Increasing cluster stability in vanet by candidate cluster head nomination algorithm

Abstract A Vehicular Ad Hoc Network (VANET) is a specialized form of Mobile Ad Hoc Network (MANET) that incorporates concepts from Intelligent Transport Systems (ITS) and road safety applications. Unlike conventional MANETs, vehicles in a VANET are required to exchange a significant amount of data within a constrained time frame while operating at high speeds, which leads to frequent network instability. Therefore, clustering methods are proposed to stabilize the VANET environment. However, improving the routing efficiency and reducing message overhead remain key challenges to be addressed. To help vehicles receive and transmit road information more quickly and efficiently in high-speed mobile environment, this study proposes a four-step Candidate Cluster Head Nomination Algorithm (CCHNA), which enables vehicles to communicate with others based on specific parameters. The algorithm also includes a CH Pruning Stage, which reduces the number of cluster heads generated during the CH Nomination Stage by comparing these parameters. Experimental results show that the proposed CCHNA reduces the average number of cluster heads by 1–3 compared to other algorithms. During the cluster maintenance stage, message overhead during cluster reorganization is also significantly reduced, achieving up to six times fewer message exchanges. Therefore, CCHNA results in fewer clusters and considerably reduces communication costs associated with cluster information.