Post-Hazard Cellular Network Recovery by Unmanned Aerial Vehicles and User Equipment Cooperation

We propose a new method for life rescue operations after a hazard where the cellular network coverage is limited or nonexistent. The aim is to find survivors quickly by locating them even without their active participation. Our approach is based on deploying unmanned aerial vehicles as parts of the cellular network. We exploit the fact that, increasingly, almost everyone carries cellular mobile devices, also called user equipment (UE). Although limited in power, they can serve as human-based wireless sensors in the DIAs even in the absence of cellular network coverage. Our method provides critical situational awareness to first responders by generating visual crisis maps based on the location distributions of the surviving UE, showing where and how (whether indoor or outdoor) the potential survivors are clustered. These maps are constructed using the signaling messages that are typically sent by UE for exchanging information with the network.