车载自组织网络中的数据分发机制

车载自组织网络（vehicular ad-hoc network，简称VANET）作为一种新型的移动自组织网络，应用前景广阔.鉴于长距离数据分发机制是支撑VANET应用的一个不可或缺的机制，提出了一种VANET下路边单元（roadsideunit，简称RSU）辅助的数据分发机制Ara，并在不同的交通场景下对其性能进行了评估.实验结果表明，即使在有RSU出现故障的情况下，Ara也可以保证较高的数据到达率、较小的延迟和较低的消息开销.同时，通过建立分析模型对Ara的数据传递延迟进行了理论分析.该分析模型建立在车辆的微观流模型之上，可以推导出不同RSU 部署场景下的数据传递延迟.模拟实验结果验证了模型的正确性，因此该分析模型可以对Ara数据传递的性能进行预测.

Data Dissemination over Vehicular Ad-Hoc Networks

Vehicular ad-hoc networks (VANETs) are a new kind of mobile ad hoc network, and applications over VANETs are emerging with bright prospects. Considering that a long-distance data dissemination mechanism is indispensable for most VANET applications, this paper presents Ara, a RoadSide Unit (RSU)-aided unicast routing mechanism for VANETs, and evaluates its performance under different traffic scenarios. The experimental results show that Ara can keep high data delivery ratios, low delay and few message overheads even in the case of RSU failures. Moreover, the paper theoretically analyzes the data delivery delay of Ara by establishing an analytical model. Based on a vehicular microscopic flow mobility model, the analytical model can deduce the delay under the different RSU conditions. The model has been verified on its validation by simulation experiments and therefore it can be applied to predict the performance of data delivery through Ara.