UWB Body Area Networks: Coexistence Analysis and Performance Optimization

Abstract: Body Area Networks (BANs) are wearable wireless sensor networks with a high potential for medical and sports applications. BANs appear to be a particularly appealing solution to provide information about the health status of a patient in medical environments such as hospitals or medical centres. Ultra Wide Band (UWB) technology grants a high temporal resolution, resistence to multipath, availability of inexpensive sensors and considerably low power requirements for extended monitoring periods. UWB is adopted by IEEE 802.15.4a standard, whose main goal is represented by the achievement of energy-efficient communications with data rates comprised between 1 kbits/s and several Mbits/s. This work analyzes the behaviour of a reference BAN composed of IEEE 802.15.4a UWB sensors in presence of a Low Data Rate (LDR) UWB interfering network represented by a second BAN located in the same room. An optimized code assignment policy to favour network coexistence is also introduced. Performance evaluation takes into account Bit Error Rate (BER) as a function of the number of nodes forming the reference BAN when a second BAN with a fixed number of nodes is present

A Three-Tiered Architecture for Large-Scale Wireless Hospital Sensor Networks

International audienceThe Utra Wide Band physical layer specified by the IEEE 802.15.4a standard [1] presents numerous advantages comparing with its original IEEE 802.15.4 standard, namely high accuracy positioning ability, high data rate up to 27 mbps, extended communication range, low power consumption and low complexity. Actually, many research and development activities focus on the design of UWB sensor nodes entities. However nodes interactions or network configuration are neglected. For that, we propose in this paper to investigate the use of UWB for large scale Wireless Hospital Sensor Networks (WHSNs) to benefit from the advantages offered by the UWB technology. This evolving networking paradigm promises to revolutionize healthcare by allowing inexpensive, non-invasive, pervasive and ubiquitous, ambulatory health monitoring. We present the design of new system architecture, based on IEEE 802.15.4a compliant sensors, suitable for health monitoring application in high dense hospital environment. The proposed system architecture is intended to support large-scale deployment and to improve the network performance in terms of energy efficiency, real-time guarantees and Quality-of-Service (QoS)

Redes de área corporal. Una perspectiva al futuro desde la investigación

Body Area Networks (BAN) is a growing field for such applications like Health monitoring and health related issues. Recently, new standards and technologies have been proposed, like Bluetooth, ZigBee, Ultra Wide Band (UWB), ECMA 386, WiFi, LTE, etc, oriented to provide solutions to different problems and requirements arising from our current life style. This document presents a revision of the current developments in Body Area Networks from a research point of view, revising aspects of standardization, applications and future trends in this amazing field.Actualmente, las redes de área corporal (Body Area Network) han logrado una especial relevancia, en particular por las tendencias que muestran su uso en la medicina, en aplicaciones de monitoreo y emergencia. Han surgido nuevos esquemas regulatorios y de estandarización, que han permitido la creación de nuevos estándares de comunicaciones, tales como Bluetooth, ZigBee, Ultra Wide Band (UWB), ECMA368, WiFi, GPRS, LTE, entre otros que tratan de dar soluciones a distintos retos y necesidades que surgen a medida que se incorporan estas tecnologías al estilo de vida. Este documento presenta el estado actual de las redes de área corporal desde una perspectiva de la investigación, que incluye un estado general de la regulación y estandarización de las redes de área corporal, la descripción de las aplicaciones y tendencias investigativas, y el posible futuro que enmarcan las comunicaciones de área personal

Performance Analysis for a Body Area Network composed of IEEE 802.15.4a devices

Body Area Networks (BANs) are wearable wireless sensor networks with a high potential for medical and sports applications. BANs appear to be a particularly appealing solution to provide information about the health status of a patient in medical environments such as hospitals or medical centres.This work analyzes the behaviour of a BAN composed of IEEE 802.15.4a ultra wideband (UWB) sensors. A Body Area Network architecture is proposed and investigated by simulation. Performance evaluation takes into account Bit Error Rate as a function of the number of nodes forming the BAN and of the asynchronism level between them. © 2007 IEEE

Human exposure to electromagnetic fields from WLANs and WBANs in the 2.4 GHz band

226 p.En los últimos años, el masivo crecimiento de las comunicaciones inalámbricas ha incrementado la preocupación acerca de la exposición humana a los campos electromagnéticos debido a los posibles efectos sobre la salud. Esta tesis surge de la necesidad de proporcionar información acerca de este tipo de exposición desde un punto de vista técnico. Por una parte, se han estudiado los niveles de exposición causados por señales WiFi, para lo cual ha sido necesario establecer un procedimiento de medida adecuado para tomar muestras de estas emisiones. Además, se han llevado a cabo campañas de medida para evaluar la exposición a señales WiFi y su variabilidad en el interior de un entorno público. Por otra parte, se ha analizado la potencia absorbida por el cuerpo humano a causa de los novedosos dispositivos wearables. Se han implementado dos antenas de este tipo, apropiadas para dispositivos wearables, se ha analizado detalladamente la exposición debida a estos aparatos y finalmente se han comparado los niveles de exposición producidos por estas antenas y por las señales WiFi

Energy-efficient design and implementation of turbo codes for wireless sensor network

The objective of this thesis is to apply near Shannon limit Error-Correcting Codes (ECCs), particularly the turbo-like codes, to energy-constrained wireless devices, for the purpose of extending their lifetime. Conventionally, sophisticated ECCs are applied to applications, such as mobile telephone networks or satellite television networks, to facilitate long range and high throughput wireless communication. For low power applications, such as Wireless Sensor Networks (WSNs), these ECCs were considered due to their high decoder complexities. In particular, the energy efficiency of the sensor nodes in WSNs is one of the most important factors in their design. The processing energy consumption required by high complexity ECCs decoders is a significant drawback, which impacts upon the overall energy consumption of the system. However, as Integrated Circuit (IC) processing technology is scaled down, the processing energy consumed by hardware resources reduces exponentially. As a result, near Shannon limit ECCs have recently begun to be considered for use in WSNs to reduce the transmission energy consumption [1,2]. However, to ensure that the transmission energy consumption reduction granted by the employed ECC makes a positive improvement on the overall energy efficiency of the system, the processing energy consumption must still be carefully considered.The main subject of this thesis is to optimise the design of turbo codes at both an algorithmic and a hardware implementation level for WSN scenarios. The communication requirements of the target WSN applications, such as communication distance, channel throughput, network scale, transmission frequency, network topology, etc, are investigated. Those requirements are important factors for designing a channel coding system. Especially when energy resources are limited, the trade-off between the requirements placed on different parameters must be carefully considered, in order to minimise the overall energy consumption. Moreover, based on this investigation, the advantages of employing near Shannon limit ECCs in WSNs are discussed. Low complexity and energy-efficient hardware implementations of the ECC decoders are essential for the target applications

Human exposure to electromagnetic fields from WLANs and WBANs in the 2.4 GHz band

226 p.En los últimos años, el masivo crecimiento de las comunicaciones inalámbricas ha incrementado la preocupación acerca de la exposición humana a los campos electromagnéticos debido a los posibles efectos sobre la salud. Esta tesis surge de la necesidad de proporcionar información acerca de este tipo de exposición desde un punto de vista técnico. Por una parte, se han estudiado los niveles de exposición causados por señales WiFi, para lo cual ha sido necesario establecer un procedimiento de medida adecuado para tomar muestras de estas emisiones. Además, se han llevado a cabo campañas de medida para evaluar la exposición a señales WiFi y su variabilidad en el interior de un entorno público. Por otra parte, se ha analizado la potencia absorbida por el cuerpo humano a causa de los novedosos dispositivos wearables. Se han implementado dos antenas de este tipo, apropiadas para dispositivos wearables, se ha analizado detalladamente la exposición debida a estos aparatos y finalmente se han comparado los niveles de exposición producidos por estas antenas y por las señales WiFi