# Video Streaming in Urban Vehicular Environments: Junction-Aware Multipath Approach
## 4 Performance Evaluation
\begin{table}
\begin{tabular}{c c} \hline \hline
**I. Parameters** & **II. Values** \\ \hline III. Urban simulation area & IV. 1000 \(\times\) 1000 m\({}^{2}\) \\ \hline V. Simulation time & VI. 600 s \\ \hline VII. Vehicle speed & VIII. 2.78 to 13.89 m/s (10 to 50 km/h) \\ \hline IX. Number of vehicles & X. 50 to 500 \\ \hline XI. MAC protocol & XII. IEEE 802.11p \\ \hline XIII. Video resolution & XIV. 352 \(\times\) 288 \\ \hline XV. Video play duration & XVI. 139 s \\ \hline XVII. Transmission range & XVIII. 250 m \\ \hline XIX. Frequency Bandwidth & XX. 5.9 GHz \\ \hline XXI. Propagation model & XXII. Shadowing \\ \hline XXIII. Antenna model & XXIV. Omni-directional \\ \hline XXV. Traffic type & XXVI. Constant Bit Rate \\ \hline XXVII. Channel type & XXVIII. Wireless \\ \hline XXIX. Transmission Protocol & XXX. UDP \\ \hline XXXI. Hello packet timeout & XXXII. 1 s \\ \hline XXXIII. Scenarios & XXXIV. High-density urban scenario \\ \hline XXXV. Comparison protocol & XXXVI. JMSR and AMVT \\ \hline XXXVII. Metrics & XXXVIII. PLR, SSIM index and E2 ED \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Simulation parameters. JMSR: Junction-Based Multipath Source Routing; AMVT: Adaptive Multipath geographic routing for Video Transmission; PLR: Packet Loss Rate; SSIM: Structural Similarity Index; E2 ED: End-to-End Delay. of 50-500 vehicles against the JMSR scheme is 12.9% and that against the AMVT scheme is 11%. Hence, the proposed JA-MVS performs better in terms of the video packet loss ratio. Figure 5b depicts the results of the PLR studied alongside the various transmitted data rates. The results show that the packet loss ratio increases as the data rate increases. At 160 to 320 kbps, there is no loss of video packetw experienced; however, a packet loss starts to manifest when the data rate is 400 kbps. The packet loss increases above 30% for JMSR and AMVT schemes as the data rate increases. However, the highest packet loss experienced for the proposed JA-MVS scheme is 5.5% when the data rate is at 1600 kbps. Therefore, the JA-MVS outperforms the two baseline schemes. The better performance achieved by the proposed scheme is related to the reliable selection of NFV based on the direction and position of the C-NFV at the junctions of the road. The aforementioned considered parameters have helped in attaining successful video packet delivery with fewer packet losses. The average percentage gains of the three schemes are 15.4%, 15.5% and 2.1% for JMSR, AMVT, and JA-MVS, respectively. The average percentage gains of the performance of JA-MVS against JMSR and AMVT are 13.3% and 13.4%, respectively. The SSIM is measured as a value between 0 and 1; the results are presented in Figure 6a,b accordingly. Figure 6a depicts the results obtained based on the SSIM index of the video transmission in relation to various vehicle densities. Based on the results obtained, the SSIM index increases gradually for both the three schemes as the vehicle density increases. The highest video SSIM index values were observed when the vehicle density is between 300 and 350. For the JMSR scheme, the SSIM index increases gradually until it starts to decline when the vehicle density is above 350; however, despite the fall in the video quality, the result is above the average value of the SSIM index of 0.5. Further, the SSIM index of the AMVT scheme also gradually increases as the number of vehicles increases; the increase almost became static with a small increase when the number of vehicles was 200 to 500. The SSIM index of the proposed JA-MVS scheme increases based on the increase in vehicle density. The proposed JA-MVS scheme performs better than the two baseline schemes in terms of the SSIM index. The observed increase in the SSIM index is connected to the approach used for the selection of the NFV in the junction area of the road. This approach avoids the drop of video packets because vehicles that are not moving towards the DVN and that do not have the required link quality are not considered.