# Adaptive QoS-Aware Multi-Metrics Gateway Selection Scheme for Heterogenous Vehicular Network +
## 5 Results and Discussions
### Evaluation of Fixed Vehicle Applications versus Number of Vehicles
The graph indicates that as the number of vehicles rose, so did the network's overall throughput. The throughput reported for the AQAGS scheme with VoIP traffic in the sparse area (i.e., 50 vehicles) was 60.86 kbps, but when the number of vehicles was increased to 500, the throughput increased to 187.18 kbps. Compared with the CMGM and Adroit schemes, this increase is higher than the two by 28.9% and 23.73%, respectively. This is because, in the case of VoIP, the communication between the vehicles and LTE-eNBs is simple and seamless, ensuring that the packets arrive at the infrastructure safely. In addition, using a direct connection to the LTE network results in less packet loss. All network throughput requirements are met by the LTE network. As more vehicles with lower packet loss rates increase throughput, the conclusion becomes apparent. Additionally, when a VoIP application is used in CMGM compared with Adroit, CMGM exhibited the lowest throughput value. When compared with Adroit, CMGM's throughput on average was 9.83% lower. However, as the number of vehicles rose, the throughput of CMGM and Adroit correspondingly rose. This is because more vehicles increase the likelihood that a broken link will be repaired, improving the network throughput. However, despite the small number of vehicles, the AQAGS FTP traffic showed a lower throughput of 150.32 kbps, which was 60 kbps and 20 kbps slower than the CMGM and Adroit algorithms. When the number of vehicles rose, the throughput for all three schemes increased. However, AQAGS with FTP reported 429.32 kbps at the interval of 500 vehicles. In comparison to the cluster-based CMGM scheme and the non-cluster-based Adroit scheme, this value was 100 kbps and 29 kbps higher, respectively. This is explained by the fact that more potential MGWs are needed as the number of vehicles increases to support the IV in a streamlined fusion. CMGM, on the other hand, requires the formation of clusters before the MGW is chosen; the VANET's overall throughput is impacted by this. Adroit had a throughput of 130.32 kbps in the sparse network, which was 40 kbps more than recorded for CMGM. Since there are fewer vehicles, the interconnection time between them is shorter, which frequently leads to link failure, many packets being dropped, and a reduction in the overall network throughput. Furthermore, even though CMGM's throughput increased to 319.32 kbps at 500 vehicles, it was still 81 kbps slower than Adroit's number at the same interval. Figure 7a illustrates how the delay constraints between the measured applications were met. VoIP applications need a delay of no more than 100 ms, according to Table 1. The figure depicts that the AQAGS scheme maintained the VoIP applications' required delay in both sparse and dense scenarios. In both instances, the average delay observed was less than 0.1 s (100 ms), which is the average delay cost designated for VoIP applications. For the CMGM and Adroit schemes, this was not the case. The delay requirements of VoIP applications were never satisfied by either of these schemes in a variety of tested vehicle numbers. When the vehicle number increased from 50 to 500, the CMGM average delay rose from 0.14 s to 0.63 s. With respect to VoIP application, this increase was 4.75% higher than in the Adroit scheme. This is reasonable, given that the CMGM cluster density rises with the number of vehicles. The overloading condition in the chosen MGW occurs as a result. In the MGW buffer, an overload causes a longer queue delay, which in turn raises the average packet delay. Additionally, the figure for the FTP application demonstrates that during peak hours, the delay of AQAGS in the FTP application increased to 0.53 s (i.e., 500 vehicles). This delay exceeded the average delays demonstrated by CMGM and Adroit, respectively, by 26% and 14%. Only when there were fewer than 250 vehicles and a total delay of less than 300 ms does AQAGS provide FTP QoS. However, as the number of vehicles increased, the delay increased as well, making it harder to maintain the required QoS.