Age of Information Under DCC Rate Constraints for V2I Broadcast Along Urban Corridors

Abstract

ETSI Decentralized Congestion Control (DCC) limits roadside unit (RSU) broadcast rates based on channel load, yet its impact on age of information (AoI) for vehicle-to-infrastructure updates remains uncharacterized under real traffic. We derive the AoI of DCC-constrained V2I broadcast, revealing a hyperbolic density dependence that induces diurnal AoI variation exceeding 4 times on a four-RSU corridor, with the DCC target CBR parameter as the dominant control. We propose a cooperative policy exploiting upstream spatial traffic correlation to improve channel load estimation, with a safeguard ensuring non-negative gains. Evaluated on a 5-day, 762,050-vehicle trace from Kuwait City, the policy reduces corridor AoI by 5% at moderate and up to 66% at conservative DCC settings.