# Adaptive QoS-Aware Multi-Metrics Gateway Selection Scheme for Heterogenous Vehicular Network +
## 5 Results and Discussions
### Evaluation of Mixed Vehicle Applications versus Number of Vehicles  
The proposed AQAGS scheme's performance was assessed and benchmarked in this scenario with CMGM [22] and Adroit [28]. MT was used for each tested scheme. The number of vehicles varied from 50 to 500 and the speed of the vehicles was kept to 60 km/h. Figure 8a demonstrates that as the number of vehicles rose, the PDR for all three algorithms fell. However, the PDR of AQAGS at non-peak hours was 99.45%, which was higher than that of CMGM and Adroit algorithms by 23.45% and 3.45%, respectively. However, during peak hours, i.e., when there were 500 vehicles on the road, the AQGS scheme also performed better than its rival algorithms by 45.01 and 16.01%, respectively. In the execution of the gateway discovery and selection processes, neither of the other benchmarked algorithms took the density of vehicles into account. As a result, even though there were few vehicles, the CMGM and Adroit schemes chose to use the MGW as a relay to the infrastructure, which increased packet loss and had an impact on the PDR. The percentage of the PDR expressed by the CMGM and Adroit algorithms during non-peak  
Figure 7: Evaluation of fixed vehicle applications (FTP vs. VoIP) vs. the number of vehicles: (**a**) the number of vehicles vs. average delay; (**b**) the number of vehicles vs. the CPO. hours (i.e., 50 vehicles), which were 76.12% and 96.23%, respectively, serve as evidence of this phenomenon. For the AQAGS scheme, the MGW selection only happens during times of high vehicle traffic (peak hours) and when delay-tolerant software is being used. As a result, the PDR increases because the vehicles have a direct, seamless connection to the LTE network, which lowers packet loss and increases the PDR. When there are more than 500 vehicles, AQAGS, CMGM, and Adroit report 95.01%, 50.22%, and 79.23% PDRs, respectively. The AQAGS scheme performed better than CMGM and Adroit overall by 33.01% and 9.6%, respectively. Figure 8b shows an evaluation of the three implemented algorithms' throughputs with the varying vehicle counts. The findings show that the throughput increased as the number of vehicles rose. This is because there are more potential gateways that can serve the IV as the number of vehicles rises. Additionally, as the number of vehicles rises, it becomes simpler to repair the IV and MGW's broken links, improving the overall throughput. The AQAGS scheme outperforms CMGM and Adroit in terms of throughput by 27.8% and 19.32%, respectively. This is a result of AQAGS's noteworthy performance in both sparse and dense areas, where the decision to execute the gateway discovery and selection depends on the vehicle density. All three mechanisms had similar throughput for a small number of vehicles, but the AQAGS algorithm had a throughput of 36.28 kbps and increased to 349.16 kbps when there were 500 vehicles. When compared with the CMGM scheme, the Adroit scheme shows a throughput improvement of 10.52%. The CMGM scheme performed less well than the other two algorithms as it groups the vehicles into clusters. When there are few clusters with insufficiently accessible MGWs, there is a chance that the chosen MGW will be overloaded with IV packets, some of which will be discarded and ultimately impact the throughput value. The CMGM algorithm reported 30.12 kbps and 298.25 kbps for the low and high vehicle numbers, respectively. In addition, we examined how much more delayed the AQAGS scheme was on average compared with the CMGM and Adroit schemes. Figure 9a demonstrates how the AQAGS scheme provided the QoS requirement for VoIP and FTP applications for a wide range of vehicle numbers between 50 and 400. According to [48], the required delay for both VoIP and FTP applications is less than 0.1 s (i.e., 100 ms), and this range's average reported delay falls under that threshold. Only the FTP application delay requirement, which must be under 0.3 s, is guaranteed for fleets of more than 400 vehicles (300 ms). Regardless, as the number of vehicles rose, the average delay did as well.