In Vehicular Adhoc Networks (VANETs), disseminating Emergency Messages (EMs) to a maximum number of vehicles with low latency and low packet loss is critical for road safety. However, avoiding the broadcast storm and dealing with large-scale dissemination of EMs in urban VANETs, particularly at intersections, are the challenging tasks. The problems become even more challenging in a dense network. We propose an Effective Emergency Message Dissemination Scheme (EEMDS) for urban VANETs. The scheme is based on our mobility metrics to avoid communication overhead and to maintain a stable cluster structure. Every vehicle takes into account its direction angle and path loss factor for selecting a suitable cluster head. Moreover, we introduce estimated link stability to choose a suitable relay vehicle that reduces the number of rebroadcasts and communication congestion in the network. Simulation results show that EEMDS provides an acceptable end-to-end delay, information coverage, and packet delivery ratio compared to the eminent EM dissemination schemes.

中文翻译：

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一种有效的城市VANET紧急消息传播方案

在车载自组织网络（VANET）中，将紧急消息（EM）分发给具有低延迟和低丢包率的最大数量的车辆对于道路安全至关重要。但是，要避免广播风暴并应对城市VANET（尤其是交叉路口）中EM的大规模传播，是一项艰巨的任务。在密集的网络中，问题变得更加具有挑战性。我们为城市VANET提出了有效的紧急消息传播计划（EEMDS）。该方案基于我们的移动性指标，以避免通信开销并保持稳定的群集结构。每辆车在选择合适的簇头时都会考虑其方向角和路径损耗因子。而且，我们介绍了估计的链路稳定性，以选择合适的中继车辆，以减少网络中的重播次数和通信拥塞。仿真结果表明，与著名的EM传播方案相比，EEMDS提供了可接受的端到端延迟，信息覆盖范围和包传递率。