The RSSI has been extensively studied for BANs. In [4],
an opportunistic medium access control (MAC) protocol for
BANs is presented. In their BAN implementation, Shimmer2r
wireless sensor nodes [5] are used to measure body motion.
The periodic fluctuations in the signal strength are determined
by the changes in the relative positions of the limbs of a
walking person. In their approach, the data are transmitted
when the RSSI is high in order to reduce the packet error
rate. In [6], the effects of human-body shadowing on RSSI are
investigated based on the Fresnel-Kirchhoff diffraction theory
in two different environments: living room and office setting.
Hence, a diffraction-based model is developed to determine
network link connectivity as a function of the locations of
stationary and moving obstacles, and based on the model, a
MAC protocol is developed that uses relay nodes when the
shadowing is strong enough to inhibit one-hop communication.
In [7], the influence of the human body, included gender
(male/female) and node location, to the RSSI is evaluated
experimentally. The results show an average attenuation of 26
dB regardless of gender.