## 5 Results and Discussion
#### Experimental Investigation  
An experimental study on the proposed energy-efficient and secure routing protocol was carried out using specific parameters. The parameters considered for analysis are average residual energy, packet loss, throughput, packet delivery ratio, end-end delay, the amount of packet received, decryption time, and encryption time. These parameters are evaluated for the proposed framework and conventional approaches to prove the optimal functioning of the proposed routing approach in comparison with conventional routing techniques. The conventional routing approaches considered for comparison studies are the energy-efficient region source routing protocol (ER-SRP) [13], energy-efficient load-balancing ant-based routing algorithm (EBAR) [14], improved LEACH protocol [16], and energy-efficient grid-based routing approach (EEGRA) [30]. Table 4 lists the estimated metric values for the proposed and conventional routing approaches. A comparison of the average residual energy metric between the proposed and existing routing protocols is shown in Figure 9. The graph shows a comparison between several techniques and the average value of the residual energy as a percentage. The average residual energy was found to be more significant for the proposed method. Figure 8: Selection of grid organizer as a relay node. The average residual energy for the proposed method is 21.87%, 18.75%, 11.45%, and 4.16% higher than those of EEGRA, I-LEACH, EBAR, and ER-SRP, respectively. Figure 10 shows a comparison study performed using the end-end delay parameter for the existing and conventional routing protocols. In this graph, the graph is plotted between the number of sensor nodes and end-end delay in milliseconds on the X- and Y-labels. The end-to-end delay value obtained in the proposed method is 2.42% less than EEGRA, 1.80% less than I-LEACH, and 0.864% less than EBAR. A comparison study performed using these two parameters revealed better functioning of the proposed routing framework in comparison to existing routing approaches. Figure 11 shows a comparison study conducted using the packet delivery ratio metric. The graph for this metric is plotted between various techniques and packet delivery ratio (PDR) in percentage on both axes. The value of PDR for the proposed routing technique is 16.66% more than EEGRA, 12.22% greater than I-LEACH, 6.66% greater than EBAR, and 2.22% greater than ER-SRP. A comparison study conducted using the throughput parameter is shown in Figure 12. The graph shows the number of iterations and throughput values in the X- and Y-axes, respectively. The throughput of the proposed method was 23.48%, 4.02%, 2.68%, and 2.01% higher than those of EEGRA, I-LEACH, EBAR, and ER-SRP, respectively. These two comparison studies demonstrate the effectiveness of the proposed routing approach in comparison with existing routing techniques. \begin{table}
\begin{tabular}{|c|c|c|c|c|c|} \hline
**Performance Metric** & **EEGRA** & **I-LEACH** & **EBAR** & **ER-SRP** & **Proposed** \\ \hline Average residual energy (\%) & 0.75 & 0.79 & 0.85 & 0.92 & 0.96 \\ \hline Amount of packet received \(\left(\times 10^{4}\right)\) & 2.48 & 2.53 & 2.55 & 2.58 & 2.63 \\ \hline Packet loss (\%) & 0.24 & 0.21 & 0.15 & 0.13 & 0.1 \\ \hline Throughput (mbps) & 1.14 & 1.43 & 1.45 & 1.46 & 1.49 \\ \hline Packet delivery ratio (\%) & 0.75 & 0.79 & 0.84 & 0.88 & 0.9 \\ \hline Encryption time (ms) & 22 & 22 & 21 & 19 & 18 \\ \hline Decryption time (ms) & 0.49 & 0.48 & 0.47 & 0.44 & 0.4 \\ \hline End-end delay (ms) & 317 & 315 & 312.2 & 309.6 & 309.3 \\ \hline \end{tabular}
\end{table} 
Table 4: Metrics evaluated for the proposed and existing routing protocol. Figure 9: Comparison of average residual energy. Figure 11: Comparison of packet delivery ratio. Figure 12: Comparison of throughput. Figure 10: Comparison of end–end delay.