An improvement of media access control scheme for inter-vehicle communications

In this paper, we propose a new media access scheme based on the ARIB STD-T109 designed for ITS communications in order to improve the system performance. The proposed scheme is totally compatible with the conventional scheme corresponding to the ARIB STD-T109 and can reduce the required transmission period per frame and the frame collision rate. By focusing attention on a periodical frame transmission characterized by ITS applications, each station in ITS network orders the frame transmission as an autonomous-decentralized system. The proposed scheme works as an expansion of the conventional one and the worst performance of the proposed scheme corresponds to that of the conventional one. We show that the proposed scheme always outperforms the conventional one by computer simulations.