Integrated Vehicle Access Protocol with Priority-Based Messaging for VANETs

Enhancing the functionality of connected and automated vehicles (CAVs) hinges on the robust exchange of real-time safety messages. These communications are critical for conveying traffic information, aiding drivers in accident prevention. Ensuring the prompt and dependable transmission of such messages is vital, necessitating effective channel access strategies. This study introduces a novel hybrid method that integrates Vehicular Deterministic Access (VDA) and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocols. This approach also incorporates a specialized algorithm for prioritizing messages, thereby optimizing the reliability and efficiency of safety message communication in vehicular networks. The hybrid model synergizes the advantages of both VDA, which is effective under high-traffic conditions, and CSMA/CA, which is preferable for lower traffic scenarios. The addition of a message prioritization approach guarantees priority for urgent communications like Decentralized Environmental Notification Messages (DENMs). Through simulations conducted using the Artery framework, our hybrid approach demonstrates a significant enhancement in performance, achieving over 93% delivery rates for DENMs, while also minimizing collision risks across various channel utilizations. This research contributes valuable insights into developing effective communication frameworks for CAVs, offering a detailed evaluation of the balance between different access protocols and message prioritization strategies in the context of vehicular networks.