Scalability Analysis of Infrastructure Networks for Vehicular Safety Applications

Vehicular adhoc networks are able to provide the awareness among cars, which is exploited by the emergent automotive safety applications, such as lane change warning and electronic brakes. Beaconing, i.e. periodic broadcasting of status messages by each vehicle, is a core communication pattern which all the critical vehicular safety applications rely on. A set of IEEE 802.11p/WAVE (Wireless Access in Vehicular Environments) protocols is specially designed to support vehicleto-vehicle communication. Notwithstanding, many studies raise the scalability problem of 802.11p carrier sense multiple access, which makes it impossible for the protocol to guarantee the required performance in dense road traffic scenarios. Thus, existing cellular broadband wireless access (BWA) infrastructure, e.g. 3GPP Long Term Evolution (LTE), IEEE 802.16e (Mobile WiMAX), can be considered as an additional opportunity to support vehicular cooperative safety applications. In this paper we introduce a simple stochastic model for the evaluation of the BWA network used for the beaconing. This model can serve as an easy tool to understand the theoretical limits of different BWA technologies in intelligent transportation systems use cases.