Vehicular networking is a cornerstone of Cooperative Intelligent Transportation Systems (C-ITSs) and autonomous vehicle management. It is expected to provide significant improvement in terms of transportation safety and efficiency. Cooperative awareness and sensing of the road environment is among the key services supported by vehicular networking. These applications rely on periodical exchange of one-hop broadcast messages.
The effectiveness of cooperative safety applications, built upon message exchange, highly depends on the accuracy and timeliness of status information contained in these messages and shared periodically among vehicles. We aim at defining a message congestion control able to cope with load limit requirements on the wireless channels and with application-relevant metrics characterizing the freshness of the collected data, namely the recently defined Age of Information (AoI).
Despite some heuristic proposals, there is still no satisfactory application-aware congestion control algorithm. In the proposed research we leverage on accurate analytic models that provide insight to identify the best message sending rate in complex vehicular scenarios where hidden vehicle nodes are possible.
The two main innovative results we tackle are therefore as follows. Identification of message congestion control to strike a controllable trade-off between efficient utilization of the wireless channel and timeliness of collected data, measured by the AoI performance (or new freshness metrics, to be identified in the course of the research). A second target is to compare the performance offered by the ETSI ITS G5 standard, based on Carrier Sense Multiple Access MAC protocol according to the amendment IEEE 802.11p, and cellular V2X (C-V2X) based on 5G New Radio. This comparison aims at contributing to the hot debate that has currently broken out in the automotive community about which technology promises better performance and safety levels.
