Radio channel models for search-and-rescue missions into collapsed structures

Propagation models in the TETRA/GSM/UMTS bands (from 433 MHz to 1.9 GHz) in partially destroyed buildings are derived, using a number of methods with respect to various collapsed structures. These models are useful in the context of pedestrian radio-localization systems relying on cell phone signals. In addition, the electromagnetic properties of concrete and ferro-concrete materials are experimentally characterized and used in the various models. Simulations show that specific attenuation levels can be very severe, from 10 to 100 dB/m, and increase with frequency. This might seriously limit the detection of victims under more than one meter of ferro-concrete rubbles in the UMTS band. However, localization algorithms based on direction-of-arrival estimation are unlikely to be degraded by multipath spreading.