A Probabilistic Model of the Age of Information for Distributed Periodic Reservations in Sidelink

To enable safety-related applications for autonomous driving, Vehicle-to-Everything (V2X) networks are required to support the dissemination of real-time status updates among neighboring vehicles. In this scenario, the 'freshness' of information with respect to an application-specific threshold is crucial for the availability of the application. In this paper, we rely on the Age of Information (AoI) as a metric that quantifies the availability of safety-related applications in V2X. Under the assumption of a distributed reservation-based channel access, we derive a probabilistic model that allows us to characterize the statistical properties of AoI and, consequently, evaluate the availability of the application in question. The analytical derivations are validated via numerical simulations.