## 4 Performance Evaluation
### Result Analysis of RMF-MVS
It can also be related to the hello message receive rate estimated before selecting an NFV for video transmission. The road vehicle density considered has influenced positively to the performance of the RMF-MVS scheme. The drop in video SSIM index might be due to the large congestion of vehicles interaction in order to transmit video data. Consequently, the result shows that RMF-MVS outperformed the 3 MRP and MSLND in terms of the SSIM index. The percentage gains of the three schemes are 79.1%, 75.8% and 81.1% for 3 MRP, MSLND and, RMF-MVS, respectively. The percentage of performance improvement of RMF-MVS against 3 MRP and MSLND are 2.0% and 5.3%, respectively. Figure 6: Signal to Noise Ratio (PSNR) Results Based on Different (**a**) Number of Vehicles and (**b**) Data Rates. Figure 7b shows that SSIM index has been studied alongside the various transmitted video data rate. The result depicts that the SSIM index of the video increases as the transmitted data rate also increases until when the data rate reaches above 1000 kbps, then the SSIM index start to drop with a small variation. The video SSIM index has maintained above the average value of the SSIM index value. Therefore, the result shows that RMF-MVS outperformed the 3 MRP and MSLND. The percentage gains of the three schemes are 79.6%, 75.01% and 82.5% for 3 MRP, MSLND and RMF-MVS, respectively. The percentage of performance improvement of RMF-MVS against 3 MRP and MSLND are 2.9% and 7.5%, respectively. Figure 8a shows that both the MSLND and RMF-MVS have lower delay compared to the 3 MRP. The E2 ED has been plotted alongside various vehicle densities. The delay experienced in 3 MRP might be related to the building obstruction detection tool incorporated into the video transmission scheme. While the MSLND also encountered some amount of delay, it is lower than that of 3 MRP. The reason for delay encountered in MSLND is due to the TCP transmission protocols that are employed, which requires acknowledgement of video packet received. However, the RMF-MVS outperformed the 3 MRP scheme because the RMF-MVS continues transmission via the selected RVN and NFV except if the vehicle is no more in the neighborhood of the PFV. The UDP employed does not requires acknowledgement, thus makes transmission faster. The percentage delay encountered is calculated based on the maximally allowable delay of 5 s. Thus, RMF-MVS, 3 MRP and MSLND schemes have 3.8%, 15.9% and 6.4% as their performance, respectively. The percentage of performance improvement of RMF-MVS against 3 MRP and MSLND are 12.1% and 2.6%, respectively. Figure 8: Delay (E2 ED) Results Based on Different Number of (**a**) Vehicles and (**b**) Data Rates. Figure 7: Structural SIMilarity (SSIM) index Results Based on Different Number of (**a**) Vehicles and (**b**) Data Rates. Figure 8 depicts that RMF-MVS has the lowest delay compared to both the 3 MRP and MSLND. The E2 ED has been plotted alongside different data rates. The delay experienced in 3 MRP might be connected to the high data rate transmitted, which causes queuing of video packets at the transmitting vehicle. In addition, the obstruction detection mechanism might also increase the transmission delay. The MSLND also has lower delay compared to that of 3 MRP. However, the RMF-MVS outperforms the 3 MRP scheme because the RMF-MVS estimates the advancement and road density of the C-NFV towards the DVN. The hello message receive rate of the C-NFV can also influence positively to the total delay encountered during transmission. The percentage delay encountered is estimated based on the maximally allowable delay of 5 s. Thus, RMF-MVS, 3 MRP and MSLND schemes have 5.2%, 17.1% and 7.1%, respectively. The percentage of performance improvement of RMF-MVS against 3 MRP and MSLND are 11.9% and 1.9%, respectively.