Analytical modelling of near-field coupling communication between persons equipped with wearable terminals through handshaking

Near-field coupling communication (NFCC) is a communication technology that treats the surface of the human body as a transmission path using a carrier frequency below 10 MHz. Because the radiation signal to a space is suppressed in NFCC, humans wearing an NFCC transceiver (TRX) can exchange personal information through handshaking without having to worry about information leakage. This work examines the mechanism of communication between wearable transceivers by NFCC through handshaking and the requirements for stable handshaking communication. The establishment of handshaking communication requires the signal propagation loss in the handshaking posture to be at least 10 dB smaller than in the standing posture. Signal propagation losses in the standing and handshaking postures were measured with an electrically isolated probe when TRXs were attached to the front of two human bodies standing face to face 600 mm apart. We investigated a simulation model of handshaking communication using a phantom we developed instead of a real human body by electromagnetic simulation and circuit simulation. On the basis of the simulation results, we proposed the signal propagation path for the realization of handshaking communication. When wearable TRXs are inserted into the soles of shoes, the signal propagation path is satisfied. In this case, we experimentally confirmed that the signal propagation loss in handshaking is smaller than that in the standing posture by 10.6dB.