1. Fastest-Vehicle Multi-hop Routing in Vehicular Ad hoc Networks 指導教授：許子衡 教授 報告學生：董藝興 學生 作者： Bilal, M. ; Chan, P.M.L. ; Pillai, P. ; 出處： Computer and Information Technology (CIT), 2010 IEEE 10th International Conference on 1

2. Introduction Alerting the drivers about real time critical situations on the road beforehand can be helpful in achieving a higher safety rate. Along with the warning message broadcasted in the network, multi-hop long range communication can also help in obtaining updated information about traffic and other relevant information. 2

3. Introduction This paper mostly concentrates on the routing protocol for efficient information exchange among the vehicles and proposes an efficient multi-hop routing technique. This is a more robust technique compared to traditional broadcasting technique that results in reduced packet collision and loss rate in the network. 3

4. Introduction In this paper the vehicle chosen for message transfer is based on both time and distance based strategy. The vehicle with the largest velocity vector and smallest distance vector in the transmission range is selected to transfer the message and this process is repeated until the message reaches its final destination. 4

5. FASTEST-VEHICLE MULTI-HOP ROUTING TECHNIQUE To perform the simulation tests, a couple of assumptions were made in the beginning as follows: 1) Vehicles are equipped with GPS for position information 2) Route is created hop by hop and assumed to be active till the destination receives the messages and sends the ACK back. 5

6. FASTEST-VEHICLE MULTI-HOP ROUTING TECHNIQUE The source vehicle is called Initial Vehicle (IV) and the Destination Vehicle to which the message is supposed to be transmitted is called Destination Vehicle (DV). The IV or Requesting Vehicle (RV) performs the beaconing process to confirm the existence of a number of different neighboring vehicles within the transmission range. 6

7. FASTEST-VEHICLE MULTI-HOP ROUTING TECHNIQUE 7

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9. Simulation Environment Total number of vehicles on simulated road: 58 Minimum transmission range: 350 meters Maximum transmission range: 750 meters Minimum speed of a vehicle: 8m/s Maximum speed of a vehicle: 50m/s Road length (where IV and DV are placed): 2.6km Distance between IV and DV: 1.98km 9

10. Simulation Environment 10

11. Simulation Environment 11