A Structure-free Aggregation Framework for Vehicular Ad Hoc Networks

Abstract — One of the major difficulties for cooper-ative, decentralized information dissemination in ve-hicular networks is the heavily varying node density, which can lead to capacity issues of the wireless chan-nel when many vehicles are driving or standing closely together. At the same time, a number of applications do not require exact information from all participating nodes, but higher-level aggregated information. For ex-ample, reports on road conditions or on flow of traffic can be aggregated before further dissemination, since remote drivers just need to know a coarse-grained pic-ture of the situation. In this paper, we propose an in-formation aggregation framework using the example of cooperative traffic congestion detection. The difference of our aggregation framework compared to other ap-proaches is that it completely abandons any predefined structures such as grids and any group establishment. First evaluation results show that our approach works well for average speed dissemination on a highway. I