Realistic Vehicular Mobility Models

In VANETs, vehicles equipped with wireless communication devices can transfer data with each other (vehicle-to-vehicle communications) as well as with the roadside infrastructure (vehicle-to-roadside communications). In order to successfully transfer data from a vehicle to another, the vehicle needs to first wait until it geographically meets other vehicles (within the communication range of each other) for data-relay. Applications based on this type of data transfer will strongly depend on vehicular mobility characteristics, especially on how often such communication opportunities take place and on how long they last. In this chapter, we focus on studying the metric called inter-contact time [28–30], which denotes the time elapsed between two successive contacts of the same two vehicles. Since data transfer arises in a store-carry-forward fashion, the inter-contact time (ICT) of the two vehicles is a major component of the end-to-end delay, as it presents how long it takes to encounter the other mobile vehicle to have any chances to forward/relay the data for communications. Larger inter-contact time results in larger end-to-end delay.