On Scheduling of Data Dissemination in Vehicular Networks with Mesh Backhaul

Vehicular networks have become increasingly popular in the research community. Messages in vehicular networks are usually subject to both time and space constraints, and therefore should be disseminated during a specified duration and within a specific coverage. Since vehicles are constantly moving in and out of a region, dissemination of a message should be repeated to achieve reliability. However, the reliable dissemination for some messages might be at the cost of unreliable or even no chance of dissemination for other messages, which raises tradeoffs between reliability and fairness. In this paper, we study the scheduling of data dissemination in vehicular networks with mesh infrastructure. Performance metrics for reliability and fairness are proposed first. Our metric for reliability covers factors in both time and space dimensions and the metric for fairness incorporates fairness in both the network-wise sense and the mesh roadside unit-wise (MRU-wise) sense. Several scheduling algorithms are developed: one reliability-oriented algorithm, one fairness- oriented algorithm and three hybrid schemes. Extensive evaluation work is performed to quantitively analyze different scheduling algorithms. Our evaluation results show that (1) hybrid schemes outperform reliability-oriented and fairness-oriented algorithms in the sense of overall efficiency and (2) different algorithms have quite different characteristics on reliability and fairness.