# 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  
Considering this scenario, we vary the node numbers as 100, 200, 300, 400, and 500 in the experiments. Figure 4 displays the comparison of the proposed OOR scheme with the existing schemes in terms of delay. The graph demonstrates that the delay of our proposed OOR scheme is lower than the existing ESN based, AOR, and Max-SNR schemes respectively. From the above Figure 4 it can be observed that delay reduces as the number of nodes increases. In OOR, the possibility of selecting the sleeping node as the relay node is less; therefore, the packet is transmitted from source to destination without much delay. Next, Table 1 depicts the performance measurement of the OOR scheme with variation in the number of nodes. Also, Table 1 shows the percentage improvement and average percentage improvement. In case of delay, the average percentage improvement of OOR is 22.18, 44.11, and 55.49 as compared to ESN based, AOR, and Max-SNR, respectively. We can show the performance comparison of OOR in a more detailed way in the following Figure 5. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{3}{c}{**Delay (ms) Comparison with Varying Number of Nodes**} & \multicolumn{3}{c}{**\% Improvement of OOR as Compared with Existing Schemes**} \\ \hline \multirow{2}{*}{**Nodes**} & \multirow{2}{*}{**AOR**} & \multirow{2}{*}{**Max-SNR**} & \multirow{2}{*}{**ESN**} & \multirow{2}{*}{**OOR**} & \begin{tabular}{c} **\% Gain of OOR** \\ **Compared with ESN** \\ \end{tabular} & \
\begin{tabular}{c} **\% Gain of OOR** \\ **Compared with ESN** \\ \end{tabular} &
\begin{tabular}{c} **\% Improvement of** \\ **OOR Compared with AOR** \\ **with AOR** \\ \end{tabular} \\ \hline
100 & 150 & 125.5 & 109.8 & 92 & 16.21 & 26.69 & 38.67 \\
200 & 130 & 108.25 & 90 & 72.25 & 19.72 & 33.26 & 44.42 \\
300 & 112 & 89.25 & 67.65 & 50 & 26.09 & 43.98 & 55.36 \\
400 & 98 & 73.2 & 50 & 36.65 & 26.70 & 49.93 & 62.60 \\
500 & 84.8 & 60 & 35.6 & 20 & 43.82 & 66.67 & 76.42 \\ \hline \multicolumn{3}{c}{**Average \% Improvement \(\rightarrow\)**} & \multicolumn{3}{c}{**22.18**} & \multicolumn{1}{c}{**44.11**} & \multicolumn{1}{c}{**55.49**} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Descriptive observations of OOR performance in terms of delay. Figure 4: Delay comparison with varying number of nodes. In Figure 5 the five different columns in the first part of the figure show the outcomes of the delay 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 first column represents the value of delay parameter as 92 ms at 100 nodes, whereas the fifth column depicts the value of 20 ms at 500 nodes. In the second part of the figure, the five different columns show the percentage improvement, and the sixth column represents the average percentage improvement. Figure 6 demonstrates the comparison of the packet delivery ratio of the proposed OOR scheme and existing schemes. The result indicates that the packet delivery ratio of the proposed OOR scheme is higher than the existing ESN based, Max-SNR, and AOR schemes, respectively. Concerning the above graph, increasing the number of nodes, packet delivery ratio (PDR) increases; this shows the perfect agreement with the theoretical background. In our proposed scheme, the possibility of selecting the sleeping forwarder node is very less because we have applied the multistage relay set optimization mechanism, which results in a higher packet delivery ratio. Hence, we can say that the proposed OOR is the best solution out of various algorithms available in the literature. Further, Table 2 depicts the performance of the OOR scheme with variation in the number of nodes. Also, Table 2 shows the percentage improvement and average percentage improvements both. Figure 5: Detailed performance reflection of OOR with a delay parameter. Figure 6: Packet delivery ratio comparison with varying number of nodes.