## 6 Results and Evaluation
### Block Transaction Rate Analysis  
Block transaction rate (BTR) denotes the number of blocks that move from one blockchain node to another in a unit of time [44]. BTR is measured in blocks per second. In a low-powered IoT blockchain sensor network, the block transaction rate is critical to avoid network failures. In this section, we evaluate the blockchain transaction rates of each blockchain network using the same test bed. As per the results in Figure 12, the Hydrachain blockchain network with seven blockchain nodes has 25 to 26 block transactions per second. The first blockchain node has a mean block transaction rate of 25.43 blocks per second, while the second node has a mean block transaction rate of 25.57 blocks per second. The third and fourth blockchain nodes have mean block transaction rates of 25.86 and 25.29 blocks per second, respectively, while the fifth and sixth nodes have mean block transaction rates of 25.57 and 25.71 blocks per second, respectively. The seventh node recorded a mean block transaction rate of 25.86 blocks per second [44]. As the results indicate in Figure 13, the block transaction rate of the Hydrachain network with fifteen blockchain nodes deviates from 19 blocks per second to 22 blocks per second. The first, second, and third blockchain nodes have mean block transaction rates of 19.86, 20.57, and 20.43 blocks per second, respectively. Also, the fourth, fifth, and sixth nodes have mean block transaction rates of 20.57, 21.14, and 20.14 blocks per second, respectively. The 7 th, 8 th, and 9 th nodes have a mean block transaction rates of 19.43, 19.43, and 20 blocks per second, respectively, while the 10 th, 11 th, and 12 th nodes have a mean block transaction rate of 20.71, 20.67, and 21.29 blocks per second, respectively. The 13 th, 14 th, and 15 th nodes have a mean block transaction rate of 19.33, 19.43, and 20.57 blocks per second. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **Hydroachain** & & & **Monero** & & & **Duino Coin** & \\ \hline
**07 Nodes** & **15 Nodes** & **20 Nodes** & **07 Nodes** & **15 Nodes** & **20 Nodes** & **07 Nodes** & **15 Nodes** & **20 Nodes** \\ \hline
410 Kbps & 1125 Kbps & 1655 Kbps & 43 Kbps & 112 Kbps & 120 Kbps & 51 Kbps & 100 Kbps & 155 Kbps \\
628 Kbps & 1245 Kbps & 1548 Kbps & 49 Kbps & 119 Kbps & 128 Kbps & 49 Kbps & 112 Kbps & 143 Kbps \\
553 Kbps & 1157 Kbps & 1577 Kbps & 53 Kbps & 124 Kbps & 136 Kbps & 49 Kbps & 128 Kbps & 115 Kbps \\
498 Kbps & 1148 Kbps & 4171 Kbps & 48 Kbps & 120 Kbps & 154 Kbps & 147 Kbps & 149 Kbps \\
673 Kbps & 1302 Kbps & 1470 Kbps & 46 Kbps & 127 Kbps & 138 Kbps & 50 Kbps & 140 Kbps & 144 Kbps \\
768 Kbps & 1024 Kbps & 1489 Kbps & 46 Kbps & 110 Kbps & 133 Kbps & 50 Kbps & 143 Kbps & 78 Kbps \\
728 Kbps & 1268 Kbps & 1602 Kbps & 51 Kbps & 111 Kbps & 158 Kbps & 51 Kbps & 157 Kbps & 280 Kbps \\
612 Kbps & 1459 Kbps & 1631 Kbps & 52 Kbps & 133 Kbps & 155 Kbps & 49 Kbps & 159 Kbps & 245 Kbps \\
558 Kbps & 1468 Kbps & 1624 Kbps & 47 Kbps & 128 Kbps & 157 Kbps & 48 Kbps & 166 Kbps & 251 Kbps \\
790 Kbps & 1520 Kbps & 1659 Kbps & 45 Kbps & 131 Kbps & 129 Kbps & 49 Kbps & 154 Kbps & 267 Kbps \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Bandwidth usage data sample of blockchain networks. Figure 12: Block transaction rate of 7 Hydrachain blockchain nodes. The results in Figure 14 indicate that the block transaction rate of the network with twenty Hydrachain blockchain nodes deviates from 12 blocks per second to 20 blocks per second. From the 1 st node to the 5 th node, the network has mean block transaction rates of 19.43, 15, 16.43, 14.43, and 15.71 blocks per second, while from the 6 th node to the 10 th node, the network has a mean block transaction of 16.86, 18.43, 16.43, 17.43, and 15.29 blocks per second, respectively.