With the constant expansion of the industrial monitoring system, there is an urgent requirement to reduce investment and operating costs for the development of industrial communication technology. For industrial real-time monitoring systems, wireless technology can be used in a practical industrial production to take advantages of its flexibility and robustness. As wireless sensor networks have many advantages such as low investment costs, flexible structure and ease of transformation, it has become the focus with regards to industrial areas. THVRG is a routing algorithm that selects the routing path based on two-hop information. Since different information sensed by the sensors may have different requirements in order to reach the sink, a priority-based routing algorithm is required in order to adapt to this kind of situation. This thesis has proposed a priority routing algorithm based on the THVRG (Priority-based THVRG). In addition, a simulation of this algorithm was performed in OPNET. Finally, the report provides an evaluation of the proposed algorithm in industrial wireless sensor networks.

Este trabalho concentra-se no aumento da robustez à taxa de erros em redes de sensores sem fio industriais (RSSFI). Para alcançar tal objetivo, é preciso, de algum modo, contornar os problemas intrínsecos da comunicação sem fio, que são, o ruído ambiental, interferências e desvanecimento por multipercurso. O multipercurso pode ser considerado um dos principais fatores que tornam as comunicações nas redes de sensores sem fio (RSSF) um verdadeiro desafio quando comparadas com outros meios, como a transmissão em fibra óptica, cabo ou mesmo transmissões de rádio ponto-a-ponto. Nesse sentido, propõe-se a diversidade de antenas como uma solução para minimizar os efeitos do multicaminho, com o objetivo de melhorar a confiabilidade do enlace de rádio para permitir o emprego de RSSF densas. O potencial da diversidade de antenas em RSSF não está totalmente explorado em aplicações industriais. Esta dissertação apresenta ainda, a técnica “Combinação de seleção” para RSSFI através de um algoritmo que seleciona a porta do receptor que apresenta o melhor indicador de qualidade de enlace e realiza a comutação das antenas nos módulos de rádio. Os resultados são analisados para dois tipos de enlaces, isto é, com e sem diversidade de antenas na recepção, e discute-se opções para melhorar o PER (“Packet Error Rate”) com as atuais técnicas de diversidade. / This work concentrates on the increase of reliability and robustness in Industrial Wireless Sensor Networks (IWSNs), decreasing the Packet Error Rate (PER). To achieve this objective, is need to somehow circumvent and reduce the underlying problems of wireless communication, which are: environmental noise, interference, and multipath fading. The multipath can be seen as the main factor which becomes the communications in the Wireless Sensor Networks (WSNs) a real challenge when compared to other types of means such as a transmission in fiber, cable or even point-to-point radio transmissions. In this sense, it is proposed antenna diversity as solution to reduce these effects, with the aim to improve the reliability of the radio link to allow the use of dense WSNs. The potential of antenna diversity in WSN is not fully exploited in industrial applications. In this sense, this dissertation presents the "Combination of selection" technique for IWSNs through an internal algorithm that selects the receiver port that has the highest LQI ("Link Quality Indicator") and performs an antenna switching in the radio modules. Also, options to improve PER using diversity techniques are discussed.

Este trabalho concentra-se no aumento da robustez à taxa de erros em redes de sensores sem fio industriais (RSSFI). Para alcançar tal objetivo, é preciso, de algum modo, contornar os problemas intrínsecos da comunicação sem fio, que são, o ruído ambiental, interferências e desvanecimento por multipercurso. O multipercurso pode ser considerado um dos principais fatores que tornam as comunicações nas redes de sensores sem fio (RSSF) um verdadeiro desafio quando comparadas com outros meios, como a transmissão em fibra óptica, cabo ou mesmo transmissões de rádio ponto-a-ponto. Nesse sentido, propõe-se a diversidade de antenas como uma solução para minimizar os efeitos do multicaminho, com o objetivo de melhorar a confiabilidade do enlace de rádio para permitir o emprego de RSSF densas. O potencial da diversidade de antenas em RSSF não está totalmente explorado em aplicações industriais. Esta dissertação apresenta ainda, a técnica “Combinação de seleção” para RSSFI através de um algoritmo que seleciona a porta do receptor que apresenta o melhor indicador de qualidade de enlace e realiza a comutação das antenas nos módulos de rádio. Os resultados são analisados para dois tipos de enlaces, isto é, com e sem diversidade de antenas na recepção, e discute-se opções para melhorar o PER (“Packet Error Rate”) com as atuais técnicas de diversidade. / This work concentrates on the increase of reliability and robustness in Industrial Wireless Sensor Networks (IWSNs), decreasing the Packet Error Rate (PER). To achieve this objective, is need to somehow circumvent and reduce the underlying problems of wireless communication, which are: environmental noise, interference, and multipath fading. The multipath can be seen as the main factor which becomes the communications in the Wireless Sensor Networks (WSNs) a real challenge when compared to other types of means such as a transmission in fiber, cable or even point-to-point radio transmissions. In this sense, it is proposed antenna diversity as solution to reduce these effects, with the aim to improve the reliability of the radio link to allow the use of dense WSNs. The potential of antenna diversity in WSN is not fully exploited in industrial applications. In this sense, this dissertation presents the "Combination of selection" technique for IWSNs through an internal algorithm that selects the receiver port that has the highest LQI ("Link Quality Indicator") and performs an antenna switching in the radio modules. Also, options to improve PER using diversity techniques are discussed.

[ES] Las redes industriales de sensores inalámbricos (IWSN - Industrial Wireless Sensor Networks) tienen una creciente aceptación en los entornos productivos debido a su facilidad de despliegue, bajos costes y eficiencia energética. Sin embargo, la complejidad y precisión que demandan estos entornos requieren que las IWSN implementen mecanismos de calidad de servicio (QoS) que les permitan operar con un alto determinismo. Por esta razón, el estándar IEEE 802.15.4e ha incorporado protocolos de acceso al medio que permiten tener un mayor control sobre las comunicaciones. Estos protocolos permiten asignar de forma predecible y cíclica instantes de tiempo donde los dispositivos de una red pueden transmitir información sin ningún tipo de interferencia o contienda con otros dispositivos de la red. Uno de ellos es el protocolo salto de canal con ranuras de tiempo (TSCH - Time Slotted Channel Hopping) el cual planifica las transmisiones entre los dispositivos en una matriz de dos dimensiones, tiempo y frecuencia. Esta planificación de las transmisiones permite que los dispositivos tengan instantes de tiempo exclusivos para la transmisión, reduciendo así la interferencia y aumentando la fiabilidad de las transmisiones. Sin embargo, este estándar no especifica como asignar los recursos temporales en la planificación TSCH, dando lugar a múltiples soluciones de planificación. Estos enfoques de planificación adquieren una gran relevancia en el actual entorno de la Industria 4.0, donde se busca aumentar de forma masiva la digitalización la interacción y la integración con los diferentes procesos industriales. Por lo tanto, hay una gran diversidad de flujos de información sobre la misma red. Además, al ser flujos de diferentes procesos, también tienen diferentes criticidades, donde deben garantizarse parámetros de QoS como latencia, throughtput, pérdida de paquetes y deadline. Esta creciente demanda de QoS y la diversidad de flujos de tráfico requieren un control estricto y dinámico que no puede lograrse con planificadores convencionales. Por esto, la evolución hacia nuevos paradigmas como las redes definidas por software (SDN - Software Defined Networks) se está convirtiendo en una interesante alternativa para abordar la complejidad de los retos actuales en las IWSN. Estas aceptan un aumento del tráfico de señalización a cambio de ventajas adicionales, tales como: una reducción de la complejidad de los procesos en los nodos, una visión global de todos los elementos de la red y una alta capacidad de reconfiguración. En el desarrollo de esta tesis, se aprovecha el alto nivel de detalle y control que ofrecen las SDN para abordar los complejos desafíos que enfrenta actualmente la adopción de las IWSN en el sector industrial, como la movilidad, la escalabilidad y la garantía de parámetros de QoS. Estos desafíos presentan una complejidad significativa al utilizar los protocolos convencionales; por ello, es necesario implementar un cambio disruptivo que permita superar estas limitaciones de manera sencilla y eficiente. En consecuencia, esta tesis se centra en la investigación y aplicación de mecanismos que permitan adaptar las IWSN al paradigma SDN, así como el desarrollo de protocolos de enrutamiento y planificación TSCH dinámicos que aseguren un alto grado de determinismo y una alta capacidad de adaptación a los cambios en la topología. De esta forma, se garantizan requisitos de QoS independientes para cada tipo de flujo de manera dinámica y con una baja complejidad, incluso en condiciones de movilidad y alta densidad de nodos. / [CA] Les xarxes industrials de sensors sense fils (IWSN - Industrial Wireless Sensor Networks) tenen una creixent acceptació en els entorns productius a causa de la seua facilitat de desplegament, baixos costs i eficiència energètica. No obstant això, la complexitat i precisió que demanden aquests entorns requerixen que les IWSN implementen mecanismes de qualitat de servici (QoS) que els permeten operar amb un alt determinisme. Per aquesta raó, l'estàndard IEEE 802.15.4e ha incorporat protocols d'accés al medi que permeten tindre un major control sobre les comunicacions. Aquest protocols permeten assignar de manera predictible i cíclica instants de temps on els dispositius d'una xarxa poden transmetre informació sense cap mena d'interferència o contesa amb altres dispositius de la xarxa. Un d'ells és el protocol salte de canal amb espais de temps (TSCH - Time Slotted Channel Hopping) el qual planifica les transmissions entre els dispositius en una matriu de dos dimensions, temps i freqüència. Aquesta planificació de les transmissions permet que els dispositius tinguen instants de temps exclusius per a la transmissió, reduint així la interferència i augmentant la fiabilitat de les transmissions. No obstant això, aquest estàndard no especifica com assignar els recursos temporals en la planificació TSCH, donant lloc a múltiples solucions de planificació. Aquest enfocaments de planificació adquireixen una gran rellevància en l'actual entorn de la Indústria 4.0, on es busca augmentar de manera massiva la digitalització, la interacció i la integració amb els diferents processos industrials. Per tant, hi ha una gran diversitat de fluxos d'informació sobre la mateixa xarxa. A més, en ser fluxos de diferents processos, també tenen diferents criticitats, on han de garantir-se paràmetres de QoS com a latència, throughtput, pèrdua de paquets i deadline. Aquesta creixent demanda de QoS i la diversitat de fluxos de trànsit requerixen un control estricte i dinàmic que no pot aconseguir-se amb planificadors convencionals. Per això, l'evolució cap a nous paradigmes com les xarxes definides per programari (SDN - Software Defined Networks) s'està convertint en una interessant alternativa per a abordar la complexitat dels reptes actuals en les IWSN. Aquestes accepten un augment del trànsit de senyalització a canvi d'avantatges addicionals, com ara: una reducció de la complexitat dels processos en els nodes, una visió global de tots els elements de la xarxa i una alta capacitat de reconfiguració. En el desenvolupament d'aquesta tesi, s'aprofita l'alt nivell de detall i control que oferixen les SDN per a abordar els complexos reptes que enfronta actualment l'adopció de les IWSN en el sector industrial, com la mobilitat, l'escalabilitat i la garantia de paràmetres de QoS. Aquests reptes presenten una complexitat significativa en utilitzar els protocols convencionals; per això, és necessari implementar un canvi transgressor que permeta superar aquestes limitacions de manera senzilla i eficient. En conseqüència, aquesta tesi se centra en la investigació i aplicació de mecanismes que permeten adaptar les IWSN al paradigma SDN, així com el desenvolupament de protocols d'encaminament i planificació TSCH dinàmics que asseguren un alt grau de determinisme i una alta capacitat d'adaptació als canvis en la topologia. D'aquesta manera, es garanteixen requisits de QoS independents per a cada tipus de flux de manera dinàmica i amb una baixa complexitat, fins i tot en condicions de mobilitat i alta densitat de nodes. / [EN] Industrial Wireless Sensor Networks (IWSNs) are becoming increasingly popular in production environments due to their ease of deployment, low cost and energy efficiency. However, the complexity and accuracy demanded by these environments require IWSNs to implement quality of service (QoS) mechanisms that allow them to operate with high determinism. For this reason, the IEEE 802.15.4e standard has incorporated medium access protocols that allow for greater control over communications. These protocols enable predictable and cyclic allocation of time slots where devices in a network can transmit information without any interference or contention with other devices in the network. One such protocol is the Time Slotted Channel Hopping (TSCH) protocol, which schedules transmissions between devices using a two-dimensional matrix of time and frequency. This scheduling of transmissions allows devices to have unique time slots for transmission, thereby reducing interference and increasing the reliability of transmissions. However, this standard does not specify how to allocate time resources in TSCH scheduling, leading to multiple scheduling solutions such as centralized scheduling, distributed scheduling, and hybrid scheduling, each with its own advantages and disadvantages. These planning approaches become highly relevant in today's Industry 4.0 environment, where digitisation, interaction and integration with different industrial processes are being massively increased. Therefore, there is a great diversity of information flows over the same network. Moreover, as they are flows of different processes, they also have different criticalities, where QoS parameters such as latency, throughput, packet loss, and deadline must be guaranteed. This increasing QoS demand and the diversity of traffic flows require strict and dynamic control that cannot be achieved with conventional schedulers. Therefore, the evolution towards new paradigms such as Software Defined Networks (SDN) is becoming an interesting alternative to address the complexity of today's challenges in IWSNs. SDNs, in the context of IWSNs, refer to the use of software to manage and control the network, allowing for a more efficient and dynamic allocation of resources. They accept an increase in signalling traffic in exchange for additional benefits, such as: a reduction of the complexity of processes at the nodes, a global view of all network elements and a high reconfiguration capacity. In the development of this thesis, the high level of detail and control offered by SDNs is leveraged to address the complex challenges currently facing the adoption of IWSNs in the industrial sector, such as mobility, scalability and QoS parameter guarantees. These challenges present significant complexity when using conventional protocols; therefore, a disruptive change needs to be implemented to overcome these limitations in a simple and efficient manner. Consequently, this thesis focuses on the investigation and implementation of specific mechanisms, such as dynamic resource allocation and traffic prioritization, to adapt IWSNs to the SDN paradigm. Additionally, new protocols, including dynamic TSCH routing and scheduling protocols, are being developed to ensure a high degree of determinism and a high adaptability to topology changes. In this way, independent QoS requirements for each flow type are guaranteed dynamically and with low complexity, even under conditions of mobility and high node density. / Esta tesis ha sido financiada por las siguientes entidades y proyectos: Instituto Tecnológico de Informática - Proyecto HYPERFACTORY: Arquitecturas, herramientas y servicios para la creación de factorías hiperconectadas: IVACE (IMDEEA/2020/68; IMDEEA/2021/87) / European Commision, IVACE 101007273; IMAMCN/2021/1 - Proyecto: DAIS: Distributed Artificial Intelligent System / Orozco Santos, F. (2024). Diseño y evaluación de redes definidas por software para la orquestación dinámica de calidad de servicio en redes industriales de sensores inalámbricos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/211263

The concept of Industrial Internet of Things (IIoT) is the tangible building block for the realisation of the fourth industrial revolution. It should improve productivity, efficiency and reliability of industrial automation systems, leading to revenue growth in industrial scenarios. IIoT needs to encompass various disciplines and technologies to constitute an operable and harmonious system. One essential requirement for a system to exhibit such behaviour is reliable exchange of information. In industrial automation, the information life-cycle starts at the field level, with data collected by sensors, and ends at the enterprise level, where that data is processed into knowledge for business decision making. In IIoT, the process of knowledge discovery is expected to start in the lower layers of the automation hierarchy, and to cover the data exchange between the connected smart objects to perform collaborative tasks. This thesis aims to assist the comprehension of the processes for information exchange in IIoT-enabled industrial automation- in particular, how reliable exchange of information can be performed by communication systems at field level given an underlying wireless sensor technology, and how data analytics can complement the processes of various levels of the automation hierarchy. Furthermore, this work explores how an IIoT monitoring system can be designed and developed. The communication reliability is addressed by proposing a redundancy-based medium access control protocol for mission-critical applications, and analysing its performance regarding real-time and deterministic delivery. The importance of the data and the benefits of data analytics for various levels of the automation hierarchy are examined by suggesting data-driven methods for visualisation, centralised system modelling and distributed data streams modelling. The design and development of an IIoT monitoring system are addressed by proposing a novel three-layer framework that incorporates wireless sensor, fog, and cloud technologies. Moreover, an IIoT testbed system is developed to realise the proposed framework. The outcome of this study suggests that redundancy-based mechanisms improve communication reliability. However, they can also introduce drawbacks, such as poor link utilisation and limited scalability, in the context of IIoT. Data-driven methods result in enhanced readability of visualisation, and reduced necessity of the ground truth in system modelling. The results illustrate that distributed modelling can lower the negative effect of the redundancy-based mechanisms on link utilisation, by reducing the up-link traffic. Mathematical analysis reveals that introducing fog layer in the IIoT framework removes the single point of failure and enhances scalability, while meeting the latency requirements of the monitoring application. Finally, the experiment results show that the IIoT testbed works adequately and can serve for the future development and deployment of IIoT applications. / SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)