Popular Content Distribution in CR-VANETs with Joint Spectrum Sensing and Channel Access using Coalitional Games

Driven by both safety concerns and commercial interests, popular content distribution (PCD), as one of the key services offered by vehicular networks, has recently received considerable attention. In this paper, we address the PCD problem in highway scenarios, in which a popular file is distributed to a group of onboard units (OBUs) driving through an area of interest (AoI). Due to high speeds of vehicles and deep fading of vehicle-to-roadside (V2R) channels, the OBUs may not finish downloading the entire file. Consequently, a peer-to-peer (p2p) network should be constructed among the OBUs for completing the file delivery process. Here, we apply the cognitive radio technique for vehicle-to-vehicle communications and propose a cooperative approach based on coalition formation games, which jointly considers the spectrum sensing and channel access performance. Simulation results show that our approach presents a considerable performance improvement compared with the non-cooperative case.