Page 51 - DCAP608_REAL TIME SYSTEMS

Real Time Systems

Notes The second outer ring in the model shows the types of services a student receives from
each of the four noted component areas. The inner three rings represent (from the
innermost): (1) the student and his or her relationship to each of these four areas;
(2) transmission systems with which the services can be accessed by students; and
(3) applications and tools to be used in offering the service elements in the outer ring. It is
important to note that in this model students are the centre of the model and all the service
components and elements are depicted in relation to the students.
Transmission Systems
The basic assumption of a virtual university is that all the services and instructions are
offered at a distance using some kind of transmission systems or telecommunications
technology. In the early days of distance learning, postal mail and telephone were the
predominant systems of delivery. However, with the advancement of telecommunications
technology and the prevalence of the Internet, a variety of delivery technologies become
available though the cost is still the limiting factor for students to have access to the full
array of technologies available. Still the most dominant mode of transmission systems
used by students is plain old telephone lines with up to 33.6kbps modems. Some higher
bandwidth technologies such as Integrated Services Digital Network (ISDN) and cable
modems are becoming common among those who use the Internet very heavily for
business, entertainment, or education from home. As more and higher bandwidth
applications utilizing voice and video capabilities become available and integrated into
online educational delivery, the attention must be paid not to discriminate students based
on their technological accessibility. There is a large difference in terms of technological
accessibility between corporate students who have access to the Internet through a high-
speed local area network and home-based students who only have access to the Internet
through regular telephone lines with a modem. The students with a limited bandwidth
should not be penalized with the limited technological accessibility in comparison to
those who have a high-speed access. To ensure that, the technology of least common
denominator has to be deployed or the institution has to be prepared to provide those less
fortunate students with necessary technologies.
In future, it is foreseeable that the bandwidth will become less of an issue as many alternative
telecommunications technologies provided by a variety of telecommunications companies,
not limited to existing local telephone companies, will become widely available at an
affordable rate.
Tools
In a traditional classroom, information is exchanged between the teacher and students,
students and other students, and students to the teacher. Sights and sounds are used for
exchanging the information. Communication is either direct between the teacher and
students or mediated using various media such as overhead projector transparencies,
video and audio tapes.

In distance learning information must be exchanged over a distance. Therefore,
telecommunication technology is often employed. Teachers and students at different
locations can no longer see and hear each other face-to-face; instead, telecommunications
media such as video and audio tapes, bulletin boards, email, facsimile, chat rooms, audio
and video conferencing, on-line applications over the Internet, etc., must now be used to
facilitate communication. Similarly, information presented by the instructor must be
communicated and support services must be provided over various telecommunications
media to the distant students.

Contd...

46 LOVELY PROFESSIONAL UNIVERSITY