Development of a Novel Bidirectional Control Telecare System over a Wireless Sensor Network and the Internet

Agriculture industries are comparatively slow in adopting emerging technologies than any other industries despite lot of exciting research. The use of Wireless sensor network (WSN) is very important role in agriculture for more productive and sustainable growth. The structure of WSN is tightly application dependent. Every WSN have sensors, processing unit, low frequency radio wave transmitter and power supply using battery. With increasing number of interconnected WSN devices, there is substantial increase in data generation. It contains both control messages as well as application dependent data, collected by the sensors. The collected data are frequently sent to the nearest centralized controller for further processing and decision making. For continuous functioning of WSN, uninterrupted power supply is needed. Many researches are carried out to overcome these challenges. In this manuscript we are proposing a simple and effective machine learning techniques combined with pause and play method to increase battery life of WSN. This could be achieved in three stages play-pause-play (PPP) model. First by gathering data for some time (play mode), Second by putting WSN to sleep (pause mode), in the backend, apply machine learning algorithm that helps to build model from training data to predict the future data. At the final stage, put WSN back to play mode. Compare the result with actual data and fine tune the model to reduce the error. Using this method WSN will get enough sleep time to increase overall life by simulating the normal behaviour of sensor node. The sleep time will be calculated dynamically.

The use of wireless sensor network (WSN) in industrial site has been increasing significantly. WSN transmits and collects the data through electromagnetic waves. The characteristic of electromagnetic wave is affected by the environment where electromagnetic wave is propagating. The electromagnetic propagation in industrial site encounters various challenges, caused not only by the object around it but also by the noise disturbances coming from the electrical machine. These disturbances can degrade the performance of WSN. Therefore, simulating the performance of WSN prior to the implementation is suggested, so that errors during implementation can be avoided. This paper presents a simulation to determine the effect of disturbances to radiation of electromagnetic wave from operating the WSN. In this research, WSN was modelled by dipole antenna with 2.4 GHz frequency, while the electrical machine was modelled as permanent magnet synchronous machine (PMSM). Both models were simulated in simple 3D industrial site consist of some object. The results show that the characteristic of radiation from dipole antennae, e.g., gain, S-parameter, and directivity was affected by electrical machine.

Modeling and experimental verification of a fractional damping quad-stable energy harvesting system for use in wireless sensor networks

The use of Wireless Sensor Network (WSN) based technologies is an attractive solution for large-scale sensing applications (wide area deployment), such as environmental monitoring, precision agriculture and industrial automation. IEEE 802.15.4/ZigBee standards are the most used communication protocols for WSN technologies, where the clustertree topology is pointed out as a suitable topology to support the implementation of large-scale WSNs. These networks are usually scheduled to prioritise convergecast (upstream) traffic generated from sensor nodes toward the sink node. However, this scheduling pattern results in higher delays for control messages (downstream traffic). Within this context, this paper proposes a Hybrid Beacon Scheduling (Fast-HyBeS) scheme to enable the periodic reconfiguration of cluster-tree WSNs. The underlying idea is to periodically schedule a downstream opportunity window, to allow a faster dissemination of control messages. This opportunity window follows a top-down scheduling approach that prioritises the downstream traffic. Simulation results show that the use of Fast-HyBeS can significantly decrease the end-to-end communication delay for control messages, when compared to the use of static convergecast scheduling schemes. Moreover, the simulation results also highlight that the Fast-HyBeS has a negligible impact upon end-to-end communication delays of the monitoring traffic.

Ongoing advancements in electromechanical, power electronics and wireless communications have made possible the use of wireless sensor networks in remote applications. A wide range of applications such as monitoring of environmental conditions, forest fire protection, disaster management, and target monitoring in military applications utilize these sensor networks to solve problems. This has made wireless sensor networks the hottest topic for research today. These remote and unattended applications require a huge number of sensor nodes working efficiently together for a common goal. Since sensor nodes have limited resources, like processing, power and sensing capacity, these resources need to be used in efficient manner in order to improve a network’s lifetime. One of the most important methods to achieve this is using clusters. Nodes may not have the same energy levels, which makes it even more important for these clusters to work efficiently together to save power. Wireless sensor networks are of homogeneous and heterogeneous type. This paper presents a survey of energy-efficient clustering mechanisms in heterogeneous wireless sensor networks. Nodes in homogeneous wireless sensor networks have similar resources, however heterogeneous networks have nodes with different energy levels that can be effectively used to enhance a network’s lifetime.

In this study, a system for monitoring the structural health of bridge deck and predicting various possible damages to this section was designed based on measuring the temperature and humidity with the use of wireless sensor networks then it was implemented and investigated. This paper also presents the experimental development of an automatic wireless sensor monitoring system for concrete structures. The objective is to provide a solution to measure both temperature and humidity inside a concrete structure. The research has been focused in the early age and curing phase period. Four solutions have been addressed. The first one involves the use of a negative temperature coefficient thermistor and an IRIS mote allowing for the creation of an IEEE 802.15.4 network. The second one considers the use of the SHT15 sensor, together with the PIC18F4680 microcontroller or the Arduino platform. The third solution involves the use of the SHT21S sensor and the eZ430-RF2500 wireless development tool platform for the MSP430 microcontroller. Finally, the fourth solution considers both the SHT15 and SHT21S sensors completely shielded allowing for the creation of a long-term solution. The potential of applying the proposed inexpensive wireless sensor network approach is completely investigated and verified.

Recently, the use of wireless sensor networks has spread to applications areas that are not viable or costefficient to be run on other types of networks. Due to some critical tasks done in these types of networks, the majority of sensor networks applications should be dependable and should be run continuously and reliably without interruption. Hence, the two more significant dependability factors that should be nowadays taken into account in developing wireless sensor networks applications are ‘availability’ and ‘reliability’ of application services. The specific characteristics and constraints of wireless sensor networks require a different interpretation of these two factors when developing applications for such networks. In this paper, we propose a middleware layer mechanism for satisfying these two factors as more important dependability issues in sensor networks applications. We propose an event-based middleware service that is specifically designed for wireless sensor networks in which a group of sensor nodes forms a cluster and a replicated service is run on each cluster head. The communication model among cluster members and cluster head is based on the publish/subscribe scheme. We show how the replicated services and communication model in cluster nodes satisfy dependability issues and increase the availability and reliability of applications running under the proposed middleware.

Background and Objectives: In this work, we explore the implementation of the binary consensus algorithm in wireless sensor networks. Binary consensus is used to allow a collection of distributed entities to reach consensus regarding the answer to a binary question. Existing work on the algorithm focuses on simulation of the algorithm under the assumption of a fully connected network topology and unlimited messaging capabilities. In this new work, we adapt the algorithm to function in wireless sensor networks where the topology might not be fully connected and the number of messages sent should be minimized in order to save power. Methods: We are deploying and testing our implementation in a hardware embedded systems, mainly IRIS Motes. Our implementation of the binary consensus algorithm is written in NesC and runs on the Tiny Operating System (TinyOS). The implementation was tested on 11 sensor nodes, with current plans to test it on far more. Results: To support our hardware implementation results, a simulation using the Tiny Operating System SIMulator (TOSSIM) was done. Our results in hardware implementation and simulation are consistent with the original binary consensus algorithm. Conclusion: In this work, we adapted the binary consensus algorithm for use in wireless sensor networks. Our implementation for a small number of IRIS motes shows correct results consistent with those of simulation. In future work we will evaluate the effectiveness of the algorithm when scaled to hundreds of sensor motes.

The use of Wireless Sensor Networks (WSN) is anticipated to bring lot of changes in data gathering, processing and dissemination for different environments and applications. Energy consumption is the most crucial design issue in WSN. In order to solve the issue and prolong the network lifetime, energy resources of each node in WSN need to be effectively managed. With respect to energy efficiency, the best known protocols are hierarchical in nature. Energy consumption can be reduced efficiently by using clustering based hierarchical routing protocols. In this paper, an energy-efficient clustering approach called Improved Minimum Separation Distance(IMSD) is proposed. IMSD extends the existing MSD [1] clustering algorithm. The simulation results show that IMSD is more energy-efficient, implying that it is more effective in prolonging the network life time.

Nowadays, the use of Wireless Sensor Networks (WSN) is gaining popularity especially in dense urban scenarios with a wide range of applications which share the same ISM band of the spectrum frequency, this situation leads to severe congestion problems. Therefore, it is important to define mechanisms that allow the use of their resources in an efficient way maintaining system quality even under harsh interferences. Under these considerations, in this paper a channel assignment management mechanism based on a centralized simulated annealing algorithm, is proposed; this mechanism is a probabilistic technique that optimizes a utility function and selects new communication channels alleviating the channel congestion problem. Furthermore, this study analyses the required WSN channel capacity that maximizes the scenario performance during the assignments of new operating channels to the whole network.

The spread use of wireless sensor networks (WSNs) in a variety of fields, ranging from the military to environmental protection, has drawn the attention of researchers to this type of networks. Despite their use in interesting applications, such as healthcare and surveillance, many shortcomings derived from their small size and constrained batteries limit their use, calling for solutions to enhance the WSNs. Born in wireless networks using the transport control protocol (TCP), cross-layer proposals have been proving that there is interdependency of parameters across the layers and that collaboration among the layers of the protocol stack can improve the performance of wireless networks in terms of quality of service, throughput, and transmission fairness. Thus, cross-layer design is merging into WSNs, especially to reduce sensors energy consumption. In this work, a cross-layer sleep and rate adaptation mechanism is proposed to operate on a slotted ALOHA WSN. Through the use of sensors sleep periods, energy consumption is reduced, and throughput reduction is mitigated by the use of the rate adaptation.

Industries can benefit a lot from integrating sensors in industrial plants, structures, machinery, shop floors, and other critical places and utilizing their sensing and monitoring power, communicating and processing abilities to deliver sensed information. Proper use of wireless sensor networks (WSNs) can lower the rate of catastrophic failures, and improve the efficiency and productivity of factory operations. Ensuring reliability and providing adequate security in these crucial services provided by WSNs will reinforce their acceptability as a viable and dependable technology in the factory and industrial domain. In this paper, we examine the reliability and security challenges of WSNs and survey their practicality for industrial adoption. We discuss the unique characteristics that distinguish the factory environment from the rest, elaborate on security and reliability issues with their respective solution measures, and analyze the existing WSN architectures and standards. A number of challenges and interesting research issues have emerged from this study and have been reported for further investigation.

Structural monitoring of critical bridge structures can greatly benefit from the use of wireless sensor networks (WSNs), however energy harvesting for the operation of the network remains a challenge in this setting. While solar and wind power are possible and credible solutions to energy generation, the need for positioning sensor nodes in shaded and sheltered locations, e.g., under a bridge deck, is also often precluding their adoption in real-world deployments. In some scenarios vibration energy harvesting has been shown as an effective solution, instead.This paper presents a multihop vibration energy-harvesting WSN system for bridge applications. The system relies on an ultra-low power wireless sensor node, driven by a novel vibration based energy-harvesting technology. We use a receiver-initiated routing protocol to enable energy-efficient and reliable connectivity between nodes with different energy charging capabilities. By combining real vibration data with an experimentally validated model of the vibration energy harvester, a hardware model, and the COOJA simulator, we develop a framework to conduct realistic and repeatable experiments to evaluate the system before on-site deployment.Simulation results show that the system is able to maintain energy neutral operation, preserving energy with careful management of sleep and communication times. We also validate the system through a laboratory experiment on real hardware against real vibration data collected from a bridge. Besides providing general guidelines and considerations for the development of vibration energy-harvesting systems for bridge applications, this work highlights the limitations of the energy budget made available by traffic-induced vibrations, which clearly shrink the applicability of vibration energy-harvesting technology for WSNs to low traffic applications.

In this article we describe a low-power processor platform for use in Wireless Sensor Network (WSN) nodes (motes). WSN motes are small, battery-powered devices comprised of a processor, sensors, and a radio frequency transceiver. It is expected that WSNs consisting of large numbers of motes will offer long-term, distributed monitoring, and control of real-world equipment and phenomena. A key requirement for these applications is long battery life. We investigate a processor platform architecture based on an application-specific programmable processor core, System-On-Chip bus, and a hardware accelerator. The architecture improves on the energy consumption of a conventional microprocessor design by tuning the architecture for a suite of TinyOS-based WSN applications. The tuning method used minimizes changes to the instruction set architecture facilitating rapid software migration to the new platform. The processor platform was implemented and validated in an FPGA-based WSN mote. The benefits of the approach in terms of energy consumption are estimated to be a reduction of 48% for ASIC implementation relative to a conventional programmable processor for a typical TinyOS application suite without use of voltage scaling.

Since Web 2.0, web applications rely more and more in JavaScript to deploy complex interaction mechanisms and visual effects in Rich Internet Applications (RIA) [6], that implement an ambivalent architecture, based on widgets to deliver rich interaction scenarios to users. The World Wide Web Consortium (W3C) define widgets as a "discrete user interface object with which the user can interact". Widgets, frequently, generate dynamic updates to the Document Object Model (DOM) structure of a webpage and require visual perception of users to notify them about these changes [4]. However, blind people employ screen readers to listen and navigate web content sequentially in the order it is laid out in HTML source code. Unfortunately, screen readers do not recognize widgets that appear dynamically on the screen if in their HTML codes the Accessible Rich Internet Applications (ARIA) rules were not included [5].