MAC and application level performance evaluation of beacon message dissemination in DSRC safety communication

In this paper, an analytic model is proposed for both MAC and application-level performance evaluation of periodic beacon message dissemination in the dedicated short range communications (DSRC) system on highways. Each vehicle can periodically generate beacon messages, which contain the information including position, velocity, direction, etc.. Out-dated message is replaced by the newly generated message. In order to develop a tractable analytic approximation, we first develop a semi-Markov process (SMP) model for the tagged vehicle to capture the periodic message generation, out-dated message replacement, channel contention and backoff behavior in IEEE 802.11 broadcast ad hoc networks. Further, an SMP model with an absorbing state is constructed to derive the message service time distribution. The fixed-point iteration method is utilized to obtain the converged solutions to resolve interactions between the SMPs of different vehicles. Both MAC-level and application-level performance metrics are derived. MAC-level analytic–numeric results are verified through extensive simulations. Application-level analytic–numerical results are evaluated subsequently to provide insights on network parameter settings. To ensure the quality of service (QoS) for a VANET application, application requirements in terms of application-level metrics are specified. Three typical safety-applications are evaluated in order to assess whether their application requirements can be satisfied or not.