Discovery and provision of content in vehicular networks

We address the problem of content discovery and provision in vehicular networks with infrastructure, when a publish/subscribe paradigm is applied. In the scenario we consider, vehicular users can be providers and consumers of generic information content, which is available through the vehicular network itself. Special infrastructure nodes act as information brokers and aid vehicles in content retrieval and dissemination. We study the performance of such a scheme by evaluating the probability that a content requested by a vehicle can be found and successfully delivered to the querying vehicle. To ensure high success probability, we design a credit-based scheme integrated with a feedback-based mechanism. The combined use of credit and feedback entices rational users to provide their content when requested by other users (thus discouraging free-riding behavior), and guarantees that no user is unduly burdened by too many requests for the same content (thus guaranteeing users a fair treatment). Also, through a banning mechanism that temporarily inhibits service to misbehaving users, we effectively counter malicious users whose sole objective is to disrupt the system. Using a simple game-theoretic formulation, we prove that these mechanisms ensure that cooperation is the best choice for rational users. The performance of our scheme for discovery and provision of content is shown through ns-3 simulations, by using a real-world road topology and realistic vehicular traces. Copyright (c) 2012 John Wiley & Sons, Ltd.