Topology characteristic analysis of vehicular ad hoc network based on time-varying complex network

Abstract

The dynamic network topology of the Vehicular Ad Hoc Network (VANET) directly affects network performances. The VanetMobiSim software was used to study the dynamic topology of VANET in detail. A time-varying model of VANET was built. First, the information transmission model of VANET was established on the basis of the time-varying network theory. The evolution of VANET characteristic parameters in a time-varying process was stimulated by using the information transmission time τ and the maximum tolerated delay time δ accessibility graph. Then, we perform mathematical analysis of the relations of (τ, δ) to the out-degrees, average packet accessibility, and asymmetry ratio. Finally, the relations of the node communication radius to the global efficiency and the average harmonic mean of the distances were analyzed. The results indicated that the time-varying accessibility graph made VANET information transmission more efficient; reducing the information transmission time τ or increasing the maximum tolerated delay time δ tends to bring out the improving temporal connectivity of the whole network, thus improving the efficiency of packet transmission.