Theoretical Design of Geographical Route of Communications Cable Network Supplied by Power Grid to Minimize Disaster Damage

This paper analyzes network disconnection due to randomly occurring natural disasters in a geographical area, which is divided into sub-areas on the basis of disaster-vulnerable (DV) levels. The DV levels against an earthquake, for example, depend on the soil-foundation-structure. The network is a communications cable network that is planned to be built between two given network nodes. To make the optical cable working between these network nodes, electric supply from a power grid to these nodes is necessary, where the power grid has already existed. In this paper, the geographical conditions are derived under which a cable route of the network maximizes the probability of connecting two given nodes for any level of disaster when the geographical route information of the power grid is given. The achievable maximum probability of connecting two given nodes or its bound is explicitly given.