A Stable Neighbor-Based Clustering Algorithm for Vehicular Ad Hoc Networks

To enhance the stability of the cluster structure and extend its lifetime, a stable neighbor-based clustering algorithm (SNB-CA) is proposed. The algorithm, which is based on the concept of “stable neighbors,” takes into account the mobility, connectivity, and distribution of surrounding stable neighbor nodes. It selects the vehicle with the minimum cluster lifetime (CL) value as the cluster head, thereby forming a stable cluster structure. Additionally, the algorithm defines an upper limit for cluster size, establishes strict conditions for cluster formation and joining, and applies relaxed criteria for cluster dissolution and node departure. This approach helps avoid frequent restructuring of the cluster, thereby increasing its stability and longevity. Furthermore, an adaptive beacon mechanism is incorporated, allowing vehicles to adjust their beacon intervals based on node status and the cluster head's speed range. This ensures accurate message transmission while reducing beacon overhead. Simulation results demonstrate that the proposed clustering algorithm successfully maintains a stable cluster structure and significantly reduces clustering overhead in both highway and urban environments.