## 4 Simulation and Performance Analysis
### Performance Analysis
evaluate the performance of EGR. In this simulation, geometrical localization for GSP outage is used with EGR. According to the result shown in Figure 11, the end-to-end delay for the EGR approach is approximately 4 ms for vehicle velocity between 10 and 40 km/h. Additionally, EGR considerably reduces end to end delay compared with the other routing approaches considered in this simulation. At a velocity greater than 40 km/h, the delay for both EGR and SLD-GEDIR is increasing with a higher rate, but the rate of increment is higher for SLD-GEDIR. This can be due to the forwarding vehicle selection procedure in EGR being done based on the most reliable link and also being made clear in favor of the most likely direction of the destination. At a velocity greater than 20 km/h, J-GEDIR and P-GEDIR performance begins to deteriorate. This is due to the fact that P-GEDIR chooses boundary vehicles as the forwarder, and J-GEDIR chooses the vehicles from the furthest junctions. The boundary and farthest crossing vehicles are sometimes sensitive to link failure because of the frequent movement of the traffic environment. The proposed EGR gives an average of 25% lower end-to-end delay compared to SLD-GEDIR, wherein the end-to-end delay for EGR is about 60% to 70% lower than that of J-GEDIR and P-GEDIR, respectively. Thus, when compared to state-of-the-art routing approaches, the proposed EGR performs better. In Figure 12, the findings demonstrate a throughput comparison between EGR and other procedures, taking into account variable velocity. The findings show that, when vehicle velocity increases, the throughput of EGR linearly decreases. The throughput for the existing routing approaches, however, dramatically drops. For example, the throughput values of J-GEDIR, P-GEDIR, SLD-GEDIR, and EGR at a vehicle velocity of 20 Km/h are 150 Kbps, 163 Kbps, 256 Kbps, and 265 Kbps, respectively; when the velocity increases to 40 Km/h, the throughput values decreased to 23 Kbps, 28 Kbps, 176 Kbps, and 231 Kbps respectively. This can be linked to the fact that, due to the high rate of link breakage with increased vehicle speed, modern protocols must frequently re-discover one-hop links. The link chosen by EGR is based on a temporal transmission probability and a residual link lifetime that increases its reliability. As a result, EGR consistently performs better than the existing routing approaches considered in this simulation. Figure 11: Effect of velocity on end-to-end delay. Figure 13 compares the results of one-hop link disconnection between EGR and contemporary routing approaches. It is evident that one-hop link disconnection for EGR is minimal compared to other contemporary routing approaches for velocities between 10 and 60 km/h. It is because the most reliable link for the transmission of information between the sender vehicle and the farthest forwarding vehicle is picked. However, at speeds over 40 km/h, one-hop link disconnections abruptly increase, since the forwarding vehicle selection process could not be finished in the residual link lifetime time in both EGR and SLD-GEDIR. In comparison to J-GEDIR and P-GEDIR, both EGR and SLD-GEDIR perform the best in relation to the quantity of one-hop link disconnections. However, it is lower for EGR compared with SLD-GEDIR. Because the forwarding technique employed in J-GEDIR and P-GEDIR does not take velocity information into account in NHV selection, one-hop link disconnections in P-GEDIR and J-GEDIR are experienced rapidly above a velocity of 20 Km/h. Due to its higher number of hops between the source and destination regions, for the proposed EGR, the average rate of one-hop link disconnection is about 5%, whereas it is about 8% for SLD-GEDIR, and it ranges from 40% to 50% for the rest of the J-GEDIR and P-GEDIR contemporary routing approaches. Thus, EGR performs better than the compared contemporary routing approaches.