asas t PowerPoint

1
Reliable Tele-Education Requirements, Scenarios
and Concepts   G. Nokas, P. Vlachopoulos Technolog
ical Educational Institute (TEI) of Patras,
GR nokas_at_teipat.gr pvlachop_at_teipat.gr
2
Tele-education The situation where a number of
classrooms are connected with audio and visual
connections.
Local room
Remote rooms
3

• Implementation of Tele- education
• Using video conference facilities
• Desktop based
• Meeting-room based

4

• Networking
• The requirement in bandwidth varies according to
  the scenarios and the quality, but it is
  generally high (gt 380Kbps).
• ISDN
• Combination of BRI through IMUX devices
• e.g 3 BRI -gt 384Kb/s
• IP
• MBONE (Multicasting Backbone)

5

• Devices
• H.320 devices or pc cards (medium bandwidth
  consumption)
• H.323 (high bandwidth consumption)
• For more than 2 access points a MCU (Multipoint
  controller unit) is used to mix and switch the
  video streams from different points.
• Use of T.120 protocol.

6
Interconnections of H.323 device
Graphics card
VCR
Instructors camera
Network
7

• TELE-TEACHING SCENARIOS
• TELE-LECTURE
• TELE-PRACTICING COURSE
• LECTURE ON DEMAND

8

• Problem definition
• Having
• 2Mb/s IP network bandwidth for communication
  outside the campus.
• 400 Mb/s for communication inside the campus.
• ISDN.
• which tele-education scenarios can be implemented?

9
Local room of tele-lecture
IP
ISDN
Remote room of tele-lecture
10
Local room of tele-practicing course
IP
ISDN
Remote room of tele-practicing course
11

• Lecture on demand
• In this case of tele-education the mode is
  asynchronous.
• Several lectures are digitally recorded and
  stored on a video-on-demand server.
• The layout of the application may involve text
  boxes, instructional material, Power Point
  presentations etc. Multiple-choice tests can
  follow the lecture for further consolidation.
• The student can access the educational material
  (MPEG video stream) through a web browser.
• Another possibility is to store the material onto
  DVD or CDROM and distribute it to the students
  along with the hard copy notes.

12
Conclusions In this paper several scenarios for
tele-education have been presented. Among the
concepts and proposed schemes from the
literature, we adapted the most appropriate to
the needs of our Institute. Tele lecture can be
used locally through IP network solving problems
with limited space and populous audiences. For
communication with a remote site, tele-lecture
can be realized, using ISDN networks for the time
being. Tele-practicing courses, could achieve
simultaneous practice for all students, taking
into account the limitations in pc-equipped
laboratories. These new educational approaches
are very promising and should soon be adopted by
our educational community.