Mitigating Broadcast Storms in VANETs: RSS-CAST vs. TD-CAST Protocols under Varying Traffic Densities

In recent decades, advancements in wireless technology have led to the development of vehicular ad hoc networks (VANETs), which provide essential services for data dissemination and emergency warnings. A significant challenge in VANETs is the broadcast storm problem, which occurs when multiple vehicles simultaneously rebroadcast emergency messages in densely populated areas, leading to network congestion and message collisions. To address these issues, this study introduces two routing protocols: Received Signal Strength-based Broadcast Suppression (RSS-CAST) and Traffic Density-based Broadcast Storm Suppression (TD-CAST). Both protocols perform effectively in dense and sparse scenarios. RSS-CAST estimates a vehicle’s location using the received signal strength (RSS) of incoming messages, eliminating the need for beacon message exchanges. In contrast, TD-CAST involves all vehicles exchanging beacon messages, enabling the source vehicle to count neighboring vehicles and dynamically allocate slots based on traffic density. The performance of RSS-CAST and TD-CAST is evaluated and compared concerning end-to-end delay, message delivery ratio, and network overhead under both dense and sparse network conditions. Simulation results show that RSS-CAST outperforms TD-CAST across various performance metrics.