## 5 RC-LARR: RSU-Assisted Cloud-Based Location-Aware Hybrid Routing
### Route Discovery
This study first investigated the influence of range, PDR, and EED on the proposed protocol. Subsequently, the link's reliability was examined under different speed conditions, providing valuable insights into its adaptability. Additionally, the analysis included an evaluation of crucial metrics such as PDR, EED, and the handling capability of the traffic density. The PDR is computed as the ratio of the number of packets received to the total number of packets. The results are shown in Fig. 13. \begin{table}
\begin{tabular}{l l} \hline \hline
**Parameters** & **Setting Value** \\ \hline Simulated environment size & 3800 m \(\times\) 3200 m \\ MAC protocol & IEEE 802.11p \\ Transmission range & 260–320 m \\ Transmission rate range & 1–12 Mbps \\ Controller & OpenFlow \\ Speed range & 20–80 km/h \\ Hello packet cycle & 50 ms \\ Simulation time & 200 s \\ Number of nodes & 50 nodes \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Simulation parameter settings. Figure 13: (**a**) Mininet Wi-Fi topology used for the simulation. (**b**) SUMO map used for the simulation. packets transmitted. The average amount of time that passes between when a packet is sent from its source node and when it arrives at its destination node is referred to as the EED. The proposed routing protocol was also assessed based on traffic density and load on the RSU and cloud for route finding. The proposed routing protocol was compared with GPSR and OPBR. ### Packet Delivery Ratio Analysis

Figure 14 depicts the variations in the packet delivery ratio in relation to the speed of the vehicle. It may be deduced from the fact that the speed of the vehicle influences the transfer of data packets. A change in the speed of the vehicle at a specific point in time influences the selection of the packet's next relay node, which will, in turn, affect the delivery ratio of the packets. The SDN controller in RC-LAHR determines the route. The route determination is performed using the location of the vehicles and the priority zone. Hence, there is less possibility of route disconnection, which leads to a higher PDR. It is observed from Figure 14 that the average PDR of RC-LAHR is better in comparison with the GPSR and OPBR. The expansion of the communication range led to an increase in the total packet delivery ratio. This may be considered a positive development. Within the context of this simulation scenario, the maximum permissible speed for the vehicles is 40 km/h. There is the possibility of additional nodes being joined because of the vehicle communication range. Figure 15 clearly shows that the PDR is better when the communication range is increased. The analysis of PDR vs. communication range is necessary for the further analysis of the network, like network density and EED. Figure 14: Average packet delivery ratio vs. vehicle speed. Figure 15: Packet delivery ratio vs. communication range. Figure 16 depicts a range of different packet transfer rates vs. the percentage of packets that are successfully delivered to their intended destinations. When there is a rise in the packet rate, also known as the number of data packets per second, there is a probability that there will also be an increase in the packet delivery ratio initially. However, if the pace at which the packets are sent remains high, the capacity of the network's communication channels will be depleted, and the proportion of packets that are successfully delivered will either stay the same or decrease. Figure 16 clearly shows that RC-LAHR performs better than the other protocols. ### End-to-End Delay Analysis

The end-to-end delay time is the time taken for a data packet to travel from its source to its destination across the network. In RC-LAHR, the next hop is calculated based on the priority zone. The vehicle available in a higher priority zone is selected for the next hop. Hence, the proposed routing approach always selects the route that has the minimum number of hops, which results in a consistently low amount of delay.