Lourdes López

An Internet of Things Approach for Managing Smart Services Provided by Wearable Devices

The Internet of Things (IoT) is growing at a fast pace with new devices getting connected all the time. A new emerging group of these devices is the wearable devices, and the wireless sensor networks are a good way to integrate them in the IoT concept and bring new experiences to the daily life activities. In this paper, we present an everyday life application involving a WSN as the base of a novel context-awareness sports scenario, where physiological parameters are measured and sent to the WSN by wearable devices. Applications with several hardware components introduce the problem of heterogeneity in the network. In order to integrate different hardware platforms and to introduce a service-oriented semantic middleware solution into a single application, we propose the use of an enterprise service bus (ESB) as a bridge for guaranteeing interoperability and integration of the different environments, thus introducing a semantic added value needed in the world of IoT-based systems. This approach places all the data acquired (e.g., via internet data access) at application developers disposal, opening the system to new user applications. The user can then access the data through a wide variety of devices (smartphones, tablets, and computers) and operating systems (Android, iOS, Windows, Linux, etc.).

QoS in wireless sensor networks: survey and approach

A wireless sensor network (WSN) is a computer wireless network composed of spatially distributed and autonomous tiny nodes -- smart dust sensors, motes -, which cooperatively monitor physical or environmental conditions. Nowadays these kinds of networks support a wide range of applications, such as target tracking, security, environmental control, habitat monitoring, source detection, source localization, vehicular and traffic monitoring, health monitoring, building and industrial monitoring, etc. Many of these applications have strong requirements for end-to-end delay and losses during data transmissions. In this work we have classified the main mechanisms that have been proposed to provide Quality of Service (QoS) in WSN at Medium Access Control (MAC) and network layers. Finally, taking into account some particularities of the studied MAC- and network-layer protocols, we have selected a real application scenario in order to show how to choose an appropriate approach for guaranteeing performance in a WSN deployed application.

Combining Wireless Sensor Networks and Semantic Middleware for an Internet of Things-Based Sportsman/Woman Monitoring Application

Wireless Sensor Networks (WSNs) are spearheading the efforts taken to build and deploy systems aiming to accomplish the ultimate objectives of the Internet of Things. Due to the sensors WSNs nodes are provided with, and to their ubiquity and pervasive capabilities, these networks become extremely suitable for many applications that so-called conventional cabled or wireless networks are unable to handle. One of these still underdeveloped applications is monitoring physical parameters on a person. This is an especially interesting application regarding their age or activity, for any detected hazardous parameter can be notified not only to the monitored person as a warning, but also to any third party that may be helpful under critical circumstances, such as relatives or healthcare centers. We propose a system built to monitor a sportsman/woman during a workout session or performing a sport-related indoor activity. Sensors have been deployed by means of several nodes acting as the nodes of a WSN, along with a semantic middleware development used for hardware complexity abstraction purposes. The data extracted from the environment, combined with the information obtained from the user, will compose the basis of the services that can be obtained.

Knowledge-Aware and Service-Oriented Middleware for deploying pervasive services

Many applications and services have emerged in the frame of new Internet of Things paradigm. This novel view has opened the Web services to a variety of devices especially to tiny and resource-constrained devices. Wireless Sensor and Actuator Networks belong to that kind of devices. Those networks have become one of the more promising technologies to take part in the Future Internet. However, the integration of Sensor and Actuator Networks into the Service Cloud is a hard challenge requiring specific new architectures and protocols. This paper presents a middleware approach addressing this important issue. A Knowledge-Aware and Service-Oriented Middleware (KASOM) for pervasive embedded networks is proposed. The major aim of KASOM is to offer advanced and enriched pervasive services to everyone connected to Internet. In this sense, KASOM implements mechanisms and protocols which allow managing the knowledge generated in pervasive embedded networks in order to expose it to Internet users in a readable way. General functional requirements of embedded sensor and actuator platforms have been taken into account when designing KASOM, with special attention in energy consumption, memory and bandwidth. The KASOM evaluation and validation will be demonstrated through a real Wireless Sensor and Actuator Network deployment based on integral healthcare services in a sanatorium.

Pervasive smart spaces and environments : a service-oriented middleware architecture for wireless Ad Hoc and sensor networks

In the twenty-first century, the impact of wireless and ubiquitous technologies is changing the way people perceive and interact with the physical world. These communication paradigms promise to change and redefine, in a reasonably short period of time, the most common way of our everyday living. The continuous advances in the field of Wireless Sensor Networks and their direct application in Smart Spaces are clear examples of it. However, in order for this kind of new generation infrastructures to have a large-scale dissemination, there are still some open issues to tackle. In this way, this paper presents nSOM, a service-oriented framework based on sensor network design that provides internetworking services with the Internet cloud. This lightweight middleware architecture implements an agent-based virtual sensor service approach which is a compact semantic knowledge management scheme based on a dynamic composition model.

Composition and deployment of e-Health services over Wireless Sensor Networks

Providing necessary background for provisioning of a new generation of enriched services over Wireless Sensor Networks is the main effort that the scientific community is currently carrying out. These services have improved a great number of aspects related to pervasive systems such as saving resources, efficiency, reliability, scalability and low power consumption. In this paper, @mSMS middleware, using an event-based service model, is presented. This novel approach makes up the design requirements previously mentioned by implementing a dynamic memory kernel and a variable payload multiplexing mechanism for the information events in order to provide advanced services. The results obtained over real-world deployments, especially those related with provision of e-Health services, reflect a significant improvement over other similar proposals, such as the RUNES approach: 50% lower memory overhead, 53% lower software components load time and 12% lower events propagation time.

The Influence of Communication Range on Connectivity for Resilient Wireless Sensor Networks Using a Probabilistic Approach

Wireless sensor networks (WSNs) consist of thousands of nodes that need to communicate with each other. However, it is possible that some nodes are isolated from other nodes due to limited communication range. This paper focuses on the influence of communication range on the probability that all nodes are connected under two conditions, respectively: (1) all nodes have the same communication range, and (2) communication range of each node is a random variable. In the former case, this work proves that, for 0 < ε < e − 1 , if the probability of the network being connected is 0.36 ε , by means of increasing communication range by constant C ( ε ) , the probability of network being connected is at least 1 − ε . Explicit function C ( ε ) is given. It turns out that, once the network is connected, it also makes the WSNs resilient against nodes failure. In the latter case, this paper proposes that the network connection probability is modeled as Cox process. The change of network connection probability with respect to distribution parameters and resilience performance is presented. Finally, a method to decide the distribution parameters of node communication range in order to satisfy a given network connection probability is developed.

XML Schema Based Faultset Definition to Improve Faults Injection Tools Interoperability

This paper describes an XML schema formalization approach for the definition of basic fault sets which specify memory and/or register value corruption in microprocessor-based systems. SWIFI (software implemented fault injection) tools use fault injectors to carry out the fault injection campaign defined in a GUI-based application. However, the communication between the fault injector and the application is defined in an ad-hoc manner. Through this proposed XML schema definition different injectors could be used to carry out the same fault set injection. To validate this approach floating point register and memory corruptions with temporal triggers and routine interception mechanisms to carry out argument and return value, corruption has been considered. Moreover, an experimental tool called Exhaustifreg, consisting of a GUI Java application for defining the fault sets and injection policies and two injectors for SPARC and i386 architectures under RTEMS, has been developed. The XML-based approach improves the interoperability between SWIFI tools by uncoupling the injectors from the experiment manager in charge of the fault campaign.

Resilient Wireless Sensor Networks Using Topology Control: A Review

Wireless sensor networks (WSNs) may be deployed in failure-prone environments, and WSNs nodes easily fail due to unreliable wireless connections, malicious attacks and resource-constrained features. Nevertheless, if WSNs can tolerate at most losing k − 1 nodes while the rest of nodes remain connected, the network is called k − connected. k is one of the most important indicators for WSNs’ self-healing capability. Following a WSN design flow, this paper surveys resilience issues from the topology control and multi-path routing point of view. This paper provides a discussion on transmission and failure models, which have an important impact on research results. Afterwards, this paper reviews theoretical results and representative topology control approaches to guarantee WSNs to be k − connected at three different network deployment stages: pre-deployment, post-deployment and re-deployment. Multi-path routing protocols are discussed, and many NP-complete or NP-hard problems regarding topology control are identified. The challenging open issues are discussed at the end. This paper can serve as a guideline to design resilient WSNs.

Exhaustif®: a fault injection tool for distributed heterogeneous embedded systems

This paper presents Exhaustif®, a SWIFI fault injection tool for fault tolerance verification and the validation of embedded software in distributed heterogeneous systems. Exhaustif® mainly consists of two parts: EEM and FIK. Exhaustif® Executive Manager (EEM) is a GUI Java application to define the fault injection campaign that uses a SQL database to save the test results obtained from the System under Test (SUT) in order to carry out a post injection data analysis. FIK is under the command of EEM to cary out fault injections in applications running under diverse operating systems using pure SWIFI techniques. Exhaustif® carries out floating point register and memory corruptions using temporary triggers and uses an optimized routine interception mechanism to carry out argument and return value corruption with a minimal time overhead. Two experimental Fault Injector Kernels (FIK) under the RTEMS operating system for an EADS-Astrium SPARC ERC32-based MCM processor board and i386 standard PC mainboard have been developed.