Analytical modelling of a vehicular ad hoc network using queueing theory models and the notion of channel availability

In this paper, we exploit the M/M/c and the M(N)/M/c queueing models in order to estimate the number of required resources that satisfy the quality of service (QoS) in a vehicular ad hoc network (VANET). Moreover, we consider a VANET which operates under ideal and non-ideal conditions where the channel failure issues are hard to avoid. The system’s performance is estimated in terms of various quantities, such as the system’s waiting time, the throughput and the number of users being served. These performance metrics are critical for a seamless VANET operation as they can directly affect the QoS. Two discrete cases of communication are considered: a) the case when a vehicle communicates directly with a gNodeB (vehicle-to-infrastructure communication) and b) the case when a vehicle communicates with other vehicles on the road (vehicle-to-vehicle communication) in order to transmit indirectly its request to the destination gNodeB. Based on the results of the employed analytical formalism, we conclude that when the minimum possible resources are exploited, the number of users being served may be significantly reduced and consequently the system’s throughput can be decreased compared to the case when the minimum possible resources condition does not hold. Finally, when the channel failure conditions are incorporated in the employed formalism, it is shown that the system’s performance is degraded in terms of both throughput and delay.