Theoretical Modeling and Analysis of Magnetic Induction Communication in Wireless Body Area Networks (WBANs)

The wireless body area network (WBAN) is a promising new communication technology operating at close proximity to the human body. Although various wireless communication techniques using electromagnetic wave propagation have been deployed for WBANs, they encounter several problems. A major issue is that electromagnetic waves in the microwave range often experience a high level of attenuation. Multipath effects and interference with other existing systems are other issues. Magnetic induction (MI) is an alternative physical layer technique, which can address some of these problems. In this paper, a circuit model for an MI system is presented to describe power transmission between the transceivers and to facilitate performance analysis of this wireless system around the human body. An analytical model is derived for the mutual inductance of two MI coils as a function of coil geometry, operating frequency, and relative position and orientation of the coils. This model provides an accurate and fast method of calculating the mutual induction, which is a key parameter in the optimal design of an MI communication system. The model is verified by experimental measurements and numerical simulations. The results show that for frequencies up to 30 MHz, the human body does not affect the performance of MI communication system.