Follow Us

Monday 19 December 2011

The role of ICT in Education




Introduction:
Thousands of years ago atthe dawn of human civilization, agricultural society evolved from the plough.In the second half of the eighteenth century, with the advent of the steamengine the industrial revolution took place in Europe. Now at the dawn of thenew millennium another revolution of entirely different kind is taking placeacross the globe -- a silent revolution, much more powerful and all pervasive-- it is information technology revolution. No wonder that the present age is beingcalled the information age.
The term informationtechnology or IT has been replaced by information and communication technologyor ICT which involves collection, storage, processing and distribution ofinformation. Computers, internet and electronic communication are integralparts of ICT. Texts, numbers, audios and videos are being exchanged throughoutthe world without space and time barrier. ICT has accelerated the pace ofglobalization. At the heart of the startling development in some of the developingcountries there lies ICT. Countries having access to and control overinformation will dominate the world economically and politically.
ICT is the backbone of any digital initiative. ICT covers the vastarea of information technology, communication technology and of course thetelecommunication technology; categorically processing of information andensuring connectivity. Digital Bangladesh is an Idea that includes the IT use formanagement, administration and governance to ensure transparency, accountabilityand answerability at all levels of society and state. One thing must bementioned that ICT is only a technology, a technology or a machine could not befunctional without a person behind. Philosophically convinced persons are thedriving force in establishing an idea in to society and state.  Building of an ITeducated work force is the most important segment of digital Bangladeshinitiative. To develop this kind of generation it needs to an education policyand national human resource policy especially in education sector.


1

The challenge Bangladesh faces is how to become a learningsociety and to ensure that its citizens are equipped with the knowledge, skillsand qualifications on information and communication technology (ICT) they willneed in the next century. ICT revolution imposes particular challenges oneducation systems in Bangladesh. These challenges reduce to three broad areas.The first has to do with participation in the information society; the secondconsiders how ICT impacts on access, cost effectiveness and quality ofeducation, while the third is to do with the way that ICT changes the educationprocess.
Formal education in computers was first started in1984 with the foundation of Computer Science and Engineering Department in BangladeshUniversity of Engineering and Technology. ICT education thereafter graduallyextended to the bachelor’s degree, higher secondary and secondary schoollevels. In Bangladesh, there are about 83,796 primary level institutions, 5,694and 15,748 junior and secondary level institutions respectively, 2,339 highersecondary and degree colleges and more than 1,000 ICT training institutes.

The introduction and status of ICT education inprimary and junior secondary, secondary and higher secondary, diploma, undergraduateand post-graduate levels, and career-oriented professional ICT trainingdescribes bellow.

Primary and juniorsecondary level
The first five years and the next three years of educationconstitute the primary and junior secondary levels respectively. Bengali andEnglish languages, history, geography, general science, mathematics andreligion are the major subjects taught at these levels. Students become, in avery small way, aware of computers and their vast applications through theirgeneral science textbooks.
Recently, the government formulated aNational Education Policy in the cabinet, which was endorsed by Parliament. Inthis Policy, introduction of ICT education at the primary and junior secondarylevel has not been included in the implementation period of 2010. A majority ofschools in the country cannot afford to buy computers for their students.Though a small number of city-based schools have very limited computerlaboratory facilities, yet they fail to make their students familiar withinternet, e-mail and related technology because of the lack of nationwidetelecommunication infrastructure and internet facilities. In addition, schoolteachers at these levels lack the minimum level of training on IT.

Secondary and highersecondary levels
The 9th and 10th years of a school-going student and the next twoyears of a college-going student constitute the secondary and higher secondarylevels respectively. Computer science was introduced as an optional subject forsecondary level students from the beginning of 1994, and about 150 schools werepermitted to start up the subject. Many more schools have shown interest, andthe quantitative expansion of ICT education at the secondary level isphenomenal. The National Education Policy has recommended compulsory computercourses from the secondary level of education. The Board of Intermediate andSecondary Education, Dhaka introduced computer science as an optional subjectin 1991. Already, more than 200 colleges have introduced computer science as anoptional subject for science stream students.
Moreover, about 30 polytechnic institutes of the country (mostlylocated in Dhaka) are offering four-year diploma courses for those who havegraduated from SSC in computer technology. Bangladesh Open University is nowoffering three-semester diplomas in computer applications.

Undergraduate andpost-graduate levels
At the moment Bangladesh has more than 30 public and 54 privateuniversities, 6 BITs and some national university-affiliated post-graduate institutesand colleges, which are offering courses related to computer science andinformation technology.
BangladeshOpen University is the only university in Bangladesh that is offering DistanceEducation. Established in 1992 by an act of Parliament, it has opened up newvistas in distance education in the country. Situated at a picturesque site ofGazipur, 30 km north of Dhaka, BOU has a printing and production division and amodern media centre. Construction of these organizational structures is almostcomplete, with financial assistance from ADB and the government of Bangladesh.BOU`s programmes are aimed at everyone, particularly working people and womenand those socially disadvantaged.
BangladeshOpen University relies heavily on print materials, electronic media likeradio-television and audio-video cassettes, tutorial services, computernetworking and the internet. The use of these techniques helps BOU to take itsacademic programs to the doorsteps of people far and wide. It makes room forin-house education.

Some other institutions have also initiated research programmes inIT-related fields. These include machine learning, pattern recognition, speechrecognition, automatic translation, computational algorithm, VLSI and 3-Dvision. Considerable research work has been done in the use of Bengali incomputers. Unfortunately, like R&D in other fields of science andtechnology, there is very little interaction between academia and industry.

E-learning
Although most commonly associated with higher education andcorporate training, e-learning encompasses learning at all levels, both formaland non-formal, that uses an information network—the Internet, an intranet(LAN) or extranet (WAN)—whether wholly or in part, for course delivery,interaction and/or facilitation. Others prefer the term online learning.Web-based learning is a subset of e-learning and refers to learning using anInternet browser (such as Netscape or Internet Explorer).

Blended learning
Another term that is gaining currency is blendedlearning. This refers to learning models that combine traditional classroompractice with e-learning solutions. For example, students in a traditionalclass can be assigned both print-based and online materials, have onlinementoring sessions with their teacher through chat, and are subscribed to aclass email list. Or a Web-based training course can be enhanced by periodicface-to-face instruction. “Blending “was prompted by the recognition that notall learning is best achieved in an electronically-mediated environment,particularly one that dispenses with a live instructor altogether. Instead,consideration must be given to the subject matter, the learning objectives andoutcomes, the characteristics of the learners, and the learning context inorder to arrive at the optimum mix of instructional and delivery methods.
Open and distancelearning
Open and distance learning is defined by the Commonwealth ofLearning as “a way of providing learning opportunities that is characterized bythe separation of teacher and learner in time or place, or both time and place;learning that is certified in some way by an institution or agency; the use ofa variety of media, including print and electronic; two-way communications thatallow learners and tutors to interact; the possibility of occasionalface-to-face meetings; and a specialized division of labour in the productionand delivery of courses.”

The Promise of ICTs inEducation
For developing countries ICTs have the potential for increasingaccess to and improving the relevance and quality of education. It thusrepresents a potentially equalizing strategy for developing countries. ICTsgreatly facilitate the acquisition and absorption of knowledge, offeringdeveloping countries unprecedented opportunities to enhance educationalsystems, improve policy formulation and execution, and widen the range ofopportunities for business and the poor. One of the greatest hardships enduredby the poor, and by many others, who live in the poorest countries, is theirsense of isolation. The new communications technologies promise to reduce thatsense of isolation, and to open access to knowledge in ways unimaginable notlong ago. However, the reality of the Digital Divide—the gap between those whohave access to and control of technology and those who do not—means that theintroduction and integration of ICTs at different levels and in various typesof education will be a most challenging undertaking. Failure to meet the challengewould mean a further widening of the knowledge gap and the deepening ofexisting economic and social inequalities.


How can ICTs help expandaccess to education?

ICTs are a potentially powerful tool for extending educationalopportunities, both formal and non-formal, to previously underserved constituencies—scatteredand rural populations, groups traditionally excluded from education due tocultural or social reasons such as ethnic minorities, girls and women, personswith disabilities, and the elderly, as well as all others who for reasons ofcost or because of time constraints are unable to enroll on campus.

Anytime, anywhere- One defining feature of ICTs is their ability to transcend timeand space. ICTs make possible asynchronous learning, or learning characterizedby a time lag between the delivery of instruction and its reception by learners.Online course materials, for example, may be accessed 24 hours a day, 7 days aweek. ICT-based educational delivery (e.g., educational programming broadcastover radio or television) also dispenses with the need for all learners and theinstructor to be in one physical location. Additionally, certain types of ICTs,such as teleconferencing technologies, enable instruction to be receivedsimultaneously by multiple, geographically dispersed learners (i.e., synchronouslearning).

Access to remote learningresources- Teachers and learners nolonger have to rely solely on printed books and other materials in physicalmedia housed in libraries (and available in limited quantities) for theireducational needs. With the Internet and the World Wide Web, a wealth of learningmaterials in almost every subject and in a variety of media can now be accessedfrom anywhere at any time of the day and by an unlimited number of people. Thisis particularly significant for many schools in developing countries, and evensome in developed countries, that have limited and outdated library resources.ICTs also facilitate access to resource persons— mentors, experts, researchers,professionals, business leaders, and peers—all over the world.

The potential of ICTs to promote the acquisition of these skillsis tied to its use as a tool for rising educational quality, includingpromoting the shift to a learner-centered environment.



How can the use of ICTshelp improve the quality of education?
Improving the quality of education and training is a criticalissue, particularly at a time of educational expansion. ICTs can enhance thequality of education in several ways: by increasing learner motivation and engagement,by facilitating the acquisition of basic skills, and by enhancing teachertraining. ICTs are also transformational tools which, when used appropriately,can promote the shift to a learner-centered environment.

Motivating to learn- ICTs such as videos, television and multimedia computer softwarethat combine text, sound, and colorful, moving images can be used to providechallenging and authentic content that will engage the student in the learningprocess. Interactive radio likewise makes use of sound effects, songs,dramatizations, comic skits, and other performance conventions to compel thestudents

Digital Age Literacy
Functional literacy Ability to decipher meaning and express ideasin a range of media; this includes the use of images, graphics, video, chartsand graphs or visual literacy Scientific literacy Understanding of both thetheoretical and applied aspects of science and mathematics Technologicalliteracy Competence in the use of information and communication technologies Informationliteracy Ability to find, evaluate and make appropriate use of information,including via the use of ICTs Cultural literacy Appreciation of the diversityof cultures Global awareness Understanding of how nations, corporations, andcommunities all over the world are interrelated.
Inventive Thinking
Adaptability Ability to adapt and manage in a complex,interdependent world Curiosity Desire to know Creativity Ability to useimagination to create new things Risk-taking Ability to take risks
Higher-Order Thinking Creative problem-solving and logical thinking that result in sound judgements


Effective Communication
Teaming Ability to work in a team Collaboration and Ability tointeract smoothly and work effectively with others Interpersonal skills Personaland social Be accountable for the way they use ICTs and to learn to use ICTs responsibilityfor the public good Interactive communication Competence in conveying,transmitting, accessing and understanding information High Productivity Abilityto prioritize, plan, and manage programs and projects to achieve the desiredresults Ability to apply what they learn in the classroom to real-life contextsto create relevant, high-quality products to listen and become involved in thelessons being delivered. More so than any other type of ICT, networkedcomputers with Internet connectivity can increase learner motivation as itcombines the media richness and interactivity of other ICTs with theopportunity to connect with real people and to participate in real world events

Facilitating theacquisition of basic skills- Thetransmission of basic skills and concepts that are the foundation of higherorder thinking skills and creativity can be facilitated by ICTs through drilland practice. Educational television programs such as Sesame Street userepetition and reinforcement to teach the alphabet, numbers, colors, shapes andother basic concepts. Most of the early uses of computers were forcomputer-based learning (also called computer-assisted instruction) thatfocused on mastery of skills and content through repetition and reinforcement.

Enhancing teacher training- ICTs have also been used to improve access to and the quality ofteacher training. For example, institutions like the Cyber Teacher TrainingCenter (CTTC) in South Korea are taking advantage of the Internet to providebetter teacher professional development opportunities to in-service teachers.The government-funded CTTC, established in 1997, offers self-directed,self-paced Web-based courses for primary and secondary school teachers. Coursesinclude “Computers in the Information Society,”“Education Reform,” and “FutureSociety and Education.” Online tutorials are also offered, with some coursesrequiring occasional face-to-face meetings.15 In China, large-scale radio and
Television-based teacher education has for many years beenconducted by the China Central Radio and TV University, the Shanghai Radio andTV University and many other RTVUs in the country.

At Indira Gandhi National Open University, satellite-based one-wayvideo- and two-way audio-conferencing was held in 1996, supplemented byprint-materials and recorded video, to train 910 primary school teachers andfacilitators from 20 district training institutes in Karnataka State. Theteachers interacted with remote lecturers by telephone and fax.

When used appropriately, ICTs—especially computers and Internettechnologies— enable new ways of teaching and learning rather than simply allowteachers and students to do what they have done before in a better way.

Active learning- ICT-enhancedlearning mobilizes tools for examination, calculation and analysis ofinformation, thus providing a platform for student inquiry, analysis andconstruction of new information. Learners therefore learn as they do and,whenever appropriate, work on real-life problems in-depth, making learning lessabstract and more relevant to the learner’s life situation. In this way, and incontrast to memorization-based or rote learning, ICT-enhanced learning promotesincreased learner engagement. ICT-enhanced learning is also “just-in-time”learning in which learners can choose what to learn when they need to learn it.

Collaborative learning- ICT-supportedlearning encourages interaction and cooperation among students, teachers, andexperts regardless of where they are. Apart from modeling real-world interactions,ICT-supported learning provides learners the opportunity to work with people fromdifferent cultures, thereby helping to enhance learners’ teaming andcommunicative skills as well as their global awareness. It models learning donethroughout the learner’s lifetime by expanding the learning space to includenot just peers but also mentors and experts from different fields.

Creative Learning- ICT-supported learning promotes the manipulation of existinginformation and the creation of real-world products rather than theregurgitation of received information.

 Integrative learning- ICT-enhancedlearning promotes a thematic, integrative approach to teaching and learning.This approach eliminates the artificial separation between the different disciplinesand between theory and practice that characterizes the traditional classroom approach.

Evaluative learning- ICT-enhancedlearning is student-directed and diagnostic. Unlike static, text- orprint-based educational technologies, ICT-enhanced learning recognizes thatthere are many different learning pathways and many different articulations ofknowledge. ICTs allow learners to explore and discover rather than merelylisten and remember.

What is teleconferencingand what have been its educational uses?

Teleconferencing refers to “interactive electronic communicationamong people located at two or more different places. There are four types ofteleconferencing based on the nature and extent of interactivity and the sophisticationof the technology: 1) audio conferencing; 2) audio-graphic conferencing, 3)videoconferencing; and 4) Web-based conferencing.

Audio conferencing involves the live (real-time) exchange of voice messages over atelephone network. When low-bandwidth text and still images such as graphs,diagrams or pictures can also be exchanged along with voice messages, then thistype of conferencing is called audio graphic. Non-moving visuals are addedusing a computer keyboard or by drawing/writing on a graphics tablet orwhiteboard.






Videoconferencing allowsthe exchange not just of voice and graphics but also of moving images. Videoconferencingtechnology does not use telephone lines but either a satellite link ortelevision network (broadcast/cable).

Web-based conferencing as the name implies, involves the transmission of text, andgraphic, audio and visual media via the Internet; it requires the use of acomputer with a browser and communication can be both synchronous andasynchronous.

Teleconferencing is used in both formal and non-formal learningcontexts to facilitate teacher-learner and learner-learner discussions, as wellas to access experts and other resource persons remotely. In open and distancelearning, teleconferencing is a useful tool for providing direct instructionand learner support, minimizing learner isolation.

For instance, an audio graphic teleconferencing network betweenTianjin Medical University in China and four outlying Tianjin municipalitieswas piloted in 1999 as part of a multi-year collaboration between TianjinMedical University and the University of Ottawa School Of Nursing funded by theCanadian International Development Agency. The audio graphic teleconferencingnetwork aims to provide continuing education and academic upgrading to nursesin parts of Tianjin municipality where access to nursing education has beenextremely limited. Other higher education institutions using teleconferencingin their online learning programs include the Open University of the UnitedKingdom, Unitar (Universiti Tun Abdul Ruzak) in Malaysia, Open University ofHong Kong, and Indira Gandhi National Open University.

How have computers andthe Internet been used for teaching and learning?
There are three general approaches to the instructional use ofcomputers and the Internet, namely:
1) Learning about computers and the Internet, in whichtechnological literacy is the end goal;

2) Learning with computers and the Internet,in which the technology facilitates learning across the curriculum; and
3) Learning through computers and the Internet, integratingtechnological skills development with curriculum applications.

What does it mean tolearn about computers and the Internet?
Learning about computers and the Internet focuses on developingtechnological literacy. It typically includes:
• Fundamentals: basic terms, concepts and operations
• Use of the keyboard and mouse
• Use of productivity tools such as word processing, spreadsheets,data base and graphics programs
• Use of research and collaboration tools such as search enginesand email
• Basic skills in using programming and authoring applicationssuch as Logo or Hyper Studio
• Developing an awareness of the social impact of technologicalchange

What about learning withcomputers and the Internet?
Learning with the technology means focusing on how the technologycan be the means to learning ends across the curriculum. It includes:
• Presentation, demonstration, and the manipulation of data usingproductivity tools
• Use of curriculum-specific applications types such aseducational games, drill and practice, simulations, tutorials, virtuallaboratories, visualizations and graphical representations of abstractconcepts, musical composition, and expert systems
• Use of information and resources on CD-ROM or online such asencyclopedia, interactive maps and atlases, electronic journals and otherreferences Technological literacy is required for learning with technologies tobe possible, implying a two-step process in which students learn about the technologiesbefore they can actually use them to learn. However, there have been attemptsto integrate the two approaches.

What does learningthrough computers and the Internet mean?
Learning through computers and the Internet combines learningabout them with learning with them. It involves learning the technologicalskills “just-in-time” or when the learner needs to learn them as he or sheengages in a curriculum-related activity. For example, secondary schoolstudents who must present a report on the impact on their community of anincrease in the price of oil for an Economics class may start doing research online, using spreadsheet anddatabase programs to help organize and analyze the data they have collected, aswell using a word processing application to prepare their written report.

Conclusion
It is generally agreed that ICT is a crucialresource in education. Children use computers from an early age and continue touniversity level. Children taught practical ICT skills that are transferable intothe work place. ICT education is a cheap, fast way to access a huge amount ofresources that are regularly updated, accessible 24/7 – allowing students tocontinue their work at home. It encourages of computer literacy, helpful in anincreasingly technologically orientated world. Teachers upload course documentsso that students misses a lesson, they can download information and do the workin their own time. Encourages student-driven lessons, where students takeresponsibility for their learning. Government sponsored learning toolsavailable to students. Government promises high-speed broadband internet accessfor every university, hospital and doctors' surgery which would allow schools tobe linked and to share resources. Educational Institutes becoming morecomputerized, proof that internet must be helping otherwise they would not bewilling to shell out to fit their schools with needed equipment.

There are some harmful matters of the internet in education suchas there is a lot ofincorrect information on the internet and students will learn more theory andless practical. Bing taught the wrong thing- Hacking, Creating Viruses, andPlagiarism. A lot of distraction such as porn, games, music, videos, chat rooms/messengers/emails as likes so.



ICT is very expensive - not all students get the sameopportunities. It can be boring sitting in front of a computer for a long time.Computers cannot interact on a personal level e.g. fuller explanation Itbecomes harder for the teachers to organise the teaching of new concepts. Somestudents find it hard to use computers. Learner minds are more likely to wander from their set task. Not allteachers are keen on ICT but, are forced to use it. Children lose socialinteraction and working on computers all day – bad for your health. Computersaren’t as reliable as teachers; computers can’t explain new concepts as well asa good teacher. If left to learn at their own speed, many students would fallbehind. Computers don’t have the motivating force that teachers have.

However, all the issues we should over come to effective use ofICT in education sector. More ever the learner can benefited to use of packages: word-processing,spreadsheets etc. There are special facilities for pupils with disabilities.The uses of ICT teacher and pupil communications are improved. ICT provideslinks with other schools or with businesses. Computers in schools provideswider access to ICT and encourages new ways of learning, it can repeat workagain and again and again and interactive teaching packages are available on CDfor different subjects. Children can learn in varied ways in the classroom. Thereare many CD-ROMs available for each level of the national curriculum.

Recommendations
Facilities should be built to promote ICT education andcomputer-aided education in all levels (primary to post-graduate). Donoragencies, non-government organizations and other development partners of thecountry should participate in building up the necessary capacity in this area.The mutually supportive roles of public and private finance point the way toraising the overall level of investment in ICT education and training.

Teachers are the most vital resource inpromoting modernization and higher standards; their recruitment, training,deployment and appropriate incentives are critical to ICT education system inBangladesh. Since there is an acute shortage of qualified teachers, short-termintensive training on ICT may be arranged. Wherever necessary an internationalfaculty or expatriate Bangladeshis working abroad may be invited as visitingfaculties at least once a year.
Modern and effective ICT networks need to be built to supporttraditional methods of teaching and learning and to increase the quantity andrange of education and training, for example, through distance learning.
          
The promotion of the study of foreign languages (mainly English)to increase the understanding of different cultures and enhance mobility in aglobalised ICT world

The developing of a culture of entrepreneurship in ICT education,not least in developing the closest R&D links between universities andcompanies.

Everyone should have access to ICT learning and training, not justthose who are intellectually gifted or economically privileged. Specialattention should be given to the needs of the disadvantaged. The use of ICT asa teaching tool and for delivery of distance learning can help stretch ourlimited teaching resources and provide a high quality education to all.
          
Everyone should be encouraged and enabled to continue ICT learningthroughout their lives, not just in the years of compulsory schooling.

For primary and junior secondary level, general science textbooksshould adequately cover fundamental concepts on computers and their numerousapplications. Differences between hardware and software, history of computersand their use, classification of computers, concept of computer network,internet and emails, introduction to computer peripherals and input/outputdevices should be introduced.

There should be uniformity in coursecurricula and degree requirements. Course curricula should be revised at nomore than two-year intervals.
Post-graduate programmes should be strengthened. Most of thegraduates leaving the country for higher studies do not return. A rigorous andstandard post-graduate programme will encourage more students to complete theirhigher studies in the country and eventually fill up the current vacuum ofqualified teaching stuffs.  Books andjournals should be made available in the University libraries.




References
1.     Internet
2.     BTTB reports and online resources
3.     Hanif Bin Azhar, Abdus Sobhan, M., Lutfor Rahman, M. ResearchActivities on Information Technology in Bangladesh; Proceedings of the NationalConference on Computer and Information Systems, 1997, Dhaka, Bangladesh
4.     Source: Jung, In Sung,“Virtual Education at the Tertiary Level:The Experience of Korea”. Available Online
http://www.TechKnowLogia.org…Accessed 4 July 2002.
5.     Source: Adapted from EnGauge. North Central Regional EducationalLaboratory. Available Online at






videobb

An Assignment on Telecommunication and Networking






OBJECTIVES


  • Describe the features of a contemporary corporate network infrastructure and key networking technologies
  • Evaluate alternative transmission media, types of networks, and network services
  • Assess the role of the Internet and the World Wide Web in a firm’s information technology infrastructure
  • Identify and describe the most important tools for communication and e-business
  • Identify and describe the challenges posed by networking and the Internet and management solutions



Telecommunications: Communication of information by electronic means themarriage of computers and communications: The 1996 TelecommunicationsDeregulation and Reform Act allowed telephone companies, broadcasters, andcable companies to enter each other’s markets.

The Information Superhighway: High-speeddigital telecommunications networks, accessible by the general public

TELECOMMUNICATIONS ANDNETWORKING IN TODAY’S BUSINESS WORLD

§Anetworking and communications revolution led by Internet-based technologies
§1billion instant messages per day
§4billion e-mails each day
§65million music files downloaded
§Estimated3.9 billion photos sent over the Internet
§$769billion spent in the United States on telecommunications equipment and services
§Today,networking and the Internet are synonymous with doing business.
§TheBusiness Telecommunications Environment
§Telecommunicationsenvironment provides connectivity by providing communication channels for text,voice, and video images.
§Thenetwork infrastructure for a large corporation consists of many different kindsof networks for both data and voice communication.
§Mostof these different kinds of networks are moving towards a common Internetfoundation.


Networkingand Communications Trends

Theseven major trends in telecommunications:

  • Rapid technological innovation has resulted in a proliferation of new hardware devices and new alternatives for business communications.

  • Continuing telecommunications deregulation has encouraged competition and created many alternatives.

  • Distinctions between telephone, cable television, Internet, and satellite telecommunication are blurred.

  • Growing dominance of Internet technologies in voice, video, and data communications

  • Rapid growth in “last-mile” high-speed broadband connections to homes and businesses

  • Rapid growth in wireless telephone, wireless computer networks, and mobile Internet devices

  • Growing scope of communication-intense services and products


The Business Value of Telecommunications andNetworking
 Businessvalue impacts of the telecommunications and Networking are:

•Declining transaction costs
•Declining agency costs
•Increased agility
•Higher quality management decisions
•Declining geographical barriers
•Declining temporal barriers
•The extremely rapid growth inbusiness networking and telecommunications results from the extraordinary valueof participating in networks like the Internet.
 Networks and Corporate Infrastructure
•Anetwork consists of two or more connected computers.

•Eachcomputer on the network contains a network interface device called a networkinterface card (NIC).

•Theconnection medium for linking network components can be a telephone wire,coaxial cable, or radio signal in the case of cell phone and wireless localarea networks.

•Thenetwork operating system (NOS) routes and manages communications on the networkand coordinates network resources.

•Networksalso contain a switch or a hub acting as a connection point between thecomputers.

•Hubsare very simple devices that connect network components, sending a packet ofdata to all other connected devices.

•Aswitch has more intelligence than a hub and can filter and forward data to aspecified destination. Switches are used within individual networks.

•Arouter is a special communications processor used to route packets of datathrough different networks, ensuring that the message sent gets to the correctaddress.





KeyDigital Networking Technologies


•Client/ServerComputing

•PacketSwitching

•TCP/IPand Connectivity
Client/ServerComputing:
Asimple definition of CS is “server software accepts requests for data fromclient software and returns the results to the client.”


Elements of C-S Computing


Client/servercomputing is a distributed computing model in which much of the processingpower is located within small, inexpensive client computers.

Thepowerful clients are linked to one another through a network that is controlledby a network server computer.

Theserver sets the rules of communication for the network and provides everyclient with an address so others can find it on the network.
PacketSwitching:
Inpacket-switched networks, messages are first broken down into small bundles ofdata called packets.

Thesepackets are sent along different communication paths and then the packets arereassembled once they reach their destinations.

Packetswitching makes more efficient use of the communications capacity of a network.
Thepackets include information for directing the packet to the right address andfor checking transmission errors along with the data.







TCP/IPand Connectivity:

TCP/IPis the communications protocol used by the Internet and all Internet devices.

TCP/IPprovides for breaking up digital messages into packets, routing them to theproper addresses, and then reassembling them into coherent messages.

TCP/IPuses a suite of protocols: TCP and IP.

Handlesthe movement of data between computers

Establishesa connection between the computers, sequences the transfer of packets, andacknowledges the packets sent


InternetProtocol (IP):
•Responsiblefor the delivery of packets

•Includesthe disassembling and reassembling of packets during transmission



Types of Signals: Analog andDigital
Analog signal

  • Continuous waveform

  • Passes through communications medium

  • Used for voice communications

Digital signal

  • Discrete waveform

  • Transmits data coded into two discrete states as 1-bits and 0-bits

  • Used for data communications
Modem

Translates computer’sdigital signals into analog and vice versa










PhysicalTransmission Media


Thedifferent kinds of physical transmission media used by the networks are:

  • Twisted-pair wire
  • Coaxial cable
  • Fiber optics
  • Optical Fiber
  • Wireless Transmission

Twisted-pair wire
Twisted paircabling comes in two varieties: shielded and unshielded. Unshielded twistedpair (UTP) is the most popular and is generally the best option for schoolnetworks (See fig. 1).

Fig.1. Unshielded twisted pair
The qualityof UTP may vary from telephone-grade wire to extremely high-speed cable. Thecable has four pairs of wires inside the jacket. Each pair is twisted with adifferent number of twists per inch to help eliminate interference fromadjacent pairs and other electrical devices. The tighter the twisting, thehigher the supported transmission rate and the greater the cost per foot. TheEIA/TIA (Electronic Industry Association/ Telecommunication IndustryAssociation) has established standards of UTP and rated six categories of wire(additional categories are emerging).
Unshielded Twisted PairConnector
The standardconnector for unshielded twisted pair cabling is an RJ-45 connector. This is aplastic connector that looks like a large telephone-style connector (See fig.2). A slot allows the RJ-45 to be inserted only one way. RJ stands forRegistered Jack, implying that the connector follows a standard borrowed fromthe telephone industry. This standard designates which wire goes with each pininside the connector.

ShieldedTwisted Pair (STP) Cable
Although UTPcable is the least expensive cable, it may be susceptible to radio andelectrical frequency interference (it should not be too close to electricmotors, fluorescent lights, etc.). If you must place cable in environments withlots of potential interference, or if you must place cable in extremelysensitive environments that may be susceptible to the electrical current in theUTP, shielded twisted pair may be the solution. Shielded cables can also helpto extend the maximum distance of the cables.
Shieldedtwisted pair cable is available in three different configurations:
1.     Each pair of wires is individuallyshielded with foil.
2.     There is a foil or braid shield insidethe jacket covering all wires (as a group).
3.     There is a shield around eachindividual pair, as well as around the entire group of wires (referred to asdouble shield twisted pair).
CoaxialCable
Coaxialcabling has a single copper conductor at its center. A plastic layer providesinsulation between the center conductor and a braided metal shield (See fig.3). The metal shield helps to block any outside interference from

Althoughcoaxial cabling is difficult to install, it is highly resistant to signalinterference. In addition, it can support greater cable lengths between networkdevices than twisted pair cable. The two types of coaxial
Thin coaxialcable is also referred to as thin net. 10Base2 refers to the specifications forthin coaxial cable carrying Ethernet signals. The 2 refers to the approximatemaximum segment length being 200 meters. In actual fact the maximum segmentlength is 185 meters. Thin coaxial cable has been popular in
Thickcoaxial cable is also referred to as thick net. 10Base5 refers to thespecifications for thick coaxial cable carrying Ethernet signals. The 5 refersto the maximum segment length being 500 meters. Thick coaxial cable has anextra protective plastic cover that helps keep moisture away from the centerconductor. This makes thick coaxial a great choice when running longer lengthsin a linear bus network. One disadvantage of thick coaxial is that it does


Coaxial Cable Connectors
The mostcommon type of connector used with coaxial cables is the Bayonne-Neill-Concelman(BNC) connector (See fig. 4). Different types of adapters are available for BNCconnectors, including a T-connector, barrel connector, and terminator.Connectors on the cable are the weakest points in any network. To help avoidproblems with your network, always use the BNC connectors that crimp, rather

FiberOptic Cable
Fiber opticcabling consists of a center glass core surrounded by several layers ofprotective materials (See fig. 5). It transmits light rather than electronicsignals eliminating the problem of electrical interference. This makes it idealfor certain environments that contain a large amount of electricalinterference. It has also made it the standard for connecting networks between
Fiber opticcable has the ability to transmit signals over much longer distances thancoaxial and twisted pair. It also has the capability to carry information atvastly greater speeds. This capacity broadens communication possibilities toinclude services such as video conferencing and interactive services. The costof fiber optic cabling is comparable to copper cabling; however, it is
The centercore of fiber cables is made from glass or plastic fibers (see fig 5). Aplastic coating then cushions the fiber center, and kevlar fibers help tostrengthen the cables and prevent breakage. The outer insulating jacket made ofTeflon or PVC.

There aretwo common types of fiber cables -- single mode and multimode. Multimode cablehas a larger diameter; however, both cables provide high bandwidth at highspeeds. Single mode can provide more distance, but it is more expensive.


Ethernet Cable Summary

Specification
Cable Type
10BaseT
Unshielded Twisted Pair
10Base2
Thin Coaxial
10Base5
Thick Coaxial
100BaseT
Unshielded Twisted Pair
100BaseFX
Fiber Optic
100BaseBX
Single mode Fiber
100BaseSX
Multimode Fiber
1000BaseT
Unshielded Twisted Pair
1000BaseFX
Fiber Optic
1000BaseBX
Single mode Fiber
1000BaseSX
Multimode Fiber





Types of Networks


Wide Area Networks (WAN)
As the termimplies, a WANspans a large physical distance. The Internet is the largest WAN, spanning theEarth.
A WAN is ageographically-dispersed collection of LANs. A network device called a routerconnects LANs to a WAN. In IP networking, the router maintains both a LANaddress and a WAN address.
A WAN differs from a LAN inseveral important ways. Most WANs (like the Internet) are not owned by any oneorganization but rather exist under collective or distributed ownership andmanagement. WANs tend to use technology like ATM,Frame Relayand X.25for connectivity over the longer distances.

          Cover a large geographic area.

          Telecommunication network

          Span large geographical distance

          Consist of variety of cable,satellite, and microwave technologies

          Switched lines, dedicated lines


Metropolitan area network (MAN)
A network is spanning a physical arealarger than a LAN but smaller than a WAN, such as a city. A MAN is typicallyowned and operated by a single entity such as a government body or largecorporation.
  • Same city (10’s of kilometers)
  • 800 Mb/s Gigabit Nectar

Campus Area Network (CAN)
 A network is spanning multiple LANs butsmaller than a MAN, such as on a university or local business campus.


Local Area Networks (LAN)
ALANconnects network devices over a relatively short distance. A networked officebuilding, school, or home usually contains a single LAN, though sometimes onebuilding will contain a few small LANs (perhaps one per room), and occasionallya LAN will span a group of nearby buildings. In TCP/IP networking, a LANis often but not always implemented as a single IP subnet.
Inaddition to operating in a limited space, LANs are also typically owned,controlled, and managed by a single person or organization. They also tendto use certain connectivitytechnologies, primarily Ethernetand Token Ring.
Connectcomputers & other information processing devices within a limited physicalarea.
Telecommunicationnetwork require its’ own dedicated channels encompass a limited distance Transmithigh volumes of data, and other functions requiring high transmission speeds

Gateway,router, Network Operating System (NOS), peer-to-peer
Thegateway is a communications processor that can connect dissimilar networks by translatingfrom one set of protocols to another.



Connectedvia ordinary telephone wiring, coaxial cable, or wireless radio & infraredsystems


Virtual Private Networks (VPN)
Asecure network that uses the Internet as its main backbone network, but relieson firewalls and other security features

Avirtual private network based on the Internet Protocol provides a secureconnection between two points across the Internet, enabling privatecommunications to travel securely over the public infrastructure


Personal Area Networks (PAN)
  • Connection of computer to peripherals or other computers
  • Connect PDA and desktop computer
  • Several connection methods:
  • Blue tooth (radio frequency – up to 300 feet)
  • IrDA (Infrared) (cheap)
  • Wi-Fi: Wireless LAN 802.11b – wireless Ethernet (more reliable)



BroadbandNetwork Services and Technologies
Anumber of network services and technologies are available to companies thatneed high-speed transmission or access to the Internet.

Framerelay:  Packages data into frames for high-speedtransmission over reliable circuits that require less error checking thanpacket switching

AsynchronousTransfer Mode (ATM):Parcels data into uniform 53-byte cells for high-speed transmission; cantransmit data, video, and audio over the same network

ATM (asynchronous transfer mode) is adedicated-connection switching technology that organizes digital data into 53-bytecellunits and transmits them over a physical medium using digital signaltechnology. Individually, a cell is processed asynchronously relative to otherrelated cells and is queued before being multiplexedover the transmission path.
BecauseATM is designed to be easily implemented by hardware (rather than software),faster processing and switchspeeds are possible. The prespecified bit rates are either 155.520 Mbpsor 622.080 Mbps. Speeds on ATM networks can reach 10 Gbps.Along with Synchronous Optical Network (SONET)and several other technologies, ATM is a key component of broadband ISDN (BISDN).
ATMalso stands for automated teller machine, a machine that bank customers use tomake transactions without a human teller.

IntegratedServices Digital Network (ISDN):Dial-up network access standard that can integrate voice, data, and videoservices.

A rather dated communicationtechnology standard for simultaneous high speed basebandtransmission of voice and data(including videoand fax) over ordinary(twisted pair)coppertelephonelines.In most of the world it has been overtaken by datacompression technologies such as ADSL.It is available in two main configurations: (1) Basic rate interface(BRI) configuration, comes with three digitalchannelscomprising of two 64 Kbps bearer(B)channels and one 16 Kbps data (D) channel that providescontrol and signaling for the B channels.A merchant,for example, could run credit cardauthorization on the D channel, use one B channel for voice, and the other forfax; or combine two B channels for 128 Kbps connectionto the internetwithout needing a modem; (2) Primaryrate interface (PRI) configuration, comes with 23 B channels and one D channel.The newer broadbandversion(B-ISDN) supportstransmission ratesof up to 1.5 Mbps but requires fiber-optic cables.

DigitalSubscriber Line (DSL):Series of technologies for high-capacity transmission over copper wire.

Stands for "Digital SubscriberLine." It is medium for transferring data over regular phone lines and canbe used to connect to the Internet. However, like a cable modem, a DSL circuitis much faster than a regular phone connection, even though the wires it usesare copper like a typical phone line.

An asymmetric DSL (ADSL)connection allows download speeds of up to about 1.5 megabits (not megabytes)per second, and upload speeds of 128 kilobits per second. That is why it iscalled ADSL and not just DSL (because of the asymmetric speeds). There is alsoa "Symmetric Digital Subscriber Line" (SDSL) which is similar toADSL, but allows data transfer speeds of 384 Kilobits per second in bothdirections. Theoretically, this type of connection allows download speeds of upto 9 megabits per second and upload speeds of up to 640 kilobits per second.The difficult part in establishing an DSL circuit is that it must be configuredto connect two specific locations, unlike a regular phone line or cable modem.DSL is often seen as the new, better alternative to the older ISDN standard
.

Cable modem: Service for high-speed transmissionof data over cable TV lines that are shared by many users
A cable modem is a device that enablesyou to hook up your PC to a local cable TVline and receive data at about 1.5 Mbps.This data rate far exceeds that of the prevalent 28.8 and 56 Kbps telephonemodems and the up to 128 Kbps of Integrated Services Digital Network (ISDN)and is about the data rate available to subscribers of Digital Subscriber Line(DSL)telephone service. A cable modem can be added to or integrated with a set-top boxthat provides your TV set with channels for Internet access. In most cases,cable modems are furnished as part of the cable access service and are notpurchased directly and installed by the subscriber.
Acable modem has two connections: one to the cable wall outlet and the other toa PC or to a set-top box for a TV set. Although a cable modem does modulationbetween analogand digitalsignals, it is a much more complex device than a telephone modem.It can be an external device or it can be integrated within a computer orset-top box. Typically, the cable modem attaches to a standard 10BASE-TEthernetcardin the computer.
Allof the cable modems attached to a cable TV company coaxial cableline communicate with a Cable Modem Termination System (CMTS) at the localcable TV company office. All cable modems can receive from and send signalsonly to the CMTS, but not to other cable modems on the line. Some services havethe upstream signals returned by telephone rather than cable, in which case thecable modem is known as a telco-return cable modem.
Theactual bandwidthfor Internet service over a cable TV line is up to 27 Mbps on the download pathto the subscriber with about 2.5 Mbps of bandwidth for interactive responses inthe other direction. However, since the local provider may not be connected tothe Internet on a line faster than a T-carriersystem at 1.5 Mpbs, a more likely data rate will be close to 1.5Mpbs.
Leadingcompanies using cable TV to bring the Internet to homes and businesses are@Home and Time-Warner.
Inaddition to the faster data rate, an advantage of cable over telephone Internetaccess is that it is a continuous connection.

Tlines: Dedicatedlines for high-speed secure data transmission and Internet connection.


 THE INTERNET
Technically,the Internet is a global information system defined by three characteristics:
•Anetwork composed of computers and other devices that are logically linkedtogether by a unique address space based on the Internet Protocol

•Anetwork where network devices are able to support communications using TCP/IPor other compatible protocols

•Anetwork that provides high-level services layered on a communication andnetwork infrastructure

InternetAddressing, Architecture, and Governance

TheDomain Name System:
Everydevice connected to the Internet has a unique 32-bit numeric IP address.
•ADomain Name System (DNS) converts IP addresses to English-like domain names.
•Thedomain name is the name that corresponds to the unique 32-bit numeric IPaddress for each computer connected to the Internet.
•DNSservers maintain a database containing IP addresses mapped to theircorresponding domain names.
•Toaccess a computer on the Internet, users need only specify its domain name.

Internet Network Architecture



InternetNetwork Architecture is by definition a meta-network, a constantly changingcollection of thousands of individual networks intercommunicating with a commonprotocol.
TheInternet's architecture is described in its name, a short from of the compoundword "inter-networking". This architecture is based in the veryspecification of the standard TCP/IPprotocol, designed to connect any two networks which may be very different ininternal hardware, software, and technical design. Once two networks areinterconnected, communication with TCP/IP is enabled end-to-end,so that any node on the Internet has the near magical ability to communicatewith any other no matter where they are. This openness of design has enabledthe Internet architecture to grow to a global scale.


InternetGovernance:
Internetgovernance is the development and application by governments, the privatesector and civil society, in their respective roles, of shared principles,norms, rules, decision-making procedures, and programmers that shape theevolution and use of the Internet.
Thisworking definition was taken up in the Tunis Agenda for the InformationSociety, one of the two outcome documents of the second phase of the WorldSummit on the Information Society (WSIS) in 2005.
Organizationsdealing with Internet Governance
Thereis a range of organizations dealing with various aspects of Internet Governancerelated issues.

No one “owns” the Internet; however,worldwide Internet policies are established by the following organizations:
•Internet Architecture Board (IAB)
•Internet Corporation for AssignedNames and Numbers (ICANN)
•Internet Network Information Center(InterNIC)
•Internet Engineering Steering Group(IESG)
•Internet Engineering Task Force(IETF)
•Internet Society (ISOC)
•World Wide Web Consortium (W3C)

Major Internet Services


•E-mail: Person-to-person messaging;document sharing
•Usenet newsgroups: Discussion groupson electronic bulletin boards
•LISTSERVs: Discussion groups usinge-mail mailing list servers
•Chatting and instant messaging:Interactive conversations
•Telnet: Logging on to one computersystem and doing work on another
•FTP: Transferring files from computerto computer
•World Wide Web: Retrieving,formatting, and displaying information (including text, audio, graphics, andvideo) using hypertext links

The Internet and Business Value

TheWorld Wide Web:

•Hypertext
•Web servers
•Searching for information on the Web
Searching and Finding Information onthe Internet
•The Internet lowers search costs
•Search engines
•Intelligent agents and shopping bots
•Broadcast and push technology
•The semantic Web

Hypertext:
Hypertext is text displayed on a computer orother electronic device with references (hyperlinks) to other text that thereader can immediately access, usually by a mouse click or key press sequence.Apart from running text, hypertext may contain tables, images and otherpresentational devices. Hypertext is the underlying concept defining thestructure of the World Wide Web, making it an easy-to-use and flexible formatto share information over the Internet

Web server:
A Web server is a computerprogram that delivers (serves) content, such as Web pages, using the HypertextTransfer Protocol (HTTP), over the World Wide Web. The term Web server can alsorefer to the computer or virtual machine running the program. In largecommercial deployments, a server computer running a Web server can berack-mounted in a server rack or cabinet with other servers to operate a Webfarm.

Web search engine:
A web search engine is designedto search for information on the World Wide Web. The search results are usuallypresented in a list of results and are commonly called hits. Theinformation may consist of web pages, images, information and other types offiles. Some search engines also mine data available in databases or opendirectories. Unlike Web directories, which are maintained by human editors,search engines operate algorithmically or are a mixture of algorithmic andhuman input.
Intranets:
An intranet is a private networkthat is contained within an enterprise.It may consist of many interlinked local area networks and also use leasedlines in the wide areanetwork. Typically, an intranet includes connections through one ormore gatewaycomputers to the outside Internet. The main purpose of an intranet is to sharecompany information and computing resources among employees. An intranet canalso be used to facilitate working in groups and for teleconferences.
Anintranet uses TCP/IP,HTTP,and other Internet protocols and in general looks like a private version of theInternet. With tunneling,companies can send private messages through the public network, using thepublic network with special encryption/decryption and other security safeguardsto connect one part of their intranet to another.
Extranets:
Anextranet is a private network that uses Internet technology and the publictelecommunication system to securely share part of a business's information oroperations with suppliers, vendors, partners, customers, or other businesses.An extranet can be viewed as part of a company's intranetthat is extended to users outside the company. It has also been described as a"state of mind" in which the Internet is perceived as a way to dobusiness with other companies as well as to sell products to customers.
Anextranet requires security and privacy. These can include firewallserver management, the issuance and use of digitalcertificates or similar means of user authentication, encryptionof messages, and the use of virtual private networks (VPNs)that tunnel through the public network.
Companiescan use an extranet to:
  • Exchange large volumes of data using Electronic Data Interchange (EDI)
  • Share product catalogs exclusively with wholesalers or those "in the trade"
  • Collaborate with other companies on joint development efforts
  • Jointly develop and use training programs with other companies
  • Provide or access services provided by one company to a group of other companies, such as an online banking application managed by one company on behalf of affiliated banks
  • Share news of common interest exclusively with partner companies


E-mail:
Electronic mail, most commonly abbreviated emailor e-mail, is a method of exchanging digital messages. E-mail systemsare based on a store-and-forward model in which e-mail server computer systemsaccept, forward, deliver and store messages on behalf of users, who only needto connect to the e-mail infrastructure, typically an e-mail server, with anetwork-enabled device for the duration of message submission or retrieval.Originally, e-mail was always transmitted directly from one user's device toanother's; nowadays this is rarely the case.

Chat:
Online chat can refer to any kind ofcommunication over the Internet, but is primarily meant to refer to directone-on-one chat or text-based group chat (formally also known as synchronousconferencing), using tools such as instant messengers, Internet Relay Chat,talkers and possibly MUDs. The expression online chat comes from theword chat which means "informal conversation.
IMs(Instant Messages):
Instant messaging, or IM in Internet slang, consists of sendingreal time messages to another Internet user. Instant messaging is comparable tochatting in your own private chat room, with only thosepeople you choose to invite. You can create a list to keep track of welcomeguests and alert you when one of them sends you a message.
VPN:
A virtual private network (VPN)is a computer network that is layered on top of an underlying computer network.The private nature of a VPN means that the data travelling over the VPN is notgenerally visible to, or is encapsulated from, the underlying network traffic.Similarly, the traffic within the VPN appears to the underlying network as justanother traffic stream to be passed. A VPN connection can be envisioned as a"pipe within a pipe", with the outer pipe being the underlyingnetwork connection.
Theterm VPN can be used to describe many different network configurations andprotocols. As such, it can become complex when trying to generalize about thecharacteristics of a VPN. Some of the more common uses of VPNs are describedbelow, along with more detail about the various classification schemes and VPNmodels.
Groupware: Provides capabilities for supportingenterprise-wide communication and collaborative work

Team-ware: Enables companies to implementcollaboration applications easily that can be accessed using Web browsersoftware

Electronic conferencingtools: Provides avirtual conference table where participants can view and modify documents andslides or share their thoughts and comments using chat, audio, or video

Internettelephony: Enablecompanies to use Internet technology for telephone voice transmission over theInternet or private networks

Voiceover IP (VoIP) technology:Uses the Internet Protocol (IP) to deliver voice information in digital formusing packet switching

Unifiedmessaging systems:Combine voice mail, e-mail, and faxes so they can all be obtained from onesystem


Optical fiber (or "fiberoptic") refers to the medium and the technology associated with thetransmission of information as light pulses along a glass or plastic strand orfiber. Optical fiber carries much more information than conventional copperwire and is in general not subject to electromagnetic interference and the needto retransmit signals. Most telephone company long-distance lines are now madeof optical fiber. Transmission over an optical fiber cable requires repeatersat distance intervals. The glass fiber requires more protection within an outercable than copper. For these reasons and because the installation of any newcabling is labor-intensive, few communities have installed optical fiber cablesfrom the phone company's branch office to local customers (known as localloops). A type of fiber known as singlemode fiber is used for longer distances; multimodefiber is used for shorter distances.


Click the link to download the doc file.........
Radio Foorti