Transcript Shing Kay Pan - CSSE / Monash

Monash University
Department of
Computer Science and Software Engineering
2002 Honours Research Project
A Supporting System
for
The CSSE Video Wall
By
Shing Kay Pan
[email protected]
Copyright 2002 by Shing Kay Pan
Outline
1. The CSSE video wall
2. Aim
3. Project specification
4. Infrared Data Association (IrDA)
5. Methodology
6. Implementation
7. Demonstration
8. Difficulties
9. Future work
10. Conclusion
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Copyright 2002 by Shing Kay Pan
1. What is the CSSE Video Wall?
A Video Conferencing facility provided by CSSE department to
allow communication between Clayton & Caulfield campuses
Clayton
Caulfield
Video
Link
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Copyright 2002 by Shing Kay Pan
2. Aim of the project
To provide an additional facility for the video wall users with
access to mobile devices.
To build an agent (or channel) that lets mobile devices at
each site communicate with each other.
Goals
•Ease of use
•Support for major kinds of mobile devices
•Minimum installation and additional hardware
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Copyright 2002 by Shing Kay Pan
3. Project specification
Communication method: IrDA (Infrared Data Association)
- Widely implemented on nearly every mobile device.
User platform: Any mobile device
- Supported by IrDA.
Agent platform: Linux
-Open-source nature allows kernel level modification
needed in this project.
Agent’s communication method: TCP/IP
- Over private networks or the Internet.
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Copyright 2002 by Shing Kay Pan
4. Infrared Data Association (IrDA)
•Wireless technology for data communication
•Technology similar to the one used in remote control
•Widely used on mobile devices
•Cheap and easy to implement
•Data rate from 9.6kbps to 16Mbps
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Copyright 2002 by Shing Kay Pan
5. Methodology - Communication model
Normal point-to-point for infrared communication:
PDA1
PDA2
Line of sight (1or 2 meter)
Unable to communicate if out of range:
Room A
PDA1
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Room B
PDA2
Copyright 2002 by Shing Kay Pan
5. Methodology – IR “tunnelling” (D. Abramson, 2002)
Room A
PDA1
Agent1
TCP/IP
Network
Room B
PDA2
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Agent2
Copyright 2002 by Shing Kay Pan
6. Implementation - Overview
irtunnel
irtunnel
IrDA stack
TCP/IP
Network
IrDA stack
Upper layers
Upper layers
Lower layer
Lower layer
PDA1
IR adpater
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PDA2
IR adpater
Copyright 2002 by Shing Kay Pan
6. Implementation - Modification of IrDA protocol
A Standard IrDA protocol will actively respond to all infrared
packets it receives.
Modifications must be done on the IrDA protocol
to make it:
•receive and send infrared packets as usual;
But…
•disable its response capability.
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Copyright 2002 by Shing Kay Pan
6. Implementation - Main program (irtunnel)
The program:
•Gets infrared packets from the IrDA stack;
•Transmits them to the other agent using TCP/IP
protocol over the network
At the same time, the program:
•Receives data from the network
•Passes it to the IrDA stack to reproduce the infrared data
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Copyright 2002 by Shing Kay Pan
7. Demonstration
Agents- Two PCs, one at Caulfield and the other at Clayton
with customised Redhat Linux 7.2 installed
Connected through the school network
Actisys 220+ has been used for infrared
transmission of the agent
PocketPCs (iPaq) are being used as the
user platform
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Copyright 2002 by Shing Kay Pan
8. Difficulties experienced:
•Short transmission range
- Increase transmission range by using customised infrared
adapter
•Speed changing problem (Limited speed: 9.6kbps)
- Support dynamic multi-speed
•Propagation delay on slow networks
- Use a faster protocol instead of TCP/IP (i.e. UDP)
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Copyright 2002 by Shing Kay Pan
8. Difficulties experienced:
Multi-user at the same site problem
PDA1
Agent1
TCP/IP
Network
PDA2
Agent2
PDA3
PDA4
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Copyright 2002 by Shing Kay Pan
9. Future work
•Increase transmission range by using customised infrared
adapter
•Support dynamic multi-speed
•Use a faster protocol instead of TCP/IP (i.e. UDP)
•Package as a standalone embedded device
•Use Bluetooth instead of IrDA
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Copyright 2002 by Shing Kay Pan
10. Conclusion
• Supporting system for the CSSE Video Wall developed
• The project has exploited the usability of infrared applications
• Possibility of application to other areas (i.e. home, business)
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The End