Measurement Stand and Methodology for Research of the Off-Body and Body-to-Body Radio Channels in WBANs with Different Diversity Schemes

The concept of an experimental test bed for system loss and channel impulse response measurements for off-body and body-to-body radio channels in wireless body area networks (WBANs) is fully described. The possible measurement scenarios that may occur in investigation of off-body and body-to-body channels are classified and described in detail. Additionally, an evaluation is provided of the standard and expanded uncertainties of the presented measurement stand and methodology. Finally, the exemplary results are presented and discussed, in order to point out the need for further investigations of different diversity schemes and their applications in WBANs

Characterization of Slow and Fast Fading in Off-Body Communication at 2.45 GHz with Space Diversity Scheme in an Indoor Environment

The characterization of slow and fast fading in wireless body area networks with space diversity scheme has been presented. The analysis, based on the measurements at 2.45 GHz in an indoor environment, has shown that for all investigated configurations of receiving wearable antennas, the correlation coefficient values of the received signals’ parameters are below the assumed value of 0.5, being close to zero for the vast majority of cases. It has been shown that the slow fading component may be modelled by a lognormal distribution with zero average and the standard deviation from the range of [1.43, 1.98] dB. The fast fading component is the best modelled by a Rice distribution with the noncentrality parameter and the scale parameter being in the range [0.8125, 0.9624] and [0.5269, 0.6954], respectively

An Off-Body Narrowband and Ultra-Wide Band Channel Model for Body Area Networks in a Ferryboat Environment

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

Characteristics of the polarised off-body channel in indoor environments

Abstract 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

A Novel Bitrate Adaptation Method for Heterogeneous Wireless Body Area Networks

In the article, a novel bitrate adaptation method for data streams allocation in heterogeneous Wireless Body Area Networks (WBANs) is presented. The efficiency of the proposed algorithm was compared with other known algorithms of data stream allocation using computer simulation. A dedicated simulator has been developed using results of measurements in the real environment. The usage of the proposed adaptive data streams allocation method by transmission rate adaptation based on radio channel parameters can increase the efficiency of resources’ usage in a heterogeneous WBANs, in relation to fixed bitrates transmissions and the use of well-known algorithms. This increase of efficiency has been shown regardless of the mobile node placement on the human body

Vehicular Communication Environments

Communication to and between road vehicles (cars, truck, buses, trains, etc.) are of growing interest. This is partly due to the attractive services that cooperative intelligent transport systems (C-ITSs) provides, mainly in the areas of traffic safety and traffic efficiency. An enabler for C-ITS is wireless vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, collectively referred to as vehicle-to-X (V2X) communication. Another driver is the advent of moving networks in the context of 5th generation (5G) systems. Moving networks includes the use of vehicles as mobile or nomadic base station (BS), with the purpose of providing connectivity to both vehicle passengers and to users outside the vehicle. In this chapter, we will discuss key issues in V2X communication: propagation, antennas, and physical (PHY) and medium access control (MAC) layer algorithms. Measurements, characterisation, and modelling of radio channel are reported for road, railway, and special environments in Sections 4.1.1, 4.1.2, and 4.1.3, respectively. Antennas are discussed in Section 4.2, while PHY and MAC layers are treated in Section 4.3

Vehicular Communication Environments

Communication to and between road vehicles (cars, truck, buses, trains, etc.) are of growing interest. This is partly due to the attractive services that cooperative intelligent transport systems (C-ITSs) provides, mainly in the areas of traffic safety and traffic efficiency. An enabler for C-ITS is wireless vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, collectively referred to as vehicle-to-X (V2X) communication. Another driver is the advent of moving networks in the context of 5th generation (5G) systems. Moving networks includes the use of vehicles as mobile or nomadic base station (BS), with the purpose of providing connectivity to both vehicle passengers and to users outside the vehicle. In this chapter, we will discuss key issues in V2X communication: propagation, antennas, and physical (PHY) and medium access control (MAC) layer algorithms. Measurements, characterisation, and modelling of radio channel are reported for road, railway, and special environments in Sections 4.1.1, 4.1.2, and 4.1.3, respectively. Antennas are discussed in Section 4.2, while PHY and MAC layers are treated in Section 4.3