解决高度分割的车载自组网络连通性问题的路侧单元最优化调度方案

An Optimized RSU Scheduling Scheme for the Connectivity Problem in the Highly-Partitioned VANET

车载自组网络VANET是一种拥有高度动态拓扑结构的移动自组网络。为了解决其频繁的网络分割问题,最新研究提出使用一种特殊的称为路侧单元RSU的基础设施部署于道路两侧来提高VANET连通性。本文主要研究RSU调度中的节能降耗问题:给定一组路侧单元,我们的目标是寻找指定时段内打开或关闭RSU的最优调度,以确保RSU系统所消耗的总能量最小化,同时维持VANET系统网络连通性。我们将这一问题分解为两个子问题,即网络瞬像调度问题和网络瞬像选取问题。网络瞬像调度问题用于决定某时刻VANET网络瞬像中所需的连通状态RSU的最小值,而网络瞬像选取问题则用于决定系统需要在哪些时刻更新网络瞬像。通过对这两个子问题的研究,我们最终给出关于RSU调度问题的完全解,并通过理论分析与实验结果证明本文的算法可以在保持VANET连通性的同时明显地节能降耗。

Vehicle Ad-hoc Network （VANET） is a mobile ad-hoc network with the feature of highly dynamic topology. Recently, a special type of infrastructure called Roadside Unit （RSU） has been proposed to deal with the frequent network partitioning issue of VANET, which is deployed along the road to improve the VANET connectivity. In this paper, we mainly focus on how to save energy in the RSU scheduling problem. Our objective is to find the optimal scheduling to turn on or turn off the deployed RSUs within the system during a given time period, so that the overall energy consumption of these RSUs is minimized while the network connectivity is maintained. In order to solve this problem, we divide it into two sub-problems, namely the snapshot scheduling problem and the snapshot selection problem. The former problem decides the minimum number of active RSUs required in a VANET snapshot at a given time point, while the latter problem decides the sequence of time points at which the snapshot must be updated. By solving these two sub-problems, we present a complete solution to our RSU scheduling problem. Theoretical analysis and experimental results confirm the efficiency of our algorithms, which achieve significant improvement in energy saving while maintaining the VANET connectivity.