1,222 research outputs found
A comprehensive survey of wireless body area networks on PHY, MAC, and network layers solutions
Recent advances in microelectronics and integrated circuits, system-on-chip design, wireless communication and intelligent low-power sensors have allowed the realization of a Wireless Body Area Network (WBAN). A WBAN is a collection of low-power, miniaturized, invasive/non-invasive lightweight wireless sensor nodes that monitor the human body functions and the surrounding environment. In addition, it supports a number of innovative and interesting applications such as ubiquitous healthcare, entertainment, interactive gaming, and military applications. In this paper, the fundamental mechanisms of WBAN including architecture and topology, wireless implant communication, low-power Medium Access Control (MAC) and routing protocols are reviewed. A comprehensive study of the proposed technologies for WBAN at Physical (PHY), MAC, and Network layers is presented and many useful solutions are discussed for each layer. Finally, numerous WBAN applications are highlighted
A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks
In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs
Autonomous optimization of UWB link access
We present a novel approach for interference management in low data rate IR-UWB networks that enables concurrent transmissions at full power while allows each source to independently adapt its pulse rate (transmitted pulses per second) to mitigate multi-user interference. The work is motivated by the fact that the distributed adaptation of IR-UWB pulse rate has not been sufficiently addressed in the literature before. Existing approaches rely on the presence of a central authority or assume a definite receiver technique. Our approach enables users to share the communication medium in an efficient way compatible with individual QoS requirements and it is independent of any particular modulation scheme or receiver technique
Diseños de capa cruzada para redes inalåmbricas de årea corporal energéticamente eficientes: una revisión
RESUMEN: El diseño de capa cruzada se considera una poderosa alternativa para dar soluciĂłn a las complejidades introducidas por las comunicaciones inalĂĄmbricas en redes de ĂĄrea corporal (WBAN), donde el modelo clĂĄsico de comunicaciones no ha exhibido un desempeño adecuado. Respecto al problema puntual de consumo de energĂa, hemos preparado la presente revisiĂłn de las publicaciones mĂĄs relevantes que tratan la eficiencia energĂ©tica para WBAN usando diseño de capa cruzada. En este artĂculo se proporciona una revisiĂłn exhaustiva de los avances en aproximaciones, protocolos y optimizaciones de capa cruzada cuyo objetivo es incrementar el tiempo de vida de las redes WBAN mediante el ahorro de energĂa. Luego, se discute los aspectos relevantes y deficiencias de las tĂ©cnicas de capa cruzada energĂ©ticamente eficientes. AdemĂĄs, se introducen aspectos de investigaciĂłn abiertos y retos en el diseño de capa cruzada para WBAN. En esta revisiĂłn proponemos una taxonomĂa de las aproximaciones de capa cruzada, de modo que las tĂ©cnicas revisadas se ajustan en categorĂas de acuerdo a los protocolos involucrados en el diseño. Una clasificaciĂłn novedosa se incluye para hacer claridad en los conceptos teĂłricos involucrados en cada esquema de capa cruzada y para luego agrupar aproximaciones similares evidenciando las diferencias con otras tĂ©cnicas entre sĂ. Nuestras conclusiones consideran los aspectos de movilidad y modelamiento del canal en escenarios de WBAN como las direcciones para futura investigaciĂłn en WBAN y en aplicaciones de telemedicina.ABSTRACT: Cross-layer design is considered a powerful alternative to solve the complexities of wireless communication in wireless body area networks (WBAN), where the classical communication model has been shown to be inaccurate. Regarding the energy consumption problem, we have prepared a current survey of the most relevant scientific publications on energy-efficient cross-layer design for WBAN. In this paper, we provide a comprehensive review of the advances in cross-layer approaches, protocols and optimizations aimed at increasing the network lifetime by saving energy in WBANs. Subsequently, we discuss the relevant aspects and shortcomings of these energy-efficient cross-layer techniques and point out the open research issues and challenges in WBAN cross-layer design. In this survey, we propose a taxonomy for cross-layer approaches to fit them into categories based on the protocols involved in the cross-layer scheme. A novel classification is included to clarify the theoretical concepts behind each cross-layer scheme; and to group similar approaches by establishing their differences from the other strategies reviewed. Our conclusion considers the aspects of mobility and channel modeling in WBAN scenarios as the directions of future cross-layer research for WBAN and telemedicine applications
A Joint PHY/MAC Architecture for Low-Radiated Power TH-UWB Wireless Ad-Hoc Networks
Due to environmental concerns and strict constraints on interference imposed on other networks, the radiated power of emerging pervasive wireless networks needs to be strictly limited, yet without sacrificing acceptable data rates. Pulsed Time-Hopping Ultra-Wide Band (TH-UWB) is a radio technology that has the potential to satisfy this requirement. Although TH-UWB is a multi-user radio technology, non-zero cross-correlation between time-hopping sequences, time-asynchronicity between sources and a multipath channel environment make it sensitive to strong interferers and near-far scenarios. While most protocols manage interference and multiple-access through power control or mutual exclusion (CSMA/CA or TDMA), we base our design on rate control, a relatively unexplored dimension for multiple-access and interference management. We further take advantage of the nature of pulsed TH-UWB to propose an interference mitigation scheme that reduces the impact of strong interferers. A source is always allowed to send and continuously adapts its channel code (hence its rate) to the interference experienced at the destination. In contrast to power control or exclusion, our MAC layer is local to sender and receiver and does not need coordination among neighbors not involved in the transmission. We show by simulation that we achieve a significant increase in network throughput
Energy-delay tradeoffs in impulse-based ultra-wideband body area networks with noncoherent receivers
© 2014 IEEE. In this paper we address the problem of rate scheduling in the Impulse Radio (IR) ultra-wideband (UWB) wireless body area networks (WBANs) and the minimum energy required to stabilize the queuing system. Targeting low complexity WBAN applications, we assume noncoherent receivers based on energy detection and autocorrelation for all nodes. The coordinating node can minimize the average energy consumption of the system and achieve the queue backlog stability of the sensor nodes by controlling the number of pulses per symbol. We first illustrate the necessary and sufficient conditions of network stability for a multi-mode UWB system and then propose a feasible rate scheduling algorithm based on the Lyapunov optimization theory. The scheduling algorithm uses the instantaneous channel state information and the length of the local queue of all sensor nodes and can approach the optimal energy-delay tradeoff of the network. We apply our theoretical framework to the IR-UWB physical layer of the IEEE 802.15.6 standard and extract the optimal physical layer modes that can achieve the desired energy-delay tradeoff
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Application priority framework for fixed mobile converged communication networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The current prospects in wired and wireless access networks, it is becoming increasingly important to address potential convergence in order to offer integrated broadband services. These systems will need to offer higher data transmission capacities and long battery life, which is the catalyst for an everincreasing variety of air interface technologies targeting local area to wide area connectivity. Current integrated industrial networks do not offer application aware context delivery and enhanced services for optimised networks. Application aware services provide value-added functionality to business applications by capturing, integrating, and consolidating intelligence about users and their endpoint devices from various points in the network. This thesis mainly intends to resolve the issues related to ubiquitous application aware service, fair allocation of radio access, reduced energy consumption and improved capacity. A technique that measures and evaluates the data rate demand to reduce application response time and queuing delay for multi radio interfaces is proposed. The technique overcomes the challenges of network integration, requiring no user intervention, saving battery life and selecting the radio access connection for the application requested by the end user. This study is split in two parts. The first contribution identifies some constraints of the services towards the application layer in terms of e.g. data rate and signal strength. The objectives are achieved by application controlled handover (ACH) mechanism in order to maintain acceptable data rate for real-time application services. It also looks into the impact of the radio link on the application and identifies elements and parameters like wireless link quality and handover that will influence the application type. It also identifies some enhanced traditional mechanisms such as distance controlled multihop and mesh topology required in order to support energy efficient multimedia applications. The second contribution unfolds an intelligent application priority assignment mechanism (IAPAM) for medical applications using wireless sensor networks. IAPAM proposes and evaluates a technique based on prioritising multiple virtual queues for the critical nature of medical data to improve instant transmission. Various mobility patterns (directed, controlled and random waypoint) has been investigated and compared by simulating IAPAM enabled mobile BWSN. The following topics have been studied, modelled, simulated and discussed in this thesis: 1. Application Controlled Handover (ACH) for multi radios over fibre 2. Power Controlled Scheme for mesh multi radios over fibre using ACH 3. IAPAM for Biomedical Wireless Sensor Networks (BWSN) and impact of mobility over IAPAM enabled BWSN. Extensive simulation studies are performed to analyze and to evaluate the proposed techniques. Simulation results demonstrate significant improvements in multi radios over fibre performance in terms of application response delay and power consumption by upto 75% and 15 % respectively, reduction in traffic loss by upto 53% and reduction in delay for real time application by more than 25% in some cases
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