Human body communication: Channel characterization issues

Human Body Communication (HBC) is a promising wireless technology that uses the human body tissues as a signal propagation medium. In HBC, the information signal is coupled to the body through an electrostatic or magnetostatic field via electrodes and is captured in another part of the body using similar electrodes. HBC has lower power consumption than conventional radio frequency (RF) approaches, because it operates at lower frequencies, usually between 0.1 MHz and 100 MHz, avoiding the body shadowing effects, complex and power hungry RF circuits and antennas. In addition, the signal is mainly confined to the human body, guaranteeing high data communication security and high efficiency in the network utilization. Designs have already been shown to achieve energy efficiency of pJ/bit and power of micro-Watts, paving the way for autonomous, energy harvested powered devices [1]. With these characteristics, HBC helps to reduce the battery volume and consequently the size and the weight of wearable devices such as watches, earphones, glasses, shoes or clothes. Overall, HBC presents itself as an interesting alternative to implement Body Sensor Networks (BSN) or Body Area Networks (BAN), especially since it is supported by the IEEE standard 802.15.6 for short-range, low-power and highly reliable wireless communication systems for use in close proximity to or within the human body [2].