# Modified Echo State Network Enabled Dynamic Duty Cycle for Optimal Opportunistic Routing in EH-WSNs
## 5 Results and Discussion
### Impact of Varying the Number of Sensor Nodes
Next for the packet delivery ratio, the average percentage improvement of OOR is 21.94, 40.46, and 58.40 as compared to ESN based, Max-SNR, and AOR, respectively. We can show the performance comparison of OOR in a more presentable way in the following Figure 7.  
In Figure 7, again, the five different columns in the first part of the figure show the outcomes of the packet delivery ratio parameter with variation in the number of nodes for each scheme, respectively. For example, consider different columns of the OOR scheme in the first part of the figure; the second column represents the value of the packet delivery ratio parameter as 77 at 200 nodes, whereas the fifth column depicts the value 92 at 500 nodes. In the second part of the figure, the five different columns show the percentage improvement, and the sixth column describes the average percentage improvement. Figure 8 depicts the comparison of the proposed OOR scheme with the existing schemes in terms of throughput. The graph demonstrates that the throughput of the proposed OOR scheme is higher than the existing ESN-based, Max-SNR, and AOR schemes, respectively. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Packet Delivery Ratio (\%) Comparison with Varying**} & \multicolumn{3}{c}{**\% Improvement of OOR as Compared with Existing Schemes**} \\  & \multicolumn{3}{c}{**Number of Nodes**} & \multicolumn{3}{c}{} \\ \hline \multirow{2}{*}{**Nodes**} & \multirow{2}{*}{**AOR**} & \multirow{2}{*}{**Max-SNR**} & \multirow{2}{*}{**ESN**} & \multirow{2}{*}{**OOR**} & **\% Gain of OOR** & **\% Gain of OOR** & **\% Improvement of** \\  & & & & & **Compared with ESN** & **Compared to** & **OOR Compared** \\  & & & & & & **Max-SNR** & **with AOR** \\ \hline
100 & 23 & 38 & 53 & 70 & 24.29 & 45.71 & 67.14 \\
200 & 30 & 45 & 58.7 & 77 & 23.77 & 41.56 & 61.04 \\
300 & 36.5 & 50 & 64.5 & 84 & 23.21 & 40.48 & 56.55 \\
400 & 45 & 58 & 73.5 & 88 & 16.48 & 34.09 & 48.86 \\
500 & 55 & 70 & 82.4 & 92 & 10.43 & 23.91 & 40.22 \\ \hline \multicolumn{2}{c}{**Average \% Improvement \(\rightarrow\)**} & \multicolumn{3}{c}{**21.94**} & \multicolumn{3}{c}{**40.46**} & \multicolumn{1}{c}{**58.40**} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Descriptive observations of OOR performance in terms of packet delivery ratio. Figure 7: Detailed performance reflection of OOR with packet delivery ratio parameter. From the above Figure 8, it is noticeable that as the number of nodes increases, throughput decreases, and the reason behind it is that the probability of packet error is proportional to the number of nodes. Therefore, the number of nodes increases, the packet error also increases, results in decreasing throughput. Moreover, Table 3 depicts the performance of the OOR scheme with variation in the number of nodes. Furthermore, Table 3 shows the percentage improvement and average percentage improvements both. From the above table, the average percentage improvement of OOR is 17.02, 33.01, and 47.72 as compared to ESN based, Max-SNR, and AOR respectively. Further, we can show the performance comparison of OOR in a more descriptive way in the following Figure 9.