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.

Monitoring is one of the best ways to evaluate the behavior of computer systems. When the monitored system is a distributed system—such as a wireless sensor network (WSN)—the monitoring operation must also be distributed, providing a distributed trace for further analysis. The temporal sequence of occurrence of the events registered by the distributed monitoring platform (DMP) must be correctly established to provide cause-effect relationships between them, so the logs obtained in different monitor nodes must be synchronized. Many of synchronization mechanisms applied to DMPs consist in adjusting the internal clocks of the nodes to the same value as a reference time. However, these mechanisms can create an incoherent event sequence. This article presents a new method to achieve global synchronization of the traces obtained in a DMP. It is based on periodic synchronization signals that are received by the monitor nodes and logged along with the recorded events. This mechanism processes all traces and generates a global post-synchronized trace by scaling all times registered proportionally according with the synchronization signals. It is intended to be a simple but efficient offline mechanism. Its application in a WSN-DMP demonstrates that it guarantees a correct ordering of the events, avoiding the aforementioned issues.

Wireless sensor networks (WSNs), as an essential part of the deployment of the Internet of Things paradigm, require an adequate debugging and monitoring procedures to avoid errors in their operation. One of the best tools for WSN supervision is the so-called Monitoring Platforms that harvest information about the WSN operation in order to detect errors and evaluate performance. Monitoring platforms for the WSN can be hardware or software implemented, and, additionally, they can work in active or passive mode. Each approach has advantages and drawbacks. To benefit from their advantages and compensate their limitations, hybrid platforms combine different approaches. However, very few hybrid tools, with many restrictions, have been proposed. Most of them are designed for a specific implementation of WSN nodes; many of them are lack of a real implementation, and none of them provides an accurate solution to synchronization issues. This paper presents a hybrid monitoring platform for WSN, called HMP. This platform combines both hardware and software, active and passive monitoring approaches. This hybridization provides many interesting capabilities; HMP harvests the information both actively (directly from the sensor nodes) and passively (by means of messages captured from the WSN), causing a very low intrusion in the observed network. In addition, HMP is reusable; it may be applied to almost any WSN and includes a suitable trace synchronism procedure. Finally, HMP follows an open architecture that allows interoperability and layered development.

Flooding is an issue that affects many cities during periods of heavy rain, especially in developing countries. This issue often happens due to the lack of timely maintenance and cleaning of rainwater drains. This work presents a proposal to detect blockages in rainwater drains to determine where maintenance and cleaning need to be performed promptly. An architecture that includes sensor nodes, a Gateway, and a cloud application was defined. The sensor nodes, which detect potential blockages in the drains, send data and status signals to the Gateway using LoRaWAN. The Gateway then passes the data to a cloud platform that records the data and issues an alert when a blockage is detected in a drain. The sensor node prototype is based on a Heltec LoRa WiFi board and has two sensors: an HC-SR04 ultrasonic sensor to measure distance and a DHT22 sensor to measure humidity and temperature. The cloud application was developed on the Arduino Cloud platform. A decision tree is proposed to detect blockages based on the readings from these sensors, particularly the distance sensor, considering four main possible states: clear, possibly blocked, potentially blocked, and blocked. The decision tree is implemented in each node. Periodically, the node collects data from the sensors and transmits them to the cloud, and if a potential blockage is detected, it sends a message that triggers an alert on the platform. Preliminary tests of the prototype show accurate and timely results in detecting potential blockages, allowing for a better use of resources allocated for maintaining drainage systems.

The use of Information and Communication Technologies (ICT) in livestock is not new; applications in this field cover from simple animal identification to complete traceability systems. The monitoring of vital signs of livestock is an issue of farming in which ICT is applied. This paper presents a systematic literature review of proposals for monitoring vital signs in different types of livestock. For this purpose, PRISMA methodology has been applied, with its three phases: Planning, Conducting, and Reporting. Papers from journals and conferences, between 2017 and 2023, have been considered. Long-range monitoring of signs, such as movement, geo-position, body temperature, or heart rate, are the main trends of the analyzed papers and commercial products. Therefore, there are opportunities for developing devices or products that monitor other vital signs, like blood pressure or blood oxygen saturation. El uso de las Tecnologías de la Información y la Comunicación (TIC) en la ganadería no es nuevo; las aplicaciones en este campo abarcan desde la simple identificación animal hasta sistemas completos de trazabilidad. La monitorización de signos vitales del ganado es uno de los aspectos de la ganadería en el que se aplican las TIC. Este artículo presenta una revisión sistemática de la literatura de propuestas para la monitorización de signos vitales en diferentes tipos de ganado. Para ello se ha aplicado la metodología PRISMA, con sus tres fases: Planificación, Ejecución y Reporte. Se han considerado artículos de revistas y congresos, entre 2017 y 2023. La principal tendencia de las publicaciones y productos comerciales analizados es el monitoreo de largo alcance de signos como movimiento, posición geográfica, temperatura corporal, o frecuencia cardiaca. Por lo tanto, existen oportunidades para desarrollar dispositivos o productos que monitoreen otros signos vitales, como la presión arterial o la saturación de oxígeno en la sangre.

In the present work, a sensor network design for monitoring carbon dioxide (CO₂) pollution in Portoviejo City, Ecuador, is evaluated through a methodology that combines simulation and physical implementation. This methodology involves the development and evaluation of two scenarios: an initial scenario (A), developed through both physical implementation and simulation, and another simulation scenario (B). Both simulated scenarios are created using CupCarbon version 6.51 software. In these scenarios, the functionality of Wireless Sensor Networks (WSNs) is analyzed by implementing the LoRaWAN communication technology. Furthermore, the MQ-135 sensor is used to obtaining data on the PPM of (CO₂) in order to examine the areas that concentrate the most significant amount of this atmospheric pollutant. The proposed networks are evaluated using the packet loss metric during data transmission. After implementation, analysis, and respective evaluation, it can be concluded that the network simulated in Scenario B is suitable for monitoring (CO₂) and other pollutants that can be analyzed within the urban environment.