# UAV-Assisted Hybrid Scheme for Urban Road Safety Based on VANETs
## 4 Experiments
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Value** & **Unit** \\ \hline Simulation Area & 9000 \(\times\) 4000 & m\({}^{2}\) \\ Road Intersection Number & 20 & - \\ Road Segments Number & 46 & - \\ Vehicular Speed Limits & 0–40 & km/h \\ UAV Speed Limits & 0–60 & Km/h \\ RSUs Number & 15 & - \\ RSUs Transmission Range & 200 & m \\ Vehicle Number & 0–106 & - \\ UAV Number & 0–4 & - \\ UAVs Transmission Range & 300 & m \\ Transport Layer & TCP, UDP & - \\ Channel Capacity & 6 & Mbps \\ Packet Size & 512 & bytes \\ Packet Type & CBR & - \\ Node Energy & 300 & joule \\ Simulation Run Time & 180 & s \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Simulation parameters. Average throughput: Represents the average rate of successfully receiving packets \(Rp\) over a communication channel from stop time Tsp to start time Ts. \[\textit{Average throughput}\ =\ \frac{Rp}{\mathrm{Tsp-Ts}}\ \times\frac{8}{100}\ ( \mathrm{in\ kbps}) \tag{1}\]  
Instant throughput: Represents the packets received successfully at the current time and packet size R (Receive packets \(Rp\) + Receive packet size Rz) over a communication channel, where time is T, current time Tcs, and previous Time Tps. \[\textit{Instant throughput}\ =\ \frac{\mathrm{R}}{\mathrm{Tcs}\ +\ (\mathrm{T-Tps})}\ \times\ \frac{8}{100}\ ( \mathrm{in\ kbps}) \tag{2}\]  
Packet Delivery Ratio (PDR): Represents the fraction of the data packets delivered from the source nodes to the destination nodes over a communication channel, where \(Rp\) is the receive packets, and \(Rs\) is the sent packets n represents the number of sensor nodes. \[\textit{Packet Delivery Ratio}\ (\textit{PDR})\ =\ \frac{Rp}{\sum_{\mathrm{i}=1}^{n}Rs}\ \times 100 \tag{3}\]  
Residual Energy: Represents the remaining node energy, where \(E\) is the total node energy and overall energy consumption \(Ec\) by a node. \[\textit{Residual energy}\ =\ E-Ec\ (\mathrm{in\ joule}) \tag{4}\]  
End-to-End Delay: Represents the average value of all successfully received packets delay \(Dn\) and receive packet \(Rp\), the total number of nodes n.  
\[\textit{End-to-End delay}\ =\ \frac{\sum_{\mathrm{n}=1}^{Rp}Dn}{Rp} \tag{5}\]  
Experimental Result Analysis:  
In this sub-section we will present our experimental results and its analysis. Average Throughput:  
The average throughput is shown in Figure 5, with traditional AODV and our proposed UAVa protocol. For both UAVa and AODV protocols, start time is 0 s, stop time is 179 s, UAVa's received packets are 95,331, and AODV's received packets are 90,148, average throughput for UAVa is 4.237 kbps, and for AODV is 4.010 kbps. The UAVa performed better than the AODV, which is reasonably justified. 2. Instant Throughput:  
Figure 6 compares instant throughput with a different time periods of simulations for UAVa and AODV protocols. We can consider along with the different time periods, the instant throughput is changed, and for AODV protocol it is changed rapidly, but for the UAVa protocol, it is changed a bit, so we can say that UAVa protocol has performed better than AODV protocol for instant throughput measured in kbps for each case. Figure 5: Average throughput. Figure 6: Instant throughput.