Improving data QoS in vehicular communication

The ability to provide various application services introduces more traffic and therefore the problem of data traffic congestion in a VANET (Vehicular Ad-Hoc Network), and hence the QoS (Quality of Service) of the application deteriorates. This paper studies an adaptive PI rate-controller to improve/restore the QoS. The controller controls the source sending rate based on the instantaneous queue length of the congested node. Our simulations demonstrate that this controller is capable of providing a smooth throughput at the source as desired by most of the applications.