Tele Education Essay
1.0 INTRODUCTION 1.1 Background of Tele-education Tele-education has a longhistory beginning with systems like that for teaching children in AustralianOutback, the British Open University and other such organizations. These builton the idea of correspondence courses where course materials are sentperiodically by post and augmented the experience with broadcasts either onradio or on TV. The problem of student isolation was addressed partially throughtechniques such as telephone access or two-way radio links with teachers. At theend of 1980s, the vest majority of distance education throughout the worlds wasstill primarily print-based. Technologies used for distance education areevolving from primarily one-way technologies and applications such ascomputer aided learning, computer based training and computer aided instruction,to more two-way technologies and applications such as computer mediatedcommunications and computer conferencing systems for education. The significanceof two-way technologies is that they allow foe interaction betweenparticipant and tutors, and perhaps even more significantly amongst participantthemselves. This development has allowed and in some senses force researches tolook more closely at the impact of educational environment, on the studentslearning experience. In the future, it is expected that thetelecommunications-based technologies to become the primary means of delivery ofdistance teaching. The reasons for this are as follows: ? a much widerrange of technologies are becoming more accessible to potential distanceeducation participants ? the costs of technological delivery are droppingdramatically ? the technology is becoming easier to use for both tutorsand learners ? the technology is becoming more powerful pedagogically? education centers will find it increasingly difficult to resist thepolitical and social pressures of the technological imperatives. 1.2 TheEmergence of Tele-education Radical changes in the computing infrastructure,spurred by multimedia computing and communication, will do more than extend theeducational system, that is revolutionize it. Technological advances will makeclassrooms mush more accessible and effective. Today, classroom educationdominates instruction from elementary school to graduate school. This method hasremained popular for a very long time and will probably persist as the mostcommon mode of education. However, classroom education has its problems, that isthe effectiveness decline with increase in the number of students per class.
Other pressures affect the instructors, many of whom are not experts in thematerial they must teach, are not good performers in class, or simply arenot interested in teaching. The biggest limitation of the classroom instructionis that a class meets at a particular time in a particular place. Thisessentially requires all students and the instructors to collect in one spot fortheir specified period. But with the emerging technology, these problems can beovercome. 1.3 Reasons for studying Tele-education The current Tele-educationsystems that have been applied in some countries are generally of multipointtransmission technique. It is found that, this kind of transmission techniquehaving several problems or defects. Mostly, problems raised during theapplication of the system. One of the significant problems raised is that, forthe multipoint transmission, the signals or information transmitted by thesender do not completely received by the receiver. This problem is might be dueto error that occurs during the transmission of the signals or information.
Another problem is lag of transmission. For this case, the signals orinformation transmitted do not arrive at all the receiver at the same time, forexample, the question raised by the lecturer might not received by the studentsat the same time and this is not a good environment for Tele-education system.
Some receiver receives the signals earlier than the others and some later oreven not receives at all. Therefore, it is important to study the Tele-educationtechnology from time to time to overcome these problems so that theTele-education system could provide a more effective way of learningenvironment. In order to have a lecture from, for example, a very famousprofessor from other country would require him to come at our place. But theamount of money spent for paying him to give lecture would be very expensive andthis also would cause troublesome for him. However, this problem can be solvedwith Tele-education system in which the professor does not need to go anywhereelse to give his lecture. This would save a lot of expenses and time. Anotherreason is that, in normal classes the learning process would not be veryeffective if the number of students in a class is very big. This is because thelecturer alone can not coordinate such a large class. With Tele-educationsystem, one lecturer could deliver his lecture to as many students as possibleeffectively in a way that a large number of students from different sites havingthe same lecture at once. 1.4 Purpose of Research The purpose of this researchis to study the current Tele-education system that has been applied in somecountries. This study covers the background of Tele-education; that is itsdefinition, the publications of Tele-education; that is any papers that discussabout Tele-education as a whole, the performance of applied Tele-education, andalso the technology of Tele-education; that is its network architecture. But themain purpose of this study is to understand the Tele-education system that havebeen applied in another country and try to implement it in our country. 1.5Acronyms ATM Asynchronous Transfer Mode CCITT Committee ConsultatifInternational Telegraphique et Telephonique CPE Customer Premises Equipment IPInternet Protocol ISDN Integrated Services Digital Network ISO InternationalStandard Organization JAMES Joint ATM Experiment on European Services LAN LocalArea Network MAC Medium Access Control Mbone Multicast Backbone PC PersonalComputer POP Point-of-Presence PVC Permanent Virtual Channel QoS Quality ofService RAT Robust Audio Tool SLIP Serial Line Internet Protocol TCP-IPTransmission Control Protocol – Internet Protocol TES Tele-Educational ServiceUI User Interface VIC Video Conferencing Tool VP Virtual Path VPN VirtualPrivate Network VSD Virtual Student Desktop WAN Wide Area Network WWW World WideWeb XC Cross Connect 2.0 METHOD OF INVESTIGATION Since Tele-education is a verynew technology that is popularly discussed today, it is quite difficult for meto find any books that discuss about Tele-education from the library. Therefore,the easiest and the fastest way to gather information relating this project isvia the Internet. I have surfed and found many interesting sites that discussabout Tele-education. Besides surfing, I also have contacted several people whoare involved in this area, Tele-education, by e-mail . But unluckily, this doesnot really help because most of them did not reply. Besides using the Internet,I also get the information for this project from the IEEE Database at thelibrary of Universiti Telekom. 3.0 BACKGROUND STUDY 3.1 Definition ofTele-education What is Tele-education? Before discussing about whatTele-education means, lets look at what distance learning is. This is becauseTele-education and distance learning are very related to each other. Distancelearning is the acquisition of skills and knowledge through electroniccommunications that allow student and instructor to be separate in either intime or space. The to distance learning is asynchronous learning which canbe defined loosely as learning at different time. It is a highly flexible methodof training because the sender and receiver do not need to be synchronized inspace or time. But Tele-education is more than that of distance learning. InTele-education, not only asynchronous but synchronous learning is also madepossible. In other words, Tele-education is the evolution of distance learning.
As stated before, asynchronous learning environment is not real-timeenvironment. It is a self-study-based application and is accessed via theInternet to a server. The requirement to the student is only an ordinary PC withstandard software and Internet access. This application is applicable for alarge amount of users who can access the course independent of each other. Thecombination of the lecture-part, group-work-part, and self-study-part is anothertype of Tele-education learning environment, which is synchronous learning. Itis a real-time environment. In this environment, students and lecturers caninteract with each other simultaneously. Tele-education use the technology ofvideo teleconferencing that allows two or more parties at different geographicalarea to interact with each other or to have learning process together. Butpeople usually get confused whether video teleconferencing can be considered asTele-education as well. Tele-education is actually different with videoteleconferencing in a way that Tele-education usually involve a large number ofpeople as compared to video teleconferencing, that is, it is in videoteleconferencing many people use a single monitor to see other people at otherarea but in Tele-education, students have their own monitor that can be used notonly to see their lecturer and colleagues but also to send and receiveeducational materials. 3.2 Publications of Tele-education There are many papersdiscussing about Tele-education. Most of these papers cover only the general oroverall scope of Tele-education. The area of discussion on Tele-education can besummarized as the following: ? Tele-education service ? Content ofTele-education ? Network architecture ? performance ofTele-education ? operation and management of Tele-education ForTele-education service, it describes about what multimedia tele-service andhyper media service is, and how it can be integrated into Tele-educationservice. It also describes about what Tele-education service facilitate. Contentof Tele-education describes about the style or mode of Tele-education system,that is, what kind of education style used, and how the lecture notes or anymaterials delivered to all the students. For network architecture, it describesabout the protocol used for the Tele-education system and its networkinfrastructure. Performance of Tele-education covers the performance of serviceof Tele-education and also the network performance. The description of theseperformances is from the customer point of view. For the operation andmanagement of Tele-education, it describes about what should be taken intoconsideration in order to provide a well managed Tele-education service. 3.3Examples of Systems From the study of materials gathered, there are generallythree examples of Tele-education system that have been applied in the Europe andCanada. Those examples are: ? Tele-education NB ? Delta ‘s VirtualCollege ? ACTS Project AC052 (RACE Project Report) The purpose of lookinginto these examples is to try to understand what kind of Tele-education systemis implemented, how Tele-education can be implemented, to know what are therequirements to implement it, and what considerations should be taken intoconsideration for implementing it. 3.3.1 Tele-education NB Tele-education NB isimplemented at the University of New Brunswick, Canada. The present physicalnetwork consists of three independent networks that operate on telephone lines;? Voice ? SMART 2000 computer teleconferencing ? ComputerMediated Communications using NBNet The SMART 2000 bridge for computer softwaresharing and audiographic teleconferencing is owned and operated by theTele-education NB. This is accessed by simple dial connections using ordinarytelephone lines. This allows for the computer monitor at each site to showimages created by users at the other sites. The software can be used like anelaborate electronic blackboard, overhead projector, or slide projector. Inaddition, it is being used for software sharing at multiple locations. Datacommunications are transmitted over NBNet using a SLIP server which resides in auser friendly simple menu front-end created by Tel-education NB to permit easyaccess to NBNet and to facilities available. Students and teachers can accessNBNet for uploading and downloading assignments and other course materials. ACD-ROM server is being set up at the central site and at the University of NewBrunswick library for permitting access to different databases. Tele-educationNB also supports an on-line learning center with a file server located at MountAllison University. Information of relevance distance education and the networkin particular can be accessed there. In Tele-education NB, a special listserv iscreated for internal communications among different sites. As an integral partof the province’s electronic information highway, Tele-education NB issupporting the development of an open, distributed network, taking advantage ofmedia available. The most widely used delivery modes are audio teleconferencingwith SMART 2000, as well as videoconferencing. However, it is not limiting thenetwork to any one technology, or suite of technologies. It is activelypromoting experimentation and cooperation in the reception and delivery ofcourses using other software and media. Tele-education NB placed routers in theCommunity College Campus in each region, and other sites in regions that do nothave a college. Initially it operates using 56K connections and will move T1.
SMART 2000 runs not only on regular telephone lines but also on LANs and WANsusing Novell, TCP-IP and other telecommunication protocols. Tele-education NBare now experimenting with synchronous transmissions using the TCP-IP protocolon NBNet. The Picturetel videoconferencing units existing in province all areCCITT compatible. Tele-education NB has provided the guidelines for selectingappropriate technology for its network as follows: ? The network shallexperiment with different technologies and endeavor not to rely on any onetechnology or any supplier. ? Existing equipment and distance educationsites in the province shall be integrated into the network wherever possible.
? The network shall establish computer teleconferencing and computerconferencing links among the sites, including access to electronic informationhighway and the Internet. ? Satellite delivery and reception capabilitiesand upgrading of sites to PC-based videoconferencing will be investigated forimplementation in future. ? Other optional equipment may be placed insites at the request of users and institutions such as MACs and CD-ROMs.
? The network should be compatible as much as possible with otherprovinces and regions. 3.3.2 DELTA’s Virtual College Delta’s Virtual College isimplemented in Denmark (Europe). It offers the opportunity for students toparticipate in desktop Tele-education from their homes or offices. This conceptmeans that individual students participate in Tele-educational courses using adesktop computer online connected to a course provider. The user interface is acommon Web browser, that is, Netscape Web-browser, extended with looselyintegrated audio and video tools. The educational environment applies themetaphor of a virtual college. The idea is that students access DELTA’s virtualcollege server when participating in a course. The user interface looks like theplan of a college. From the college hallway, the student can enter differentrooms with different functions. Those rooms are: ? classrooms whereon-line lectures and presentation take place, ? group rooms where on-linecooperative work takes place, ? studies where off-line study such asself-study material, exercises, slides from previous lectures, supplementarymaterial and links to other sites on the Web take place, ? teacheroffices where it is furnished with course administration tools, ? tearoom where it is used for informal chat and social contact with fellow studentsduring break. The following figure, the “floor plan”, illustratesthose rooms: Figure 1 : The floor plan The goal of this virtual college is tointegrate different modes of teaching and learning. This includes synchronousmode like on-line lectures and group exercises as well as asynchronous mode likeinteractive self study, participation and threaded bill board conferences andsharing of documents. The virtual college is run primarily in a local networkenvironment in order easily to monitor and control the students and technology.
Then, when there are several countries participate, each sites are connected bythe JAMES (Joint ATM Experiment on European Services) broadband network. 3.3.3ACTS Project AC052 (RACE Project Report) This is a big project onTele-education. It covers the whole aspects that should be taken intoconsideration for implementing Tele-education in Europe such as service aspects,management aspects, network architecture, etc. In this project, there areseveral trials have been done in order to obtain an effective Tele-educationsystem. The details of this will be discussed later throughout this report. 4.0CONSIDERATIONS It is not easy to find materials or any papers reporting thearchitecture of Tele-education. Most of the materials found are basicallydiscussing about the general idea on what Tele-education system is, for examplesome papers discuss about the general system of a Tele-education serviceoffered, its advantages over current educational environment, etc. However, Imanaged to find a very interesting material discussing about Tele-education as awhole, that is the ACTS Project AC052 (RACE Report Project). Therefore, I choosethis report as my main reference in doing my study on Tele-education overallsystem description covering the architecture. There are basically five maintopics that are going to be discussed in quite detail regarding theTele-education as a whole in this report. These main topics are: ?Tele-education service ? Tele-education content ? Networkarchitecture of Tele-education system ? Performance of Tele-educationservice ? Operation and management of Tele-education service 4.1Tele-education Service The multimedia tele-service provides both core andmanagement services. The multimedia tele-services are briefly described asVideo/audio conferencing service, which based on the MBONE (Multicast Backbone)tools VIC (video conferencing) and RAT (audio conferencing). Hypermedia serviceallows access to be provided to hypermedia information stored on a WWW server.
The WebStore service is a managed WWW based multimedia document store, whichallows users to store and retrieve arbitrary documents (text, video, audio,etc.), using the well-known interface of the WWW. The management of the WebStoreincludes subscription, accounting and access control. A mapping between thelearning forms and the multimedia teleservices has resulted in a list of fourbasic paradigms: a) Self-study ? Individual work with web based coursematerial including exercises and discovery/reference search. ? Thisparadigm is supported by the hypermedia and WebStore services. b) Lecture? Teacher to class presentation. ? Supported by the conferencingand hypermedia services. c) Group work ? Discussions, exercises orproject work performed by the students in groups. This paradigm can also includeshared discovery/reference search. ? It is supported by conferencing,hypermedia, and WebStore services. d) Consultation ? Student to tutorconsultation ? Supported by video/audio conferencing and hypermediaservices. In order to support these four paradigms the multimedia services areintegrated into a Tele-educational Services (TES) which provides both the coreservice and the management service functionality. The core Tele-educationalservice provides two user interfaces, one for the teacher and one for thestudents. In Tele-educational service, each course, presented as part ofTele-educational service, would involve the rendering and seamless integrationof audio, text, graphics/bitmaps and appropriate video segments, to suit thepresentation of the course material. An educational service would alsofacilitate the interaction of course participants with one another in classdiscussions, as well as with the course tutor. In this way, a course tutor canguide debates on issues arising from course material and allow participants toexchange views and share experience. This interaction is very important, asparticipants need to be encouraged to learn both from the tutored course as wellas from each other’s practical experience. This forum of discussion alsosupports the tutor in assessing feedback from the participants concerning thecomprehension, benefit and effectiveness of a course for participants. Theeducational service could also facilitate access to simulation environments and’live systems’, which are parts of the participant’s course material. Forexample, it could provide access to specific commercial database information,which would be part of a Database Modeling course. In this way, access may begained to systems and information, which would otherwise not be available on theparticipant’s site. Course could be taken when the participant’s work schedulespermitted. Similarly, participant/participant interaction could be scheduledflexibly. An educational service can be seen as incorporating severalinteraction (tele-services) and course presentation mechanism, for example,multimedia presentation tools conferencing, e-mail or notice board systems. Thefollowing is an example of service layer used in the ACTS Project AC052: Figure2 : Service Layer In the ACTS Project AC052, there are two Tele-educationalcourses offered as a trial of the management service. These courses are “An Introduction to ATM ” and ” An Introduction to Relational Databasesand SQL “. 4.1.1 An Introduction to ATM The course includes bothsynchronous and asynchronous delivery methods. The duration of the course isthree to four days with approximately three hours of teaching and studying eachday. The course consists of five lectures, three self study modules and threegroup exercises with a follow-up discussion of the results. The differentmodules and modes of the course are conducted in a Tele-educational environmentwhich includes course outline information, a database of participants withpictures and CVs, a WWW billboard supporting off-line discussions, access to aWebStore and a tea-room which participants can visit for informal chats. Thelectures are performed by using video/audio conference tools. A system was usedto show slides on the participants web-browsers. The self study modulescontained web pages with information to read and small built-in exercises. Thegroup exercises consist of a number of questions to be answered by the group andreturned to the teacher for correction afterwards. When the teacher hascorrected the answers they are discussed in a conference with all theparticipants. In the first trial a shared editor was introduced for use in groupexercises. The shared editor is a tool for synchronous collaboration on smallertexts, and is meant to complement the chat and whiteboard tools used in earliertrials. An illustration of the new shared editor can be found below. In thesecond trial, a new floorcontrol-system for use during lectures as well as acomplete new graphical design of the virtual learning environment was tested.
The floorcontrol system was used by the teacher during lectures, to determinewhich students wanted to ask a question, and to mute or unmute the microphonesand video cameras accordingly. A new graphical design of the User Interface (UI)was introduced, in an attempt to create an even more homogenous UI. Thefloorplan metaphore was kept, but new images and controls where implementedthroughout the environment. 4.1.2 An Introduction to Relational Databases andSQL This course covered the theoretical principles of relational databasetechnology as well as supporting the hands-on skills of using relationaldatabase language (SQL). Students took the course over a three day period, fortwo hours each day. At the beginning of the course a one hour lecture outlinedthe objectives of the course and provided an introduction to the topics. Theeducational content comprised of text, graphics, and animation and was dividedinto four sections, consisting of a total of twenty one modules (a moduletypically being 1-5 pages). The course was made available via the ProspectTele-educational environment. On accessing the course, a separate coursewarebrowser window was opened, called the Virtual Student Desktop (VSD). All studentinteractions with the courseware are facilitated via this VSD. TheTele-educational environment is also accessible by the student for conferencingand synchronous interaction. The VSD is rendered as a set of WWW windows,frames, tool bar and icons. All native WWW browser buttons are suppressed(hidden) so as not to distract the user from the main goal of education. A toolbar specially designed for educational use is provided by the VSD at the bottomof the screen. From this tool bar the student is able to contact tutors orfellow students (asynchronously), access external systems, as well as navigateand interact with the educational course material. Figure 3 illustrates a pagefrom a module in the course, and shows the educational toolbar at the bottom ofthe screen and an index of the topics dealt with by this particular module inthe course on the left hand side of the screen. Figure 3 : page from module inthe course Overall the course comprised several different types of information:Administrative (i.e. how to use the course etc.); A database of (self contained)modules; Indexes or Roadmaps of specific courses through various modules;Evaluation Forms and a Case Study. The roadmaps were important as the modulescan be combined in several ways to satisfy the different requirements fordifferent student objectives. Each roadmap corresponds to different learningobjectives of the RDBMS course. Thus the roadmaps provide a means of re-usingexisting modules with as little redundancy as possible of educational materialand administrative overhead. A significant feature of the system was to providedirect access to a real commercial RDBMS via the same interface as theeducational course. The relational DBMS is seamlessly integrated into thestudent educational desktop. Thus the tool bar offered by the VSD contains anicon which allows students to issue SQL queries on a live database. The idea ofthis is to deliberately blur the distinction between the educational environmentand the target systems. This encourages students to try out variousparts of the course before attempting a larger project. Another feature was theability of the student to store references to distinct locations in the coursematerial (bookmarks). Traditionally these are stored locally on the studentsmachine. However this has disadvantages as students rarely use the same machineall the time. The VSD allows such bookmarks to be stored within the educationalservice and are thus (privately) accessible to an individual student at anytime. Also if the student has logged off the course and logs back on, the VSDallows him/her the ability to resume at his/her most recent position or restartat the beginning. Various forms of on-line tutorials are embedded into thecourse. True or False and Multiple Choice Questions are supported,with automatic correction and notification of marks to the student. Form based(short unstructured text style) answers are also facilitated in some tutorials.
In these cases the student answers are automatically delivered to course tutorsfor subsequent correction. Also integrated into the course are evaluation formswhich, when completed, are automatically submitted and stored for later analysisby course tutors. The VSD provides buttons to contact other class members or toseek tutor assistance. Again, this is offered via WWW forms and integratedtransparently with an email delivery system. 4.2 Tele-education Content Thereare several modes of educational interaction, which could be supported by avirtual theatre/study room. These would include lecture presentation, coursematerial presentation and browsing, self-study, group work (sharedapplication/work, class discussions, group presentations), consultation(tutor/participant, participant/participant), tutorial sessions, virtual coffeeroom/virtual lounge, and continuous assessment. There are also some other formof learning that have been identified. These forms of learning are: ?Self learning ? delivery of formatted courses material for students ownstudy ? Lecture presentation ? a one-to-many presentation by thetutor of course or organizational material. ? Exercises ? thefacility to perform exercises either in groups or individually ? Projectwork ? the development of sizeable projects using software outside theteaching environment. ? Discovery/Reference research ? ability tolocate and access background or supplemental learning material ?Seminar/Class discussion groups ? many-to-many communication betweenparticipants. ? Consultation ? private one-to-one communicationbetween participants. There is some overtap between these learning forms. Forexample, exercises, project work, discovery/reference search can be part of theself-learning form, but all of learning forms are listed here for completeness.
It has been pointed out that not only should the different modes of teaching besupported in the Tele-educational environment but also the different styles oflearning adopted by the students need to be supported. So for instance studentswho like to annotate their work or their course material should be facilitatedin doing so. This is very much in the spirit of hypertext origins of the WWW.
Another point raised is that multimedia activity in the virtual classroom shouldbe captured and associated with relevant course material. For instance, theteachers comments on a particular slide could be captured with the slide inquestion. Also the conversation of students working on group could also berecorded and stored with the exercise. Course material could be presented as ahyper-document with the participant capable of navigating through the documentor choosing the prescribed ordering of the presentation. In addition, theparticipant could also be given access to the more traditional learningmaterial, for example, notes, books, etc. Course assignments could also beelectronically submitted to promote fast feedback on performance. An importantelement of assignments and project work is the need to allow participants toco-operate in groups. 4.3 Network Architecture of Tele-education System From theapplication’s point of view, network operates as IP (Internet Protocol) networkrouting both multicast and unicast IP packets. Connection from network level tothe Q-adapters managing the switches communicate via ISO stack over X.25 links,but apart from this instances all network infrastructure is in support of IPtraffic. This network structure connects seven sites. The aim of the logicalnetwork infrastructure is to provide stable network interconnections as well asto be managed to some extent by the network management, and to provide aworking, broadband network infrastructure while also supporting an enterprisemodel suitable for multi-domain environment. For the separate customer networks,each sites posses of LANs of Ethernet, or mixed ATM/Ethernet LAN technologies.
For maximum efficiency of scarce international, broadband resources, only onesite in each countries (that taking part in Tele-education system) areconnected. The connection, internationally connected customer sites access thepublic network ATM service via an ATM cross-connect (ATM XC) providing ATMpublic network provider’s Point-of-Presence (POP) in each of relevant countries.
Each customer sites posses ATM Customer Premises Equipment (CPE) which is usedto interconnect ATM public network with local routers. For the connection withinthe same country, it is performed via leased lines between routers atinternationally connected customer sites and sites not connected to ATM publicnetwork provider. The ATM CPEs at internationally connected sites and routers atall customer sites managed by VPN (Virtual Private Network) provider. It isperformed in concert with management of ATM public service by VPN provider toprovide Intranet style connectivity between hosts on customer site LANs. Thisnetwork is quite complicated because it connects seven sites in four countriesand consisting of the following core components: ? Four ATM LANs ?Seven Ethernet based LANs ? Four ATM Cross Connects ? Eight staticIP routes ? Seven multicast routers ? Two 2 Mbps leased lines? Ten International ATM links (virtual path) ? One basic rate ISDNlink The following is the figure of logical network infrastructure: Figure 4 :Logical Network Infrastructure. The ATM infrastructure that represents ATMpublic network provider consists of a single ATM XC at each internationallyconnected sites. These XCs are interconnected by permanent VPs (Virtual Paths).
The ATM CPE at each site based on one or more Fore System ASX-200 switches. Itis employed as logically separate ATM LANs besides as providing ATM accessbetween public network and routers at each site. The following is the figure ofATM configuration. Figure 5 : ATM Configuration. The IP configuration consistsof routers at each connected sites being connected by Permanent Virtual Channel(PVC) running over VPs. The routing function at each site performed either bydedicated hardware router or by workstations running routing daemon software.
Routing of multicast IP packets (used for multimedia conferencing applications)is not fully supported by most current IP routers, therefore, routing performedby multicast routing daemon (mrouteds) running on workstations. The mrouteds areinterconnected by unicast IP tunnels, which can be used to be routed via routerstogether with all other unicast traffic. The IP tunnels between mrouted atinternationally connected sites used the second sets of VPs. This supportspartition of multicast traffic from other unicast traffic and thus enablesprovision of more deterministic Quality of Service (QoS) for multimediaconferencing application. For external infrastructure, the aim is to provideinternational ATM links between IP routers at the customer sites. Parallel VPsare used between each pair of sites; one for multicast routing and another onefor unicast routing. Figure 6 : The network configuration Reflecting thecontemporary trends in multimedia and information services, all softwarecommunication is over IP, including management system traffic. For the networkinfrastructures that are conducted at a single site, the requirement its networkis fairly simple, requiring simply Ethernet connection to support IPcommunication between PCs and workstations. If the system includes themanagement of connections over IP switches, then the network infrastructurewould include both a representative public network ATM cross connect andcustomer premises network ATM work-group switch (a FORE systems ASX200). Theseare connected and configured with multiple VPs to emulate a network with alarger number of nodes. IP routing functions in this network are provided by theSPARC workstations with ATM interface cards performing IP forwarding. Thefollowing is the network configuration of this kind of network: Figure 7 :Network configuration For this network configuration, the TES Customer is ableto request the set-up of a new connection to the TES provider. The TES providerthen requested the VPN provider to do likewise. The VPN provider made a requestto the Public Network Provider and Customer Premises Network Provider to ensurethat the end-to-end IP/ATM connection was in place for the TES Customer. This isthe goal for the configuration scenario. One of the most important on an ATMnetwork level management system is to provide end-to-end connectivity acrossconstituent ATM network element, and so support the connectivity provisioningwith fault management and quality of service features. Challenged by theserequirements, a system that is able to set up ATM Virtual Paths and to correlatefaulty conditions, determining how these fault effect the connectivity for eachend user has been built. The following is the Network infrastructure of thissystem: Figure 8 : Network infrastructure The figure shows that all the networkequipment is connected to one Ethernet hub, that is, the hub that acts as abackbone for one Public Network domain and two Customer Premises Networks. Inreality, this hub could be partitioned into a number of internets that areinter-connected by routers, also known as the Internet. For the network that isrequired to operate over six sites in four different countries, would require amuch more comprehensive network infrastructure. This infrastructure consisted ofan ATM VP service, leased lines, and the internal ATM and IP networkinfrastructure. The following is the example of this network infrastructure :Figure 9 : Network infrastructure 4.4 Performance of Tele-educational Service4.4.1 Courses There were two courses, both aimed at students with above averageprior knowledge of computing and/or computer networks. The first, anintroduction to SQL, was a self-study course, consisting mainly of modules ofwritten text with assessments based on these. The second course, an introductionto ATM, was led by a tutor and involved varied methods of delivery, includinglecture/seminar, individual study and group work. Students were thereforeexpected to interact both with one another and with the tutor. This course, too,included assessment modules. Both of the courses were offered over a three-dayperiod and students were expected to participate for three half days. Withinthis time, those taking the SQL course was able to pace their own study. On theATM course, the students use of the different resources was timetabled anddirected by the tutor. Time was divided between events, such as lectures, atwhich all students were expected to be present, and study time, during whichthey would work through a series of modules, with assessment associated witheach one. 4.4.2 Students There were 16 students on the more interactive of thetwo courses, the Introduction to ATM, and a similar number on the self-pacedstudy course, An Introduction to SQL. All the students appeared to beexperienced computer users. This has to be accepted as necessary in a trial suchas this , which takes place in the context of a research project which usesleading edge technology, some of it is still being tested. The prototypicalnature of parts of the system may make unusual demands on the students, such asimposing unexpected delays. Having students who appreciate the difficulties maywell be important. Having said this, it appeared that although they wereknowledgeable about computers, these students were not experts in networkedmultimedia technology, and did need some initial training in the use of thesoftware. This was given prior to the start of the course. The courses wereclearly directed at this target group, as their titles suggest. The studentsalso stated that they had a genuine wish to learn the subjects being offered andthat this was a major motivating factor. They were also paid for theirparticipation, which may have helped improve their persistence when there weretechnical hitches. 4.4.3 System The system used for the ATM course is describedhere. Those taking the SQL course used only those parts suited to self study.
There are three main elements: audio, and video communications channels supporta Tele-education system built on a web-browser base, but with considerablefunctionality added. The audio tool, rat, allows participants to receive andtransmit audio, to identify who is speaking, control the volume of incoming andoutgoing audio streams. Since this tool was developed as a research platform,there are many extra features which the average end-user is not likely to use inan application such as this one, for example, the facility to change the audioencoding scheme. The tools basic functionality is easy to learn and use. Thevideo tool, vic, also offers functionality suitable for its use as a platformfor research into networked video. For the non-expert, however, the mostimportant features are that multiple users can send and receive videosimultaneously and that they can control some features of both display andcapture/transmission (image size and frame rate are two examples). Video imagescan be displayed at various sizes from thumbnail image to CIF. Enlarging imagesdoes, however, involve creating a new window for each one. Students access theTele-education system via a web browser and navigate within it using hypertextlinks, buttons and active areas of images. Initial access is password protectedand the system supports the notion of groups and hence, presumably of multipleclasses and tutorial groups. The interface is based on the metaphor of aneducational institution, a building divided into rooms whose function moststudents will be able to predict from their real-life experience of education:classroom, tea room, hall, office, library and seminar room. Users are presentedwith an aerial view of the layout, in which the rooms are labeled. They gainaccess to a room by clicking on the appropriate part of this image. Theresulting window sometimes maintains the metaphor but is more often mainlytextual – a list of hypertext links, for example. Once “in” a room,students have access to the resources they need for the part of the course theyare taking. As might be assumed from the description, the system is intended tosupport a mixed mode of course delivery, including lectures, group discussionsand assignments, individual study, assessment with feedback. The existence ofthe office implies that students can also access relevant course administrativeinformation. The Hall and tea rooms suggest that the intention is also tosupport less formal, social interactions. 4.4.4 Positive Findings The coursesboth seemed to be appropriate for the target group. Students reported that theybelieved they had learned a considerable amount and felt they would retain theimportant points. The pacing of the study also seemed successful. The tutorclearly had a sense that this was a real class in a real institution and madeconsiderable efforts to generate a relaxed and positive atmosphere. Use ofstudents names, and greeting them as soon as they logged in, contributed tothis. This is no mean achievement, given the constraints. The tutor tended torefer to the environment as if it were a real place, arranging with students,for example, to “meet in the tea room” or telling them to “go tothe library”. Whether the students shared this perception is less clear.
This may be due to the short time available to become familiar with it. It wouldbe interesting to see whether the environment would become more “real”to the students over a longer course. The room-based structure therefore seemsto have been successful. The metaphor seems to have been well chosen, sincestudents seemed to have appropriate expectations of each “room”. Noneof them appeared to have difficulty navigating between different rooms.
Observation did show that some students had to scroll up and down repeatedly,however, when they were working on individual study texts. This seemedparticularly to be the case where they found the material more difficult. Again,there was no sign that they were unsure of where to go or had difficulty innavigation. In terms of course delivery, the trial showed that studentsexperienced considerable variety in the ATM course (inevitably less so in theSQL course). Not only this, but the tutor seemed able to exploit the flexibilityof the system and to direct the student to alternative areas of study from whathad been planned originally, if necessary. One of the problems with distanceeducation is that such flexibility can be harder to achieve than in aface-to-face situation, so this is promising and an interesting result of havingdifferent applications integrated in this way. It also has a pragmatic use:given technical problems in one area, it was possible to shift students toanother activity quite easily. Interactivity, both structured and casual waspotentially considerable. The shared whiteboard used for group work wasperceived by students as a good feature. It seemed, however, that they did notall realize at first that they could write and draw on it. Perhaps this shouldbe pointed out in the introductory sessions, or the whiteboard should beaccompanied by a short explanatory note. It would also be fair to say that thiswas not a long enough trial to assess usability of this part of the system. Inthe limited time it was also not easy for students to establish relationships.
The system and the way the tutor used it did encourage students to get to knowone another since, for example, one of the first activities for students was toupload their CVs and pictures and to browse through those of other students. Thelevel of concentration appeared to be high. Naturally, as in a classroom, therewere moments when students attention moved away from the subject of study butthese were not frequent. Interestingly, they usually stayed at the workstationbut moved to another activity such as reading e-mail. The students observed”live” appeared to maintain concentration despite considerablebackground noise and other potential distractions. This is not a surprise, sinceother computer-based teaching and learning trials have drawn similar conclusions- but it is another promising feature. At best, the material with which thestudents were engaged appeared well designed for delivery on a computer screen.
The information was “packaged” into manageable chunks and was visuallystimulating. Diagrams, colour and animation were used effectively, and thelayout was clear and appealing. As the next section suggests, however, not allof the written material was so suitable for this method of presentation.
Feedback was given to students both by the tutor, during discussions (for theATM course), and as a result of assessments done at the end of each module.
Students appeared to take these assessments seriously and were observed toreturn to the relevant part of the notes when unsure or when they had given anincorrect answer. The scope of this evaluation did not extend to assessing thecourse design or the assessment methods, but it is worth mentioning that theregular assessment seems to have been a successful feature of the course.
Awareness of other students is something that is hard to achieve in distanceeducation. Interestingly, with the audio channel left open during private studyperiods, it appeared that students experienced something similar to working in alibrary with other students around them. They were able to hear conversationsand could have asked questions if they needed to. The potential disadvantage isthat the additional background noise might interfere with concentration. Itwould probably be worth investigating whether the availability or otherwise ofthe audio channel makes a difference to students. 4.5 Operation and Managementof Tele-education Service A vital element of any service is the reliability,configurability and administration of that service. In order to ensure successof an educational service from both the participants and tutorsperspectives, the delivered service must be well managed and monitored. It iscrucially important to realize the software and procedures necessary to manageand deliver Tele-educational services over broadband networks. Four basicprinciples for successful teaching in a virtual classroom environment have beenidentified as ? media richness, ? interaction, ? timelyresponsiveness and ? organization of materials. Media richness andinteraction mechanisms can be satisfied by the educational services describedearlier. The organization of course materials and the insurance of timelyresponse by systems, participants and tutors are goals of the managementservice. During the delivery of a course, there is a significant mass ofmaterial presented to participants as well as a high degree of interactiveresponses amongst participants. Unless this mass of materials is organized andinteraction controlled, participants can become confused and disillusioned.
Proper maintenance and management of the dissemination of material must be putin place to provide an effective learning environment. Segregation of material,both between and within course modules should also be supported. The strategy ofparticipant-paced learning is important so as to ensure that the classmoves through the modules of a course together in order for the interactions tobe meaningful. Timely responsiveness has also been identified as a keyrequirement for Tele-education. Thus access to course material, as well as otherparticipants and tutors, should be reliable and timely. To achieve successfuloperation of the tele-educational service, participant (on-site) software shouldbe configurable for a wide range of computing environments. Also participationof the class members should be manageable e.g. course registration, controllingaccess to class discussions, automatic collection/distribution of assignmentsand projects etc. The on-line management system should provide the range ofservices as required by each course leader. 5.0 CONCLUSION Tele-education systemis a very new emerging technology. It has been applied in Europe and Canada, andis still under study in order to improve it from time to time. From thisproject, it is known that Tele-education is a revolution of distance learning inwhich distance learning basically only provides asynchronous learningenvironment. But Tele-education has improved it by providing both asynchronousand synchronous learning environment. After studying all the materials found forthis material, it was found that Tele- education is not easy to implement. Thisis because there are a lot of things need to be considered before implementingsuch as what kind of network structures available, what kind of service can beprovided by network service provider, what is the most suitable network forinterconnection among the involved sites, etc. Another reason is that, afterimplementing it, there need to have several trials on the service to look at itsefficiency which would take a long time. In general, it can be concluded thatTele-education is becoming popular as the emerging of multimedia technology. Itsadvantages that could overcome the problem in current learning environment alsohas made it a preferable way of learning process. 6.0 REQUIRED EQUIPMENT ANDMATERIALS The following are the equipment or materials needed for the completionof this project in third semester : a) Opnet software (Sun workstation) – usedto perform simulation b) TV Conferencing System with; i. ISDN Interface ii. H324TV Conferencing Interface iii. Small TV camera iv. Speaker (stereo) ?this is required for some experiment purposes on Tele-education system c)Satellite System with; i. Antenna (2.6 m) ii. RF receiver (C-band) iii. 2 MbpsTV conferencing Interface iv. ISDN (2B+D) Interface – Still understudy/discussion 7.0 SCHEDULE OF PLANNING (Timetable)Bibliography1 Krebs, A.M, “D21A – The Initial Requirement Analysis”, ACTSProject AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D21A2 Jain, R, ” A Revolution In Education”, IEEE, 1997, pp. 1 3Bison, T, “Distance Learning Is an Opportunity” , Circuit and Devices,March 1997, pp. 41. 4 GammelGaard, A, “D21B – Final RequirementAnalysis”, ACTS Project AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D21B5 Nielsen, A.B, “D53A – Evaluation of the First Trial Phase”, ACTSProject AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D53A6 Krebs, A.M, ” D53B – Evaluation of The Second Trial”, ACTS ProjectAC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D53B7 Nielsen, A.B, “D51A -Operational Plan for First Trial”, ACTSProject AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D51A8 Johansen, A, “D51B – Operational Plan for Trial 2”, ACTS ProjectAC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D51B