# A Deep-Learning-Based Secure Routing Protocol to Avoid Blackhole Attacks in VANETs +
## 5 Performance Evaluation
### Numerical Results
Conversely, CH and GW are the only nodes involved in the proposed DLSR+DLC protocol, which leads to enhancing the efficiency of the routing process. Thus, the DLSR+DLC protocol with the RPGM model can transmit packets with the least amount of delay compared to other protocols. The control overhead, which includes the control overhead for cluster construction, is compared as a function of node speed in Figure 16. As we can see in Figure 16, the control overhead slightly increases as the speed increases. The reason is that when the number of node speeds increases, nodes can be broken more easily, leading to an increase in the control overhead. Furthermore, when comparing the two mobility models, it is clear that the RPGM protocol shows lower control overhead due to high stability than the RWP model. In contrast to other scenarios, the control overhead in our proposed routing protocol can be decreased by the DLC protocol. The decrease in control overhead is significantly lower in the case of the DLSR+DLC protocol than in other scenarios, as the DLC protocol only involves CH and GW nodes in the routing operation. Thus, it was  
Figure 14: PDR with various scenarios as a function of node speed. Figure 15: Routing delay with various scenarios as a function of node speed. shown that the DLSR+DLC protocol with the RPGM model may increase connectivity while simultaneously being the most stable in terms of control overhead. The focus of our attention is now on security issues. In order to evaluate the impact of node speed on the network performance, we conduct a comparison analysis of the packet loss ratio and number of packet losses under various scenarios, as shown in Figure 17. Figure 17a displays the average packet loss ratio, which is calculated as the ratio of the number of loss packets to the total number of sent packets. It is evident that when the node speed increases, the average packet loss ratio also increases. Similarly, in Figure 17b, when the node speed increases, the average number of packet losses also increases. The observed behavior can be attributed to the increased node speed, causing the node's location to change more frequently. Consequently, packets are more likely to be sent directly to the blackhole node, resulting in a higher packet loss rate. On the other hand, by using the RPGM model over the RWP model, we can handle movement-related issues better. The RPGM model ensures the predictable and collective movement of nodes. Thus, the RPGM model leads to fewer route changes, more stable connections, and ultimately, a lower chance of packet loss. However, clustering plays a significant role in reducing the number of links between nodes. Therefore, the proposed DLSR+DLC protocol under the RPGM model showcases enhanced network security, making it a promising and effective approach from a network security perspective. Figure 10:0 Control overhead with various scenarios as a function of node speed. Figure 10:1 The comparison of packet loss ratio and number of packet losses as a function of node speed is performed under different scenarios. Finally, we analyze how the number of nodes affects the network performance metric, as shown in Figure 10:2 In Figure 18a, we analyze the PDR as the function of node speed with various numbers of nodes in the proposed DLSR with DLC protocol. The PDR slightly decreases as the node speed increases. However, the PDR slightly increases as the number of nodes increases. This behavior can be attributed to the more predictable movement patterns in the RPGM model, leading to less frequent route changes and fewer packet losses. Furthermore, Figure 18b shows the routing delay as the function of node speed with various numbers of nodes in the proposed DLSR with DLC protocol. As the node speed and the number of nodes increase, a slight increase in routing delay can be observed, although not significantly. This can be attributed to the fact that with more nodes and higher speeds, the number of hops in the routing path increases, leading to a slightly longer routing process.