In this article, an analysis of system loss and depolarization in body area networks (BANs) for body-to-infrastructure (B2I) communications based on a measurement campaign in the 5.8 GHz band in an indoor environment is performed. Measurements were performed with an off-body antenna transmitting linearly polarized signals and dual-polarized receiving antennas carried by the user on the body. A normal distribution with a mean of 2.0 dB and a standard deviation of 4.3 dB is found to be the best fit for modeling cross-polarization (XP) discrimination. The average correlation between the signals received by the orthogonally polarized antennas is below 0.5, showing that polarization diversity can be used. A model for the average value of the standard deviation of the XP discrimination ratio as a function of the transmitted polarization, the mobility of users, and the link dynamics is presented, together with a detailed description of the methodology being used.

In this paper, an analysis of depolarisation in Body Area Networks for Body-to-Infrastructure communications based on a measurement campaign in the 5.8 GHz band in an indoor environment is performed. Measurements were made with an off-body antenna transmitting linearly polarised signals and dual-polarised receiving antennas carried by the user on the body. A Normal Distribution with a mean of 2.0 dB and a standard deviation of 4.3 dB is found to be the best fit for modelling cross-polarisation discrimination. The average correlation between the signals received by the orthogonally polarised antennas is below 0.5, showing that polarisation diversity can be used. A model is proposed for the average value of the standard deviation of the cross-polarisation discrimination ratio as a function of the transmitted polarisation, the mobility of users and link dynamics.

Cardiovascular events occurring in the bloodstream are responsible for about 40% of human deaths in developed countries. Motivated by this fact, we present a new global network architecture for a system for the diagnosis and treatment of cardiovascular events, focusing on problems related to pulmonary artery occlusion, i.e., situations of artery blockage by a blood clot. The proposed system is based on bio-sensors for detection of artery blockage and bio-actuators for releasing appropriate medicines, both types of devices being implanted in pulmonary arteries. The system can be used by a person leading an active life and provides bidirectional communication with medical personnel via nano-nodes circulating in the bloodstream constituting an in-body area network. We derive an analytical model for calculating the required number of nano-nodes to detect artery blockage and the probability of activating a bio-actuator. We also analyze the performance of the body area component of the system in terms of path loss and of wireless links budget. Results show that the system can diagnose a blocked artery in about 3 h and that after another 3-h medicines can be released in the exact spot of the artery occlusion, while with current medical practices the average time for diagnosis varies between 5 and 9 days.

This paper considers second-order statistics of non-stationary channels with arbitrary mobile antenna motion, by relaxing the constant velocity assumption inherent to stationary channel models. By assuming obstructed Line-of-Sight and horizontal signal propagation, analytical expressions for the Level-Crossing Rate (LCR) and Average Fade Duration are derived for non-isotropic scattering scenarios with Von Mises Distribution of angles of arrival. To demonstrate the non-stationary effects arising from non-linear motion, the obtained expressions are employed to investigate an off-body communications scenario with the user walking and the wearable antennas placed on the torso, wrist and lower leg. While the torso antenna yields an essentially stationary channel, for the latter two antenna locations the fading dynamics change periodically over the walking cycle. Two distinct phases with faster and slower signal variations are observed, with the former yielding 4.64 times higher LCR for the lower leg antenna.

In this paper, a measurement campaign for off-body communications in an indoor environment is investigated for a set of on-body antennas. The channel impulse response was measured with the user approaching and departing from an off-body fixed antenna using two user dynamics, standing at fixed positions and walking. The processing of the measurement data allowed to evaluate system loss statistics. Different antenna configurations are classified in terms of mobility and visibility depending on the on-body antenna placement. A dependence on distance is found for the antennas with the lowest mobility (chest and head), while no significant dependence is found for the antennas with the highest mobility (arms and legs). Regarding the standard deviation of system loss, higher values are found in walking scenarios (above 1.0 dB) compared to the standing ones (below 0.6 dB) showing a clear dependence on mobility.

In this paper, Body-to-Body communications in indoor and outdoor environments for different on-body antenna configurations and different mobility scenarios were studied, based on system loss measurements at 2.45 GHz. The main objective is to properly characterise the influence of the Transmitter-Receiver configuration on system loss and fast fading behaviour, the latter being modelled by the Rice Distribution. Globally, it is observed that there is no significant difference on the measured average system loss between indoor and outdoor environments, but a strong dependence is seen on the configuration of the antennas and on the mobility scenario. Concerning the Rice Factor, as expected, higher values were obtained in outdoor environments, due to the lower level of multipath, the difference to the indoor case being below 4 dB, depending on the mobility environment and on the positioning of the antennas.

This paper presents the initial results of wideband channel measurements for polarised off-body communications at 5.8 GHz in an indoor environment. Channel Impulse Response measurements were performed simultaneously for two orthogonal polarisations of a wearable antenna (several placements) and repeated for vertical and horizontal orientations of the off-body one. Four types of scenarios were considered in order to investigate the influence of user dynamics, presence of people in the environment, and body-shadowing effects from the user or other persons obstructing Line-of-Sight in between transmitter and receiver. Initial results are presented.

This article presents an overview of future truly personal communications, ranging from networking inside the human body to the exchange of data with external wireless devices in the surrounding environment. At the nano- and micro-scales, communications can be realized with the aid of molecular mechanisms, Förster resonance energy transfer phenomenon, electromagnetic or ultrasound waves. At a larger scale, in the domain of Body Area Networks, a wide range of communication mechanisms is available, including smart-textiles, inductive- and body-couplings, ultrasounds, optical and wireless radio transmissions, a number of mature technologies existing already. The main goal of this article is to identify the potential mechanisms that can be exploited to provide interfaces in between nano- and micro-scale systems and Body Area Networks. These interfaces have to bridge the existing gap between the two worlds, in order to allow for truly personal communication systems to become a reality. The extraordinary applications of such systems are also discussed, as they are strong drivers of the research in this area.