Tele Education Essay, Research Paper
1.0 INTRODUCTION 1.1 Background of Tele-education Tele-education has a long
history beginning with systems like that for teaching children in Australian
Outback, the British Open University and other such organizations. These built
on the idea of correspondence courses where course materials are sent
periodically by post and augmented the experience with broadcasts either on
radio or on TV. The problem of student isolation was addressed partially through
techniques such as telephone access or two-way radio links with teachers. At the
end of 1980s, the vest majority of distance education throughout the worlds was
still primarily print-based. Technologies used for distance education are
evolving from primarily ?one-way? technologies and applications such as
computer aided learning, computer based training and computer aided instruction,
to more ?two-way? technologies and applications such as computer mediated
communications and computer conferencing systems for education. The significance
of ?two-way? technologies is that they allow foe interaction between
participant and tutors, and perhaps even more significantly amongst participant
themselves. This development has allowed and in some senses force researches to
look more closely at the impact of educational environment, on the students
learning experience. In the future, it is expected that the
telecommunications-based technologies to become the primary means of delivery of
distance teaching. The reasons for this are as follows: a much wider
range of technologies are becoming more accessible to potential distance
education participants the costs of technological delivery are dropping
dramatically the technology is becoming easier to use for both tutors
and learners the technology is becoming more powerful pedagogically
education centers will find it increasingly difficult to resist the
political and social pressures of the technological imperatives. 1.2 The
Emergence of Tele-education Radical changes in the computing infrastructure,
spurred by multimedia computing and communication, will do more than extend the
educational system, that is revolutionize it. Technological advances will make
classrooms mush more accessible and effective. Today, classroom education
dominates instruction from elementary school to graduate school. This method has
remained popular for a very long time and will probably persist as the most
common mode of education. However, classroom education has its problems, that is
the effectiveness decline with increase in the number of students per class.
Other pressures affect the instructors, many of whom are not experts in the
material they must teach, are not good ?performers? in class, or simply are
not interested in teaching. The biggest limitation of the classroom instruction
is that a class meets at a particular time in a particular place. This
essentially requires all students and the instructors to collect in one spot for
their specified period. But with the emerging technology, these problems can be
overcome. 1.3 Reasons for studying Tele-education The current Tele-education
systems that have been applied in some countries are generally of multipoint
transmission technique. It is found that, this kind of transmission technique
having several problems or defects. Mostly, problems raised during the
application of the system. One of the significant problems raised is that, for
the multipoint transmission, the signals or information transmitted by the
sender do not completely received by the receiver. This problem is might be due
to error that occurs during the transmission of the signals or information.
Another problem is lag of transmission. For this case, the signals or
information transmitted do not arrive at all the receiver at the same time, for
example, the question raised by the lecturer might not received by the students
at 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 or
even not receives at all. Therefore, it is important to study the Tele-education
technology from time to time to overcome these problems so that the
Tele-education system could provide a more effective way of learning
environment. In order to have a lecture from, for example, a very famous
professor from other country would require him to come at our place. But the
amount of money spent for paying him to give lecture would be very expensive and
this also would cause troublesome for him. However, this problem can be solved
with Tele-education system in which the professor does not need to go anywhere
else to give his lecture. This would save a lot of expenses and time. Another
reason is that, in normal classes the learning process would not be very
effective if the number of students in a class is very big. This is because the
lecturer alone can not coordinate such a large class. With Tele-education
system, one lecturer could deliver his lecture to as many students as possible
effectively in a way that a large number of students from different sites having
the same lecture at once. 1.4 Purpose of Research The purpose of this research
is to study the current Tele-education system that has been applied in some
countries. This study covers the background of Tele-education; that is its
definition, the publications of Tele-education; that is any papers that discuss
about Tele-education as a whole, the performance of applied Tele-education, and
also the technology of Tele-education; that is its network architecture. But the
main purpose of this study is to understand the Tele-education system that have
been applied in another country and try to implement it in our country. 1.5
Acronyms ATM Asynchronous Transfer Mode CCITT Committee Consultatif
International Telegraphique et Telephonique CPE Customer Premises Equipment IP
Internet Protocol ISDN Integrated Services Digital Network ISO International
Standard Organization JAMES Joint ATM Experiment on European Services LAN Local
Area Network MAC Medium Access Control Mbone Multicast Backbone PC Personal
Computer POP Point-of-Presence PVC Permanent Virtual Channel QoS Quality of
Service RAT Robust Audio Tool SLIP Serial Line Internet Protocol TCP-IP
Transmission Control Protocol – Internet Protocol TES Tele-Educational Service
UI User Interface VIC Video Conferencing Tool VP Virtual Path VPN Virtual
Private Network VSD Virtual Student Desktop WAN Wide Area Network WWW World Wide
Web XC Cross Connect 2.0 METHOD OF INVESTIGATION Since Tele-education is a very
new technology that is popularly discussed today, it is quite difficult for me
to find any books that discuss about Tele-education from the library. Therefore,
the easiest and the fastest way to gather information relating this project is
via the Internet. I have surfed and found many interesting sites that discuss
about Tele-education. Besides surfing, I also have contacted several people who
are involved in this area, Tele-education, by e-mail . But unluckily, this does
not 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 the
library of Universiti Telekom. 3.0 BACKGROUND STUDY 3.1 Definition of
Tele-education What is Tele-education? Before discussing about what
Tele-education means, lets look at what distance learning is. This is because
Tele-education and distance learning are very related to each other. Distance
learning is the acquisition of skills and knowledge through electronic
communications that allow student and instructor to be separate in either in
time or space. The to distance learning is ?asynchronous learning? which can
be defined loosely as learning at different time. It is a highly flexible method
of training because the sender and receiver do not need to be synchronized in
space or time. But Tele-education is more than that of distance learning. In
Tele-education, not only asynchronous but synchronous learning is also made
possible. In other words, Tele-education is the evolution of distance learning.
As stated before, asynchronous learning environment is not real-time
environment. It is a self-study-based application and is accessed via the
Internet to a server. The requirement to the student is only an ordinary PC with
standard software and Internet access. This application is applicable for a
large amount of users who can access the course independent of each other. The
combination of the lecture-part, group-work-part, and self-study-part is another
type of Tele-education learning environment, which is synchronous learning. It
is a real-time environment. In this environment, students and lecturers can
interact with each other simultaneously. Tele-education use the technology of
video teleconferencing that allows two or more parties at different geographical
area to interact with each other or to have learning process together. But
people usually get confused whether video teleconferencing can be considered as
Tele-education as well. Tele-education is actually different with video
teleconferencing in a way that Tele-education usually involve a large number of
people as compared to video teleconferencing, that is, it is in video
teleconferencing many people use a single monitor to see other people at other
area but in Tele-education, students have their own monitor that can be used not
only to see their lecturer and colleagues but also to send and receive
educational materials. 3.2 Publications of Tele-education There are many papers
discussing about Tele-education. Most of these papers cover only the general or
overall scope of Tele-education. The area of discussion on Tele-education can be
summarized as the following: Tele-education service Content of
Tele-education Network architecture performance of
Tele-education operation and management of Tele-education For
Tele-education service, it describes about what multimedia tele-service and
hyper media service is, and how it can be integrated into Tele-education
service. It also describes about what Tele-education service facilitate. Content
of 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 any
materials delivered to all the students. For network architecture, it describes
about the protocol used for the Tele-education system and its network
infrastructure. Performance of Tele-education covers the performance of service
of Tele-education and also the network performance. The description of these
performances is from the customer point of view. For the operation and
management of Tele-education, it describes about what should be taken into
consideration in order to provide a well managed Tele-education service. 3.3
Examples of Systems From the study of materials gathered, there are generally
three examples of Tele-education system that have been applied in the Europe and
Canada. Those examples are: Tele-education NB Delta ’s Virtual
College ACTS Project AC052 (RACE Project Report) The purpose of looking
into these examples is to try to understand what kind of Tele-education system
is implemented, how Tele-education can be implemented, to know what are the
requirements to implement it, and what considerations should be taken into
consideration for implementing it. 3.3.1 Tele-education NB Tele-education NB is
implemented at the University of New Brunswick, Canada. The present physical
network consists of three independent networks that operate on telephone lines;
Voice SMART 2000 computer teleconferencing Computer
Mediated Communications using NBNet The SMART 2000 bridge for computer software
sharing and audiographic teleconferencing is owned and operated by the
Tele-education NB. This is accessed by simple dial connections using ordinary
telephone lines. This allows for the computer monitor at each site to show
images created by users at the other sites. The software can be used like an
elaborate electronic blackboard, overhead projector, or slide projector. In
addition, it is being used for software sharing at multiple locations. Data
communications are transmitted over NBNet using a SLIP server which resides in a
user friendly simple menu front-end created by Tel-education NB to permit easy
access to NBNet and to facilities available. Students and teachers can access
NBNet for uploading and downloading assignments and other course materials. A
CD-ROM server is being set up at the central site and at the University of New
Brunswick library for permitting access to different databases. Tele-education
NB also supports an on-line learning center with a file server located at Mount
Allison University. Information of relevance distance education and the network
in particular can be accessed there. In Tele-education NB, a special listserv is
created for internal communications among different sites. As an integral part
of the province’s electronic information highway, Tele-education NB is
supporting the development of an open, distributed network, taking advantage of
media available. The most widely used delivery modes are audio teleconferencing
with SMART 2000, as well as videoconferencing. However, it is not limiting the
network to any one technology, or suite of technologies. It is actively
promoting experimentation and cooperation in the reception and delivery of
courses using other software and media. Tele-education NB placed routers in the
Community College Campus in each region, and other sites in regions that do not
have 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 WANs
using Novell, TCP-IP and other telecommunication protocols. Tele-education NB
are now experimenting with synchronous transmissions using the TCP-IP protocol
on NBNet. The Picturetel videoconferencing units existing in province all are
CCITT compatible. Tele-education NB has provided the guidelines for selecting
appropriate technology for its network as follows: The network shall
experiment with different technologies and endeavor not to rely on any one
technology or any supplier. Existing equipment and distance education
sites in the province shall be integrated into the network wherever possible.
The network shall establish computer teleconferencing and computer
conferencing links among the sites, including access to electronic information
highway and the Internet. Satellite delivery and reception capabilities
and upgrading of sites to PC-based videoconferencing will be investigated for
implementation in future. Other optional equipment may be placed in
sites at the request of users and institutions such as MACs and CD-ROMs.
The network should be compatible as much as possible with other
provinces and regions. 3.3.2 DELTA’s Virtual College Delta’s Virtual College is
implemented in Denmark (Europe). It offers the opportunity for students to
participate in desktop Tele-education from their homes or offices. This concept
means that individual students participate in Tele-educational courses using a
desktop computer online connected to a course provider. The user interface is a
common Web browser, that is, Netscape Web-browser, extended with loosely
integrated audio and video tools. The educational environment applies the
metaphor of a virtual college. The idea is that students access DELTA’s virtual
college server when participating in a course. The user interface looks like the
plan of a college. From the college hallway, the student can enter different
rooms with different functions. Those rooms are: classrooms where
on-line lectures and presentation take place, group rooms where on-line
cooperative work takes place, studies where off-line study such as
self-study material, exercises, slides from previous lectures, supplementary
material and links to other sites on the Web take place, teacher
offices where it is furnished with course administration tools, tea
room where it is used for informal chat and social contact with fellow students
during break. The following figure, the "floor plan", illustrates
those rooms: Figure 1 : The floor plan The goal of this virtual college is to
integrate different modes of teaching and learning. This includes synchronous
mode like on-line lectures and group exercises as well as asynchronous mode like
interactive self study, participation and threaded bill board conferences and
sharing of documents. The virtual college is run primarily in a local network
environment in order easily to monitor and control the students and technology.
Then, when there are several countries participate, each sites are connected by
the JAMES (Joint ATM Experiment on European Services) broadband network. 3.3.3
ACTS Project AC052 (RACE Project Report) This is a big project on
Tele-education. It covers the whole aspects that should be taken into
consideration for implementing Tele-education in Europe such as service aspects,
management aspects, network architecture, etc. In this project, there are
several trials have been done in order to obtain an effective Tele-education
system. The details of this will be discussed later throughout this report. 4.0
CONSIDERATIONS It is not easy to find materials or any papers reporting the
architecture of Tele-education. Most of the materials found are basically
discussing about the general idea on what Tele-education system is, for example
some papers discuss about the general system of a Tele-education service
offered, its advantages over current educational environment, etc. However, I
managed to find a very interesting material discussing about Tele-education as a
whole, that is the ACTS Project AC052 (RACE Report Project). Therefore, I choose
this report as my main reference in doing my study on Tele-education overall
system description covering the architecture. There are basically five main
topics that are going to be discussed in quite detail regarding the
Tele-education as a whole in this report. These main topics are:
Tele-education service Tele-education content Network
architecture of Tele-education system Performance of Tele-education
service Operation and management of Tele-education service 4.1
Tele-education Service The multimedia tele-service provides both core and
management services. The multimedia tele-services are briefly described as
Video/audio conferencing service, which based on the MBONE (Multicast Backbone)
tools VIC (video conferencing) and RAT (audio conferencing). Hypermedia service
allows access to be provided to hypermedia information stored on a WWW server.
The WebStore service is a managed WWW based multimedia document store, which
allows users to store and retrieve arbitrary documents (text, video, audio,
etc.), using the well-known interface of the WWW. The management of the WebStore
includes subscription, accounting and access control. A mapping between the
learning forms and the multimedia teleservices has resulted in a list of four
basic paradigms: a) Self-study Individual work with web based course
material including exercises and discovery/reference search. This
paradigm is supported by the hypermedia and WebStore services. b) Lecture
Teacher to class presentation. Supported by the conferencing
and hypermedia services. c) Group work Discussions, exercises or
project work performed by the students in groups. This paradigm can also include
shared discovery/reference search. It is supported by conferencing,
hypermedia, and WebStore services. d) Consultation Student to tutor
consultation Supported by video/audio conferencing and hypermedia
services. In order to support these four paradigms the multimedia services are
integrated into a Tele-educational Services (TES) which provides both the core
service and the management service functionality. The core Tele-educational
service provides two user interfaces, one for the teacher and one for the
students. In Tele-educational service, each course, presented as part of
Tele-educational service, would involve the rendering and seamless integration
of audio, text, graphics/bitmaps and appropriate video segments, to suit the
presentation of the course material. An educational service would also
facilitate the interaction of course participants with one another in class
discussions, as well as with the course tutor. In this way, a course tutor can
guide debates on issues arising from course material and allow participants to
exchange views and share experience. This interaction is very important, as
participants need to be encouraged to learn both from the tutored course as well
as from each other’s practical experience. This forum of discussion also
supports the tutor in assessing feedback from the participants concerning the
comprehension, benefit and effectiveness of a course for participants. The
educational service could also facilitate access to simulation environments and
‘live systems’, which are parts of the participant’s course material. For
example, it could provide access to specific commercial database information,
which would be part of a Database Modeling course. In this way, access may be
gained to systems and information, which would otherwise not be available on the
participant’s site. Course could be taken when the participant’s work schedules
permitted. Similarly, participant/participant interaction could be scheduled
flexibly. An educational service can be seen as incorporating several
interaction (tele-services) and course presentation mechanism, for example,
multimedia presentation tools conferencing, e-mail or notice board systems. The
following is an example of service layer used in the ACTS Project AC052: Figure
2 : Service Layer In the ACTS Project AC052, there are two Tele-educational
courses offered as a trial of the management service. These courses are "
An Introduction to ATM " and " An Introduction to Relational Databases
and SQL ". 4.1.1 An Introduction to ATM The course includes both
synchronous and asynchronous delivery methods. The duration of the course is
three to four days with approximately three hours of teaching and studying each
day. The course consists of five lectures, three self study modules and three
group exercises with a follow-up discussion of the results. The different
modules and modes of the course are conducted in a Tele-educational environment
which includes course outline information, a database of participants with
pictures and CVs, a WWW billboard supporting off-line discussions, access to a
WebStore and a tea-room which participants can visit for informal chats. The
lectures are performed by using video/audio conference tools. A system was used
to show slides on the participants web-browsers. The self study modules
contained web pages with information to read and small built-in exercises. The
group exercises consist of a number of questions to be answered by the group and
returned to the teacher for correction afterwards. When the teacher has
corrected the answers they are discussed in a conference with all the
participants. In the first trial a shared editor was introduced for use in group
exercises. The shared editor is a tool for synchronous collaboration on smaller
texts, and is meant to complement the chat and whiteboard tools used in earlier
trials. An illustration of the new shared editor can be found below. In the
second trial, a new floorcontrol-system for use during lectures as well as a
complete new graphical design of the virtual learning environment was tested.
The floorcontrol system was used by the teacher during lectures, to determine
which students wanted to ask a question, and to mute or unmute the microphones
and video cameras accordingly. A new graphical design of the User Interface (UI)
was introduced, in an attempt to create an even more homogenous UI. The
floorplan metaphore was kept, but new images and controls where implemented
throughout the environment. 4.1.2 An Introduction to Relational Databases and
SQL This course covered the theoretical principles of relational database
technology as well as supporting the hands-on skills of using relational
database language (SQL). Students took the course over a three day period, for
two hours each day. At the beginning of the course a one hour lecture outlined
the objectives of the course and provided an introduction to the topics. The
educational content comprised of text, graphics, and animation and was divided
into four sections, consisting of a total of twenty one modules (a module
typically being 1-5 pages). The course was made available via the Prospect
Tele-educational environment. On accessing the course, a separate courseware
browser window was opened, called the Virtual Student Desktop (VSD). All student
interactions with the courseware are facilitated via this VSD. The
Tele-educational environment is also accessible by the student for conferencing
and 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 tool
bar specially designed for educational use is provided by the VSD at the bottom
of the screen. From this tool bar the student is able to contact tutors or
fellow students (asynchronously), access external systems, as well as navigate
and interact with the educational course material. Figure 3 illustrates a page
from a module in the course, and shows the educational toolbar at the bottom of
the screen and an index of the topics dealt with by this particular module in
the course on the left hand side of the screen. Figure 3 : page from module in
the 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 modules
can be combined in several ways to satisfy the different requirements for
different student objectives. Each roadmap corresponds to different learning
objectives of the RDBMS course. Thus the roadmaps provide a means of re-using
existing modules with as little redundancy as possible of educational material
and administrative overhead. A significant feature of the system was to provide
direct access to a real ?commercial? RDBMS via the same interface as the
educational course. The relational DBMS is seamlessly integrated into the
student educational desktop. Thus the tool bar offered by the VSD contains an
icon which allows students to issue SQL queries on a live database. The idea of
this is to deliberately blur the distinction between the educational environment
and the ?target? systems. This encourages students to ?try out? various
parts of the course before attempting a larger project. Another feature was the
ability of the student to store references to distinct locations in the course
material (bookmarks). Traditionally these are stored locally on the student?s
machine. However this has disadvantages as students rarely use the same machine
all the time. The VSD allows such bookmarks to be stored within the educational
service and are thus (privately) accessible to an individual student at any
time. Also if the student has logged off the course and logs back on, the VSD
allows him/her the ability to resume at his/her most recent position or restart
at the beginning. Various forms of on-line tutorials are embedded into the
course. ?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 tutors
for subsequent correction. Also integrated into the course are evaluation forms
which, when completed, are automatically submitted and stored for later analysis
by course tutors. The VSD provides buttons to contact other class members or to
seek tutor assistance. Again, this is offered via WWW forms and integrated
transparently with an email delivery system. 4.2 Tele-education Content There
are several modes of educational interaction, which could be supported by a
virtual theatre/study room. These would include lecture presentation, course
material presentation and browsing, self-study, group work (shared
application/work, class discussions, group presentations), consultation
(tutor/participant, participant/participant), tutorial sessions, virtual coffee
room/virtual lounge, and continuous assessment. There are also some other form
of learning that have been identified. These forms of learning are:
Self learning delivery of formatted courses material for students own
study Lecture presentation a one-to-many presentation by the
tutor of course or organizational material. Exercises the
facility to perform exercises either in groups or individually Project
work the development of sizeable projects using software outside the
teaching environment. Discovery/Reference research ability to
locate and access background or supplemental learning material
Seminar/Class discussion groups many-to-many communication between
participants. Consultation private one-to-one communication
between participants. There is some overtap between these learning forms. For
example, exercises, project work, discovery/reference search can be part of the
self-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 be
supported in the Tele-educational environment but also the different styles of
learning adopted by the students need to be supported. So for instance students
who like to annotate their work or their course material should be facilitated
in 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 should
be captured and associated with relevant course material. For instance, the
teachers comments on a particular slide could be captured with the slide in
question. Also the conversation of students working on group could also be
recorded and stored with the exercise. Course material could be presented as a
hyper-document with the participant capable of navigating through the document
or choosing the prescribed ordering of the presentation. In addition, the
participant could also be given access to the more traditional learning
material, for example, notes, books, etc. Course assignments could also be
electronically submitted to promote fast feedback on performance. An important
element of assignments and project work is the need to allow participants to
co-operate in groups. 4.3 Network Architecture of Tele-education System From the
application’s point of view, network operates as IP (Internet Protocol) network
routing both multicast and unicast IP packets. Connection from network level to
the 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 IP
traffic. This network structure connects seven sites. The aim of the logical
network infrastructure is to provide stable network interconnections as well as
to be managed to some extent by the network management, and to provide a
working, broadband network infrastructure while also supporting an enterprise
model 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 one
site in each countries (that taking part in Tele-education system) are
connected. The connection, internationally connected customer sites access the
public network ATM service via an ATM cross-connect (ATM XC) providing ATM
public network provider’s Point-of-Presence (POP) in each of relevant countries.
Each customer sites posses ATM Customer Premises Equipment (CPE) which is used
to interconnect ATM public network with local routers. For the connection within
the same country, it is performed via leased lines between routers at
internationally connected customer sites and sites not connected to ATM public
network provider. The ATM CPEs at internationally connected sites and routers at
all customer sites managed by VPN (Virtual Private Network) provider. It is
performed in concert with management of ATM public service by VPN provider to
provide Intranet style connectivity between hosts on customer site LANs. This
network is quite complicated because it connects seven sites in four countries
and consisting of the following core components: Four ATM LANs
Seven Ethernet based LANs Four ATM Cross Connects Eight static
IP routes Seven multicast routers Two 2 Mbps leased lines
Ten International ATM links (virtual path) One basic rate ISDN
link The following is the figure of logical network infrastructure: Figure 4 :
Logical Network Infrastructure. The ATM infrastructure that represents ATM
public network provider consists of a single ATM XC at each internationally
connected 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. It
is employed as logically separate ATM LANs besides as providing ATM access
between public network and routers at each site. The following is the figure of
ATM configuration. Figure 5 : ATM Configuration. The IP configuration consists
of routers at each connected sites being connected by Permanent Virtual Channel
(PVC) running over VPs. The routing function at each site performed either by
dedicated 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 performed
by multicast routing daemon (mrouteds) running on workstations. The mrouteds are
interconnected by unicast IP tunnels, which can be used to be routed via routers
together with all other unicast traffic. The IP tunnels between mrouted at
internationally connected sites used the second sets of VPs. This supports
partition of multicast traffic from other unicast traffic and thus enables
provision of more deterministic Quality of Service (QoS) for multimedia
conferencing application. For external infrastructure, the aim is to provide
international ATM links between IP routers at the customer sites. Parallel VPs
are used between each pair of sites; one for multicast routing and another one
for unicast routing. Figure 6 : The network configuration Reflecting the
contemporary trends in multimedia and information services, all software
communication is over IP, including management system traffic. For the network
infrastructures that are conducted at a single site, the requirement its network
is fairly simple, requiring simply Ethernet connection to support IP
communication between PCs and workstations. If the system includes the
management of connections over IP switches, then the network infrastructure
would include both a representative public network ATM cross connect and
customer premises network ATM work-group switch (a FORE systems ASX200). These
are connected and configured with multiple VPs to emulate a network with a
larger number of nodes. IP routing functions in this network are provided by the
SPARC workstations with ATM interface cards performing IP forwarding. The
following is the network configuration of this kind of network: Figure 7 :
Network configuration For this network configuration, the TES Customer is able
to request the set-up of a new connection to the TES provider. The TES provider
then requested the VPN provider to do likewise. The VPN provider made a request
to the Public Network Provider and Customer Premises Network Provider to ensure
that the end-to-end IP/ATM connection was in place for the TES Customer. This is
the goal for the configuration scenario. One of the most important on an ATM
network level management system is to provide end-to-end connectivity across
constituent ATM network element, and so support the connectivity provisioning
with fault management and quality of service features. Challenged by these
requirements, a system that is able to set up ATM Virtual Paths and to correlate
faulty conditions, determining how these fault effect the connectivity for each
end user has been built. The following is the Network infrastructure of this
system: Figure 8 : Network infrastructure The figure shows that all the network
equipment is connected to one Ethernet hub, that is, the hub that acts as a
backbone for one Public Network domain and two Customer Premises Networks. In
reality, this hub could be partitioned into a number of internets that are
inter-connected by routers, also known as the Internet. For the network that is
required to operate over six sites in four different countries, would require a
much more comprehensive network infrastructure. This infrastructure consisted of
an ATM VP service, leased lines, and the internal ATM and IP network
infrastructure. The following is the example of this network infrastructure :
Figure 9 : Network infrastructure 4.4 Performance of Tele-educational Service
4.4.1 Courses There were two courses, both aimed at students with above average
prior knowledge of computing and/or computer networks. The first, an
introduction to SQL, was a self-study course, consisting mainly of modules of
written text with assessments based on these. The second course, an introduction
to ATM, was led by a tutor and involved varied methods of delivery, including
lecture/seminar, individual study and group work. Students were therefore
expected 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-day
period and students were expected to participate for three half days. Within
this time, those taking the SQL course was able to pace their own study. On the
ATM course, the students? use of the different resources was timetabled and
directed by the tutor. Time was divided between events, such as lectures, at
which all students were expected to be present, and study time, during which
they would work through a series of modules, with assessment associated with
each one. 4.4.2 Students There were 16 students on the more interactive of the
two courses, the Introduction to ATM, and a similar number on the self-paced
study course, An Introduction to SQL. All the students appeared to be
experienced computer users. This has to be accepted as necessary in a trial such
as this , which takes place in the context of a research project which uses
leading edge technology, some of it is still being tested. The prototypical
nature of parts of the system may make unusual demands on the students, such as
imposing unexpected delays. Having students who appreciate the difficulties may
well be important. Having said this, it appeared that although they were
knowledgeable about computers, these students were not experts in networked
multimedia technology, and did need some initial training in the use of the
software. This was given prior to the start of the course. The courses were
clearly directed at this target group, as their titles suggest. The students
also stated that they had a genuine wish to learn the subjects being offered and
that this was a major motivating factor. They were also paid for their
participation, which may have helped improve their persistence when there were
technical hitches. 4.4.3 System The system used for the ATM course is described
here. Those taking the SQL course used only those parts suited to self study.
There are three main elements: audio, and video communications channels support
a Tele-education system built on a web-browser base, but with considerable
functionality added. The audio tool, rat, allows participants to receive and
transmit audio, to identify who is speaking, control the volume of incoming and
outgoing 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 in
an application such as this one, for example, the facility to change the audio
encoding scheme. The tool?s basic functionality is easy to learn and use. The
video tool, vic, also offers functionality suitable for its use as a platform
for research into networked video. For the non-expert, however, the most
important features are that multiple users can send and receive video
simultaneously and that they can control some features of both display and
capture/transmission (image size and frame rate are two examples). Video images
can be displayed at various sizes from thumbnail image to CIF. Enlarging images
does, however, involve creating a new window for each one. Students access the
Tele-education system via a web browser and navigate within it using hypertext
links, buttons and active areas of images. Initial access is password protected
and the system supports the notion of groups and hence, presumably of multiple
classes and tutorial groups. The interface is based on the metaphor of an
educational institution, a building divided into rooms whose function most
students will be able to predict from their real-life experience of education:
classroom, tea room, hall, office, library and seminar room. Users are presented
with an aerial view of the layout, in which the rooms are labeled. They gain
access to a room by clicking on the appropriate part of this image. The
resulting window sometimes maintains the metaphor but is more often mainly
textual – 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 they
are taking. As might be assumed from the description, the system is intended to
support a mixed mode of course delivery, including lectures, group discussions
and assignments, individual study, assessment with feedback. The existence of
the office implies that students can also access relevant course administrative
information. The Hall and tea rooms suggest that the intention is also to
support less formal, social interactions. 4.4.4 Positive Findings The courses
both seemed to be appropriate for the target group. Students reported that they
believed they had learned a considerable amount and felt they would retain the
important points. The pacing of the study also seemed successful. The tutor
clearly had a sense that this was a real class in a real institution and made
considerable efforts to generate a relaxed and positive atmosphere. Use of
students? names, and greeting them as soon as they logged in, contributed to
this. This is no mean achievement, given the constraints. The tutor tended to
refer 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 to
the 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 would
be interesting to see whether the environment would become more "real"
to the students over a longer course. The room-based structure therefore seems
to have been successful. The metaphor seems to have been well chosen, since
students seemed to have appropriate expectations of each "room". None
of 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 seemed
particularly 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 in
navigation. In terms of course delivery, the trial showed that students
experienced considerable variety in the ATM course (inevitably less so in the
SQL course). Not only this, but the tutor seemed able to exploit the flexibility
of the system and to direct the student to alternative areas of study from what
had been planned originally, if necessary. One of the problems with distance
education is that such flexibility can be harder to achieve than in a
face-to-face situation, so this is promising and an interesting result of having
different applications integrated in this way. It also has a pragmatic use:
given technical problems in one area, it was possible to shift students to
another activity quite easily. Interactivity, both structured and casual was
potentially considerable. The shared whiteboard used for group work was
perceived by students as a good feature. It seemed, however, that they did not
all realize at first that they could write and draw on it. Perhaps this should
be pointed out in the introductory sessions, or the whiteboard should be
accompanied by a short explanatory note. It would also be fair to say that this
was not a long enough trial to assess usability of this part of the system. In
the 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 know
one another since, for example, one of the first activities for students was to
upload their CVs and pictures and to browse through those of other students. The
level of concentration appeared to be high. Naturally, as in a classroom, there
were moments when students? attention moved away from the subject of study but
these were not frequent. Interestingly, they usually stayed at the workstation
but moved to another activity such as reading e-mail. The students observed
"live" appeared to maintain concentration despite considerable
background noise and other potential distractions. This is not a surprise, since
other computer-based teaching and learning trials have drawn similar conclusions
- but it is another promising feature. At best, the material with which the
students were engaged appeared well designed for delivery on a computer screen.
The information was "packaged" into manageable chunks and was visually
stimulating. Diagrams, colour and animation were used effectively, and the
layout was clear and appealing. As the next section suggests, however, not all
of the written material was so suitable for this method of presentation.
Feedback was given to students both by the tutor, during discussions (for the
ATM course), and as a result of assessments done at the end of each module.
Students appeared to take these assessments seriously and were observed to
return to the relevant part of the notes when unsure or when they had given an
incorrect answer. The scope of this evaluation did not extend to assessing the
course design or the assessment methods, but it is worth mentioning that the
regular assessment seems to have been a successful feature of the course.
Awareness of other students is something that is hard to achieve in distance
education. Interestingly, with the audio channel left open during private study
periods, it appeared that students experienced something similar to working in a
library with other students around them. They were able to hear conversations
and could have asked questions if they needed to. The potential disadvantage is
that the additional background noise might interfere with concentration. It
would probably be worth investigating whether the availability or otherwise of
the audio channel makes a difference to students. 4.5 Operation and Management
of Tele-education Service A vital element of any service is the reliability,
configurability and administration of that service. In order to ensure success
of an educational service from both the participants? and tutor?s
perspectives, the delivered service must be well managed and monitored. It is
crucially important to realize the software and procedures necessary to manage
and deliver Tele-educational services over broadband networks. Four basic
principles for successful teaching in a virtual classroom environment have been
identified as media richness, interaction, timely
responsiveness and organization of materials. Media richness and
interaction mechanisms can be satisfied by the educational services described
earlier. The organization of course materials and the insurance of timely
response by systems, participants and tutors are goals of the management
service. During the delivery of a course, there is a significant mass of
material presented to participants as well as a high degree of interactive
responses amongst participants. Unless this mass of materials is organized and
interaction controlled, participants can become confused and disillusioned.
Proper maintenance and management of the dissemination of material must be put
in place to provide an effective learning environment. Segregation of material,
both between and within course modules should also be supported. The strategy of
?participant-paced? learning is important so as to ensure that the class
moves through the modules of a course together in order for the interactions to
be meaningful. Timely responsiveness has also been identified as a key
requirement for Tele-education. Thus access to course material, as well as other
participants and tutors, should be reliable and timely. To achieve successful
operation of the tele-educational service, participant (on-site) software should
be configurable for a wide range of computing environments. Also participation
of the class members should be manageable e.g. course registration, controlling
access to class discussions, automatic collection/distribution of assignments
and projects etc. The on-line management system should provide the range of
services as required by each course leader. 5.0 CONCLUSION Tele-education system
is a very new emerging technology. It has been applied in Europe and Canada, and
is still under study in order to improve it from time to time. From this
project, it is known that Tele-education is a revolution of distance learning in
which distance learning basically only provides asynchronous learning
environment. But Tele-education has improved it by providing both asynchronous
and synchronous learning environment. After studying all the materials found for
this material, it was found that Tele- education is not easy to implement. This
is because there are a lot of things need to be considered before implementing
such as what kind of network structures available, what kind of service can be
provided by network service provider, what is the most suitable network for
interconnection among the involved sites, etc. Another reason is that, after
implementing it, there need to have several trials on the service to look at its
efficiency which would take a long time. In general, it can be concluded that
Tele-education is becoming popular as the emerging of multimedia technology. Its
advantages that could overcome the problem in current learning environment also
has made it a preferable way of learning process. 6.0 REQUIRED EQUIPMENT AND
MATERIALS The following are the equipment or materials needed for the completion
of this project in third semester : a) Opnet software (Sun workstation) – used
to perform simulation b) TV Conferencing System with; i. ISDN Interface ii. H324
TV 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 Mbps
TV conferencing Interface iv. ISDN (2B+D) Interface – Still under
study/discussion 7.0 SCHEDULE OF PLANNING (Timetable)
[1] Krebs, A.M, "D21A – The Initial Requirement Analysis", ACTS
Project AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D21A
[2] Jain, R, " A Revolution In Education", IEEE, 1997, pp. 1 [3]
Bison, T, "Distance Learning Is an Opportunity" , Circuit and Devices,
March 1997, pp. 41. [4] GammelGaard, A, "D21B – Final Requirement
Analysis", ACTS Project AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D21B
[5] Nielsen, A.B, "D53A – Evaluation of the First Trial Phase", ACTS
Project AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D53A
[6] Krebs, A.M, " D53B – Evaluation of The Second Trial", ACTS Project
AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D53B
[7]] Nielsen, A.B, "D51A -Operational Plan for First Trial", ACTS
Project AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D51A
[8] Johansen, A, "D51B – Operational Plan for Trial 2", ACTS Project
AC052, http://www.fokus.gmd.de/research/cc/platun/coop/prospect/new/delivara.htm#D51B
! |
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