1,914 research outputs found

    Wireless body area sensor networks signal processing and communication framework: Survey on sensing, communication technologies, delivery and feedback

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    Problem statement: The Wireless Body Area Sensor Networks (WBASNs) is a wireless network used for communication among sensor nodes operating on or inside the human body in order to monitor vital body parameters and movements.This study surveys the state-of-the-art on Wireless Body Area Networks, discussing the major components of research in this area including physiological sensing and preprocessing, WBASNs communication techniques and data fusion for gathering data from sensors.In addition, data analysis and feedback will be presented including feature extraction, detection and classification of human related phenomena.Approach: Comparative studies of the technologies and techniques used in such systems will be provided in this study, using qualitative comparisons and use case analysis to give insight on potential uses for different techniques.Results and Conclusion: Wireless Sensor Networks (WSNs) technologies are considered as one of the key of the research areas in computer science and healthcare application industries.Sensor supply chain and communication technologies used within the system and power consumption therein, depend largely on the use case and the characteristics of the application.Authors conclude that Life-saving applications and thorough studies and tests should be conducted before WBANs can be widely applied to humans, particularly to address the challenges related to robust techniques for detection and classification to increase the accuracy and hence the confidence of applying such techniques without physician intervention

    Practical rectennas : far-field RF power harvesting and transport

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    Ultra Small Antenna and Low Power Receiver for Smart Dust Wireless Sensor Networks

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    Wireless Sensor Networks have the potential for profound impact on our daily lives. Smart Dust Wireless Sensor Networks (SDWSNs) are emerging members of the Wireless Sensor Network family with strict requirements on communication node sizes (1 cubic centimeter) and power consumption (< 2mW during short on-states). In addition, the large number of communication nodes needed in SDWSN require highly integrated solutions. This dissertation develops new design techniques for low-volume antennas and low-power receivers for SDWSN applications. In addition, it devises an antenna and low noise amplifier co-design methodology to increase the level of design integration, reduce receiver noise, and reduce the development cycle. This dissertation first establishes stringent principles for designing SDWSN electrically small antennas (ESAs). Based on these principles, a new ESA, the F-Inverted Compact Antenna (FICA), is designed at 916MHz. This FICA has a significant advantage in that it uses a small-size ground plane. The volume of this FICA (including the ground plane) is only 7% of other state-of-the-art ESAs, while its efficiency (48.53%) and gain (-1.38dBi) are comparable to antennas of much larger dimensions. A physics-based circuit model is developed for this FICA to assist system level design at the earliest stage, including optimization of the antenna performance. An antenna and low noise amplifier (LNA) co-design method is proposed and proven to be valid to design low power LNAs with the very low noise figure of only 1.5dB. To reduce receiver power consumption, this dissertation proposes a novel LNA active device and an input/ouput passive matching network optimization method. With this method, a power efficient high voltage gain cascode LNA was designed in a 0.13um CMOS process with only low quality factor inductors. This LNA has a 3.6dB noise figure, voltage gain of 24dB, input third intercept point (IIP3) of 3dBm, and power consumption of 1.5mW at 1.0V supply voltage. Its figure of merit, using the typical definition, is twice that of the best in the literature. A full low power receiver is developed with a sensitivity of -58dBm, chip area of 1.1mm2, and power consumption of 2.85mW

    Wireless Sensor Network: At a Glance

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    Average Load Distance (ALD) radio communication model for wireless sensor networks

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    The lifetime of network is one of the most critical issues that have to be considered in the application of wireless sensor networks. The network nodes are battery powered and remain operational as long as they can transmit the sensed data to the processing (sink) node. The main energy consumption of sensor node can be attributed to the task of data transmission to sink node or cluster head. Hence, conserving energy in transmitting data shall maximize functional life of the wireless networks. In this paper we proposed a computationally efficient Average Load Distance (ALD) communication model for forwarding data from sensor to the cluster head. Experiment results indicate that the proposed model can be up to 88% more efficient over direct mode of communication, in respect of per-round maximum energy consumption. An application study shows that ALD can save up to 89% of wireless sensor networks operational cost when compared to direct mode transmission

    A review of Energy Hole mitigating techniques in multi-hop many to one communication and its significance in IoT oriented Smart City infrastructure

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    A huge increase in the percentage of the world's urban population poses resource management, especially energy management challenges in smart cities. In this paper, the growing challenges of energy management in smart cities have been explored and the significance of elimination of energy holes in converge cast communication has been discussed. The impact of mitigation of energy holes on the network lifetime and energy efficiency has been thoroughly covered. The particular focus of this work has been on energy-efficient practices in two major key enablers of smart cities namely, the Internet of Things (IoT) and Wireless Sensor Networks (WSNs). In addition, this paper presents a robust survey of state-of-the-art energy-efficient routing and clustering methods in WSNs. A niche energy efficiency issue in WSNs routing has been identified as energy holes and a detailed survey and evaluation of various techniques that mitigate the formation of energy holes and achieve balanced energy-efficient routing has been covered

    Evaluation of Energy Costs and Error Performance of Range-Aware Anchor-Free Localization Algorithms for Wireless Sensor Networks

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    This research examines energy and error tradeoffs in Anchor-Free Range-Aware Wireless Sensor Network (WSN) Localization algorithms. A concurrent and an incremental algorithm (Anchor Free Localization (AFL) and Map Growing) are examined under varying network sizes, densities, deployments, and range errors. Despite current expectations, even the most expensive configurations do not expend significant battery life (at most 0.4%), implying little energy can be conserved during localization. Due to refinement, AFL is twice as accurate, using 6 times the communication. For both, node degree affects communication most. As degree increases, Map Growing communication increases, while AFL transmissions drop. Nodes with more neighbors refine quicker with fewer messages. At high degree, many nodes receive the same message, overpowering the previous effect, and raising AFL received bits. Built from simulation data, the Energy Consumption Model predicts energy usage of incremental and concurrent algorithms used in networks with varying size, density, and deployments. It is applied to current wireless sensor nodes. Military WSNs should be flexible, cheap, and long lasting. Anchor-Free, Range-Aware algorithms best fit this need

    Zenneck Waves in Decision Agriculture: An Empirical Verification and Application in EM-Based Underground Wireless Power Transfer

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    In this article, the results of experiments for the observation of Zenneck surface waves in sub GHz frequency range using dipole antennas are presented. Experiments are conducted over three different soils for communications distances of up to 1 m. This empirical analysis confirms the existence of Zenneck waves over the soil surface. Through the power delay profile (PDP) analysis, it has been shown that other subsurface components exhibit rapid decay as compared to the Zenneck waves. A potential application of the Zenneck waves for energy transmission in the area of decision agriculture is explored. Accordingly, a novel wireless through-the-soil power transfer application using Zenneck surface waves in electromagnetic (EM) based wireless underground communications is developed
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