“…Several earlier studies are developed in cluster-based VANETs and CR-VANETs as well some of them are discussed in this section. They are, clustering of the VANETs in a highway environment [8], clustering oriented rouing model and in gets enhanced with the help of modified K-means method [9], efficient cluster head selection (ECHS) [10], fuzzy logic-based clustering control technique [11], in recent works clustering concept is combined with the medium access control (MAC) layer protocols to improve its efficiency [12], to reduce the power utilization and control the vehicle speed the connectivity prediction based clustering model with dynamic connectivity is developed [13], dual-slot transmission with mobile edge computing (MEC) [14], cluster-based resource management system [15], to minimize the broadcast overhead during communication the novel scheme is developed in VANETs called emergency message dissemination [16], to improve vehicles reliability during data transmission in real roads anovel idea id developed namely diverted path approach [17], destination-aware context-centered routing architecture [18], to optimize the power utilization in VANETs the concept of multi-hop clustering is developed [19], clustering particle swarm optimization (PSO)-based V2V routing method [20], clustering approach based on self-adaptive multi-kernel clustering [21], to develop a noise free and adaptive network structure in VANETs both novel clustering and adapted ordering points are built [22], effective channel selection in CR-VANETs [23], fuzzy cluster head (CH) selection scheme in CR-VANETs [24], and later multiple user based several inputs and outputs are collaborated with clustering model with the novel idea of cooperative spectrum sensing in CR-VANETs [25]. Once after analyzing the earlier research, it is understood that the CR-VANETs suffer from communication link failure, high energy consumption, and packet loss.…”