LECTURE OUTLINE: TELECOMMUNICATIONS AND THE INTERNET
Use of the Internet in Schools
Teachers can use the Internet to post exams online; find lesson plans and instructional materials; share common problems with other teachers; work in collaborative projects; and communicate through e-mail and videoconferencing.
Students can use the Internet to research projects; get homework and tutorial help; do practice quizzes; work on collaborative science investigations; and videoconference with other students.
Telecommunications
Telecommunications is the electronic transmission of information including data, television pictures, sound and facsimiles, which usually involves a computer, modem, software, and a printer.
Telecommunications should be used because it is easy and convenient, decreases car pollution, saves time and money, allows the home to serve as an office, and promotes distance learning in which students can share information and computer research findings.
Networking
Networking means several computers are connected together, in order to communicate with each other.
A network system generally includes a file server, which is a large computer with a large data capacity that serves as a repository for information and directs the flow of information to and from the computers in the network.
networking capabilities are not built or plugged into a computer, the user needs cables, wires, hookups, and operating system software, as well as networkable software that runs on the network.
A network needs a variety of devices to connect parts of a network or handle traffic among the various components.
Hubs are placed at different, central points to connect computers to different sections of the same network.
Switches and routers are devices used to organize communications traffic along the right path.
A network can have a permanent connection through a cable or a temporary connection through the telephone or other communication device.
The computer's network cables can be either copper or fiber optic. Fiber optic cables are more expensive and are a transmission medium consisting of glass fibers that can transmit digital signals in the form of pulses of light produced by a laser. Two glass optical fibers can transmit 6,000 telephone conversations at a time, which would require 250 copper wires.
A wireless network allows the user to transmit data "between computers, servers, and other network devices without physically using cable or wire" (Freedman, 2003).
Different means are used to provide wireless transmission via infrared, cellular, microwave, and satellite.
Current portable computers have infrared transceivers, so they can send files to a printer, computer, or handheld computers.
Apple's Airport Wireless is an example of a wireless technology that uses radio signals to communicate and does not require an unobstructed line of sight to make a connection; is fast; works without cables or complicated networking hardware; and allows students to go on the Internet wirelessly at home, school, or in the dorm.
Wireless technology allows users to operate computers as far away as 150 feet from the network and as fast as 54 megabits per second.
Bluetooth is a wireless technology and short-range radio communication that uses radio waves to transmit through walls and nonmetal objects, with a data rate of 750 kilobits to 1 megabit per second across distances of up to 100 meters. Bluetooth also allows a variety of devices, such as laptops, PCs phones, personal data assistants (PDAs), and printers, to communicate with each other without cables.
Wireless networks continue to gain ground in the schools, eliminating the need for cables throughout the building and permitting users to move the machines freely around the room.
Using wireless networking, students or faculty can access a network from different areas of campus through base stations that transmit radio frequency over the campus.
the cost of wireless technology becomes cheaper and the speed of the computer increases, wireless networks will some day be in every school across the country, with the possibility of every classroom being connected to the Internet.
Local area networks (LAN), wide area networks (WAN), and telephones are three types of networks.
LANs provide communication within a local area, usually within 200 to 300 feet, such as in an office building or school.
WANs provide communication for a larger area that requires miles of communication linkage.
A telephone network connects computers via telephones.
WANs and LANs communicate all the time, whereas telephone communication is intermittent.
The three most common network arrangements are the ring, the star, and the shared-bus.
The ring network, commonly found in university administrative offices, is a communication network that connects devices such as computers in a closed loop or ring, does not rely on a file server or central computer, and still operates if one computer in the ring is down.
The star network, commonly found in a school computer center, has a file server with several computers or terminals and becomes inoperable if the file server fails, because the server has in its memory all the data the computers use for processing.
The shared-bus network, used by small, local networks, is a single bidirectional cable that acts as a "bus line" to carry messages to and from devices, with information stored in a central computer and collision detection to help regulate network traffic.
Advantages of networking
Networking establishes communication among computers and is especially helpful when people work on different floors in different buildings.
Networks improve the speed and accuracy of communication, preventing messages from being misplaced and automatically ensuring total distribution of key information.
Networks save money, because users share software and equipment such as word processing programs and laser printers.
Disadvantages of networking
Networking costs can be high depending on the cost of hardware, computer training, and maintenance.
Networking requires expertise that may not always be readily available.
Networking requires that competent technicians be available to repair equipment.
Networking may cause frustration among teachers who have to learn a new system.
Networking may cause computer dependency, as teachers who rely on the network may be at a loss if the system crashes.
The networking software necessary may not always be available.
Networking is subject to system security problems, as unauthorized individuals can access all the information if the network is unprotected.
The Internet
The Internet is a large network that links smaller computer networks together.
The Internet is "made up of computers in more than 100 countries, in commercial, academic, and government efforts" (Freedman, 2003).
Access to the Internet means the user can tap into thousands of databases and talk electronically with experts worldwide on any subject.
Historical Background
1969, the Department of Defense created the Internet for military research purposes, with major goals to ensure mass communication of information with maximum security.
The original network was called ARPAnet, as it was designed by the Advanced Researched Projects Agency, with a goal of building a centralized network that would run even if nuclear war destroyed part of it.
Researchers devised a protocol for sending data efficiently called Internet Protocol or IP, to be used along with Transmission Control Protocol, or TCP.
its initial stages, the electronic highway provided a way of exchanging electronic mail and linking online libraries to government agencies and universities, which served as testers for the service's integrity.
the early 1980s, the original ARPAnet divided into two networks, ARPAnet and Milnet.
The connection between the two networks was called the Defense Advanced Research Projects Agency, or DARPA Internet.
DARPA Internet was soon shortened to the Internet.
1986, the National Science Foundation encouraged nondefense use of the Internet by creating a special network called NSFNet, which connected five new supercomputing centers across the country, into which universities all over the country began connecting.
Different national networks appeared, and more countries joined the Internet to share its rich resources.
the late 1980s, students gained Internet access when they registered at their colleges.
More businesses and individuals have accessed the Internet since it became available to them, with 605 million users all over the world reported in the year 2002.
Figures given by researchers on Internet use differ according to the age definition of the user population.
Gore called for the creation of national networks known as "information highways" in the 1980s.
Recent Growth of the Internet
Swiss researchers developed the World Wide Web, a system that lets the user move smoothly through the Internet, jumping from one document to another.
Software tools called browsers were developed that made access to the Internet resources uncomplicated.
Delphi was the first online service to offer access to the Web.
Paid Internet Service Providers (ISPs) such Microsoft Software Network (MSN) provide Internet access and e-mail, while the world's largest ISP, EarthLink Network, provides network access and home pages. Free Internet service providers also exist.
The proliferation of e-mail through online services such as America Online and CompuServe has made Internet mail protocol the world standard for electronic mail.
Internet 2 development, led by 205 universities, brings government and industry together to develop advanced network applications and technologies. Internet 2 is designed primarily to exchange multimedia data in real time at high speeds.
Modems are internal or external devices that adapt computers to analog telephone lines by converting digital pulses to audio frequencies and the reverse. Modem is a contraction of Modulator/DEModulator.
Current high-speed modems are 56 Kbps and achieve their speed using regular telephone lines.
A good-quality phone line and close proximity to the phone company's switch are needed for quality transmission.
Internet Service Providers (ISPs) are required to provide hardware support for high-speed modems such as cable modems that let users connect to the Internet with the same cable that attaches to a standard television set.
DSL is a digital technology that offers high-speed transmission over standard copper telephone wiring.
DSL is point-to-point technology providing downloading at speeds up to 8 Mbps.
DSL can carry both voice and data signal at the same time, in both directions.
DSL comes in many versions, with varying transmission speeds.
DSL allows the user to use the phone and the Web at the same time, without separate phone lines.
DSL lines are tied to distance between the user and the central office and may not be available in all areas.
Integrated Services Digital Network (ISDN), designed in the early 1980s, is a replacement for analog telephone service that uses high-speed digital phone lines offered by the phone companies in most areas, with connections from 64 Kbps to 128 Kbps and not universally available or affordable.
Satellite data service uses a satellite dish to connect to the user's computer, gives 400 Kbps for downloading, and can be connected to via an analog modem, with expensive installation charges.
Internet Access
Current choices for home users of technology are 56-Kbps modems, cable modems, digital subscriber lines (DSL), ISDN, and satellite data services.
The percentage of homes in the United States with broadband or high-speed transmission Internet access will increase from 5 percent in 2000 to 66 percent in 2008, according to a study by the investment bank Goldman Sachs.
Companies providing DSL have been in competition with cable companies to provide faster service.
Connecting to an Online Service
access the Web, the user needs a connection to the Internet through a commercial online service such as America Online or EarthLink.
Online services provide access to a range of information, e-mail, news, downloading of free programs, free help from experts, connections to the Internet, participation in conferences, and hardware/software support.
Most services initially give free time online, and then charge a monthly fee for their service.
Popular commercial services are America Online (AOL) and Microsoft Software Network (MSN), differentiated by the services they provide, with America Online as the world's largest online information service.
Internet Resources
Electronic mail (e-mail) can be used to send messages to individuals at local or distant locations in seconds, is less time-consuming than social interaction, and can generate answers quickly and inexpensively.
A typical e-mail address has two parts, the user's identification followed by the @ symbol, and the domain information, consisting of the site name and type of organization.
Organization names at the end of e-mail addresses are known as domains, for example, gov for government organization, edu for educational institution, org for a non-profit organization, and com for commercial organizations, with new domain types such as name, museum, and biz added in 2000 to accommodate the exponential growth of the Internet.
E-mail did not develop as rapidly as everyone thought it would in the beginning, because of two impediments: the traditional fax machine, which already allowed for quick exchange of information, and many incompatible electronic mail systems.
The Internet has solved the incompatibility problems of electronic mail systems, becoming the forum for e-mail and communications.
Browsers such as Internet Explorer and Netscape Communicator have e-mail applications integrated into their respective programs, while stand-alone programs such as Eudora Pro and Pegasus are loaded with features.
Free browser software can be downloaded, and free Web-based e-mail services such as Yahoo! and Hotmail with many features exist.
Chat rooms provide another Internet service, a discussion by keyword on a specific topic, addressing various subjects and allowing individuals to have private conversations on the Internet, with services available from America Online, Web sites, and the IRC system.
Instant messaging programs such as America Online let the user receive instant alerts, send instant messages, share photos, pictures, and sound, and enjoy conversations and chat online.
Internet Relay Chat (IRC) allows the user to do computer conferencing on the Internet, with IRC channels on a wide range of topics that take place on the IRC servers around the world; once the user joins, messages are broadcast to everyone listening on that channel.
Netiquette is the etiquette users should follow when they use the Internet, such as keeping messages brief and to the point and not using all caps, which is considered shouting. A complete list of tips is found on p. 218.
addition to electronic mail, the Internet offers many useful resources which can be found in Table 9.1 on p. 217.
Integrating the Internet into the Classroom
The percentage of public schools with Internet access in the United States has increased from 35 percent in 1994 to 99 percent in 2002, while the ratio of students per instructional computer is approximately 4.8 to 1.
The Internet offers many exciting possibilities for the classroom, with many online projects and tutorials. See pp. 219-223 for a description of several Internet-based lesson plans.
