1. Broadcast Methods for Inter-Vehicle Communications System T. Fukuhara, T. Warabino, T. Ohseki, K. Saito, K. Sugiyama, T. Nishida, K. Eguchi IEEE Communications Society / WCNC 2005 Speaker: 69721039 楊政叡 69821018 辜紹桓 69818005 王力

2. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

3. Introduction  Intelligent Transport System (ITS)  Roadside-to-vehicle communications  client – server  Inter-vehicle communications  peer to peer

4. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

5. Proposed Methods  Conventional broadcast  Emergency information is relayed and notified in all directions.  May cause secondary accidents.  Resources wasted.  Emergency Information is needed by vehicles in a particular area.

6. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

7. Principle of Proposed Method  Emergency vehicle transmit a broadcast packet including its own location, forward movement direction, available relay range and available notification range.  The information is notified only to vehicles which are both within the available notification range and in front of the emergency vehicle.

8. Principle of Proposed Method  Broadcast area for emergency-vehicle-approach information.

9. Procedure of Proposed Method  Definition of calculation parameters.

10. Procedure of Proposed Method  Vehicle receiving the broadcast packet determines the following expressions.

11. Procedure of Proposed Method  Vehicle is within the available notification range.  Both (1) and (2) are satisfied.  Vehicle is within the available relay range.  Both (1) and (3) are satisfied.

12. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

13. Principle of Proposed Method  Broadcast area for Traffic Accident information.

14. Procedure of Proposed Method  Definition of parameters in calculation

15. Procedure of Proposed Method  Vehicle receiving the broadcast packet determines the following expressions.

16. Procedure of Proposed Method  Vehicle is within the available notification range.  Both (4) and (5) are satisfied.  Vehicle is within the available relay range.  Both (4) and (6) are satisfied.

17. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

18. Simulation Results  Simulation system  evaluation node  pseudo-node.  Wireless Local Area Network ( WLAN )  Routing protocol  Ad Hoc On-demand Distance Vector ( AODV )

19. Simulation Results

21. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

22. Experimental System  The terminal has three communication devices:  WLAN for Ad Hoc mode communications.  WLAN for infrastructure mode communications.  PHS(Personal Handy-phone System in Japan).  Broadcast Method  Based on AODV protocol and the proposed method.  Source transmits the RREQ packet, does not include the information of a particular destination.  RREQ message is relayed using the position and route direction of the node obtained by the GPS receiver.  The unit forward direction vector is calculated in the relay node from the route direction.

23. Experimental System  Linux OS version 2.4.21  Programmed with JAVA.

24. Experimental System  GPS data obtained during the vehicle runs in the test course.

25. Experimental System  Experimental terminal GUI for controlling transmission of emergency-vehicle-approach information and traffic accident information.

26. Experimental System  Display on GUI in vehicle 1 when vehicle 2 transmits emergency-vehicle-approach information.

27. Experimental System  Display on GUI in vehicle 2, when vehicle 1 transmits traffic accident information

28. Outline  Introduction  Proposed Methods  Emergency-vehicle-approach Information  Principle of Proposed Method  Procedure of Proposed Method  Traffic-accident-notification Method  Principle of Proposed Method  Procedure of Proposed Method  Simulation Results  Experimental System  Conclusions

29. Conclusions  Proposed novel broadcast methods for inter- vehicle communication on ITS.  More efficient emergency broadcasts.  Results from the simulation and experimental system confirmed that information is broadcast to the desired area.