Passive wireless localization strategies for security in large indoor areas

The localization and tracking of moving people in indoor areas play a key-role in most of the applications related to security, ranging from intrusion detection up to crowd management. Such application fields deal with non-cooperative targets. To the best of authors knowledge, a simple, non-invasive, inexpensive, and scalable solution for the localization of transceiver-free people and crowd is still not available. The opportunistic exploitation of standard wireless technologies for the passive localization of people is here proposed. The propagation of wireless signals in complex and noisy environment can be inferred from the standard signal quality indicators, freely available on most of wireless commercial devices. Such information is related to the characteristics of the environment as well as to the people presence. In this paper, a multi-step procedure for the detection, occupancy level, and position estimation of moving people is presented.