Survivability Improvement Against Earthquakes in Backbone Optical Networks Using Actual Seismic Zone Information

Optical backbone networks carry a huge amount of bandwidth and serve as a key enabling technology to provide telecommunication connectivity across the world. Currently, fiber-optic cables carry about 99% of global Internet traffic. Hence, in events of network component (node/link) failures, communication networks may suffer from huge amount of bandwidth loss and service disruptions. Natural disasters such as earthquakes, hurricanes, tornadoes, etc., occur at different places around the world, causing severe communication service disruptions due to network component failures. Most of the previous works on optical network survivability assume that the failures are going to occur in future, and the network is made survivable to ensure connectivity in events of failures. With the advancements in seismology, the predictions of earthquakes are becoming more accurate. Earthquakes have been a major cause of telecommunication service disruption in the past. Hence, the information provided by the meteorological departments and other similar agencies of different countries may be helpful in designing networks that are more robust against earthquakes. In this work, we consider the actual information provided by the Indian meteorological department (IMD) on seismic zones, and earthquakes occurred in the past in India, and propose a scheme, called seismic zone aware node relocation (SZANR), to improve the survivability of the existing Indian optical network through minute changes in network topology. We take Indian RailTel optical network as a case study in this work. Simulations show significant improvement in the network survivability can be achieved using the proposed SZANR in events of earthquakes.