Towards realistic vehicular network simulation models

Recently, testbed deployments using real IEEE 802.11p devices have allowed making performance measurements using this technology. The results obtained in those experiments evidence that lots of factors influence wireless communications: small obstacles like trees, small moving obstacles like cars, or large obstructions like buildings. All of them affect the transmission range, reducing the communication possibilities. Based on the insight provided by these results, in this work we propose a propagation model that attempts to replicate all these effects in simulation in order to increase the accuracy of experiments. Our solution combines (i) an attenuation model that replicates transmission range and fading behavior of real 802.11p devices, both in line-of-sight conditions and when obstructed by small obstacles, and (ii) a visibility model to deal with large architectonic obstacles, such as buildings. Our model was evaluated using the OMNeT++ platform, and results show that having the exact building positions and shapes is a critical parameter, introducing performance differences of up to 50% compared to simpler models.