Transmission Capacity Analysis For Cellular Based Clustered Vanet

As basic data-bearing platform of Intelligent Transportation System,Vehicular Ad-Hoc Network,that is,the VANET,has been paid more and more attention in recent years.Different from traditional Mobile Ad-Hoc Network,on one hand,high-speed mobility of vehicles makes actual topology of VANET very complex,on the other hand,the sharp increase in the number of vehicles in urban area and the explosion of non-security messages make the efficient utilization of dynamic spectrum resources particularly important.However,most of existing researches on VANET still follow traditional models and protocols in Mobile Ad-Hoc Network,rather than the clustered VANET model and dynamic spectrum access protocol in real scene,and lack of consideration for actual vehicle mobility rule.This paper studies the Cellular based Clustered VANET(CC-VANET)model and the Interference Avoidance oriented Cellular based Clustered VANET(IACC-VANET)model,analyzes their dynamic spectrum access protocol respectively,derives transmission opportunity and capacity of these two models.Firstly,in view of actual transmission demand of non-security messages and actual topology structure of VANET,a CC-VANET model is constructed.Its dynamic spectrum access protocol is a cluster based spectrum access control protocol.Secondly,aiming at the additional interference brought by cluster members in the process of accessing cellular spectrum,a IACC-VANET model is constructed.Its dynamic spectrum access protocol is an interference avoidance oriented cognitive contention protocol.Finally,transmission opportunity of two models under corresponding protocols are analyzed,and upper and lower bounds of transmission capacity are derived.Through simulation,the relationship between influence factors and the transmission opportunity and the upper and lower bounds of transmission capacity are verified.Simulation results show that the cluster based spectrum access control protocol can effectively improve transmission opportunity and capacity in dynamic spectrum channels.The threshold based interference avoidance method makes IACC-VANET model has a certain increase in the transmission opportunity and capacity in cellular spectrum channels as compared with CC-VANET model.This paper provides two kinds of practical clustered VANET model and network performance analysis method,which provides technical support for intelligent transportation in the construction of intelligent city.It has theoretical significance and practical application value.