Constrained geocast to support Cooperative Adaptive Cruise Control (CACC) merging

In this paper we introduce a new geocasting concept to target vehicles based on where they will be in the direct future, in stead of their current position. We refer to this concept as constrained geocast. This may be useful in situations where vehicles have interdependencies based on (future) maneuvers. We have developed a first version of such a protocol in the context of an automated merging application, and tested it using simulations. Results show that the protocol is able to meet the requirements of such applications. Compared to a common geo-broadcast protocol this protocol becomes more reliable as road traffic densities increase, but in other aspects the performance is so far lacking. Based on our experiences with implementing the protocol however we see plenty of room for further improvement.