## 4 Privacy-Preserving Optimization Based on Advanced CH Selection (P2O-ACH)
### Enhanced ROA-Based CH Selection
Discussion Performance Analysis Based on the Number of Vehicles

The major conceptual concentration of the proposed P2O-ACH method is the creation of advanced CH selection with rider optimization algorithm and security-based privacy-preserving mobility pattern generation. Due to this, we can increase the efficiency, throughput, and packet delivery ratio, whilst likewise reducing the latency, overhead, and packet loss. Because the major drawbacks identified from the earlier works are, in the GWO-CH method, energy efficiency and the lifetime are moderate, in ACO-SCRS, the overhead is high and throughput is low, and in QMM-VANET the throughput is low. These are the major drawbacks of the earlier works. The parameters that are used for performance analysis of the proposed research are energy efficiency, energy consumption, packet loss, network lifetime, packet delivery ratio, latency, routing overhead, and throughput. According to these parameters, the proposed P2O-ACH is compared with earlier works. Some of the common drawbacks which are identified in this earlier work are low throughput, low efficiency, high congestion, overhead, and delay. So to overcome these drawbacks in the proposed P2O-ACH, CH selection, optimization, and secured mobility models are constructed. Due to ROA optimization-based clustering in the proposed method, network efficiency reached up to 864 Joules, whereas the earlier work reached up to 650 Joules at maximum. The network energy consumption is reduced up to 157 Joules, whereas the earlier works range from 358 Joules to 658 Joules. By the use of ROA optimization, congestion is reduced, which reduced the packet loss and routing overhead of the network. The packet loss of the proposed P2O-ACH is 458 packets, whereas the earlier work ranged from 867 packets to 1578 packets. The routing overhead of the proposed P2O-ACH is 2547 packets, whereas the earlier work ranged from 3467 packets to 7658 packets. Similarly, by using the secured mobility model, the parameters which are improved are packet delivery ratio, throughput, and latency. The packet delivery ratio of the proposed P2O-ACH is 95.13%, whereas the earlier work ranges from 75.12% to 89.46%. The throughput achieved by the proposed P2O-ACH is 1047.467 Kbps, whereas the earlier work ranges from 301.124 Kbps to 857.845 Kbps. The latency produced by P2O-ACH is 253.79 ms, whereas the earlier work ranges from 502.48 ms to 681.92 ms. Finally, by analyzing all the parameters, it is understood that our proposed P2O-ACH outperforms the earlier methods in many cases. ### Performance Analysis Based on Speed

In Figure 10, the graphical representation of energy efficiency calculation is performed. The results show that the proposed P2O-ACH outperforms when compared with the earlier works in terms of energy efficiency. It is achieved by using the optimization-based CH selection process. Figure 10: Energy Efficiency Calculation. The consumption of energy is highly reduced using this method. This leads to an increase in the energy efficiency. The graphical representation for the calculation of energy consumption is shown in Figure 11, but according to speed variation, it is understood that an increase in speed reduces efficiency and increases the energy consumption of the network. In Figure 12, the packet loss is shown, where the performance of the proposed P2O-ACH is compared with the earlier approaches, such as GWO-CH, ACO-SCRS, and QMM-VANET. In the proposed P2O-ACH, congestion control is properly done, which helps to reduce packet loss compared to the earlier methods. Meanwhile, from the figure, it is understood that, according to the increase in speed, packet loss also increased. In Figure 13, the lifetime of the network is calculated. The network lifetime is high when compared with the earlier methods, such as GWO-CH, ACO-SCRS, and QMM-VANET; however, according to the increase in speed, the lifetime of the network is reduced. Figure 11: Energy Consumption Calculation. Figure 12: Packet Loss Calculation.