This paper presents an off-body channel model for body area networks (BANs) in indoor environments. The proposed model, which is based on both simulations and measurements in a realistic environment, consists of three components: mean path loss, body shadowing, and multipath fading. Seven scenarios in a realistic indoor office environment containing typical scatterers have been measured: five were static (three standing and two sitting) and two dynamic (walk in a fixed place and real walk). The measurement equipment and measurement procedures are described. The mean path loss component is modeled as a log function of distance, the path loss exponent being in the range between 0.4 and 1.6, while a statistical perspective is taken for the other two components, i.e., body shadowing is found to be well modeled by a log normal distribution and multipath fading by Rice or Nakagami-m distributions, depending on body motion characteristics. The correlation between the selected distributions and empirical data is not lower than 0.95, typically being greater than 0.98. The novelty of this model is that it takes the statistical influence of various parameters and features present in BANs into account, such as body influence, placement of the wearable antennas, user orientation in the environment, dynamism of the BAN scenario, and propagation conditions.

This paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving antennas, type of dynamic scenarios and investigated environments. In general, the lowest mean path loss value (below 57 dB) is obtained for the scenario where two bodies are walking in the same direction along parallel routes and the distance in between bodies equals 1 m; in contrast, the highest value (over 70 dB) is observed for the scenario where both bodies depart from each other being turned back to back. Moreover, the highest standard deviation value (over 13 dB) is obtained for scenarios with antennas mounted on the wrists, which are the most movable parts of the body while walking, and the lowest value (around 2 dB) has been measured for antennas mounted on the head.

This paper addresses the depolarisation effect in off-body body area networks channels, based on measurements performed at 2.45 GHz in an indoor environment. Seven different scenarios, involving both static and dynamic users, were considered, taking a statistical perspective. The analysis of the cross-polarisation discrimination is performed, as well as the analysis of path loss in co- and cross-polarised channels. Results show a strong dependence of the cross-polarisation discrimination and of channel characteristics on the polarisation and propagation condition, i.e. line-of-sight (LoS), non-LoS or quasi-LoS. Distance, varied between 1 and 6 m in the considered scenarios, is observed to have very little impact on the cross-polarisation discrimination. In the considered dynamic scenario, the channel is characterised by lognormal-distributed shadowing and Nakagami-distributed multipath fading. Parameters of the Nakagami distribution have essentially different values in the co- and cross-polarised channels, showing a trend towards Rice in the former and Rayleigh in the latter. Based on results, a model is proposed for a dynamic off-body channel.

In this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting and receiving antenna heights and relative polarisation of both antennas. It is proved that the Generalised Additive Model allows for mean path loss estimation with a higher accuracy in comparison with Linear Regression. The obtained mean error is 0 dB, the root mean square error is 5.52 dB and the adjusted coefficient of determination is 61.2%.

In the article an off-body narrowband and ultra-wide band channel model for body area networks in a ferryboat environment is described. Considering the limited number of publications there is a need to develop an off-body channel model, which will facilitate the design of radio links, both from the multimedia services provider and the security point of view, for body area networks in this atypical environment. A mobile heterogeneous measurement stand, using radio distance measurements, which consists of three types of devices: miniaturized mobile nodes, stationary reference nodes, and a data acquisition server, was developed. A detailed analysis of both radio channels’ parameters was carried out. An analysis of system loss for off-body communication, including mean system loss, large-scale fading (corresponding to body shadowing), and small-scale fading (associated with the multipath phenomenon), both for 868 MHz narrowband and for 6489 MHz ultra-wide band channels, was performed. A statistical analysis of the obtained system loss model parameters was also carried out; good fit to the empirical data is observed.

This paper presents a description of new global monitoring system for containers with its layer-modular structure, as a solution for enhance security and efficiency of container transport with particular emphasis on the practical implementation of that system for maritime container terminals. Especially the Smart Container Module (SCM) architecture and its operation as a part of the Self-Organizing Container Monitoring Network is presented.