## Optimal Vehicle Number and Coding Decision in Vehicular DTNs

**Brief Introduction**

Vehicular Delay Tolerant Networks (VDTN) are used to distribute a large amount of mobile data by high-capacity device-to-device communication. Given a number of available vehicles in VDTN, the current vehicular data sharing models always utilize all of them to achieve the best effect, failing to balance the performance gained and cost of employing them. Taking the cost into account, we study the problem of the optimal number of vehicles to be deployed in the data sharing system, which considers using erasure codes to further increase the system efficiency if possible. By establishing the system goal which consists both the effectiveness and the cost of the vehicular network mathematically, we formulate the above problem as a utility function minimization problem. Finally, we solve the problem by theoretical derivation, and demonstrate the efficiency of the obtained solution through simulations using real vehicular traces of Beijing and Shanghai.

**My Contribution**

As the student in charge of this project, I do most of the work independently under the supervision of Prof. Depeng Jin. I am responsible for both the theoretical analysis and the simulation verification part of the project. I take the cost into account and prove that it is not always true that the more the number of vehicles involved in the data sharing, the better the performance. I also establish a mathematical method to decide the optimal number of vehicle to deploy in the network and whether to use erasure coding when storing the files.