Improving broadcast reliability in IEEE 802.11p/1609.4 standard

IEEE 802.11p/1609.4 standard is based on a multichannel system consisting of multiple service channels (SCH) and a control channel (CCH). Most messages broadcast in the CCH belong to safety application that must be received with high reliability by all vehicles. This paper proposes a novel mechanism based on which the size of the contention window and the time interval of the CCH is tuned adaptively according to the vehicle traffic and the channel load. The proposed mechanism sets an adequate CCH duration such that the Packet Reception Probability (PRP) of CCH channel remains satisfactory and also saves a sufficient amount of bandwidth for SCH usages. Extensive simulations with Veins simulator show that the proposed mechanism outperforms the original WAVE standards and also is less aggressive is extending CCH duration compared to previous enhancement of WAVE standard.