Research On The Survivability Of Vehicular Ad Hoc Network

As an important part of intelligent transportation systems,vehicular ad hoc network has become one of the hottest research topics in the field of wireless network and intelligent transportation.In VANET,due to the high speed of vehicles and wireless channel fading,the network topology changes frequently,having a direct impact on the performance of VANET.Survivability can depict characteristics of network topology,so the study on survivability of VANET is conducive to finding weak points for the network topology and optimizing it to improve the service quality of VANET,which plays a quite significant role in protocol development and network management for VANET.This paper aims at studying survivability of VANET based on intelligent driver model with lane changes and vehicular ad hoc network mobility simulator.The main work is concluded as the following three aspects:(1)Survivability of VANET based on static network is studied.Firstly,the model of VANET is built by means of considering VANET in each time slot as a static network.Then,the experiment discussing influences on survivability of VANET by communication radius,network densities and attack modes on the basis of complex network is conducted.The results show that VANET ha s strong survivability faced with random attacks while it has weak survivability under intentional attacks as the result of uneven degree distribution.At the same time,the intentional attack based on node betweenness has a more significant impact on VANET than the one based on node degree.What is more,when the number of vehicles in VANET is constant,the larger communication radius is,the better survivability will be.Similarly,as the network density becomes larger,the survivability of VANET will be greater as well.However,if the connectivity of VANET is good enough,network densities will have little influence on survivability;(2)Survivability of VANET based on temporal network is studied.Firstly,the temporal model of VANET is constructed.Some temporal survivability metrics are also introduced.Then,the experiment discussing influences on survivability of VANET by communication radius,network densities and attack modes on the basis of temporal network is conducted.The results show that the survivability of VANET facing intentional attacks based on the largest temporal degree nodes is the worst,but the survivability of VANET under random attacks is the greatest.Moreover,both communication radius and network densities have positive impacts on the survivability;(3)The results of survivability for VANET derived from three approaches,on the basis of static network,static aggregative network and temporal network respectively,to modelling VANET are compared.What is presented is that the way to model VANET based on static network underestimates the connectivity of VANET and the way based on static aggregative network overestimates the connectivity,but they both overestimate the survivability of VANET.Besides,the model based on temporal network can not only depict dynamic topology structure of VANET,but also reasonably evaluate the network survivability.