End-to-end reliability for Wireless Sensor Network communications is usually provided by upper stack layers. Furthermore, most of the studies have been related to star, mesh, and tree topologies. However, they rarely consider the requirements of the multi-hop linear wireless sensor networks, with thousands of nodes, which are universally used for monitoring applications. Therefore, they are characterized by long delays and high energy consumption. In this paper, we propose an energy efficient link level routing algorithm that provides end-to-end reliability into multi-hop wireless sensor networks with a linear structure. The algorithm uses implicit acknowledgement to provide reliability and connectivity with energy efficiency, low latency, and fault tolerance in linear wireless sensor networks. The proposal is validated through tests with real hardware. The energy consumption and the delay are also mathematically modeled and analyzed. The test results show that our algorithm decreases the energy consumption and minimizes the delays when compared with other proposals that also apply the explicit knowledge technique and routing protocols with explicit confirmations, maintaining the same characteristics in terms of reliability and connectivity.

Ensuring reliable communication in remote or disaster-affected areas is a technical challenge due to unplanned deployment and mobilization, meaning placement difficulties and high operation costs of conventional telecommunications infrastructures. To address this problem, unmanned aerial vehicles (UAVs) have emerged as an excellent alternative to provide quick connectivity in remote or disaster-affected regions at a reasonable cost. However, the limited battery autonomy of UAVs restricts their flight service time. This paper proposes a communication system based on a tethered UAV (T-UAV) capable of continuous operation through a wired power network connected to a ground station. The communications system is based on low-cost devices, such as Raspberry Pi platforms, and offers wireless IP telephony services, providing high-quality and reliable communication. Experimental tests assessed power consumption, UAV stability, and data transmission performance. Our results prove that the T-UAV, based on a quadcopter drone, operates stably at 16 V and 20 A, ensuring consistent VoIP communications at a height of 10 m with low latency. These experimental findings underscore the potential of T-UAVs as cost-effective alternatives for extending or providing communication networks in remote regions, emergency scenarios, or underserved areas.

Las redes de sensores inalámbricos continúan atrayendo la atención de la academia y la industria que promueven implementaciones a gran escala en aplicaciones relacionadas con Internet de las Cosas (IoT). Desafortunadamente, una red que contiene una gran cantidad de nodos también genera dificultades en el proceso de configuración y asignación de identificadores a los nodos. Se han propuesto varios enfoques para resolver problemas de autoconfiguración en WSN, sin embargo, todavía quedan algunos problemas relacionados con la asignación automática de identificadores. Se propone un esquema de asignación de direcciones global jerárquica basado en clústeres para una red de sensores inalámbricos. La propuesta utiliza el protocolo IEEE 802.15.4 y tiene como objetivo reducir la latencia de las asignaciones de identificadores y los procesos a nivel de red que se ejecutan en el nodo. El proceso de asignación de direcciones asigna a cada nodo una dirección global única, lo que permite que el nodo tenga conectividad de extremo a extremo sin implicación a nivel de red. Se contempla el escenario de agregar nuevos nodos a la red o nodos que la abandonen. Finalmente, se evalúa experimentalmente el esquema propuesto verificando el correcto funcionamiento del algoritmo propuesto en el prototipo implementado.

Wireless sensor networks, which are used for monitoring large-scale linear structures, are having a significant importance due to its implementation and low cost maintenance. The main challenges that this technology faces are the location and automatic identification of thousands of nodes that are part of a linear large-scale infrastructure, with minimum processing and low power consumption of the nodes. This paper proposes an automatic identification and location mechanism of the nodes that are part of a linear structure using link-level processes and the IEEE 802.15.4 protocol. This mechanism improves the reliability in the allocation process of identifiers without using routing protocols to minimize the number of sent messages, also the computation process is done at the nodes, and therefore it reduces energy consumption. The proposed algorithm is evaluated using a prototype, for which we present initial performance analysis results focusing on delay. The implementation results confirm that with the proposed algorithm we obtain automatic allocations of identifiers.

Over the last years, Wireless Sensor Networks (WSN) went from being a promising technology for countless industrial applications to a de facto technology used in todays' applications. WSNs have been gaining momentum over costly wired technologies, offering low installation costs, self-organization, and added functionality. As a consequence of their enormous potential, WSNs were subject to standardization and some industrial standards and open source solutions like WirelessHART, Zigbee, ISA100, IEEE802.15.4 and OpenWSN were announced. However, despite considerable efforts to provide mechanisms that increase the availability, reliability, security and maintainability of this type of networks, WSNs have kept one of their main characteristics: fault-proneness. As a result, the offer of post-deployment diagnostic tools has been increasing in the last decade in order to diagnose WSN failures as soon as possible. Nevertheless, current WSN diagnostic tools still have many limitations and cannot be considered “ready to use” in real-world scenarios. In this paper we present an autonomous diagnostic tool that addresses these limitations in a real industrial Internet of Things (IIoT) scenario. Our tool is based on simple metrics, a logging tool, a data-mining algorithm, and available network metrics, and it monitors the condition of the sensor nodes firmware, hardware and the network itself. The proposed demonstration was tested and validated using the WirelessHART IIoT standard.

Currently, the Message Queuing Telemetry Transport for Sensor Networks (MQTT - SN) protocol has been implemented in operating systems such as TinyOS and Contiki to operate above the network layer, in sensor nodes with low processing capacity, powered by batteries and operating in various topologies. However, minimizing the processes at the node side is necessary to make the MQTT - SN protocol applicable in wireless sensor networks (WSNs) with large-scale linear structures. In this context, this paper presents the development of the MQTT-SN protocol’s finite state machine (FSM) for its operation over IEEE 802.15.4 in linear topologies. For this purpose, an FSM for each of the twelve procedures indicated in the MQTT-SN specification is obtained. Furthermore, each of the FSMs is represented using the specification and description language, and the characteristics of the IEEE 802.15.4 protocol and the sensor node are considered. Through simulation and the exchange of messages between nodes, the operation of the FSMs is verified. Subsequently, implementing the FSMs in WSNs allows for validating the deployment of the MQTT-SN protocol in linear topologies.