Wireless Access in Vehicular Environments Using BitTorrent and Bargaining

Wireless Access in Vehicular Environment (WAVE) technology such as IEEE 802.11p has emerged as a state-of-the-art solution to vehicular communications. The major challenges in WAVE arise due to the fast changing communication environment and short durations of communications due to the mobility. As a result, it is difficult to transmit a large amount of data in such a network for vehicle-to-roadside and/or vehicle-to-vehicle communications. To overcome this problem, we propose a solution based on the idea of BitTorrent used for peer-to-peer networking, and the concept of bargaining game used in game theory. Similar to the distribution of data to peers in BitTorrent, the roadside units (RSUs) randomly distribute the data to the passing vehicles. Then, the on board units (OBUs) on the vehicles with different data, exchange the information among each other using bargaining considering channel adaptations and fairness in their achieved utility. We formulate two optimization problems - one for the RSUs and the other for the OBUs. For OBUs, the bargaining solutions are proposed which are based on three fairness criteria. For RSUs, depending on the traffic pattern, distribution of packets to the OBUs is optimized considering the different priority of the packets so that the overall utilities of the OBUs are maximized. Simulation results show that the proposed schemes can ensure fairness among the OBUs, and adapt to different traffic scenarios with different vehicular traffic intensity.