## 6 Simulation Results and Analysis  
The performance of our proposed model was evaluated by performing some additional experimental results using the RMASE simulator [49]. Two routing protocols were used for the simulations: (1) improved energy efficient ant-based routing (IEEABR) protocol and (2) the message-initiated constrained-based routing protocol. The full details for IEEABR and MCBR can be found in [50; 51], respectively. MCBR is a proactive routing algorithm representing a recognized constraint-based flooding scheme, whereas IEEABR is a state-of-the-art routing protocol that utilizes the swarm-based ant behavior to give a low node-energy consumption. The node-energy consumption was modelled in accordance with the Waspmote-802.15.4 sensor-node using a transmission range of 35 m. Some of the simulation parameters used include a collection rate from 0.0 to 0.9 across 200 nodes, data rate is 250 kbps, data length is 512 bits, etc. Other parameters of the simulation are shown in Table 4.  
Figure 6 shows the impact of varying times of the wireless energy transmitters (power chargers) on the power transfer efficiency for MCBR-Flooding and IEEABR protocols respectively. As shown, IEEABR (being an ant-based protocol) performed better than \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Values** \\ \hline Routing Protocols & MCBR\_Flooding, IEEABR \\ X\_dist, Y\_dist, X-offset, Y-offset, X-density, Y-density, & 1, 1, 0.1, 0.1, 1, 1, 0.2, 0.2 \\ X-shift, Y-shift & \\ Node distribution & Random distribution \\ Source type, Destination type & Static, Mobile \\ Center type, radius, Destination rate & Random, 1, 0.5, 0 \\ Maximum number of retransmissions (n) & 3 \\ Strength, Initial power, Random power, Cycle time, & 1, 1000, 0, 10 \\ Active period, Init active cycles & 10, 0.1, 0 \\ Propagation model & Two-ray ground reflection \\ Data traffic & Constant bit rate (CBR) \\ Data rate & 250 kbps \\ Simulation time, Average simulation time & 360 s, 10 \\ Number of nodes (N) & 200 \\ Energy consumption & Wasp note-802.15.4 \\ Propagation model & Probabilistic \\ Time of topology change & 2 s \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Simulation parameters. MCBR-Flooding in terms of WPT efficiency. The figure shows that inter-meeting times (T\({}_{\text{m}}\)) affect the energy provisioning to the sensor-nodes. The inter-meeting time (T\({}_{\text{m}}\)) is defined here as the time-interval between a wireless mobile power charger (energy transmitter) and a sensor-node for data exchange or the time spent by a wireless MBC with a given IoT sensor-node in order to collect data and transmit energy to the node. Now, we will consider the different trade-offs (\(\lambda\)) for the energy provisioning process. For \(\lambda=1\), T\({}_{\text{m}}=\) High, the wireless energy transmitters are within the vicinity of the nodes and the inter-meeting time between the energy transmitters and the sensor-nodes is relatively high. This implies that the energy transmitters are moving at a minimal speed within the coverage area. Thus, at a constant distance (same vicinity of the nodes) and reduced speed, time is increased and the nodes can receive enough energy to be able to charge their batteries. This is designated as \"battery charging\" in Figure 6 because the sensor-nodes are able to charge their batteries at a high inter-meeting time with the power chargers. We assume a uniform charging for all the sensor-nodes provided that the wireless energy transmitters are within the vicinity of the nodes. Hence, increasing the inter-meeting time between the wireless energy transmitters and the sensor-nodes increases the WPT efficiency as shown in Figure 6. This also justifies the graph of Figure 5 obtained through empirical model which shows WPT efficiency increasing inversely proportionally with the distance (i.e., WPT efficiency increased as distance reduced and vice versa). This shows that wireless mobile power chargers within the vicinity of the sensor-nodes and moving at a minimum speed have high WPT efficiency.