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Earthquakes cause huge data loss when a major ground motion strikes backbone telecom infrastructure. However, necessary actions can be taken if an earthquake early warning system is integrated to optical WDM networks, which is the typical architecture of backbone telecom networks. While earthquake early warning systems are used to provide warnings to railway transportation, nuclear power plants, or semiconductor factories, they have been not used to provide warnings to telecom networks. However, many connections can be reprovisioned to avoid data loss in case of a disaster if a warning is provided seconds before a major earthquake. In this study, we explore three different strategies for such situation; 1) Extreme approach that reprovisions all connections in danger with full or degraded bandwidth, 2) relax approach that reprovisions only critical connections, and 3) careful approach that reprovisions some or all connections based on the alarm level. We compare these strategies for a case study, an earthquake on San Andreas Fault Line. We conduct numerical examples over a 24-node US-wide topology where the connections have heterogeneous bandwidth and availability requirements. The numerical examples show that careful approach provides a better solution than extreme and relax approaches, especially for heavy network loads in terms of expected penalty in case of an earthquake. |
