communication computer networks in education 6

8/9/2019 Communication Computer Networks in Education 6

1/32

Unit 6

Communication and computernetworks in education


2/32

Learning outcomes

Explain the term network communication anddescribe the hardware and software componentsof computer networks

Describe what the Internet is and how one canaccess and use the Internet

Describe the WWW

Identify and describe other Internet services

Explain acceptable code of conduct on the Internet


3/32

Communication networks

Also called telecommunicationsA collection of computers and other equipments organised to

share data, information, hardware and software (e.g.printers)

Allows computers to communicate with each other usingtelephone lines or wireless connection

Other applications are:l Internet -

World Wide Web (WWW or Web) E-mail

Conferencing systems

Online services

Fax

Voice mail


4/32

Basic structure of acommunications network/system

One computersends and other one receivesdata

Communications devices to send and route data

Communications channel over which data is sent(telephone lines, underground cables orsatellites)

Communications software to managetransmission of data between or amongcomputers


5/32

A communications system


6/32

Transmission media

Twisted pair cables as communication channel


7/32

Transmission media

Modem: modulator-demodulator:-l converts digital signals into analog signals and vice

versa


8/32

Network Interface Card (NIC)connects to computers without

modem


9/32

NIC allows computers tocommunicate over a computer

network or wireless network


10/32

LAN and WAN

Local Area Network: covers a limitedgeographical area (school, computer lab, anoffice)

Wider Area Network: covers a largegeographical region (city, school district) Server- a computer that stores and manages

resources or data on a network:la file server stores filesla print server manages one or more printersla network server manages network trafficla web server requests web pagesl


11/32

LANs and WANs

A number of computer devices connected to a server using NICs and cables


12/32

LANs and WANs in schools

SA not networked to the extent that the US orAustralia is

Schools there have LANs, but are alsoconnected to district offices

Data and resources are easily sharedlDatabases are online

lResources (learning materials) are online

Facilitates the use of the INTERNET


13/32

What is the INTERNET?

Worlds largestnetwork

Thousands ofcomputerdevices areconnected via

telephonelines,dedicateddigital lines or

satellite signals


14/32

What is the Internet?A global massive network of networks, super-network


15/32

How data is transmitted ortravel over the Internet?

Computers software divides data into smallpieces called packets:

packetsdone through the technique calledpacketswitchingadheres toTransmission Control Protocol/IP

routers (hardware devices) determine thepaths and transferdata packets

recipient computer reassembles datapacketsinto the original massage


16/32


17/32

How to connect to theInternet?

Computer(sender) divides data into:l packets through packet switching technique adheres to the

Transmission Control Protocol/IPl modem (modulator + demodulator) converts digital signals into

analog signalsl telephone linesl packets travel through routersl Internet Service Provider (ISP):

Local ISP limited to a small geographical area

National ISP large geographical region, nationwide

Local ISP limited to a small geographical areal modem (modulator + demodulator) converts analog signals into

digital signals of the recipientcomputer

Recipient computerreassembles packetsinto the originalmassage + FTP


18/32

How the Internet works?

Computer (sender)Digital packets

Modem

Analog packets

Telephone ISP/ L

Routers

ISP/ N

RoutersISP/ L Telephone Modem

Analog packets Digital packetsComputer - receiver

Routers


19/32

Connecting to the Internet

Dial-up access: Using your phone line or an Integrated Services DigitalNetwork (ISDN) line

Always on lines like Digital Subscriber Line (DSL) lines

From home connect to an ISP (modem needed)

ISP connects to national ISP

National ISP will route to a national ISP in other country via underwatercables or satellite

Re-routed to local ISP

Re-routed to destination web server

This is called the Internet back bone


20/32


21/32

How the Internet works?


22/32

The benefits of computernetworks in education

Sharing of hardware, software andeducational resources

Enabling communications among andbetween schools and otherorganisations

Storing student information/recordsCreating teaching and learning

opportunities or timeless possibilities


23/32

What can you do on the Internet?

Publish any information that you like Search for information on any topic that you can

imagine Access online databases

Access educational materials Shop Bank Book tickets

Share resources or information Online service provider (members) - special

content: news, weather, education


24/32

Internet addresses

http://www.uj.ac.za/index.html

hypertexttransferprotocol

Domainname:

compute

r

address

Organisation Country code Documentname


25/32

The World Wide Web

A service available on the Internet Collection of electronic documents hyperlinks: text,

graphics, video, sound, animations l When one follows links, its called surfing the web

Web browser: Microsoft Internet Explorer, Netscape Web pages are developed using a language called

HTML

Finding information one needs to know URL orsearch engine(s) Plug-ins or helper application extents the capability of

the web browser


26/32

Other Internet services

EmaillEmail addresses e.g. [email protected] email client like OutlooklAlso web-based email systems

www.webmail.co.za www.ananzi.co.za www.hotmail.com

FTP used for transferring files, now a servicethat the WWW offers

Telnet (not popular in SA), Newsgroups Mailing lists like LISTSERV Chat rooms
mailto:[email protected]://www.webmail.co.za/http://www.ananzi.co.za/http://www.hotmail.com/http://www.hotmail.com/http://www.ananzi.co.za/http://www.webmail.co.za/mailto:[email protected]


27/32

Netiquetteand security

Acceptable code of behaviour on the Internet

Netiquette (see p 2.33)

lEmail: brief, use proper grammar and spellinglBe polite, consider other cultures

lAvoid flames (abusive or insulting messages)

l

Avoid spam (sending junk mail)lDont SHOUT

Security: Cookies, privacy, filters (net nannies)

l


28/32


29/32

Impact on education

E-learning or online education

Resourcesl

www.merlot.org Collaboration (E-pals)

Assessment

In SA:lwww.learn.co.za

lhttp://www.mweb.co.za/hub/learn/
http://www.merlot.org/http://www.merlot.org/


30/32


31/32


32/32

communication computer networks in education 6

Documents