In recent years, the decentralized wireless Vehicular Ad hoc Networks (VANETs) have emerged as a key technology for Intelligent Transportation Systems (ITS). The need for an efficient and reliable broadcast protocol, mainly in urban VANETs, is of great importance to support different services such as road safety, traffic efficiency, entertainment and advertisement. This paper proposes two new routing broadcast protocols: the Enhanced Counter-based broadcast protocol in Urban VANET (ECUV) and the Enhanced distance-based broadcast protocol in Urban VANET (EDUV). Both of them improve the distribution of data on urban VANETs. ECUV and EDUV use a road-network-topology-based approach to select a set of relay nodes with enhanced coverage capabilities during the data delivery in urban Vehicle to Vehicle (V2V) scenarios. They also improve the performance of the receiver-based protocols by alleviating the negative effect of their stochastic behavior. We study the behavior of these protocols with an analytical model, which shows that the enhanced versions reduce the transmission probability in high vehicle density to avoid the broadcast storm problem. Moreover, the obtained results proved that these proposed protocols increase the transmission probability in low vehicle density to satisfy the reachability requirement of data broadcasting. The network simulation results show clearly that ECUV and EDUV outperform other methods in terms of coverage capacity and efficiency.

近年来，分散式无线车载自组织网络（VANET）成为智能交通系统（ITS）的一项关键技术。对于主要在城市VANET中有效而可靠的广播协议的需求，对于支持各种服务（例如道路安全，交通效率，娱乐和广告）至关重要。本文提出了两种新的路由广播协议：Urban VANET中基于增强型计数器的广播协议（ECUV）和Urban VANET中基于增强型距离的广播协议（EDUV）。两者都改善了城市VANET上的数据分布。ECUV和EDUV使用基于路网拓扑的方法来选择一组在城市车辆到车辆（V2V）场景中进行数据传输期间具有增强覆盖能力的中继节点。它们还通过减轻其随机行为的负面影响来提高基于接收器的协议的性能。我们使用解析模型研究了这些协议的行为，该模型表明增强版本降低了高车辆密度下的传输概率，从而避免了广播风暴问题。此外，获得的结果证明，这些提议的协议增加了在低车辆密度下的传输概率，以满足数据广播的可达性要求。网络仿真结果清楚地表明，就覆盖能力和效率而言，ECUV和EDUV优于其他方法。这表明增强版本降低了高车辆密度时的传输概率，从而避免了广播风暴问题。此外，获得的结果证明，这些提议的协议增加了在低车辆密度下的传输概率，以满足数据广播的可达性要求。网络仿真结果清楚地表明，就覆盖能力和效率而言，ECUV和EDUV优于其他方法。这表明增强版本降低了高车辆密度时的传输概率，从而避免了广播风暴问题。此外，获得的结果证明，这些提议的协议增加了在低车辆密度下的传输概率，以满足数据广播的可达性要求。网络仿真结果清楚地表明，就覆盖能力和效率而言，ECUV和EDUV优于其他方法。