1 An Information Propagation Scheme for VANETs 學生： 簡志閔 彭彥能 黃尚文 Thomas D.C. Little, Senior Member, IEEE, and Ashish Agarwal, Student Member, IEEE IEEE Conference on Intelligent Transportation Systems Vienna, Austria, September 13-16, 2005

2 Authors Thomas D.C. Little, Professor Boston University Department of Electrical and Computer Engineering 研究領域 : Mobile ad hoc, opportunistic, and delay tolerant networking Vehicular (V2V and V2X) networking Video streaming in wireless sensor nets Communications with LEDs and ambient computing Ashish Agarwal PhD Candidate, Electrical and Computer Engineering Boston University

3 Abstract A goal in Vehicular Ad hoc Networks (VANETs) is to enable the dissemination of traffic and road conditions such as local congestion and surface ice as detected by independently moving vehicles. We assume the use of multi-hop routing in clusters of connected vehicles to achieve a propagation rate that exceeds the speeds of individual carrier vehicles.

4 Outline Introduction The VANET Characteristics And Assumptions Proposed DPP Scheme For VANETs Analysis And Discussion Conclusion

5 Introduction 方向性傳輸協定 Directional Propagation Protocol (DPP) ，主要由 3 個部份組成： Custody Transfer Protocol (CTP) adopted from Delay Tolerant Networking concepts overcoming the lack of a sustained end-to-end path between source and destination. Inter-Cluster Routing Protocol 、 Intra-Cluster Routing Protocol 。

6 The VANET Characteristics And Assumptions

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9 Related Work ： CARTALK is characterized by the use of map information, GPS coordinates and spatially aware routing. The key feature of this technique is the use of map information to forward messages using awareness of roadway paths instead of infeasible line-of-sight chord paths. FleetNet, the authors explored the prospect of using roadside gateways to deal with the sparse traffic scenario.

10 Proposed DPP Scheme For VANETs A. Cluster Formation and Maintenance

11 Proposed DPP Scheme For VANETs B. Custody Transfer Mechanism

12 Proposed DPP Scheme For VANETs C. The Use of Attribute Based Data

13 Proposed DPP Scheme For VANETs

14 Proposed DPP Scheme For VANETs D. Implementation of Directional Propagation Protocol

15 Analysis And Discussion Analysis We characterize the behavior of the system in terms of four transition states for analyzing the performance of the proposed scheme. These are: 1. Data are traveling along on a vehicle in the N direction 2. Data are propagating multi-hop within a cluster in the N direction 3. Data are traveling along a vehicle in the S direction 4. Data are propagating multi-hop within a cluster in the S direction

16 Analysis And Discussion

17 Proposed DPP Scheme For VANETs

18 Analysis And Discussion We have used c as 20m/s and v as 1000m/s

19 Conclusion We have proposed a new algorithm and protocol to enable data propagation of messages in VANETs without the use of fixed infrastructure such as access points or satellite communication. We have shown that the cost of message exchange is deterministic and the cost in different scenarios is a function of c, speed of vehicle, v, speed of message propagation and the different traffic conditions.

20 Thanks!!!