LTE-based Passive Device-Free Crowd Density Estimation

In the last few years, there has been a growing interest in developing sensing systems using RF signals of opportunity, especially exploiting radar-based techniques. Long Term Evolution (LTE) signals are excellent candidates as signals of opportunity thanks to their wide availability and penetration in indoor environments. This is the first work investigating the possibility to use LTE signals for crowd density estimation. The proposed approach is not radar-like but it exploits the correlation between the variations of the received LTE signals (in particular, of the Reference Signal Received Power) and the number of people. An experimental evaluation of the performance is carried out in a indoor environment testing three different positions of the LTE receiver. Achieved results in terms of classification accuracy are very promising.