## 4 Privacy-Preserving Optimization Based on Advanced CH Selection (P2O-ACH)
### Enhanced ROA-Based CH Selection
According to the analysis, it is understood that the overall packet loss performance of the proposed P2O-ACH is lesser than the other works. The network lifetime of the proposed P2O-ACH varies from 98% to 94%, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, vary from 72% to 65%, 78% to 71%, and 85% to 81%, respectively. In terms of speed variation, the lifetime of the P2O-ACH is reduced by up to 4%, and the performance of the earlier work GWO-CH is reduced by 7%; ACO-SCRS is reduced by 7%; and QMM-VANET is reduced by 5%. From the analysis, it is understood that the network lifetime of the proposed P2O-ACH is superior to the earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET. In Table 10, the performance analysis values of the parameters, such as packet delivery ratio, latency, routing overhead, and throughput, are given. The packet delivery ratio of the proposed P2O-ACH is reduced from 98% to 95%, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, are reduced from 68% to 57%, 73% to 65%, and 88% to 84%, respectively. In terms of speed variation, the packet delivery ratio of the P2O-ACH is reduced up to 3%, and the performance of the \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Parameters** & **Speed (km/h)** & **GWO-CH** & **ACO-SCRS** & **QMM-VANET** & **P2O-ACH** \\ \hline \multirow{6}{*}{\begin{tabular}{c} Packet \\ Delivery Ratio \\ (\%) \\ \end{tabular} } & 10 & 68.16 & 73.19 & 88.14 & 98.15 \\  & 15 & 65.17 & 72.45 & 87.16 & 98.01 \\  & 20 & 62.17 & 71.26 & 86.29 & 97.46 \\  & 25 & 58.29 & 68.46 & 86.11 & 96.17 \\  & 30 & 57.19 & 69.17 & 85.13 & 95.44 \\  & 35 & 57.24 & 65.24 & 84.25 & 95.02 \\ \hline \multirow{6}{*}{\begin{tabular}{c} Latency (ms) \\ 30 \\ 35 \\ \end{tabular} } & 10 & 168.2 & 142.7 & 102.41 & 55.13 \\  & 15 & 171.2 & 145.8 & 114.80 & 72.19 \\  & 20 & 189.2 & 153.2 & 129.76 & 78.14 \\  & 25 & 201.3 & 152.4 & 141.27 & 81.25 \\  & 30 & 221.5 & 164.2 & 145.76 & 85.76 \\  & 35 & 243.6 & 167.2 & 151.23 & 88.76 \\ \hline \multirow{6}{*}{\
\begin{tabular}{c} Overhead \\ (packets) \\ 30 \\ \end{tabular} } & 10 & 1356 & 1243 & 865 & 568 \\  & 15 & 1475 & 1386 & 874 & 567 \\  & 20 & 1538 & 1427 & 892 & 586 \\  & 25 & 1689 & 1628 & 964 & 625 \\  & 30 & 1758 & 1625 & 1028 & 645 \\  & 35 & 1869 & 1689 & 1142 & 692 \\ \hline \multirow{6}{*}{
\begin{tabular}{c} Throughput \\ (Kbps) \\ 30 \\ \end{tabular} } & 10 & 121.3 & 153.4 & 212.45 & 356.2 \\  & 15 & 129.4 & 158.3 & 221.35 & 386.1 \\ \cline{1-1}  & 20 & 136.2 & 161.2 & 235.27 & 425.1 \\ \cline{1-1}  & 25 & 137.1 & 165.2 & 245.69 & 452.1 \\ \cline{1-1}  & 30 & 141.8 & 171.4 & 249.38 & 486.2 \\ \cline{1-1}  & 35 & 156.7 & 175.2 & 259.36 & 489.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Performance Analysis of Packet Delivery Ratio, Latency, Routing Overhead, and Throughput in Terms of Varying Speed. earlier work GWO-CH is reduced by 11%; ACO-SCRS is reduced by 8%; and QMM-VANET is reduced by 5%. From the analysis, it is stated that the packet delivery ratio performance of the proposed P2O-ACH is more improved than the others. The latency of the proposed P2O-ACH increases from 55.13 ms to 88.76 ms, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, increase from 168.24 ms to 243.68 ms, 142.71 ms to 167.28 ms, and 102.41 ms to 151.23 ms, respectively. In terms of speed variation, the latency of the P2O-ACH is increased up to 33 ms, and the performance of the earlier work GWO-CH is increased by 75 ms; ACO-SCRS is increased by 25 ms; and QMM-VANET is increased by 50 ms. According to the analysis, it is understood that the overall latency performance of the proposed P2O-ACH is lesser than the earlier works. The routing overhead of the proposed P2O-ACH increases from 568 packets to 692 packets, whereas earlier works, such as GWO-CH, ACO-SCRS, and QMM-VANET, increase from 1356 packets to 1869 packets, 1243 packets to 1689 packets, and 865 packets to 1142 packets, respectively.