## 6 Simulation Results and Discussions
### Simulation Scenarios and Results
#### 6.3.2 Simulation Scenario 2: Alive Nodes Evaluation  
This scenario uses the HND and LND metrics pertaining to the number of SNs that are still active to conduct a detailed investigation of the network lifespan. Furthermore, Figure 11 clearly displays the examination's results by contrasting the performance of our proposed protocol, that is, without routing and with multi-hop routing, with that of the LDIWPSOC, PSO-EEC, OFCA, and NPSOP protocols. Figure 11 illustrates a common and steady trend: The number of alive SNs for all protocols decreases as the number of rounds rises. This pattern is rather expected because as the number of rounds rises, the SNs' energy consumption increases as a result of the exchange of messages and lengthy communication distances, drawing the network closer to its endpoint. The outstanding results achieved by the proposed protocol can be attributed to several key amendments. The first of these is the selection of an optimal number of PDFHs as the network demands rather than a fixed number of PDFHs. This efficiency stems largely from the fact that most message exchanges occur within the Friis free space channel propagation model. Second, the proposed protocol includes an efficient technique for selecting PDFHs, FSDFHs, and SSDFHs, utilizing the MPA. The protocol does this by, interestingly, not only choosing the right optimization method (MPA), but by also incorporating five crucial RMs in its DFFF, which made a powerful impact, taking the results to a whole new level. It is worth noting that ASBO is an innovative RM that we pioneered, specifically designed to reflect real-world conditions where obstacles interfere with wireless signals. This groundbreaking approach brings us closer to the complexities of everyday applications by factoring in the impact of obstructions on signal transmission. Additionally, unlike the methods used in directly connected protocols, the proposed protocol significantly reduces setup overhead by employing batch-round data fusion grouping. This means that data fusion grouping does not occur every round but rather in batches, and only when the energy of PDFH drops below the threshold energy, which is the average energy of DFGMs. The sink node efficiently manages this responsibility, ensuring an equal distribution of energy depletion among SNs. This significant reduction in control overhead greatly contributes to extending the IoT network's lifetime. Additionally, after selecting PDFHs, the sink node sends a TDMA schedule through an informative message table. This message is sent only once, which minimizes the number of message exchanges between the sink node, PDFHs, and DFGMs, thereby reducing energy consumption and further prolonging the network's lifetime. Remarkably, the proposed protocol with multi-hop routing boasts a significantly extended network lifetime, surpassing other protocols. This success is attributed to its use of multi-hop routing, where data are sent to PRs instead of directly to the sink node, regardless of the distance between PDFHs and the sink node (single-hop communication). PRs are carefully selected based on an innovative RDCF, which has significant factors, including the distance to the sink node, CPRs' RE, and ASBO. Consequently, the advantages of our proposed concepts are clearly evident, demonstrating superior performance compared to other protocols. Notably, the HND and LND values in the proposed protocol are