Paper detail

Coalitional Graph Games for Popular Content Distribution in Cognitive Radio VANETs

Popular content distribution is one of the key services provided by vehicular ad hoc networks (VANETs), in which a popular file is broadcasted by roadside units (RSUs) to the on-board units (OBUs) driving through a particular area. Due to fast speed and deep fading, some file packets might be lost during the vehicle-to-roadside broadcasting stage. In this paper, we propose a peer-to-peer (P2P) approach to allow the OBUs to exchange data and complement the missing packets. Specifically, we introduce a coalitional graph game to model the cooperation among OBUs and propose a coalition formation algorithm to implement the P2P approach. Moreover, cognitive radio is utilized for vehicle-to-vehicle transmissions so that the P2P approach does not require additional bandwidth. Simulation results show that the proposed approach performs better in various conditions, relative to the non-cooperative approach, in which the OBUs share no information and simply response to any data request from other OBUs.