Vehicular Ad-hoc Network (VANET) is a subset of Mobile Ad-hoc Network (MANET) enabling communication between vehicles for safety, traffic updates, entertainment, and data sharing. Due to the high mobility in VANETs, routing messages to their final destination is challenging. Various protocols, such as broadcasting, multicasting, and geo-casting, are used to disseminate data. Multicasting protocols are effective in conserving bandwidth. One such protocol, Bandwidth Efficient Acknowledgment Based Multicasting Protocol (BEAM), improves VANET performance by minimizing in-network message transactions, particularly in emergencies. However, BEAM may cause multi-car collisions due to the absence of vehicle-to-vehicle (V2V) communication. To address this, we propose an algorithm that incorporates clustering, grouping vehicles based on predefined metrics like density, velocity, and location. Clustering controls VANET topology dynamics, enhancing stability and reducing communication barriers and RSU installation costs. The proposed approach uses static and mobile agents for communication between vehicles and RSUs. In multicast groups, RSUs manage communication, while cluster heads (CHs) handle non-multicast groups. Agents decide cluster size and select primary and secondary cluster heads based on vehicle speed and connectivity. A backup cluster head prevents re-clustering during high mobility, extending cluster life and reducing routing overhead. Simulation results demonstrate improved performance in terms of throughput, PDR, and end-to-end delay compared to BEAM

翻译：车载自组织网络是移动自组织网络的一个子集，可实现车辆间在安全、交通更新、娱乐和数据共享等方面的通信。由于车载自组织网络中的高移动性，将路由消息传递至最终目的地具有挑战性。广播、多播和地理播送等多种协议被用于数据分发。多播协议在节省带宽方面效果显著。其中，带宽高效确认多播协议通过最小化网络内消息事务（尤其在紧急情况下）提升了车载自组织网络的性能。然而，由于缺乏车辆间通信，该协议可能导致多车碰撞。为解决此问题，我们提出一种融合分簇的算法，依据密度、速度和位置等预定义指标对车辆进行分组。分簇能控制车载自组织网络的拓扑动态，增强稳定性，降低通信障碍及路侧单元部署成本。所提方法采用静态与移动代理实现车辆与路侧单元间的通信。在多播组中，路侧单元管理通信；而在非多播组中，则由簇头负责。代理根据车速和连接性决定簇规模，并选择主簇头与副簇头。备用簇头可在高移动性场景下避免重新分簇，从而延长簇生命周期并降低路由开销。仿真结果表明，与带宽高效确认多播协议相比，所提方案在吞吐量、分组投递率和端到端时延方面均表现出更优的性能。