# Energy Efficient Routing Protocol in Sensor Networks Using Genetic Algorithm
## 6 Results and Discussion
### Comparison with Genetic Algorithm-Based Protocols  
This section compares our protocol with other genetic algorithm-based protocols, including LEACH-GA [28] and GA-AODV [31]. In this regard, GA-AODV is a single route topological reactive protocol that selects a route with the highest fitness among the discovered and generated routes. It keeps the record of the most optimized route for data forwarding and drops the other routes. Therefore, the protocol must go through the route discovery phase in the case of link failure, which imposes a significant load on the network. LEACH-GA is a clustering-based algorithm. This method uses GA to select the cluster head in each section. End-to-end delay is subjected to increase when the number of nodes in the network increases. Having a higher number of nodes increases the chance of having data congestion and this enlarges the queuing time. Additionally, the wireless channel is more occupied; therefore, a node in the network requires waiting for a longer period to access the medium and this extends the data transmission time. Selection of a route with the highest energy level can, therefore, maintain the load-balancing among nodes. GA-AODV is a multi-path routing protocol optimizing routes based on residual energy. Therefore, alternate routes and nodes are used whenever nodes fail. In all these cases, our mechanism will not go through the route discovery process and therefore the end-to-end delay would be minimal as shown in Figure 4.  
When the network is congested where an excessive amount of routing packets circulates and more nodes are involved in the process of route finding and data transmission, obvious energy is consumed by network nodes. Frequent selection of cluster head process by LEACH-GA will consume energy and this does not happen with GA-AODV. On the other hand, GA-AODV is a single path routing mechanism and a new route is required every time a node failure occurs and therefore a route-finding process is triggered and thus consumes more energy. From all of that, GA-AODV has the least energy consumption as shown in Figure 5. Table 2 shows that GA-AODV saves energy with 11% to 19.65% compared to other protocols. Figure 4: E2E vs. No of Nodes. In Figure 6, expanding the number of nodes results in better connectivity and consequently a higher throughput. GA-AOMDV shows a superior performance due to alternative routes and the data load distributed more evenly through the network. Based on Table 3, GA-AOMDV improves throughput by 7.96% and 20.82% in comparison with LEACH-GA and GA-AODV, respectively. According to the given reasoning, the packet delivery ratio increases in Figure 7, where GA-AOMDV shows the highest performance followed by LEACH-GA and GA-AODV. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{4}{c}{**Energy (in Joules)/Protocol**} \\ \hline
**No of Node** & **GA-AOMDV** & **LEACH-GA** & **GA-AODV** \\ \hline
100 & 130.22 & 145.11 & 155.23 \\
150 & 156.26 & 174.13 & 188.08 \\
200 & 192.20 & 214.18 & 229.64 \\
250 & 234.49 & 261.32 & 281.73 \\
300 & 283.11 & 319.63 & 347.16 \\
350 & 341.05 & 370.62 & 398.30 \\ Sum & 1337.33 & 1484.99 & 1600.14 \\ Saving \% & & 11.04 & 19.65 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Energy consumption values for Figure 5.  
Figure 5: Energy consumption vs. No of Nodes. Figure 6: Throughput vs. No of Nodes. The network topology is subjected to frequent change where there is nodal mobility. With a higher mobility speed, the topology changes more often; therefore, the performance degrades due to a higher chance of link failure. In Figure 8, the end-to-end delay increases with the higher mobility speeds. Every time a link fails to deliver data, the GA-AODV goes through the route discovery phase. Therefore, the data packet should remain in the queue link until a route is discovered. On the other hand, LEACH-GA has to go through cluster head selection more frequently. Therefore, data senders should adapt to the new cluster head, which increases the delay.