## 4 Privacy-Preserving Optimization Based on Advanced CH Selection (P2O-ACH)
### Enhanced ROA-Based CH Selection
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**S. No** & **GWO-CH** & **ACO-SCRS** &
\begin{tabular}{c} **QMM-** \\ **VANET** \\ \end{tabular} & **P2O-ACH** \\ \hline Energy Efficiency & 357 Joules & 598 Joules & 657 Joules & 864 Joules \\ Energy Consumption & 658 Joules & 486 Joules & 358 Joules & 157 Joules \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Performance Values of Energy Efficiency and Energy Consumption of the Network. Figure 2: Energy Efficiency Calculation. lower than earlier works where the consumption of the P2O-ACH is 157 Joules and the consumption of the GWO-CH, ACO-SCRS, and QMM-VANET is 658 Joules, 486 Joules, and 358 Joules, respectively. In the proposed P2O-ACH method, advanced CH selection is done using a rider optimization algorithm, especially to reduce the energy consumption of the network. The network becomes more stable with the help of this CH selection process. In Figure 4, the pictorial representation of the calculation packet loss is shown where the performance of the proposed P2O-ACH is compared with the earlier approaches. With the use of the enhanced ROA method privacy-preserving mobility model, congestion of the network is reduced and security is improved, which leads to the reduction of the packet loss in the network. From the results, it is proven that the proposed P2O-ACH generates very low packet loss when compared with the others. In the proposed P2O-ACH method, the concept of a privacy-preserving mobility model is used that works on the fusion of nodes and the node migration process. In a maximum of the cases, the packet loss will occur during grouping and migration. This mobility pattern creates a stable grouping and migration; this leads to reducing the loss of packets in the network. In Figure 5, the lifetime of the network is calculated. Hence, our method achieves high energy efficiency, which automatically reflects in the generation of a higher lifetime. This is achieved with the help of the stable and optimized cluster head selection process where energy consumption is reduced during the process of communication in the network, which increased efficiency and lifetime. In Table 6, the simulation result values of packet loss and network lifetime are given. The values stated in Table 6 prove that the lifetime achieved by the proposed P2O-ACH is better than earlier works where the lifetime of the P2O-ACH is 97.46% and the lifetimes of the GWO-CH, ACO-SCRS, and QMM-VANET are 65.22%, 71.86%, and 85.47%, respectively. The proposed P2O-ACH method achieved around 10% to 30% more life time by using the rider optimization-based CH selection process. Hence, firmer and more effective CH is created, which helps communication with minimum utilization of energy. Then, the packet loss of the proposed P2O-ACH is lower than earlier works where the packet loss of the P2O-ACH is 458 packets and the packet losses of the GWO-CH, ACO-SCRS, and QMM-VANET are 1578 packets, 1248 packets, and 867 packets, respectively. The proposed method works with an effective mobility pattern where the grouping and migration of the vehicle are processed stably. This reduces the packet loss of the network, which amounts to 400 packets to 1000 packets lower than the earlier works. From Figure 6, the graphical representation of the packet delivery ratio calculation of the proposed P2O-ACH is given and it is compared with the earlier approaches. The packet delivery ratio is one of the core parameters which decide the quality of the network. Figure 4: Packet Loss Calculation. The proposed P2O-ACH has a higher packet delivery ratio when compared with the earlier works. Lower packet loss reflects an increase in the packet delivery ratio of the network. In the proposed P2O-ACH method, the packet loss is very low using the mobility patterns that lead to improving the packet delivery ratio. In Figure 7, the latency is calculated, which is defined as the overall delay time of the network. In Table 7, the simulation result values of packet delivery ratio and latency are given.