Fernando Losilla

Wireless Sensor Network Deployment for Monitoring Wildlife Passages

Wireless Sensor Networks (WSNs) are being deployed in very diverse application scenarios, including rural and forest environments. In these particular contexts, specimen protection and conservation is a challenge, especially in natural reserves, dangerous locations or hot spots of these reserves (i.e., roads, railways, and other civil infrastructures). This paper proposes and studies a WSN based system for generic target (animal) tracking in the surrounding area of wildlife passages built to establish safe ways for animals to cross transportation infrastructures. In addition, it allows target identification through the use of video sensors connected to strategically deployed nodes. This deployment is designed on the basis of the IEEE 802.15.4 standard, but it increases the lifetime of the nodes through an appropriate scheduling. The system has been evaluated for the particular scenario of wildlife monitoring in passages across roads. For this purpose, different schemes have been simulated in order to find the most appropriate network operational parameters. Moreover, a novel prototype, provided with motion detector sensors, has also been developed and its design feasibility demonstrated. Original software modules providing new functionalities have been implemented and included in this prototype. Finally, main performance evaluation results of the whole system are presented and discussed in depth.

A Comprehensive Approach to WSN-Based ITS Applications: A Survey

In order to perform sensing tasks, most current Intelligent Transportation Systems (ITS) rely on expensive sensors, which offer only limited functionality. A more recent trend consists of using Wireless Sensor Networks (WSN) for such purpose, which reduces the required investment and enables the development of new collaborative and intelligent applications that further contribute to improve both driving safety and traffic efficiency. This paper surveys the application of WSNs to such ITS scenarios, tackling the main issues that may arise when developing these systems. The paper is divided into sections which address different matters including vehicle detection and classification as well as the selection of appropriate communication protocols, network architecture, topology and some important design parameters. In addition, in line with the multiplicity of different technologies that take part in ITS, it does not consider WSNs just as stand-alone systems, but also as key components of heterogeneous systems cooperating along with other technologies employed in vehicular scenarios.

Wireless sensor network application development: an architecture-centric MDE approach

Nowadays, Wireless Sensor Networks (WSN) are a very promising research field since they find application in many different areas. Current proposals for WSN system development are mainly focused on implementation issues and they rarely rely on a Software Engineering methodology which supports their entire development life-cycle. The Model-Driven Engineering (MDE) approach can contribute to solve this problem by allowing designers to model their systems at different abstraction levels, providing them with automatic model transformations to incrementally refine abstract models into more concrete ones. In this vein, this paper presents a MDE approach to WSN application development. Three levels of abstraction have been defined which allow designers to build: (1) domain-specific models, (2) component-based architecture descriptions, and (3) platform-specific models. Automatic model transformations between these three abstraction levels have been designed and, in order to demonstrate the viability of the proposal, a real WSN application has been developed using the implemented tools.

APPLYING MDE TO THE DEVELOPMENT OF FLEXIBLE AND REUSABLE WIRELESS SENSOR NETWORKS

Wireless Sensor Networks (WSN) are a very promising research field since they are applicable in many different areas. Current proposals for WSN system development are mainly focused on implementation issues and rarely use a Software Engineering methodology to support their development life cycle. The Model-Driven Engineering (MDE) approach can be used as a solution to this by allowing designers to model their systems at different abstraction levels, providing them with automatic model transformations to incrementally refine abstract models into more concrete ones. In this vein, this paper presents an MDE approach to WSN application development. Three levels of abstraction have been defined which allow designers to build: (1) domain-specific models, (2) component-based architecture descriptions, and (3) platform-specific models. Automatic model transformations between these three abstraction levels have been designed and, in order to demonstrate the viability of the proposal, a real WSN application has been developed using the implemented tools.

A cross-layer solution for enabling real-time video transmission over IEEE 802.15.4 networks

Over the last few years, the research community has devoted great attention to video transmission on wireless sensor networks, and in particular to their recent evolution, the one based on IEEE 802.15.4 standard. This cost-efficient wireless technology is aimed at transmitting information at low rates and short distances. Extending the use of this technology for intensive bandwidth applications is a challenge that offers the opportunity to support value-added services. This paper deals with this issue and evaluates, by analysis and computer simulation as well as by developing a first prototype, the feasibility of transmitting MPEG-4 video information over an IEEE 802.15.4 network. The study of power-consumption is also considered and so are the Quality of Service parameters together with the human quality perception of the received video streaming. A detailed cross-layer solution is offered, and the results obtained are presented and discussed.

Design, Implementation and Evaluation of an Indoor Navigation System for Visually Impaired People.

Indoor navigation is a challenging task for visually impaired people. Although there are guidance systems available for such purposes, they have some drawbacks that hamper their direct application in real-life situations. These systems are either too complex, inaccurate, or require very special conditions (i.e., rare in everyday life) to operate. In this regard, Ultra-Wideband (UWB) technology has been shown to be effective for indoor positioning, providing a high level of accuracy and low installation complexity. This paper presents SUGAR, an indoor navigation system for visually impaired people which uses UWB for positioning, a spatial database of the environment for pathfinding through the application of the A* algorithm, and a guidance module. The interaction with the user takes place using acoustic signals and voice commands played through headphones. The suitability of the system for indoor navigation has been verified by means of a functional and usable prototype through a field test with a blind person. In addition, other tests have been conducted in order to show the accuracy of different relevant parts of the system.

On the role of wireless sensor networks in intelligent transportation systems

Currently Vehicular Ad-hoc Networks (VANET) are receiving great attention by researchers because of their potentiality for developing innovative applications in the Intelligent Transportation Systems (ITS) context and are expected to be a widely adopted technology in the medium/long term. However, for the near future, the adoption of this technology is difficult since its performance relies excessively on its penetration rate into vehicles. In addition VANET are only able to gather information about the road while vehicles equipped with the appropriate technology are nearby, otherwise information can only be obtained by expensive and therefore scarcely deployed Roadside Units (RSU). Wireless Sensor Networks (WSN), on the contrary, can be deployed along a road (or in a parking lot area) with very little installation and maintenance costs. They can be used to constantly acquire information related to the road condition and the traffic state and, in addition, execute collaborative in-road processing for safety purposes. These properties make WSN an effective complement to VANET, since they can cooperate with them in order to mitigate their limitations. On the other hand, WSN deployments can also benefit from VANET and other communication technologies such as cellular networks in order to disseminate the information gathered to distant places. Consequently, WSN can also play a major role in ITS.

Automatic Ada code generation using a model-driven engineering approach

Currently, Model-Driven Engineering (MDE) is considered one of the most promising approaches for software development. In this paper, a simple but complete example based on state-machines will be used to demonstrate the benefits of this approach. After defining a modelling language (meta-model) for state-machines, a graphical tool will be presented which is aimed at easing the description and validation of state-machine models. These models will then be used as inputs for another tool which will automatically generate the corresponding Ada code, including a simulation program to test the correctness and performance of the implemented application.

On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies.

Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks.

An educational tool for wireless sensor networks

The present paper introduces a tool, which simplifies the description of Wireless Sensor Networks (WSN) applications by means of a visual language and automatic generation of executable code. The tool has been used to provide non‐experienced students with a practical introduction to WSN concepts in a short period of time. Using the tool allowed students to quickly develop their own applications and test with them, focusing on their functional aspects rather than on programming and platform‐dependent matters. This has yielded good results in the adaptation to the new European Higher Education Area (EHEA) envisaged by the Bologna Process, promoting an increased role of students in education as well as improving their motivation.