Lifeline Infrastructures Resilience: Case Study of Telecom Network

Telecommunication infrastructures provide essential services to urban communities. During an emergency caused by a seismic event, their functionality is essential to facilitate search and rescue operations. The aim of this study is to introduce a simplified method for assessing the vulnerability of a wireless telecommunication network under seismic action. The case study is a virtual city called Ideal City and part of a larger project on assessing the resilience of vital infrastructure in an urban environment. The wireless network composed of three operators is built starting from information on the real wireless network of the city of Turin. Some simplifications and assumptions are introduced due to the confidentiality of the data, as communications networks are strategic infrastructures. This defines a complete parameter database necessary to describe the various components of the network. Each component is then modeled through equivalent simplified models (SDOF). Once the results of the structural simulations are known, the vulnerability of the individual components is assessed, also considering the interdependence with the built environment that the various elements may have. For example, the BTS on residential buildings will certainly be affected by the behavior of the building under seismic action. Three resilience indices based on failed telecommunication towers, throughput, and number of users per base station were defined and calculated after four different seismic scenarios. It has been found that the topology and vulnerability of base controller stations are key aspects in the resilience of an urban wireless network.