AAF: Analog superposition assisted forwarding node selection and density estimation in vehicular networks

In this paper, we propose an efficient forwarding node selection and density estimation mechanisms for vehicular networks (VANETs). Density estimation is performed without using beacons. Basically, the transmission range is divided into segments. Then, we apply a superposition based analog signal transmission and exploit multi-user capability of OFDM to collect density in each lane and in each segment. With such fine-grained information, a farthest node can be successfully located and selected as the forwarder. The one hop delay is substantially reduced by reducing the contention time and relying mostly on signals instead of control packets to assist the forwarder node selection process. In the simulations, it is observed that the proposed protocol accurately estimates the node density. Also, it outperforms existing multi-hop broadcast protocols in terms of end-to-end delay.