## 5 Performance Evaluation
### Numerical Results
It means that ASCS clustering protocol only involves CH and GW in the routing process and the decrease in control overhead is significantly less in case HPA-SR+ASCS protocol than in other cases. Thus, the HPA+ASCS protocol demonstrated that it can improve connectivity while also being the most stable in terms of control overhead. Figure 10: Control overhead as function of node speed with difference scenarios. Figure 9: Routing delay as a function of node speed with different scenarios. Now, we turn to our attention to security perspective. Figure 11 shows the comparison of the average packet loss ratio Figure 11a and number of packet loss Figure 11b in each session as a function of node speed in km/h, respectively. The average packet loss ratio shown in Figure 11a is defined by the ratio of the number of loss packets to the total number of sent packets. As can observed in Figure 11a, when the node speed increases, the average packet loss ratio is increased. At the same time in Figure 11b, when the node speed increases, the average number of packet loss is increased. One of the possible reasons is that when the node speed increase, the location is changed frequently, which causes the packet to be sent directly to the sinkhole node. However, we can notice that the clustering can reduce the number of links between nodes. Thus, the proposed HPA-SR+ASCS protocol is proved to be secure in terms of network security perspective. Finally, we exploit the impact of the number of nodes on the network metrics. In Figure 12, we evaluate the packet delivery ratio in the effect of the number of node on the proposed routing protocol with the proposed clustering as a function of node speed with a different number of nodes. As we can see in Figure 12, when the node speed is increased, the PDR will decrease a little bit. Besides, when the number of node increases, the PDR will be increased little bit. The reason is that when the number of node increases, the density of network is increased, which provides more strong connectivity between nodes. The HPA-SR+ASCS protocol with number of nodes N = 100 outperforms with the high packet delivery ratio. Figure 11: The comparison of packet loss ratio and number of packet loss as a function of node speed with different scenarios. Figure 12: Packet delivery ratio as function of node speed with different number of nodes. Figure 13 presents the routing delay in the effect of the number of node on the proposed routing protocol with the proposed clustering as a function of node speed with different number of nodes. As can be seen in Figure 13, when the node speed and the number of node increases, the routing delay is increased little bits, but not significantly. It can be explained that when the number of node and speed increased, the number of hop is increased, which causes the routing process to take longer. Figure 14 presents the control overhead as function of node speed with different number of nodes on HPA-SR+ASCS protocol with different number of nodes. As can be observed in Figure 14, when the speed and number of nodes increases, the control overhead is increased. There are two possible reasons as follows. Firstly, when the number of node increases, the density of the network is increased, which leads to the increasing of RREQ and RREP packet transmission frequency. Secondly, when the number of node speed increases, since the node is more easily broken, the control overhead is increased. Figure 14: Control overhead as function of node speed with different number of nodes. Figure 13: Routing delay as a function of node speed with different number of nodes.