Towards Wi-Fi Radar in Collapsed Structures

Recent years have witnessed an increased dependency of IoTs in our daily lives. Wi-Fi that was once a mode of Internet connectivity is also being used as IoT particularly Wi-Fi signals are acting like sensors. Currently, there are many novel applications of these signals as sensors such as breathing detection, sleep monitoring, indoor localization, human computer interaction to name a few. All these applications work for normal indoor environments as Wi-Fi signal is very weak to penetrate through heavy obstacles. This work investigates a similar problem of Wi-Fi signal coverage in complex environments such as collapsed structures. The objectives of this paper are first to consider a debris scenario and then Wi-Fi signal coverage in this collapsed structured debris model is to be worked out. We have proposed a novel Wi-Fi Radar approach which exploits the existing path loss models with radar range equation for computation of signal coverage. We predefine Signal to Noise Ratio (SNR) threshold for various modulation schemes adopted for comparison to figure out the best case of signal reception. Further, we perform simulations on Wi-Fi Halow as Wi-Fi Radar to verify our approach. Moreover, we compare our results at various antenna gains, signal intensities and SNR thresholds. Comparison of results put emphasis on the low transmission power with better antenna gains to achieve the desired objective. This work paves way for the ubiquitous post-disaster rescue. This is because of the fact that signal coverage in collapsed structure may also exploit the concept of channel state information for breathing detection in the future.