Abstract
Vehicle-to-infrastructure (V2I) communication, a subset of Vehicle-to-everything (V2X), plays a critical role in enhancing road safety and traffic efficiency. While DSRC and C-V2X technologies have standardised physical layer communication, the upper layers remain flexible and open to diverse implementations. Existing IoT application layer protocols (ALPs), built on legacy TCP and UDP transport protocols, may exhibit suboptimal performance in dynamic V2I environments. This study evaluates six ALPs, i.e., AMQP, CoAP, DDS, MQTT, WebSocket (WS), and XMPP, across twenty protocol combinations, including modern QUIC and SCTP transport protocols. Using a simulation framework that integrates Omnet++, SUMO, Veins, and OpenStreetMap data, we assess key performance metrics: latency, packet delivery ratio, throughput, inter-arrival time, and connection establishment time. Our results indicate that while most protocol combinations perform adequately under low node densities (e.g., fewer than 100 nodes), network congestion leads to performance degradation. Nevertheless, CoAP over QUIC/UDP and WS over QUIC emerge as promising candidates for disseminating awareness messages across diverse V2I communication scenarios within the context and test limits.
