Adaptive beaconing for delay-sensitive and congestion-aware traffic information systems

We present Adaptive Traffic Beacon (ATB), a fully-decentralized car-to-X protocol built around the central ideas of delay sensitivity and congestion awareness. From previous research findings, we see that centralized solutions, VANETs, and broadcasting based approaches each show benefits and drawbacks depending on traffic density, penetration, network utilization, and other parameters; intelligent transportation systems are therefore tuned for specific settings. In order to overcome this limitation, we developed a broadcast-based solution that has been designed to carefully use only the remaining capacity of the wireless channel. Thus, it will not influence other applications using the same radio network. ATB is adaptive in two dimensions: First, the beacon interval is adapted dynamically according to the channel quality and the importance of messages in the local knowledge base, and, secondly, the protocol can dynamically make use of available infrastructure elements. Simulation experiments demonstrate that ATB performs well in a broad range of settings. It maintains a non-congested wireless channel to prevent collisions during the data exchange.