Congestion Control and Revocation of Misbehaving Vehicles in VANET

Abstract

The wireless access in vehicular environment system is developed for enhancing the driving safety and comfort of automotive users. However, such system suffers from quality of service degradation for safety applications caused by the channel congestion in scenarios with high vehicle density. The present work is a congestion control mechanism in vehicular ad hoc network. It also revokes the misbehaving vehicles from the network. It supports vehicle to vehicle and vehicle to infrastructure communication of safe messages using control channel and unsafe messages using service channel. The proposed scheme reduces the channel congestion by allowing only the authentic vehicles to participate in vehicle to vehicle and vehicle to infrastructure communication. Each vehicle generates beacon message periodically for its neighbors. The size of the beacon message is controlled dynamically to minimize channel congestion. The duplicate message truncation algorithm at each vehicle also reduces channel congestion by discarding the
duplicate safe messages. The proposed scheme also reduces the loss and delay in transmission of safe and unsafe messages by
sharing the available bandwidth of the channels among vehicles efficiently. The unsafe messages at a vehicle may also be
transmitted using control channel provided the control channel is free and service channel is overloaded which helps to reduce
the loss of unsafe message at a vehicle which in turn reduces the congestion of a vehicle and also improves its quality of service.
The performance of the proposed scheme is evaluated on the basis of average loss of unsafe message, average delay in safe and
unsafe message, storage overhead per vehicle.