# Performance Evaluation of Multi-UAV Network Applied to Scanning Rocket Impact Area +
## 6 Results
### Experimental Results
#### 6.3.2 Scenario 2  
In scenario 2, three different configurations were set to evaluate the performance:  
* first case: the peer-to-peer transmission between ED and BS was performed, shown in Figure 14a. There was no packet hop through a multi-hop network. The distance between ED and BS nodes was less than 800 m.
* second case: the transmission was carried out with a hop through a hub. The position of the nodes was the same as that in scenario 1, shown in Figure 13.
* third case: the configuration was the same as that in case 2, shown in Figure 14b but the hub node that routed the packets was deactivated during transmission, thus exiting the network, Figure 14c.  
In the first case with peer-to-peer configuration, 36 experiments were performed and packet loss was verified during 15 of the existing sessions, that is, 58.33% of the tests did occur without loss. 17 packets were lost during the remaining tests, where 99.90% of the transmitted packets were received. The average throughput was 8.92 kbps, with an average transmission time of 116 s and average local and remote RSSIs of \(-\)49.40 and \(-\)51.20 dBm, respectively.  
In the multi-hop configuration corresponding to the second case, 36 experiments were performed and packets were lost during only two ones. In other words, 94.44% of the performed tests did not present packet loss. In the remaining experiments, only two packets were lost, that is, 99.98% of the transmitted packets were successfully received. The average throughput was 7.48 kbps, with an average transmission time of 138 s and average local and remote RSSIs of \(-\)50.88 and \(-\)50.92 dBm, respectively.  
In the last case using multi-hop failure configuration, 36 experiments were also performed and packets were lost during 30 sessions, that is, 16.67% of the tests were carried out without loss. Among the remaining experiments, the total amount of lost packets was 31, that is, 99.82% f the transmitted packets were successfully received. The average throughput was 7.13 kbps, with an average transmission time of 143 s and average local and remote RSSIs of \(-\)51.24 and \(-\)50.86 dBm, respectively. In all experiments, the connection could be successfully reestablished. The aforementioned results are summarized in Tables 10 and 11.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Received Bytes** & \begin{tabular}{c} **Sent Time** \\ **(seconds)** \\ \end{tabular} & \begin{tabular}{c} **Local RSSI** \\ **(dBm)** \\ \end{tabular} & \
\begin{tabular}{c} **Remote RSSI** \\ **(dBm)** \\ \end{tabular} &
\begin{tabular}{c} **Tx (kbps)** \\ \end{tabular} & **Received Packets** & **Lost Packets** \\ \hline Average & 127,925 & 01:07 & \(-\)50 & \(-\)50 & 15.56 & 499.7 & 0.3 \\ Best Result & 128,000 & 01:02 & \(-\)48 & \(-\)47 & 16.38 & 500 & 0 \\ Worst Result & 126,976 & 01:36 & \(-\)49 & \(-\)54 & 10.56 & 496 & 4 \\ mean deviation & 237 & 00:10 & 2.79 & 2.79 & 1.63 & 0.93 & 0.93 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Results obtained in scenario 1.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Results** \\ \hline Number of tests & 72 \\ Tests without lost packets & 90.28\% \\ Received bytes & 99.96\% \\ Average Throughput & 15.56 kbps \\ Average time to send image & 67 s \\ \hline \hline \end{tabular}
\end{table}
Table 9: Analysis of results obtained in scenario 1.