Influence of the shadowing on the information transmission distance in inter-vehicle communications

To achieve efficient traffic control, Intelligent Transportation System (ITS) has been widely deployed in many regions such as America, Europe, Australia, Japan, and Taiwan. To prevent the unnecessary losses, ITS adopts the inter-vehicle communications to inform the drivers if there are accidents nearby. However, the ability of effective transmission distance of the emergency information depends notably on the percentage of the vehicles equipped with communication device and the characteristics of radio wave propagation. The vehicles which are not equipped with these communication devices will block the radio propagation and result in the undesirable shadowing attenuation. This paper surveys the impact of the shadowing effect for the inter-vehicle communications via the computer simulations and the field measurements. Besides, a modified three-ray shadowing model suitable for the inter-vehicle communication is proposed. With the proposed model, the influence of the showing effect on the effective transmission distance will be evaluated.