Channel characterisation for personal area networks (original) (raw)

Wideband channel characterisation for body and personal area networks

2004

Indoor channel measurements for body and personal area network applications have been conducted between a number of on-body positions and to three nearbypeer locations. Particular attention has been paid to the relation between the channel characteristics and the user's motion. The results demonstrate how the channel characteristics in BANs/PANs are dominated by the effects of body blocking. With body shadowing losses reaching 40 dB, non-LOS links rely on multipath propagation in the surrounding environment. Key words-personal area networks (PAN), body area networks (BAN), propagation measurements, channel characteristics.

On-body channel statistical analysis based on measurements in an indoor environment at 2.45 GHz

This study investigates the propagation phenomena and the fading experienced by on-body channels at 2.45 GHz, focusing on the effect of the human body in an indoor office environment. This investigation is based on signal measurements conducted for both stationary and mobile user cases using bodyworn antennas placed at various positions on the human body. The effect of the antenna location and the human body movement on the fading characteristics of the on-body channels is extensively studied through statistical analysis of the measurement data. First- and second-order statistics are also presented

Body Area Networks: Radio channel modelling and propagation characteristics

2008

Human body will act as a transmission channel in wearable wireless devices in the near future. Inclusion of the body as a transmission channel will see future wireless networks rely heavily on Body Area Networks (BAN) with applications in medical and personal area networks. In order to build BAN devices, it is imperative to model the channel accurately. Channel measurements are important, however, a closer look on the body channel can only be attained through Electromagnetic (EM) propagation modelling. This paper presents a preliminary analytical EM channel model for BAN. Specifically, the dyadic Green's function for a simple cylindrical human body model is used to propose a channel model. Four possible cases are considered, where the transmitter and receiver are either inside or outside of the body. An exact analytical expression is derived for the case where both the transmitter and receiver are outside of the body. This case is then used to show how the received signal power varies around the body, with the receiver at a constant radial distance from the cylindrical axis of the body.

Three Dimensional Motion Analysis of Antennas on Body for BAN Channel Modeling

Knowledge of the on-body antenna movement due to the body motion is an important key toward a useful channel model for body area network (BAN). This paper presents the three-dimensional motion analysis of onbody antenna based on the real human body motion captured by specific motion capture equipments. The variation of distance between transmitter and receiver antennas and the antenna rotation during the the body motion derived from the measured data.

Characterization of Wireless On-Body Channel Under Specific Action Scenarios at Sub-GHz Bands

IEEE Transactions on Antennas and Propagation, 2012

Body area network is an emerging area of wireless communication for medical healthcare applications. This paper characterizes the narrowband wireless on-body channels under specific action scenarios by measurement at the three different sub-GHz frequencies of 444.5, 611, and 953 MHz, which are the candidate frequency bands of narrowband body area network systems with low data rates in IEEE 802.15.6 standard. The channel responses at ten different antenna positions were measured in an office room environment for the two dynamic action scenarios of "walking on the spot" (Action I) and "standing up/sitting down" (Action II). This paper provides generalized on-body channel models of Nakagami-and Weibull distributions for Actions I and II, respectively. Notably, this paper shows that the shadowing effect due to body movement is dominant over the multipath fading. The results were obtained by the statistical analyses of channel fading properties at three different frequencies including level crossing rate, average fade duration and channel dwelling time. Index Terms-Body area networks (BAN), on-body propagation, fading channels, shadowing, UHF, WMTS. I. INTRODUCTION T HE IEEE 802.15 Task Group (TG) 6 for body area networks (BAN) has recently finalized a standard for various short range wireless applications in the vicinity of humans; these applications include medical and healthcare services and consumer electronics [1], [2]. In medical and healthcare applications, wireless sensor devices are implanted within the human body or attached to the body surface in case where wireless connections between these devices are preferred for ease of use, and comfort and mobility of the patients. In the IEEE 802.15 TG6, the considered frequency bands include medical implant communications services (MICS) at 402-405 MHz, wireless medical telemetry systems (WMTS) at several bands below 1.5 GHz, industrial-scientific-medical (ISM) band at around 2.45 GHz, ultra-wideband (UWB), etc. [3]. Reliability, quality-ofservice (QoS) and energy conservation are particular concerns for BAN medical and healthcare applications. Although the assumed coverage distances of BAN systems are relatively short, the link quality can become marginal due to the small form Manuscript

Radio channel characterisation and antennas for on-body communications

2005

Modern body area networks (BANs) and personal area networks (PANs) require efficient and high capacity wireless communication channels between various devices worn on a user's body. In this paper the on-body radio propagation channel was studied experimentally as well as theoretically. Both narrowband and wideband channel characteristics were investigated. Path loss and delay spread for a number of propagation scenarios were studied as well as statistical variations of the path loss. Two approaches to modelling channel path loss are discussed. They include a simplistic method based on the Friis formula and a novel local distorted non-orthogonal FDTD (LN-FDTD). Investigations of antenna optimisation for on-body applications are also presented.

A review of channel modelling for wireless body area network in wireless medical communications

2008

In the Wireless Body Area Network (WBAN), radio propagations from devices that are close to or inside the human body are complex and distinctive comparing to the other environments since the human body has a complex shape consisting of different tissues. Therefore, the channel models are different from the ones in the other environments. We present a literature survey on channel characterizations and modelling for WBAN. The interesting common result is that the propagation wave is diffracting around the human body rather than passing through it. The path loss is very high especially when the receive antenna is placed on the different side from the transmit antenna. The lognormal distribution turns to be the best fit for the small-scale fading rather than the traditional Rayleigh and Ricean distributions in the other environments. Moreover, the high correlation between delay bins is observed. In addition to the literature survey, we propose a procedure including the measurement campaigns and the channel characterizations to obtain the channel models with fulfilling what they are missing.

Statistical characterization of 4.5 GHz narrowband on-body propagation channel

This article presents the characterization of on-body propagation channel with specific activity of a body analyzing measurement results of a male subject in a radio anechoic chamber. To capture the dynamic behavior of the channel a commercial real-time channel sounding system for 4.5 GHz was used. The measurement scenarios included two repetitive actions of walking on the spot and standing up and sitting down at 10 different receive antenna locations, respectively, where the fading caused by the action is observed and statistically modeled.

Indoor body-area channel model for narrowband communications

IET Microwaves, Antennas & Propagation, 2007

Using wireless sensors placed on a person to continuously monitor health information is a promising new application. At the same time, new low-power wireless standards such as Bluetooth and Zigbee have been proposed for short range, low data-rate communication matching the requirements of these bio-medical applications. However, there are currently few measurements or models describing propagation around the body. To address this problem, electromagnetic waves near the torso are measured and a statistical model is derived for communication in the 915 MHz and 2.45 GHz industrial, scientific and medical bands associated with Zigbee and Bluetooth. Measurement setup and statistical analysis are described.