Search results for "Wireless sensor networks"
showing 10 items of 159 documents
MAC Protocols for WuR Enabled WSNs : Design and Performance Evaluation
2017
Master's thesis Information- and communication technology IKT591 - University of Agder 2017 Increasing energy efficiency is a challenging task for protocol design in wireless sensor networks (WSNs) as well as in Internet of things (IoT). Traditionally, duty-cycled (DC) protocols have been widely adopted for data transmissions in WSNs for energy conservation by reducing idle listening and overhearing. Recently, wake-up radio (WuR) has merged as a promising technique to replace DC protocols thanks to its superior performance in both network lifetime and transmission latency. This thesis work focuses on the design and performance evaluation of WuR-enabled MAC protocols considering various traf…
Advanced Monitoring Systems Based on Battery-Less Asset Tracking Modules Energized through RF Wireless Power Transfer
2020
Asset tracking involving accurate location and transportation data is highly suited to wireless sensor networks (WSNs) featuring battery-less nodes that can be deployed in virtually any environment and require little or no maintenance. In response to the growing demand for advanced battery-less sensor tag solutions, this article presents a system for identifying and monitoring the speeds of assets in a WSN with battery-less tags that receive all their operating energy through radio frequency (RF) wireless power transfer (WPT) architecture, and a unique measurement approach to generate time-domain speed readouts. The assessment includes performance characteristics and key features of a syste…
Optimized secure and reliable distributed data storage scheme and performance evaluation in unattended WSNs
2013
Unattended Wireless Sensor Networks (UWSNs), characterized by the absence of real-time communication between sensors and sinks, impose sensors to retain data till the next visit of a mobile sink to off-load their data. In such networks, if a sensor is compromised, data accumulated in the sensor are exposed to attackers. In addition, by holding the secret key of the compromised sensor, attackers can also learn post-compromise data accumulated by the sensor. Furthermore, once sensors stop working due to, for instance, node crash or battery depletion, all the accumulated data will be lost. In this paper, we propose a secure and reliable data distribution scheme that addresses these challenges.…
Concurrent and Distributed Projection through Local Interference for Wireless Sensor Networks
2012
In this paper we use a gossip algorithm to obtain the projection of the observed signal into a subspace of lower dimension. Gossip algorithms allow distributed, fast and efficient computations on a Wireless Sensor Network and they can be properly modified to evaluate the sought projection. By combining computation coding with gossip algorithms we proposed a novel strategy that leads to important saving on convergence time as well as exponentially decreasing energy consumption, as the size of the network increases.
An Efficient, Robust, and Scalable Trust Management Scheme for Unattended Wireless Sensor Networks
2012
Unattended Wireless Sensor Networks (UWSNs) are characterized by long periods of disconnected operation and fixed or irregular intervals between visits by the sink. The absence of an online trusted third party, i.e., an on-site sink, makes existing trust management schemes used in legacy wireless sensor networks not applicable to UWSNs directly. In this paper, we propose a trust management scheme for UWSNs to provide efficient, robust and scalable trust data storage. For trust data storage, we employ geographic hash table to efficiently identify data storage nodes and to significantly reduce storage cost. We demonstrate, through detailed analyses and extensive simulations, that the proposed…
Printed Antennas for Sensor Applications: A Review
2014
With the expansion in number and requirements of modern wireless communications, the technology related to their associated antennas has been continuously improved. Among other options, printed antennas offer excellent features, such as low weight, profile, and cost, while maintaining good performance characteristics. In addition, their straightforward integration with electronics has opened new fields of application such as smart sensing systems. Printed antennas can be used in different parts of a wireless smart sensor as a radio link, sensing element, or even as energy harvester. In this paper, we present a thorough review of recent advances of printed antennas as regards their use in sm…
A hybrid network for maritime on-board communications
2012
Current maritime on-board communications have to be enhanced for safety and security, where ubiquitous technologies can help, together with providing comfort and convenience to the crew and passengers. Employing wireless sensor networks on board is one recent practice of implementing ubiquitous technology for ships, where further study is needed because of the connectivity challenges. Meanwhile, it is important for an on-board communication system to be reliable and flexible for handling emergency situations. In this paper, we propose a solution of employing ubiquitous technology on ships in a way that both connectivity and emergency handling are examined. Two key aspects of this proposal a…
Towards a layer-less network architecture — A case from Wireless Sensor Networks
2011
Ad hoc and Wireless Sensor Networks (WSNs) form a challenging domain for existing network protocols and paradigms to fit into. The traditional models conceived for wired networking and adapted for wireless and mobile environments provide an inefficient and ungraceful outcome when exercised against highly dynamic and highly mobile nature of ad hoc wireless sensor networks. Efforts are being made to tweak existing (and sometimes create from scratch) principles and models that can provide a concrete framework for such newer paradigms. The momentum of the traditional layered architecture carried over from the wired networks to infrastructure based wireless networks pushes the same approaches as…
A Multisensor Proposal for Wireless Sensor Networks
2008
Every sensor node in a wireless sensor network (WSN) has a microcontroller, a transmitter/receiver and a sensor. It is able to acquire data from specific point in a real environment and transmit it through the WSN. Sometimes it is useful to gather different type of data from the same place in order to obtain a final result. In the related literature, very few works are about sensing different parameters using a unique sensor. In this paper we propose a Wireless IP multisensor that is able to gather several types of data from the environment and transmit the result of their combination. Our proposal decision has being mainly based on its development costs, its expansion capacity and its flex…
A Note on the Local Minimum Problem in Wireless Sensor Networks
2013
The Local Minimum Problem occurs in geographic routing scenarios. In this paper two solutions to this problem for certain network topologies are proposed. By using the notion of virtual coordinates a theoretical and a practical constructions are presented. A distributed algorithm for the practical approach is proposed.