecom and Business
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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
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Reduces effect of geography
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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)
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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
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Variable requirements
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Some applications need round-the-clock
availability
Some businesses operate 8am to 5pm
Time zone effects
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Must take into account working hours in other
locations you must communicate with, nationally
and internationally
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Reliability
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MTBF - mean time between failure
MTTR - Mean time to repair
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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
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1847 - Telegraph
1877 - Telephone
1885 - American Telephone and Telegraph Company (AT&T) 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
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1969 - ARPANET
 An experimental data network
1970 - Fiber optics
1970s - Dial-up computer communications
1978 - Cellular phone
1981 - IBM PC
1984 - AT&T 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
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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
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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
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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
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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, VoiceOver-IP, Virtual Private Networks, etc.
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Major Internet Components
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Backbone
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Backbone routers
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Main infrastructure of Internet
Main nodes connected by T1, T3, OC3, OC12
links
Packet switches route data
A DSU/CSU (Data Service Unit / Channel Service
Unit) interfaces router to backbone
Internet Service Provider (ISP)
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Company that links many users to backbone
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Major Internet Components
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Concentrator
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Interfaces several network technologies in a
single chassis
Similar to a router
Site Router
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Also known as an Access Router or Premise
Router
Connects a customer-s computers to the ISP
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Major Internet Components
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T. Fallon, The Internet Today, Upper Saddle River, NJ, Prentice Hall, 2000
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Case Study - Dow Corning
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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
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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)
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11,000 personal computers and terminals
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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
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