Channel Models for Inter-body Communication in Ultra Wideband-Based Body Area Networks

Body area networks (BANs) are evolving tremendously over the years and with the progress in the area of internet of things, the BANs are more important than ever. Ultra wideband (UWB), a communication technology, due to its enormous 7.5 GHz bandwidth and low transceiver complexity has been suggested for BANs by several researchers. The development of an efficient transceiver is very important to effective implement the technology and requires through knowledge of channel conditions. The existing channel models for UWB-based BANs do not consider the sub-bands allocated in the IEEE 802.15.6. Besides, there is an absence of channel models that consider the cooperative inter-body communication scenarios in BANs, in which the communication is between two nodes located on two separate human bodies. Thus, channel models for inter-body communication in body surface to body surface communication scenario are yet to be developed. Such channel models will not only help in determining the treacherous nature of the channel around the human body but also helpful in further studies on cooperative communication-based body area networks and efficient transceivers. In this paper, we propose a channel model for body surface to body surface inter-body signal propagation. The channel model has been developed from real-time measurements using multiple human subjects over a span of several days and compiled from more than 250,000 individual received power measurements. Path loss equations for both line of sight and non line of sight scenarios have been formulated using curve fitting. Median path loss for the various frequency bands have been provided to offer insight into the channel conditions.