Initial Attempt on Outdoor Human Detection using IEEE 802.11ac WLAN Signal

In recent years, the functionality of wireless communications has not only been limited to communication between users, but has also been extended to sensing applications. In fact, several WLAN-based sensing technologies, which rely on changes in multipath radio propagation derived from a channel state information (CSI) in indoor environments, have already been developed. In this paper, we present a WLAN-based outdoor human detection system - the first in IEEE 802.11ac WLAN CSI-based outdoor sensing attempts. The number of multipaths in an outdoor environment is limited, thus, making sensing difficult. To realize outdoor CSI sensing, we present an IEEE 802.11ac WLAN-based sensing system. Specifically, this paper tries to answer the question, "How do we install a transmitter-receiver pair?" based on an analysis of the experimental results. Moreover, we provide open discussions regarding the optimum installation of WLAN sensing devices.