## 2 Related Works  
[PERSON] et al. [8] offered a comparison study between the DSRC and LTE standards, which was evaluated with various communication scenarios, and the authors concluded that DSRC is superior to LTE in collision avoidance and safety applications. The integrated DSRC and LTE systems, according to the author, can help provide safe communication over a greater distance. [PERSON] et al. [9] proposed an efficient integrated DSRC WiMAX system based on common physical layer parameters to create communication for the intelligent transportation system. [PERSON] et al. [10] established an uplink communication simulation model based on several vehicular communication scenarios, such as sending data from WiMAX to DSRC using FFT subcarrier matching. [PERSON] et al. [11] presented a physical layer OFDM parameter, which was simulated by mixing DSRC and WiMAX and tested with image samples to demonstrate that successful communication between multiple standards can be established. [PERSON] et al. [12] investigated the performance of several vehicular communication situations by considering payload calculation and resource allocation. It can be evaluated in terms of how the resource is assigned to the vehicle's users via sub-channelization. [PERSON] et al. [1] presented a novel approach to converge DSRC and WiMAX by considering common physical layer parameters and testing them using picture transmission between DSRC and WiMAX. [PERSON] et al. [13] developed an OpenFlow SDN controller-controlled vehicle ad hoc network augmentation technique. [PERSON] et al. [14] developed an optimal energy-efficient system for vehicle networks, which they evaluated using a multicast routing protocol controlled by SDN and fog computing. In a vehicle network, [PERSON] et al. [15] suggested a durable and efficient routing technique and a secure channel using software-defined networks. [PERSON] et al. [16] presented a DCF mechanism in the DSRC standard to increase the performance of a vehicular network utilizing SDN, which they tested with a vertical handoff method between the car and the roadside unit. By addressing load balancing and multipath routing, [PERSON] et al. [17] offered a comparative analysis of how the software-defined network helps to govern vehicular networks and how it may be used for intelligent transportation system applications. Based on SDN technology, [PERSON] et al. [2] suggested an architecture to establish a secure traffic vehicular network to prevent unwanted user access. [PERSON] et al. [18] proposed an efficient model for traffic analysis using a software-defined network to describe the vehicular communication network. [PERSON] et al. [4] suggested an offloading technique based on handover between different networks, such as DSRC and Wi-Fi, as well as an analysis of network quality and signal strength for the vehicle to a fixed infrastructure scenario. The SDN aids in the control and monitoring of a stable IEEE 802.11P and Wi-Fi connection. [PERSON] et al. [19] proposed a unique technique based on IP and software vehicular networks to offer safe and lossless communication. Figure 1: CR-VANET architecture. [PERSON] et al. [5] suggested an SDN-based routing technique for vehicular networks that may be used for geographical position sharing by routing messages over connected, accessible mobile networks. A survey of SDN-based security threats and services for automotive networks was proposed by [PERSON] et al. [20]. Based on a background analysis of several SDN-based VANET systems, the authors concluded that deploying a single distant SDN controller will improve overall network efficiency. By utilizing effective fog computing, [PERSON] et al. [21] suggested virtualized security for vehicle networks. This methodology aids in the secure and rapid communication of vehicles operating in high-dynamic environments. [PERSON] et al. [22] suggested a fuzzy-based SDN controller improves traffic signals in large cities by taking into account various environmental scenarios, such as emergencies, typical traffic, and congestion.