DCC-enabled contention based forwarding scheme for VANETs

Abstract

Although IEEE 802.11p technology is standardized for road safety and efficiency applications, the channel congestion problem is its key weakness necessitating distributed congestion control (DCC) algorithms on different layers of the communication stack. In this paper, we propose DCC-enabled Contention based Forwarding scheme targeting multi-hop dissemination of Decentralised Event Notification Messages (DENMs). The proposed scheme adapts the parameters of the ETSI standardised forwarding scheme, contention based forwarding (CBF), by taking account the channel load condition. Simulation evaluations are carried out to investigate the performances of the proposed scheme targeting a highway scenario and considering that the wireless channel is shared by DENMs and Cooperative Awareness Messages (CAMs), which are periodically broadcasted by individual vehicles. In the simulations, a dual DCC, the facilities layer DCC, which controls CAM generation rates, and the networking layer DCC, CBF2C, which targets DENMs, are applied and evaluated. Simulation results clearly show that DCC on CAM has a significant impact on communication performances of both the DENM and CAM messages. DCC on networking layer further improves performances in terms of packet delivery ratio (PDR), delay, and communication overhead.