## 6 Results and Evaluation
### Block Transaction Rate Analysis
The fourth and fifth Duino coin blockchain nodes have mean block transaction rates of 61.43 and 62 blocks per second, while the sixth and seventh nodes have mean block transaction rates of 59.43 and 62.29 blocks per second, respectively. Also, as per the results shown in Figure 19, the block transaction rate of the network with fifteen Duino coin blockchain nodes has a deviation from 10 to 50 blocks per second. The mean block transaction rates of first five nodes were recorded as 25, 26.29, 32.86, 26.86, and 31.57 blocks per second. The nodes from 6 to 10 have mean block transaction rates of 24, 27.14, 24.14, 30.71, and 27.14 blocks per second, respectively. Also, from the 11 th node to the 15 th node, the mean block transaction rates were recorded as 24.14, 26.71, 23.71, 35.14, and 30.5 blocks per second, respectively [45]. The block transaction rate of the network with twenty Duino coin blockchain nodes in Figure 20 deviated from 14 to 26 blocks per second. As the results indicate, the mean block transaction rates of the blockchain nodes from the first blockchain node to the fifth node were recorded as 23.57, 23.71, 23, 20.71, and 21.43 blocks per second. Nodes 6 to 10 have mean block transaction rates of 16.43, 23.71, 21.29, 19, and 16.43 blocks per second. Also, the results show that nodes from 11 to 15 have mean block transaction rates of 23.43, 21.86, 24.43, 20.86, and 19.14 blocks per second while the 16 th, 17 th, 18 th, 19 th, and 20 th nodes have mean block transaction rates of 20.57, 16.57, 22.29, 24.43 and 22.43 blocks per second. We can emphasize that the block transaction rate gradually decreases with the increase in blockchain nodes. Figure 19: Block transaction rate of 15 Duino coin blockchain nodes. Figure 18: Block transaction rate of 7 Duino coin blockchain nodes. Figure 21 summarizes the average mean block transactions through the blockchain network. As per the results, Monero blockchain networks reached higher block transaction rates compared to the Hydrachain and Duino coin blockchain networks. In summary, we can emphasize that the number of blockchain users affects the overall block transaction rate and the scalability of blockchain networks. Table 3 shows a data sample of the block transaction rates of the Hydrachain, Monero, and Duino coin blockchain networks. As per the results, we can emphasize that the block transaction rate decreases with the increase in the node number. Most low-powered IoT applications use wireless technologies for data transmission, and the impact of network scalability limitations can be a critical consideration [46]. The deployment of blockchain-based sensor networks also faces the  
Figure 21: Summary of average mean block transaction rates. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **Hydrachain** & \multicolumn{4}{c}{**Monero**} & \multicolumn{4}{c}{**Duino Coin**} \\ \hline
**07 Nodes** & **15 Nodes** & **20 Nodes** & **07 Nodes** & **15 Nodes** & **20 Nodes** & **07 Nodes** & **15 Nodes** & **20 Nodes** \\ \hline
25 & 21 & 13 & 53 & 39 & 28 & 61 & 15 & 14 \\
25 & 21 & 19 & 51 & 45 & 33 & 56 & 21 & 18 \\  
impact of scalability limitations [46]. As per the results, the latency, bandwidth usage, and data block transaction rates vary based on the blockchain network architecture and number of users. The results indicate that the increment of blockchain nodes significantly increases the latency of blockchain networks. The deployment of blockchain-based IoT sensor networks in industries, including healthcare, is critical as the latency or loss of sensitive data can have significant consequences [46]. Also, the latency or loss of sensitive medical data can put lives at risk. It is important to understand the scalability capabilities of different blockchain networks before the deployment of blockchain-based IoT sensor networks in any industry [46]. The results of this research provide an overview of the scalability limitations that can occur with the use of Hydrachain, Monero, and Duino coin blockchain networks.