A Black-Burst Based Time Slot Acquisition Scheme for the Hybrid TDMA/CSMA Multichannel MAC in VANETs

In the hybrid time division multiple access (TDMA)/carrier sense multiple access multichannel medium access control protocols for vehicular ad hoc networks, each vehicle randomly selects a time slot from available ones for the transmission of safety message in the TDMA-based part. However, the access collision will occur when two or more vehicles within two-hop range of each other attempt to acquire an identical idle slot, which degrades the performance of access process. In this letter, we propose a novel time slot acquisition scheme based on jamming signal, also known as black-burst. To reduce access collisions, each vehicle tries to send a randomly shifted black-burst to inform its one and two hop neighbors when it reserves an idle time slot. Simulation results show that the proposed scheme outperforms the state-of-the-art scheme in terms of time slot acquisition efficiency.