An efficient QoS MAC for IEEE 802.11p over cognitive multichannel vehicular networks

One of the most challenging issues facing vehicular networks lies in the design of an efficient MAC protocol adaptable to different traffic scenarios (urban and suburban environments). While each environment has its own characteristics leading to different challenges, the merit of this paper lies in developing a MAC protocol suitable for both. In this work, we propose an efficient Multichannel QoS Cognitive MAC solely dedicated for Vehicular Environments (MQOG). MQOG incorporates efficient channel negotiation on the dedicated control channel whereas data is transmitted on other channel without contention. Since vehicular environments are widely known to suffer from interference and multipath, MQOG assesses the quality of channel prior to transmission employing a dynamic channel allocation and negotiation algorithm to achieve significant increase in channel reliability and throughput. The channel assignment problem was solved in an integrated manner while taking into account the QoS of different frames(Safety and NonSafety. The uniqueness of this protocol lies in making use of the ISM Band and UNII-3 in case all available channels in DSRC were considered unreliable. The proposed protocol was implemented in OMNET++ 4.1 and extensive experiments demonstrated that the proposed MAC ensures the reception of safety messages much faster, more efficient and reliable than other existing VANet MAC Protocols.