# OpticalTrust: A Sensor-to-Blockchain Framework Using Free-Space Optical Communication
## 4 Results and Discussion
### Evaluate FSOs Design  
The results presented in Tables 2 and 3 demonstrate a comprehensive analysis of the FSOs system performance comparing scenarios with and without EDFAs across various transmission ranges and bit rates. Table 2 shows the analysis for 8 and 12 Gbps, while Table 3 presents data for 16 and 20 Gbps configurations.  
From Table 2, at a 10 km transmission distance, the system without an EDFA shows a Q-Factor of 64.5921 at 8 Gbps, which significantly improves to 201.041 with EDFA implementation.  
Table 3 reveals that at 15 km and 16 Gbps, the Q-Factor is 14.1135 without an EDFA, improving to 18.2861 with EDFA implementation, as shown in Figure 2. The Bit Error Rate (BER) improvements are notably strong; specifically, Table 2 shows that at 20 km and  
12 Gbps, the BER improves from \(2.49892\times 10^{-24}\) without an EDFA to 0 with an EDFA, indicating error-free transmission.  
As evidenced in both Tables 2 and 3, the benefits of the EDFA become more pronounced at longer distances. Table 3 shows that at 25 km and 16 Gbps, the system without an EDFA has a BER of \(1.41034\times 10^{-6}\), while with an EDFA, it improves to \(6.98702\times 10^{-65}\).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Range**} & \multicolumn{2}{c}{**8 Gbps**} & \multicolumn{2}{c}{**12 Gbps**} \\ \cline{2-5}  & **Q-Factor** & **BER** & **Q-Factor** & **BER** \\ \hline \multicolumn{5}{c}{Without EDFA} \\ \hline
5 km & 261.522 & 0 & 203.885 & 0 \\
10 km & 64.5921 & 0 & 59.2321 & 0 \\
15 km & 23.7374 & \(7.41938\times 10^{-125}\) & 22.137 & \(2.27474\times 10^{-109}\) \\
20 km & 10.7113 & \(4.50513\times 10^{-27}\) & 10.1092 & \(2.49892\times 10^{-24}\) \\
25 km & 5.4449 & \(2.59161\times 10^{-8}\) & 5.19627 & \(1.01019\times 10^{-7}\) \\ \hline \multicolumn{5}{c}{With EDFA} \\ \hline
5 km & 404.078 & 0 & 299.537 & 0 \\
10 km & 201.041 & 0 & 184.905 & 0 \\
15 km & 117.834 & 0 & 117.422 & 0 \\
20 km & 75.4062 & 0 & 78.1821 & 0 \\
25 km & 51.2158 & 0 & 54.0116 & 0 \\ \hline \hline \end{tabular}
\end{table}
Table 2: FSOs system analysis comparison with and without an EDFA (8 and 12 Gbps).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Range**} & \multicolumn{2}{c}{**16 Gbps**} & \multicolumn{2}{c}{**20 Gbps**} \\ \cline{2-5}  & **Q-Factor** & **BER** & **Q-Factor** & **BER** \\ \hline \multicolumn{5}{c}{Without EDFA} \\ \hline
5 km & 18.2725 & \(6.83964\times 10^{-75}\) & 6.909782 & \(2.42704\times 10^{-12}\) \\
10 km & 17.6694 & \(3.59862\times 10^{-70}\) & 6.822931 & \(4.45979\times 10^{-12}\) \\
15 km & 14.1135 & \(1.55927\times 10^{-45}\) & 6.43107 & \(6.33487\times 10^{-11}\) \\
20 km & 8.52489 & \(7.58394\times 10^{-18}\) & 5.32369 & \(5.08281\times 10^{-8}\) \\
25 km & 4.68169 & \(1.41034\times 10^{-6}\) & 3.68705 & \(0.00011338\) \\ \hline \multicolumn{5}{c}{With EDFA} \\ \hline
5 km & 18.5811 & \(2.28094\times 10^{-77}\) & 6.97469 & \(1.53263\times 10^{-12}\) \\
10 km & 18.5113 & \(8.36557\times 10^{-77}\) & 6.96062 & \(1.69365\times 10^{-12}\) \\
15 km & 18.2861 & \(5.32776\times 10^{-75}\) & 6.93119 & \(2.08615\times 10^{-12}\) \\
20 km & 17.8006 & \(3.47995\times 10^{-71}\) & 6.87587 & \(3.07932\times 10^{-12}\) \\
25 km & 16.9683 & \(6.98702\times 10^{-65}\) & 6.78159 & \(5.93766\times 10^{-12}\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: FSOs system analysis comparison with and without an EDFA (16 and 20 Gbps).  
Figure 2: Comparison of Q-Factor values: without using an EDFA (**left**) and with using an EDFA (**right**).  
The data from both tables illustrate the challenges of increasing bit rates. For example, Table 2 shows that at 25 km, the Q-Factor for 8 Gbps is 5.4449 without EDFA, and decreases to 5.19627 at 12 Gbps.