## 4 Privacy-Preserving Optimization Based on Advanced CH Selection (P2O-ACH)
### Enhanced ROA-Based CH Selection
In Figure 14, 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 of the proposed P2O-ACH is high because, here, optimization-based CH selection is done and the privacy-preserving mobility pattern is initiated, which helps to increase the packet delivery ratio of the P2O-ACH compared to the earlier works, but due to the increase in speed, the packet delivery ratio is slightly reduced. In Figure 15, the latency of the proposed P2O-ACH is the calculation and it is compared with the earlier works. The proposed P2O-ACH is highly concerned with reducing the congestion in the network, which reflects in the reduction of latency when compared with the earlier works, but according to the increase of speed the latency is also increased. In Figure 16, the routing overhead of the network is calculated. Hence, by using the enhanced ROA-based CH selection in the proposed P2O-ACH, energy consumption of the network is reduced, which reflects in the reduction of the routing overhead in the network. According to the varying speed, if the speed increases that will increase the overhead, comparatively. Figure 14: Packet Delivery Ratio Calculation. Figure 13: Network Lifetime Calculation. In Figure 17, the throughput of the proposed P2O-ACH is calculated and then compared with the earlier works. The throughput performance of the proposed work is high when compared with the earlier works. According to the varying speed, the throughput of the proposed is maintained. That leads to an increase in the performance of the network. Results Discussion

The parameters that are calculated according to the varying speed are energy efficiency, energy consumption, packet loss, network lifetime, packet delivery ratio, latency, routing overhead, and throughput. In Table 9, the performance analysis values of the parameters, such as energy efficiency, energy consumption, packet loss, and network lifetime, are given. Figure 16: Routing Overhead Calculation. Figure 15: Latency Calculation. The energy efficiency of the proposed P2O-ACH varies from 97% to 91%, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, vary from 73% to 55%, 75% to 62%, and 88% to 78%, respectively. In terms of speed variation, the efficiency of the P2O-ACH is reduced by up to 6%, and the performance of the earlier work GWO-CH reduced by 18%; ACO-SCRS reduced by 13%; and QMM-VANET reduced by 10%. Finally, according to the analysis, it is understood that the overall energy efficiency performance of the proposed P2O-ACH is more improved than the others. The energy consumption of the proposed P2O-ACH increases from 8% to 22%, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, increase from 18% to 48%,

Figure 17: Network Throughput Calculation. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Parameters** & **Speed (m/s)** & **GWO-CH** & **ACO-SCRS** & **QMM-VANET** & **P2O-ACH** \\ \hline  & 10 & 72.86 & 75.16 & 88.18 & 97.17 \\  & 15 & 68.17 & 72.18 & 87.35 & 96.35 \\ Energy & 20 & 65.17 & 71.96 & 86.89 & 95.92 \\ Efficiency (\%)



15% to 41%, and 11% to 33%, respectively. In terms of speed variation, the consumption of the P2O-ACH increased by up to 14%, and the performance of the earlier work GWO-CH increased by 30%; ACO-SCRS increased by 26%; and QMM-VANET increased by 20%. According to the analysis, it is understood that the overall energy consumption performance of the proposed P2O-ACH is reduced compared to the existing works. The packet loss of the proposed P2O-ACH increases from 86 packets to 182 packets, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, increase from 169 packets to 359 packets, 153 packets to 350 packets, and 125 packets to 287 packets, respectively. In terms of speed variation, the packet loss of the P2O-ACH is increased by up to 100 packets, and the performance of the earlier work GWO-CH increased by 250 packets; ACO-SCRS increased by 200 packets; and QMM-VANET increased by 150 packets.