Progress in radiowave propagation studies of on-body communications channels

On-body communication channels are used in an increasing number of applications, including headsets and wristwatch controllers for mobile phones, and systems for emergency personnel and for personal medical support. In channels for such systems, at ISM band frequencies, the movement of the body causes significant fading, in addition to that caused by scattering from the local environment. Statistical modelling is important and difficult because of the non-stationary nature of body movement. Results for the belt to head and belt to wrist channels, for a walking body, are presented. Diversity is being considered to reduce fading, and results presented show that useful gain can be obtained using practical small antenna pairs with small spacing. Finally, angle of arrival data may help in the design of such antennas and some results are also given.