Connectivity Probability Analysis for VANET Freeway Traffic Using a Cell Transmission Model

The connectivity probability analysis for vehicular ad hoc network (VANET) freeway traffic is of practical significance and can provide theoretical guidance to reduce the occurrence of traffic accidents and also enhance the traffic efficiency. The cell transmission model (CTM) can describe highly dynamic characteristics of VANET freeway traffic and has been recognized as a traffic flow model. However, few previous studies have used such a model to investigate the connectivity probability for VANET freeway traffic. In this article, a new approach for cooperative communication is proposed for a bidirectional two-lane freeway that utilizes a CTM to dynamically describe the variety of vehicle flows with on-ramp/off-ramp and effectively repair broken chains. The mathematical formulas of the connectivity probability for VANET freeway traffic are derived. Some parameters of traffic flow, such as the vehicle flow, path loss exponent, the communication radius, the message size, and the data rate, are dynamically set and studied. The numerical simulation results are consistent with the actual situation that confirms the accuracy of our theoretical results.