Vehicular MAC Protocol Data Unit (V-MPDU): IEEE 802.11p MAC Protocol Extension to Support Bandwidth Hungry Applications

Vehicular ad-hoc networks (VANETs) have been a hot research topic in academia and industry with respect to safety of drivers and entertainment applications. Many MAC layer protocols have defined in research. The IEEE 802.11p is one of the popular carrier sense multiple access (CSMA)-based MAC layer protocol for VANET and is successfully used for safety applications. However, IEEE 802.11p is less efficient for bandwidth hungry and delay-sensitive applications as there is significant fixed overhead of channel access, the inter-frame spaces, and acknowledgments of each frame transmitted. In this paper, an aggregation mechanism, named Vehicular MAC protocol data unit (V-MPDU) with block acknowledgment as an extension of the existing IEEE 802.11p is proposed. The proposed aggregation technique collects frames against each destined node and wraps each frame in a single IEEE 802.11p header. Moreover, it permits each of the aggregated data frames to acknowledge individually or re-transmit in case of any transmission error. Hence, it improves the channel access mechanism in terms of efficiency as multiple frames transmit in single transmission opportunity, which ultimately reduce number of potential collisions and re-transmissions as well. Further, effective bandwidth automatically improves.