Vulnerability of opportunistic parking assistance systems to vehicular node selfishness

Opportunistic networking leverages the volume, heterogeneity and mobility of end user nodes to foster the dissemination of information in the absence of network infrastructure. Nevertheless, in competitive settings (where the possession of information itself is an asset) user nodes often face a strategic dilemma: cooperate, to realize the network and support the information flow, or not do so, to gain competitive advantage over the other nodes. In this paper, we investigate realistic scenarios of opportunistic parking assistance service that instantiate such dilemmas. Ideally the vehicular nodes opportunistically collect and share information on the location and availability status of the parking spots. Yet the competition for parking spots may give rise to various facets of misbehaviors, such as deferring from sharing information (free riders) and/or deliberately falsifying disseminated information (selfish liars) so as to divert others away from a particular area of own interest. Simulation results indicate that misbehaviors tend to reduce the distance between the destination and the occupied parking spot for all vehicles at the expense of higher parking search times. However, misbehaving nodes fail to obtain any substantial performance advantage that would indeed encourage their misbehaviors. The addition of Mobile Storage Nodes compensates for the reduction of the information flow due to free riders but has almost no effect against selfish liars. Simple analytical models drawing on mean-field arguments provide further evidence for the fundamental dynamics that emerge from the interaction of the vehicular nodes.