Dynamic Service-Channels Allocation (DSCA) in vehicular ad-hoc networks

Providing tools to achieve a high level of safety transportation is the important objective in VANETs research. Hence, most of the works are devoted to developing safety-message dissemination algorithms. However, non-safety applications can also contribute to the network efficiency by exchanging traffic information. To support these applications, VANETs adopt the wireless access in the vehicular environment (WAVE) to guarantee the quality of service (QoS) using four different access categories. However, the WAVE could not provide the QoS to the users due to the collisions caused by the small contention-window size for the top priority traffic when top-priority traffic is dominant. Therefore, this small contention-window size setting for the prioritization induces severe performance degradation. In this paper, the Dynamic Service-Channels Allocation (DSCA) method is proposed to maximize throughput by dynamically assigning different service channels to the users. Theoretical analysis and extensive simulation works suggest that the DSCA improves the average throughput by 22% over the uniform channel allocation method. Moreover, the DSCA can be easily implemented in real devices without any protocol modifications.