Juan Vicente Capella

Underwater Acoustic Wireless Sensor Networks: Advances and Future Trends in Physical, MAC and Routing Layers

This survey aims to provide a comprehensive overview of the current research on underwater wireless sensor networks, focusing on the lower layers of the communication stack, and envisions future trends and challenges. It analyzes the current state-of-the-art on the physical, medium access control and routing layers. It summarizes their security threads and surveys the currently proposed studies. Current envisioned niches for further advances in underwater networks research range from efficient, low-power algorithms and modulations to intelligent, energy-aware routing and medium access control protocols.

A Wireless Sensor Network approach for distributed in-line chemical analysis of water.

In this work we propose the implementation of a distributed system based on a Wireless Sensor Network for the control of a chemical analysis system for fresh water. This implementation is presented by describing the nodes that form the distributed system, the communication system by wireless networks, control strategies, and so on. Nitrate, ammonium, and chloride are measured in-line using appropriate ion selective electrodes (ISEs), the results obtained being compared with those provided by the corresponding reference methods. Recovery analyses with ISEs and standard methods, study of interferences, and evaluation of major sensor features have also been carried out. The communication among the nodes that form the distributed system is implemented by means of the utilization of proprietary wireless networks, and secondary data transmission services (GSM or GPRS) provided by a mobile telephone operator. The information is processed, integrated and stored in a control center. These data can be retrieved--through the Internet--so as to know the real-time system status and its evolution.

Smartphone-Based Industrial Informatics Projects and Laboratories

The use of IT technologies plays an important role in the training of future engineers. In this paper, smartphones and multimedia technologies are proposed as an innovative way to tackle the formation of students, at different levels, in the Industrial Informatics (II) subject of the Industrial Electronics Engineering (IEE) degree. II instructs future Engineers in the design of IT systems to control industrial processes. In the first level, smartphones are used to display a web-based multimedia tool that is implemented to register the lecture explanations regarding the design of II systems, so as it facilitates student to guide him/her self in the learning process. In the second level, the smartphone is proposed as the control system of a medium size industrial process (e.g., water tank). Since II uses a problem-based learning methodology (miniproject) to instruct the design of II systems, for each lecture, laboratory practices are tackled, and the solutions obtained are embedded in the smartphone to control the corresponding part of the miniproject. An application of the Smartphone multimedia tool is presented to show how students interact with the developed system. The successful evaluation of the proposed tools, by more than 900 IEE students during three years, is shown.

Historical Building Monitoring Using an Energy-Efficient Scalable Wireless Sensor Network Architecture

We present a set of novel low power wireless sensor nodes designed for monitoring wooden masterpieces and historical buildings, in order to perform an early detection of pests. Although our previous star-based system configuration has been in operation for more than 13 years, it does not scale well for sensorization of large buildings or when deploying hundreds of nodes. In this paper we demonstrate the feasibility of a cluster-based dynamic-tree hierarchical Wireless Sensor Network (WSN) architecture where realistic assumptions of radio frequency data transmission are applied to cluster construction, and a mix of heterogeneous nodes are used to minimize economic cost of the whole system and maximize power saving of the leaf nodes. Simulation results show that the specialization of a fraction of the nodes by providing better antennas and some energy harvesting techniques can dramatically extend the life of the entire WSN and reduce the cost of the whole system. A demonstration of the proposed architecture with a new routing protocol and applied to termite pest detection has been implemented on a set of new nodes and should last for about 10 years, but it provides better scalability, reliability and deployment properties.

WSN with energy-harvesting: modeling and simulation based on a practical architecture using real radiation levels

This paper presents a new energy-harvesting provider for ns-3 simulation tool. The provider model assumes solar energy harvesting and super-capacitor storage to supply power to a Wireless Sensor Node. Super-capacitors charge and discharge is dynamically estimated based on both power consumption in the node and solar radiation levels. On one hand, super-capacitors voltage level is refreshed within each radio mode change. However, because a radio mode can be longer than few milliseconds, refreshments are also time schedule. On the other hand, solar radiation data in CSV format (comma-separated values) can be downloaded from public meteorological data bases. The model incorporates these input data being possible to simulate from one minute to weeks or months using real radiation curves observed in a specific world location at a year period. The research presented in this paper will be very useful for the study and development of energy-efficient algorithms with energy-neutral operation to build everlasting Wireless Sensor Networks.

A New Energy-Efficient, Scalable and Robust Architecture for Wireless Sensor Networks

The major problem for most of wireless sensor networks applications is the energy consumption. In this paper we propose a new architecture called EDETA (Energy-efficient aDaptive hiErarchical and robusT Architecture) optimized to save nodes power. This architecture is scalable and suitable for heterogeneous and homogeneous wireless sensor networks, supports single or multiple sinks, and also provides features increasely-demanded in the current applications such as fault tolerance and bounded-time response communications. The proposed protocol is able to autoconfigure, and it is based on two-levels hierarchical architecture. The lower level is based on cluster organization, while the upper one is formed as a dynamic tree of clusters heads to send the data to the sink. Our experiments, based on real energy measures, show that EDETA can reduce the energy consumption in typical applications in a factor of 8x compared with most popular power-aware protocols. Furthermore, EDETA multiplies the lifetime of the sensor network while providing, in addition, extra-features such as fault-tolerant mechanisms and bounded time.

Wireless sensor network with energy harvesting: modeling and simulation based on a practical architecture using real radiation levels

This paper presents a new energy‐harvesting model for a network simulator that implements super‐capacitor energy storage with solar energy‐harvesting recharge. The model is easily extensible, and other energy‐harvesting systems, or different energy storages, can be further developed. Moreover, code can be conveniently reused as the implementation is entirely uncoupled from the radio and node models. Real radiation data are obtained from available online databases in order to dynamically calculate super‐capacitor charge and discharge. Such novelty enables the evaluation of energy evolution on a network of sensor nodes at various physical world locations and during different seasons. The model is validated against a real and fully working prototype, and good result correlation is shown. Furthermore, various experiments using the ns‐3 simulator were conducted, demonstrating the utility of the model in assisting the research and development of the deployment of everlasting wireless sensor networks. Copyright

A Reference Model for Monitoring IoT WSN-Based Applications

The Internet of Things (IoT) is, at this moment, one of the most promising technologies that has arisen for decades. Wireless Sensor Networks (WSNs) are one of the main pillars for many IoT applications, insofar as they require to obtain context-awareness information. The bibliography shows many difficulties in their real implementation that have prevented its massive deployment. Additionally, in IoT environments where data producers and data consumers are not directly related, compatibility and certification issues become fundamental. Both problems would profit from accurate knowledge of the internal behavior of WSNs that must be obtained by the utilization of appropriate tools. There are many ad-hoc proposals with no common structure or methodology, and intended to monitor a particular WSN. To overcome this problem, this paper proposes a structured three-layer reference model for WSN Monitoring Platforms (WSN-MP), which offers a standard environment for the design of new monitoring platforms to debug, verify and certify a WSN’s behavior and performance, and applicable to every WSN. This model also allows the comparative analysis of the current proposals for monitoring the operation of WSNs. Following this methodology, it is possible to achieve a standardization of WSN-MP, promoting new research areas in order to solve the problems of each layer.

A New Robust, Energy-efficient and Scalable Wireless Sensor Networks Architecture Applied to a Wireless Fire Detection System

In this work a new architecture called EDETA (Energy-efficient aDaptive hiErarchical and robusT Architecture) optimized to save node’s power is presented. This architecture is scalable and suitable for heterogeneous and homogeneous wireless sensor networks, supports single or multiple sinks, and also provides features increasely-demanded in the current applications such as fault tolerance and bounded-time response communications. All these features make EDETA suitable for the implementation of safety applications such as a wireless fire detection system. The proposed protocol is able to auto-configure, and it is based on two-levels hieratical architecture. The lower level is based on cluster organization, while the upper one is formed as a dynamic tree of clusters heads to send the data to the sink. A wireless fire detection system based on EDETA has been implemented, obtaining very satisfactory results about the reliability, response time and the consumption, the implemented system based on EDETA reduce the energy consumption in a factor of 8x compared with most popular power-aware protocols. Furthermore, EDETA multiplies the lifetime of the sensor network while providing, in addition, extra-features such as fault-tolerant mechanisms and bounded time.

Active Low Intrusion Hybrid Monitor for Wireless Sensor Networks.

Several systems have been proposed to monitor wireless sensor networks (WSN). These systems may be active (causing a high degree of intrusion) or passive (low observability inside the nodes). This paper presents the implementation of an active hybrid (hardware and software) monitor with low intrusion. It is based on the addition to the sensor node of a monitor node (hardware part) which, through a standard interface, is able to receive the monitoring information sent by a piece of software executed in the sensor node. The intrusion on time, code, and energy caused in the sensor nodes by the monitor is evaluated as a function of data size and the interface used. Then different interfaces, commonly available in sensor nodes, are evaluated: serial transmission (USART), serial peripheral interface (SPI), and parallel. The proposed hybrid monitor provides highly detailed information, barely disturbed by the measurement tool (interference), about the behavior of the WSN that may be used to evaluate many properties such as performance, dependability, security, etc. Monitor nodes are self-powered and may be removed after the monitoring campaign to be reused in other campaigns and/or WSNs. No other hardware-independent monitoring platforms with such low interference have been found in the literature.