COMPUTERS IN THE CLASSROOM CT 243 Emery Roth eroth hartford edu http uhaweb hartford edu eroth CHAPTER 2 Communications Networks th by rjz61441

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									COMPUTERS IN THE
  CLASSROOM
        CT 243


                       Emery Roth
               eroth@hartford.edu
  http://uhaweb.hartford.edu/eroth/
 CHAPTER 2
Communications,
 Networks, the
Internet, and the
World Wide Web
http://www.scsite.com/tdc2/
Q&A
What are the two
main categories of
software…
and how are they
different? (1.13-1.14)
What are the “National
Educational Technology
Standards for Teachers”
(NETS-T), and where do
they come from? (1.19-1.20)
What is a “motherboard,”
and
what are its two main
components? (1.08)
What are 5 components
of a computer?
…and give examples of
each. (1.07-1.10)
What is, “the Internet,”
 and
what are several ways it
is useful for teachers?
(1.17-1.18)
http://www.scsite.com/tdc2/
     Click on “Chapter 1”
 From the menu on the left,
 select “Integration Corner,”
       then “chapter 1”
 Scroll to any level of personal
interest & explore one resource
PROCESSING YOUR CLASSMATE SKETCHES
  1.    Gather by teams to regroup
  2.    Read at least 3 sketches.
  3.    Select group recorder (WP).
  4.    Process:
       • I really liked…
       • I learned to…
       • How do I…?
       • Publish???
To publish or not
  to publish…
          Drawing Tablet




• pressure-sensitive
• designed to work with software applications that
  simulate real artists’ media
spreadsheet
ASSIGNMENT
  posted on blackboard & web site


          Web site:
http://uhaweb.hartford.edu/eroth/
 CHAPTER 2
Communications,
 Networks, the
Internet, and the
World Wide Web
                     Objectives
 Define communications
 Identify the basic components of a communications system
 Describe how and why network computers are used in
  schools and school districts
 Explain how the Internet works
 Describe the World Wide Web portion of the Internet
 Specify how Web documents are linked to one another
 Explain the use of Web browser software
 Explain how to use a Web search tool to find information
 Identify several types of multimedia products available on
  the Web
 Explain how Internet services such as e-mail, newsgroups,
  chat rooms, and instant messaging work
 Describe how to connect to the Internet and the WWW
         Communications Networks
 Communications - refers to the transmission of data
  and information between two or more computers
  using a communications channel such as standard
  telephone lines
 Communications network - is a collection of
  computers and other equipment organized to share
  data, information, hardware, and software
 Communications software - programs that manage the
  transmissions of data between computers
 Communications channel - is the path the data follows
  as the data is transmitted from the sending equipment
  to the receiving equipment in a communications
  system.
  Communications Networks Continued
 Transmission media - is the physical
  materials or other means used to establish a
  communications channel
     Twisted-pair cable - consists of pairs of plastic-
      coated copper wire twisted together
     Other examples (coaxial cable, fiber-optic
      cable, microwave transmission,
      communications satellites, and wireless
      transmissions
 Communications Networks Continued
 Digital signals - are individual electric pulses
  that a computer uses to represent data
 Analog signals - continuous electrical wave
  used for telephone transmission and other
  devices
 Modem - converts analog signals into digital
  signals
 Network interface card (NIC) - connects
  computers directly to a school or business
  network without using a modem
                Types of Networks
 Local area networks (LAN) - is a communications
  network that covers a limited geographical area such
  as a school, an office, a building, or a group of
  buildings
 Wireless LAN (WLAN) - uses no wires, instead it
  uses wireless media, such as radio waves.
 Wide area networks - covers a large geographical
  region and used regular telephone cables, digital lines,
  microwaves, wireless systems, satellites, or other
  combinations of communications channels.
 Home networks - if you have multiple computers in
  your home or home office you can create your own
  network
           History of the Internet
 ARPANET - Advanced Research Projects Agency
  Network
    allow scientists to share information

    parts could function even if some of it went down

    Established 1969 and by 1984 it had 1,000 hosts

 In 1986 NSFnet joined together with ARPANET to
  serve as the backbone of the Internet
 In 1995 NSF turned over responsibilities to major
  corporations
 Internet2 - extremely high speed network that will
  develop and test advanced Internet technologies for
  research, teaching, and learning.
          How the Internet works
 Step 1. Data is divided into small pieces, called
  packets.
 Step 2. Packets travel over the Internet via routers.
 Step 3. At the destination, the packets are
  reassembled into the original message.
      Packet switching
 TCP/IP - transmission control protocol/Internet
  protocol - protocol used to define packet switching
          ISP vs. OSP vs. WSP
 Internet service provider (ISP) - allows you to
  connect to the internet for a fee. (ex. Netzero,
  ATT)
 Online service provider (OSP) - allows you to
  connect to the internet and also provides other
  personalized options for a higher fee than an ISP
 Wireless service provider (WSP) - allows users to
  connect to the internet without any wires. (ex.
  Palm)
     Ways to Connect to the Internet

 Dial-up access - you use your computer and
  a modem to dial in to the internet. (56k)
 Cable modem - you use your existing tv
  cable and a cable modem (20-50 x faster)
 Digital subscriber line - you use digital
  phone lines and dsl card. (25-150 x faster)
             Internet Backbone
 Step 1: Request a web page from your home computer
 Step 2: Modem converts digital to analog
 Step 3: Data travels through telephone lines to local
  ISP
 Step 4: Data may travel through 1 or more routers
 Step 5: Regional ISP uses lines, leased from a
  telephone company, to send data to a national ISP
 Step 6: A national ISP routes data across the country
  to another national ISP
 Step 7: Data moves from a national ISP to a local ISP
  to a server that contains the requested site
 Step 8: The server requests the data and sends it back
  through the internet.
                 Internet Addresses
 The Internet uses addresses the same way the post
  office does. Each computer has a specific numeric
  address.
       I.e. 137.49.1.150
 Domain name - the text version of a computer
  address
 Domain abbreviations - .com, .edu, .gov, .mil,
  .net, .org, .k12
 Country abbreviations
      Au - Australia; CA - Canada; UK - United Kingdom
             World Wide Web
 The Web - consists of electronic documents that
  have built in hyperlinks to other related documents
 Hyperlinks - allow users to navigate quickly from
  one page to another
 Web page - electronic document viewed on the
  Web that can contain audio, video, text, etc.
   Web site - a collection of related web pages
   Home page - starting point of a web site
   URL - uniform resource locator
   HTTP - hypertext transfer protocol
       How a Web Page Works
 Three types of hyperlinks exist
     Target hyperlinks - links within the same page
     Relative hyperlinks - link to another document
      on the same Internet computer (server)
     Absolute hyperlinks - link to another document
      that could be located on a computer across the
      country
 HTML - hypertext mark-up language - the
  code that defines what a website will look
  like
      Web Browser Software

 A web browser is a program that interprets
  HTML and displays Web pages and allows
  links to other pages
 Mosaic - developed in 1993 by Marc
  Andreesen, a student at the University of
  Illinois
 Netscape, Internet Explorer, AOL, Safari
Searching for Info. on the Web
 Search tools - enable users to locate information
  found at Web sites all over the world
 Search engine - a type of search tool that uses
  keywords
 Subject directory - a type of tool that allows the
  user to navigate the directories and subdirectories
           Multimedia on the Web
 Multimedia is the combination of graphics,
  animation, audio, video, and virtual reality
 Graphics - were the first media used to enhance
  text only sites
 Animation - is the appearance of motions created
  by displaying a series of still images in rapid
  sequence
 Audio - you can listen to prerecorded audio clips
  and live audio
 Video - consists of full motion images that are
  played back at various speeds
 Virtual reality - is the simulation of a real or
  imagined environment
                  E-mail
 E-mail (electronic mail) - is the
  transmission of messages and files via a
  computer network
 E-mail program - allows you to compose,
  view, send, and receive email
 E-mail address - is a combination of a user
  name and a domain name
File Transfer Protocol
 FTP - is an Internet standard that allows you
  to exchange files with other computers on
  the Internet.
 Anonymous FTP - anyone can transfer files
  on this type of site.
     Information Sharing via the Web
 Newsgroup - is an online area in which users
  conduct written discussions about a particular
  subject
 Mailing list - is a group of email addresses given a
  single name
 Chat rooms - is a real-time typed conversation
 Instant messaging - is real-time Internet
  communications service that notifies you when
  one or more people are online.
 Netiquette - is the code of acceptable behavior
  while on the Internet
Interesting Sites
 http://www.epals.com

								
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