# Earthquake-Tolerant Energy-Aware Algorithm for WDM Backbone Network
## 3 Results  
To assess the effectiveness of the proposed algorithm, a series of simulation experiments were conducted, and the detailed parameters are presented in Section 2.4. Table 3 provides a comprehensive view of affected areas, critical links, and links earmarked for removal or deactivation, calculated by the proposed algorithm across four scenarios (>20%, >30%, >40%, and >50% earthquake occurrence probability thresholds). Figure 5: (**a**) Greek IP over WDM network. (**b**) Regions of Greece. Affected areas encompass regions with a high probability of destructive earthquakes. Critical links are those traversing these areas, removable without disrupting network connectivity. Chosen links represent a judicious selection by the algorithm for removal or deactivation, strategically aimed at minimizing energy consumption. By removing or deactivating these chosen links, the algorithm eliminates the need to calculate backup paths for affected lightpaths, a crucial aspect significantly contributing to the total power consumption. This is especially pertinent in scenarios with numerous affected regions, necessitating a substantial number of backup paths to mitigate the disruption of lightpaths caused by damaged links. In specific scenarios with earthquake occurrence probabilities exceeding 20% and 30% (magnitude 5 Richter or above), the total energy consumption of all backup paths constituted 66% and 20% of the network's total energy consumption, respectively. Conversely, in scenarios exceeding 40% and 50%, the energy consumption contribution of all backup paths significantly reduced to 9% and 4%, respectively. The algorithm strategically removes links traversing regions deemed to have a high earthquake occurrence probability, resulting in a noteworthy decrease in power consumption. This reduction stems from the algorithm's ability to avoid creating extra backup paths for those links. Figures 6-9 depict the network used in the simulation, showcasing a chart presenting the total power consumption of the EAFFB algorithm [6] alongside the comparative results of the proposed algorithm for each of the four cases (>20%, >30%, >40%, and >50% earthquake occurrence probability thresholds). Critical regions, calculated by the algorithm, are marked with an orange \"x\" sign on the network maps for each case. Specifically, in the >20% case, the removal of three selected links ('279', '125', and '99') led to a 9% reduction, while in the >30% case, the removal of link '62' resulted in an 8% reduction in total energy consumption. Similarly, in the >40% and >50% cases, where only one link ('341') passed through affected areas, the calculated energy consumption for all backup paths exhibited a decrease of approximately 9% and 4%, correspondingly. \begin{table}
\begin{tabular}{c c c c} \hline
**Earthquake Occurrence** & **Affected Areas** & **Critical Links** & **Chosen Links** \\
**Probability Threshold** & **Affected Areas** & **Critical Links** & **Chosen Links** \\ \hline \multirow{8}{*}{20\%} & 1 & 279 & 279 \\  & 4 & 125 & 125 \\  & 7 & 236 & 99 \\  & 11 & 147 & \\  & 15 & 99 & \\  & 16 & 62 & \\  & 18 & 157 & \\  & 21 & & \\  & 25 & & \\  & 34 & & \\  & 35 & & \\ \hline \multirow{2}{*}{30\%} & 1 & 62 & 62 \\  & 21 & & \\ \multirow{2}{*}{30\%} & 34 & & \\  & 35 & & \\ \hline \multirow{2}{*}{40\%} & 1 & 341 & 341 \\  & 34 & & \\ \hline \multirow{2}{*}{50\%} & 1 & 341 & 341 \\  & 34 & & \\ \hline \end{tabular}
\end{table} 
Table 3: For each earthquake occurrence probability threshold, the affected areas, critical links, and chosen links that Algorithm 1 calculated are depicted. Figure 6: (**a**) The critical regions of Greece for the probability of earthquake occurrence > 20%. (**b**) Energy consumption of EAFFB algorithms and the proposed algorithm for the probability of earthquake occurrence > 20% (9% reduction). Figure 7: (**a**) The critical regions of Greece for the probability of earthquake occurrence > 30%.