# Efficient Next-Hop Selection in Multi-Hop Routing for IoT Enabled Wireless Sensor Networks
## 5 Results and Analysis
### Average Data Collection Time and Lifetime  
Figure 4a presents the number of time slots needed to forward data to the BS. In the case of EMRP, the packet size of control information is quite small as compared to the size of the data packet. The earlier studies verified that the top-down method DADCNS  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Value** \\ \hline Transmission Radius & 60 m \\ Initial Node Energy & 1000 J \\ Tx Node Power & 0.819 \(\mu\)J \\ Rx Receiving Power & 0.049 \(\mu\)J \\ Data Collection & Periodically \\ Simulation Time & 20 min \\ Minimum Energy Level & 300 mJ \\ Mac Protocol Type & Mac/802-11 \\ Queue Type & DropTail/PriQue \\ Queuing Delay & 10 ms \\ Tracing for Router & ON \\ Agent Tracing & ON \\ Max Packets in Queue & 50 \\ Control Packet Size & 96 bits \\ Number of Nodes & 5–70 nodes \\ Communication Time & 100–1000 s \\ Sensor Field & 250 m \(\times\) 250 m \\ \hline \hline \end{tabular}
\end{table}
Table 2: Simulation Parameters for EMRP.  
and L-VH are much better than other existing strategies, including LEACH, PEDAP, and PEGASIS, for efficient data forwarding. Results show the sovereignty of EMRP as compared to counterparts. For the number of nodes equal to 50, L-VH, DADCNS, PEGASIS and LEACH require 10, 11, 17 and 24 time slots, respectively. The proposed EMRP performs quickly in six time slots by finishing extra data gathering processes within the required time. PEGASIS uses more slots when sharing the messages over nearby neighbors, but their distance was long with the BS. LEACH consumes much more as the strategy was to forward towards any of the selected neighbors. DADCNS identified the track with less delay, but the number of time slots remained somewhat higher. Similarly, L-VH consumed fewer slots by considering better tracks and neighboring nodes. Figure 4b illustrates the average number of data collection rounds performed in a specific timespan. For 50 nodes, 130, 128, 107 and 71 rounds of data collection are performed by L-VH, DADCNS, PEGASIS and LEACH, respectively. The proposed EMRP outperforms with 150 rounds. In these schemes, the number of rounds may vary as per the time of reply by the member nodes, and the delay increases when more packets are dropped on a selected path, e.g., in the case of 20 to 25 nodes. In the case of 30 nodes per cluster, improvements were made to achieve fewer delays and rounds. This metric helps to explore the network lifetime. The sensors perform a limited number of rounds for data sharing due to the insufficient battery power of sensor nodes. We varied the number of nodes from 5 to 70 for measuring the network lifetime by using the average number of rounds for data sharing. The number of nodes in a cluster was varied from a small number to a large number of deployed sensors. This increases the size of the entire network in a specified region with more density of nodes. Next, we evaluated the performance in terms of the first node's energy expiry within the network. In Figure 4c, several existing routing mechanisms are graphically analyzed based on the first node expiry. Results show that in the case of PEDAP, LEACH, PEGASIS, DADCNS, and LV-H, the first node expires after 4.1, 4.21, 4.4, 4.58 and 4.65 min, respectively. EMRP achieves a better lifetime, where the first node expires after 4.71 min. In existing schemes, more energy is consumed for the data sharing messages, where a number of long tracks may be chosen to consume more energy. It results in early expiry of the node's battery.