## 5 Result Analysis  
In this section, the suggested scheme's performance is explained. The total packet delivery cost for intra-domain and inter-domain handover for VANET in PMIPv6 with the IP multicasting approach and without multicasting is analyzed. The total cost relies on several components, including the binding update, the authentication of network entities such as the LMA/MGA along with vehicles, and the packet delivery costs, as described in the previous section. By assessing the impact on the total cost of packet delivery by varying the number of parameters, such as the MAGs present in the PMIPv6 domain, and the unit transmission cost for wired and wireless links, the setup time cost is observed. This part also includes a comparison study of the factors under consideration with and without the use of IP multicasting of authentication information in intra-domain handover, as well analyzing the total cost in the inter-domain handover for VANET in the proposed architecture. The different parameter values [19] used in analyzing the cost are listed in Table 2.  
To establish a communication link, we require a wired and wireless connection that involves a fixed setup cost associated with it. Due to the unreliability of wireless connectivity, the setup time for the communication channel is longer in wireless connection. The setup cost has a significant impact on the total packet delivery cost. The effect of varying the setup cost on the overall costs of the suggested architecture, i.e., IP multicasting, and without multicasting, is shown in Figure 6. We estimated the total cost for both the suggested architecture that makes use of IP multicasting and PMIPv6 without multicasting, by varying the setup cost ranging from 100 to 500. When the setup costs vary at 100, 200, and 500, and with the increase in the number of vehicles from 100 to 1000, the total cost marginally increases for the proposed scheme as compared to the PMIPv6 approach of intra-domain handoff. The setup cost and the number of vehicles have no bearing on the final cost when the multicasting of authentication information is taken into account. Due to the proposed architecture, the security is enhanced as authentication is used during intra-domain handoff, and the proposed architecture is able to provide inter-domain handoff by using the IP multicasting scheme. Figure 7 shows the impact of changes in traffic density and unit transmission cost on the wired link. The total cost for the intra-domain handoff of a vehicle in PMIPv6 increases proportionally to an increase in the wired link's packet's unit transmission cost, \(\tau\), from 1 to 10, with IP multicasting and without multicasting. As the unit transmission cost, \(\tau\), i.e., the number of hops, increases from 1 to 10, the total cost increases linearly in proportion. Regarding the impact on the total cost calculated with the proposed architecture, and when it is compared with the total cost without multicasting in PMIPv6, we observed very slight  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Variable Used** & **Default Value** & **Minimum** & **Maximum** \\ \hline Tsetup(ms) & 200 & 100 & 500 \\ NUHAMG & 200 & 100 & 1000 \\ \(N_{\text{MAG}}/\text{LMA1}\) & 20 & 10 & 200 \\ NMOG/LMA2 & 30 & 10 & 300 \\ NMAG/LMA3 & 50 & 10 & 500 \\ TMAG-LMA/HMAG-LMA & 20 & 10 & 10  
variation, which can be considered negligible on account of the authentication achieved during the intra-domain handover of the vehicle. Figure 8 illustrates the effect of changing the unit transmission cost on the wireless link in the intra-domain handoff of a vehicle on PMIPv6 with the proposed scheme, as compared to intra-domain handoff in the traditional PMIPv6. We know that as the wireless link delay increases, there is more interference in the wireless channel, and the performance quality of PMIPv6 degrades. The increased latency in the wireless area has little impact on the suggested architecture because PMIPv6 is used.