Showing papers on "Key distribution in wireless sensor networks published in 2013"

Wireless Sensor Network -A Survey

Abstract: Wireless sensor networks are the networks consisting of large number of small and tiny sensor nodes. The nodes are supplied with limited power, memory and other resources and perform in-network processing. In this paper, various issues are discussed that actually put the limitations in the well working and the life time of the network. In Wireless sensor network, nodes should consume less power, memory and so data aggregation should be performed. Security is another aspect which should be present in the network. Quality of service, routing, medium access schemes all are considered in designing the protocols.

Throughput Maximization in Wireless Powered Communication Networks

Abstract: This paper studies the newly emerging wireless powered communication network in which one hybrid access point (H-AP) with constant power supply coordinates the wireless energy/information transmissions to/from a set of distributed users that do not have other energy sources. A "harvest-then-transmit" protocol is proposed where all users first harvest the wireless energy broadcast by the H-AP in the downlink (DL) and then send their independent information to the H-AP in the uplink (UL) by time-division-multiple-access (TDMA). First, we study the sum-throughput maximization of all users by jointly optimizing the time allocation for the DL wireless power transfer versus the users' UL information transmissions given a total time constraint based on the users' DL and UL channels as well as their average harvested energy values. By applying convex optimization techniques, we obtain the closed-form expressions for the optimal time allocations to maximize the sum-throughput. Our solution reveals an interesting "doubly near-far" phenomenon due to both the DL and UL distance-dependent signal attenuation, where a far user from the H-AP, which receives less wireless energy than a nearer user in the DL, has to transmit with more power in the UL for reliable information transmission. As a result, the maximum sum-throughput is shown to be achieved by allocating substantially more time to the near users than the far users, thus resulting in unfair rate allocation among different users. To overcome this problem, we furthermore propose a new performance metric so-called common-throughput with the additional constraint that all users should be allocated with an equal rate regardless of their distances to the H-AP. We present an efficient algorithm to solve the common-throughput maximization problem. Simulation results demonstrate the effectiveness of the common-throughput approach for solving the new doubly near-far problem in wireless powered communication networks.

Design of a WSN Platform for Long-Term Environmental Monitoring for IoT Applications

Abstract: The Internet of Things (IoT) provides a virtual view, via the Internet Protocol, to a huge variety of real life objects, ranging from a car, to a teacup, to a building, to trees in a forest. Its appeal is the ubiquitous generalized access to the status and location of any “thing” we may be interested in. Wireless sensor networks (WSN) are well suited for long-term environmental data acquisition for IoT representation. This paper presents the functional design and implementation of a complete WSN platform that can be used for a range of long-term environmental monitoring IoT applications. The application requirements for low cost, high number of sensors, fast deployment, long lifetime, low maintenance, and high quality of service are considered in the specification and design of the platform and of all its components. Low-effort platform reuse is also considered starting from the specifications and at all design levels for a wide array of related monitoring applications.

Wireless power transfer and applications to sensor networks

Abstract: Energy constraints are widely regarded as a fundamental limitation of wireless and mobile devices. For sensor networks, a limited lifetime due to battery constraint poses a performance bottleneck and barrier for large scale deployment. Recently, wireless power transfer has emerged as a promising technology to address energy and lifetime bottlenecks in a sensor network. In this article, we give a review of the history of wireless power transfer and describe its recent developments. We show how such technologies can be applied to sensor networks and address their energy constraints.

Localization algorithms of Wireless Sensor Networks: a survey

Abstract: In Wireless Sensor Networks (WSNs), localization is one of the most important technologies since it plays a critical role in many applications, e.g., target tracking. If the users cannot obtain the accurate location information, the related applications cannot be accomplished. The main idea in most localization methods is that some deployed nodes (landmarks) with known coordinates (e.g., GPS-equipped nodes) transmit beacons with their coordinates in order to help other nodes localize themselves. In general, the main localization algorithms are classified into two categories: range-based and range-free. In this paper, we reclassify the localization algorithms with a new perspective based on the mobility state of landmarks and unknown nodes, and present a detailed analysis of the representative localization algorithms. Moreover, we compare the existing localization algorithms and analyze the future research directions for the localization algorithms in WSNs.

A Survey on Distributed Topology Control Techniques for Extending the Lifetime of Battery Powered Wireless Sensor Networks

Abstract: Large-scale, self-organizing wireless sensor and mesh network deployments are being driven by recent technological developments such as The Internet of Things (IoT), Smart Grids and Smart Environment applications. Efficient use of the limited energy resources of wireless sensor network (WSN) nodes is critically important to support these advances, and application of topology control methods will have a profound impact on energy efficiency and hence battery lifetime. In this survey, we focus on the energy efficiency issue and present a comprehensive study of topology control techniques for extending the lifetime of battery powered WSNs. First, we review the significant topology control algorithms to provide insights into how energy efficiency is achieved by design. Further, these algorithms are classified according to the energy conservation approach they adopt, and evaluated by the trade-offs they offer to aid designers in selecting a technique that best suits their applications. Since the concept of "network lifetime" is widely used for assessing the algorithms' performance, we highlight various definitions of the term and discuss their merits and drawbacks. Recently, there has been growing interest in algorithms for non-planar topologies such as deployments in underwater environments or multi-level buildings. For this reason, we also include a detailed discussion of topology control algorithms that work efficiently in three dimensions. Based on the outcomes of our review, we identify a number of open research issues for achieving energy efficiency through topology control.

A Survey on Topology Control in Wireless Sensor Networks: Taxonomy, Comparative Study, and Open Issues

Abstract: The wireless sensor network (WSN) technology spawns a surge of unforeseen applications. The diversity of these emerging applications represents the great success of this technology. A fundamental performance benchmark of such applications is topology control, which characterizes how well a sensing field is monitored and how well each pair of sensors is mutually connected in WSNs. This paper provides an overview of topology control techniques. We classify existing topology control techniques into two categories: network coverage and network connectivity. For each category, a surge of existing protocols and techniques are presented with the focus on blanket coverage, barrier coverage, sweep coverage, power management, and power control, five rising aspects that attract significant research attention in recent years. In this survey, we emphasize the basic principles of topology control to understand the state of the arts, while we explore future research directions in the new open areas and propose a series of design guidelines under this topic.

An Efficient Genetic Algorithm for Maximum Coverage Deployment in Wireless Sensor Networks

Abstract: Sensor networks have a lot of applications such as battlefield surveillance, environmental monitoring, and industrial diagnostics. Coverage is one of the most important performance metrics for sensor networks since it reflects how well a sensor field is monitored. In this paper, we introduce the maximum coverage deployment problem in wireless sensor networks and analyze the properties of the problem and its solution space. Random deployment is the simplest way to deploy sensor nodes but may cause unbalanced deployment and therefore, we need a more intelligent way for sensor deployment. We found that the phenotype space of the problem is a quotient space of the genotype space in a mathematical view. Based on this property, we propose an efficient genetic algorithm using a novel normalization method. A Monte Carlo method is adopted to design an efficient evaluation function, and its computation time is decreased without loss of solution quality using a method that starts from a small number of random samples and gradually increases the number for subsequent generations. The proposed genetic algorithms could be further improved by combining with a well-designed local search. The performance of the proposed genetic algorithm is shown by a comparative experimental study. When compared with random deployment and existing methods, our genetic algorithm was not only about twice faster, but also showed significant performance improvement in quality.

Low-Power Far-Field Wireless Powering for Wireless Sensors

Abstract: This paper discusses far-field wireless powering for low-power wireless sensors, with applications to sensing in environments where it is difficult or impossible to change batteries and where the exact position of the sensors might not be known. With expected radio-frequency (RF) power densities in the 20-200- μW/cm2 range, and desired small sensor overall size, low-power nondirective wireless powering is appropriate for sensors that transmit data at low duty cycles. The sensor platform is powered through an antenna which receives incident electromagnetic waves in the gigahertz frequency range, couples the energy to a rectifier circuit which charges a storage device (e.g., thin-film battery) through an efficient power management circuit, and the entire platform, including sensors and a low-power wireless transmitter, and is controlled through a low-power microcontroller. For low incident power density levels, codesign of the RF powering and the power management circuits is required for optimal performance. Results for hybrid and monolithic implementations of the power management circuitry are presented with integrated antenna rectifiers operating in the 1.96-GHz cellular and in 2.4-GHz industrial-scientific-medical (ISM) bands.

Load-Balanced Clustering Algorithm With Distributed Self-Organization for Wireless Sensor Networks

Abstract: Wireless sensor networks (WSNs) are composed of a large number of inexpensive power-constrained wireless sensor nodes, which detect and monitor physical parameters around them through self-organization. Utilizing clustering algorithms to form a hierarchical network topology is a common method of implementing network management and data aggregation in WSNs. Assuming that the residual energy of nodes follows the random distribution, we propose a load-balanced clustering algorithm for WSNs on the basis of their distance and density distribution, making it essentially different from the previous clustering algorithms. Simulated tests indicate that the new algorithm can build more balanceable clustering structure and enhance the network life cycle.

Does Wireless Sensor Network Scale? A Measurement Study on GreenOrbs

Abstract: Sensor networks are deemed suitable for large-scale deployments in the wild for a variety of applications. In spite of the remarkable efforts the community put to build the sensor systems, an essential question still remains unclear at the system level, motivating us to explore the answer from a point of real-world deployment view. Does the wireless sensor network really scale? We present findings from a large-scale operating sensor network system, GreenOrbs, with up to 330 nodes deployed in the forest. We instrument such an operating network throughout the protocol stack and present observations across layers in the network. Based on our findings from the system measurement, we propose and make initial efforts to validate three conjectures that give potential guidelines for future designs of large-scale sensor networks. 1) A small portion of nodes bottlenecks the entire network, and most of the existing network indicators may not accurately capture them. 2) The network dynamics mainly come from the inherent concurrency of network operations instead of environment changes. 3) The environment, although the dynamics are not as significant as we assumed, has an unpredictable impact on the sensor network. We suggest that an event-based routing structure can be trained and thus better adapted to the wild environment when building a large-scale sensor network.

Cognitive Radio Wireless Sensor Networks: Applications, Challenges and Research Trends

Abstract: A cognitive radio wireless sensor network is one of the candidate areas where cognitive techniques can be used for opportunistic spectrum access. Research in this area is still in its infancy, but it is progressing rapidly. The aim of this study is to classify the existing literature of this fast emerging application area of cognitive radio wireless sensor networks, highlight the key research that has already been undertaken, and indicate open problems. This paper describes the advantages of cognitive radio wireless sensor networks, the difference between ad hoc cognitive radio networks, wireless sensor networks, and cognitive radio wireless sensor networks, potential application areas of cognitive radio wireless sensor networks, challenges and research trend in cognitive radio wireless sensor networks. The sensing schemes suited for cognitive radio wireless sensor networks scenarios are discussed with an emphasis on cooperation and spectrum access methods that ensure the availability of the required QoS. Finally, this paper lists several open research challenges aimed at drawing the attention of the readers toward the important issues that need to be addressed before the vision of completely autonomous cognitive radio wireless sensor networks can be realized.

A novel evolutionary approach for load balanced clustering problem for wireless sensor networks

Abstract: Clustering sensor nodes is an effective topology control method to reduce energy consumption of the sensor nodes for maximizing lifetime of Wireless Sensor Networks (WSNs). However, in a cluster based WSN, the leaders (cluster heads) bear some extra load for various activities such as data collection, data aggregation and communication of the aggregated data to the base station. Therefore, balancing the load of the cluster heads is a challenging issue for the long run operation of the WSNs. Load balanced clustering is known to be an NP-hard problem for a WSN with unequal load of the sensor nodes. Genetic Algorithm (GA) is one of the most popular evolutionary approach that can be applied for finding the fast and efficient solution of such problem. In this paper, we propose a novel GA based load balanced clustering algorithm for WSN. The proposed algorithm is shown to perform well for both equal as well as unequal load of the sensor nodes. We perform extensive simulation of the proposed method and compare the results with some evolutionary based approaches and other related clustering algorithms. The results demonstrate that the proposed algorithm performs better than all such algorithms in terms of various performance metrics such as load balancing, execution time, energy consumption, number of active sensor nodes, number of active cluster heads and the rate of convergence.

Integration of wearable devices in a wireless sensor network for an E-health application

Abstract: Applications based on Wireless Sensor Networks for Internet of Things scenarios are on the rise. The multiple possibilities they offer have spread towards previously hard to imagine fields, like e-health or human physiological monitoring. An application has been developed for its usage in scenarios where data collection is applied to smart spaces, aiming at its usage in fire fighting and sports. This application has been tested in a gymnasium with real, non-simulated nodes and devices. A Graphic User Interface has been implemented to suggest a series of exercises to improve a sportsman/woman s condition, depending on the context and their profile. This system can be adapted to a wide variety of e-health applications with minimum changes, and the user will interact using different devices, like smart phones, smart watches and/or tablets.

Method and apparatus for wirelessly charging multiple wireless power receivers

Abstract: A method and apparatus are provided for transmitting wireless power to at least one wireless power receiver. The apparatus includes a communication unit that receives power management information from the at least one wireless power receiver, wherein the power management information includes a power capacity of each of the at least one wireless power receiver; and a controller that analyzes the power management information and determines whether an output capacity of the wireless power transmitter is greater than a total sum of the power capacities of the at least one wireless power receiver.

Energy Efficient Routing in Wireless Sensor Networks Through Balanced Clustering

Abstract: The wide utilization of Wireless Sensor Networks (WSNs) is obstructed by the severely limited energy constraints of the individual sensor nodes. This is the reason why a large part of the research in WSNs focuses on the development of energy efficient routing protocols. In this paper, a new protocol called Equalized Cluster Head Election Routing Protocol (ECHERP), which pursues energy conservation through balanced clustering, is proposed. ECHERP models the network as a linear system and, using the Gaussian elimination algorithm, calculates the combinations of nodes that can be chosen as cluster heads in order to extend the network lifetime. The performance evaluation of ECHERP is carried out through simulation tests, which evince the effectiveness of this protocol in terms of network energy efficiency when compared against other well-known protocols.

Algorithm design for data communications in duty-cycled wireless sensor networks: A survey

Abstract: Although duty-cycling has long been a critical mechanism for energy conservation in wireless sensor networks, it is only recently that research efforts have been put to design data communication protocols that perform efficiently in duty-cycled wireless sensor networks (DC-WSNs). In this article, we survey these research problems, aiming at revealing insights into the following three key questions: what are the meaningful (algorithm design) problems for DC-WSNs, which problems have been studied and which have not, and what are the essential techniques behind the existing solutions? All these insights may serve as motivations and inspirations for further developments in this field.

Method and apparatus for providing wireless charging power to a wireless power receiver

Abstract: A method and apparatus for transmitting charging power to a wireless power receiver. The method includes detecting the wireless power receiver by applying different detection powers with different power levels; applying a driving power to drive the detected wireless power receiver; receiving a request signal for communication from the detected wireless power receiver using the driving power; determining whether or not to subscribe the detected wireless power receiver to a wireless power network; transmitting, to the detected wireless power receiver, a response signal to the request signal for communication, the response signal indicating whether or not the detected wireless power receiver is subscribed to the wireless power network; and transmitting charging power to the detected wireless power receiver, when the detected wireless power receiver is subscribed to the wireless power network.

Wireless charging and powering of healthcare gadgets and sensors

Abstract: The present disclosure provides wireless charging and powering methods for healthcare gadgets and wireless sensors. The method may include wireless power transmission through suitable techniques such as pocket-forming. The methods may include one or more transmitters and one or more receivers. In some embodiments the transmitters and receivers may be embedded to medical devices and wireless sensors, respectively. In other embodiments, the receiver may be integrated into wireless sensors. In yet another embodiment, the transmitters may be positioned on strategic places so as to have a wider range for wireless power transmission to portable electronic medical devices and wireless sensors.

Improvement on LEACH Protocol of Wireless Sensor Network

Abstract: Wireless sensor networks comprise of minor battery driven devices with restricted energy resourcesOnce installed,the minor sensor nodes are usually unapproachable to the operator, and thus auxiliary of the energy source is not practicableHence,energy proficiency is a vital design issue that needs to be boosted in order to increase the lifetime of the network LEACH is a popular hierarchical routing protocol which efficiently maintains the energy storage of nodes in Wireless Sensor Network (WSN)The nodes using LEACH are divided into clustersThe advantage of LEACH is that each node has the equal probability to be a cluster head,which makes the energy dissipation of each node be relatively balanced This paper studies LEACH protocol, and focuses on how to decide the next hop nodes more reasonable when the data are transmitted at the steady state Simulation has been done in NS2 and the results show that the algorithm after improved is more energy-efficient than LEACH protocol

Fault Diagnosis in Wireless Sensor Networks: A Survey

Abstract: The sensor nodes in wireless sensor networks may be deployed in unattended and possibly hostile environments. The ill-disposed environment affects the monitoring infrastructure that includes the sensor nodes and the network. In addition, node failures and environmental hazards cause frequent topology changes, communication failures, and network partitioning. This in turn adds a new dimension to the fragility of the network topology. Such perturbations are far more common than those found in conventional wireless networks thus, demand efficient techniques for discovering disruptive behavior in such networks. Traditional fault diagnosis techniques devised for multiprocessor systems are not directly applicable to wireless sensor networks due to their specific requirements and limitations. This survey integrates research efforts that have been produced in fault diagnosis specifically for wireless sensor networks. The survey aims at clarifying and uncovering the potential of this technology by providing the technique-based taxonomy. The fault diagnosis techniques are classified based on the nature of the tests, correlation between sensor readings and characteristics of sensor nodes and the network.

Robust Analog Function Computation via Wireless Multiple-Access Channels

Abstract: Wireless sensor network applications often involve the computation of pre-defined functions of the measurements such as for example the arithmetic mean or maximum value. Standard approaches to this problem separate communication from computation: digitized sensor readings are transmitted interference-free to a fusion center that reconstructs each sensor reading and subsequently computes the sought function value. Such separation-based computation schemes are generally highly inefficient as a complete reconstruction of individual sensor readings at the fusion center is not necessary to compute a function of them. In particular, if the mathematical structure of the channel is suitably matched (in some sense) to the function of interest, then channel collisions induced by concurrent transmissions of different nodes can be beneficially exploited for computation purposes. This paper proposes an analog computation scheme that allows for an efficient estimate of linear and nonlinear functions over the wireless multiple-access channel. A match between the channel and the function being evaluated is thereby achieved via some pre-processing on the sensor readings and post-processing on the superimposed signals observed by the fusion center. After analyzing the estimation error for two function examples, simulations are presented to show the potential for huge performance gains over time- and code-division multiple-access based computation schemes.

Practical Secure Communication for Integrating Wireless Sensor Networks Into the Internet of Things

Abstract: If a wireless sensor network (WSN) is integrated into the Internet as a part of the Internet of things (IoT), there will appear new security challenges, such as setup of a secure channel between a sensor node and an Internet host. In this paper, we propose a heterogeneous online and offline signcryption scheme to secure communication between a sensor node and an Internet host. We prove that this scheme is indistinguishable against adaptive chosen ciphertext attacks under the bilinear Diffie-Hellman inversion problem and existential unforgeability against adaptive chosen messages attacks under the q-strong Diffie-Hellman problem in the random oracle model. Our scheme has the following advantages. First, it achieves confidentiality, integrity, authentication, and non-repudiation in a logical single step. Second, it allows a sensor node in an identity-based cryptography to send a message to an Internet host in a public key infrastructure. Third, it splits the signcryption into two phases: i) offline phase; and ii) online phase. In the offline phase, most heavy computations are done without the knowledge of a message. In the online phase, only light computations are done when a message is available. Our scheme is very suitable to provide security solution for integrating WSN into the IoT.

Minimizing charging delay in wireless rechargeable sensor networks

Abstract: As a pioneering experimental platform of wireless rechargeable sensor networks, the Wireless Identification and Sensing Platform (WISP) is an open-source platform that integrates sensing and computation capabilities to the traditional RFID tags. Different from traditional tags, a RFID-based wireless rechargeable sensor node needs to charge its onboard energy storage above a threshold in order to power its sensing, computation and communication components. Consequently, such charging delay imposes a unique design challenge for deploying wireless rechargeable sensor networks. In this paper, we tackle this problem by planning the optimal movement strategy of the RFID reader, such that the time to charge all nodes in the network above their energy threshold is minimized. We first propose an optimal solution using the linear programming method. To further reduce the computational complexity, we then introduce a heuristic solution with a provable approximation ratio of (1 + θ)/(1 - e) by discretizing the charging power on a two-dimensional space. Through extensive evaluations, we demonstrate that our design outperforms the set-cover-based design by an average of 24.7% while the computational complexity is O((N/e)2).

Context-Adaptive Multimodal Wireless Sensor Network for Energy-Efficient Gas Monitoring

Abstract: We present a wireless sensor network (WSN) for monitoring indoor air quality, which is crucial for people's comfort, health, and safety because they spend a large percentage of time in indoor environments A major concern in such networks is energy efficiency because gas sensors are power-hungry, and the sensor node must operate unattended for several years on a battery power supply A system with aggressive energy management at the sensor level, node level, and network level is presented The node is designed with very low sleep current consumption (only 8 μA), and it contains a metal oxide semiconductor gas sensor and a pyroelectric infrared (PIR) sensor Furthermore, the network is multimodal; it exploits information from auxiliary sensors, such as PIR sensors about the presence of people and from the neighbor nodes about gas concentration to modify the behavior of the node and the measuring frequency of the gas concentration In this way, we reduce the nodes' activity and energy requirements, while simultaneously providing a reliable service To evaluate our approach and the benefits of the context-aware adaptive sampling, we simulate an application scenario which demonstrates a significant lifetime extension (several years) compared to the continuously-driven gas sensor In March 2012, we deployed the WSN with 36 nodes in a four-story building and by now the performance has confirmed models and expectations

A Survey on Mobility and Mobility-Aware MAC Protocols in Wireless Sensor Networks

Abstract: In wireless sensor networks nodes can be static or mobile, depending on the application requirements. Dealing with mobility can pose some formidable challenges in protocol design, particularly, at the link layer. These difficulties require mobility adaptation algorithms to localize mobile nodes and predict the quality of link that can be established with them. This paper surveys the current state-of-art in handling mobility. It first describes existing mobility models and patterns; and analyzes the challenges caused by mobility at the link layer. It then provides a comparative study of several mobility-aware MAC protocols.

LIGHTNETs: Smart LIGHTing and Mobile Optical Wireless NETworks — A Survey

Abstract: Recently, rapid increase of mobile devices pushed the radio frequency (RF)-based wireless technologies to their limits. Free-space-optical (FSO), a.k.a. optical wireless, communication has been considered as one of the viable solutions to respond to the ever-increasing wireless capacity demand. Particularly, Visible Light Communication (VLC) which uses light emitting diode (LED) based smart lighting technology provides an opportunity and infrastructure for the high-speed low-cost wireless communication. Though stemming from the same core technology, the smart lighting and FSO communication have inherent tradeoffs amongst each other. In this paper, we present a tutorial and survey of advances in these two technologies and explore the potential for integration of the two as a single field of study: LIGHTNETs. We focus our survey to the context of mobile communications given the recent pressing needs in mobile wireless networking. We deliberate on key challenges involved in designing technologies jointly performing the two functions simultaneously: LIGHTing and NETworking.

Compression in wireless sensor networks: A survey and comparative evaluation

Abstract: Wireless sensor networks (WSNs) are highly resource constrained in terms of power supply, memory capacity, communication bandwidth, and processor performance. Compression of sampling, sensor data, and communications can significantly improve the efficiency of utilization of three of these resources, namely, power supply, memory and bandwidth. Recently, there have been a large number of proposals describing compression algorithms for WSNs. These proposals are diverse and involve different compression approaches. It is high time that these individual efforts are put into perspective and a more holistic view taken. In this article, we take a step in that direction by presenting a survey of the literature in the area of compression and compression frameworks in WSNs. A comparative study of the various approaches is also provided. In addition, open research issues, challenges and future research directions are highlighted.