Wireless Process Control using IEEE 802.15.4 Protocol

Projecte final de carrera fet en col.laboració amb KTH Royal Institute of TechnologyCatalà:: Considerant els beneficis potencials de les xarxes sense fils de sensors (WSNs), s'estan convertint en una interessant tecnologia tant per processos com per al control industrial així com per xarxes intel·ligents. Aquestes aplicacions motiven altres companyies, comunitats industrials i a universitats a centrar la investigació en aquesta direcció. El IEEE 802.15.4 és un estàndard proposat per ser utilitzat en comunicacions de baix consum energètic on les WSNs formen part. Malgrat l'existència de moltes implementacions d'aquests estàndard per el nostre sistema operatiu, TinyOS, no estan completament validats o no existeix un anàlisi suficient del rendiment de l'estàndard en una implementació real. En aquest projecte, es compara dues implementacions a través de diferents experiments per comprovar la validesa de les implementacions. Però la implementació seleccionada no incorpora el mecanisme de Guaranteed Time Slots (GTSs), es per això, que en aquest projecte es proporcionen tots els mecanismes necessaris per transmetre durant el Contention-Free Period (CFP): assignació, expiració, reassignació i deassignació. D'aquesta manera proporcionem la implementació del IEEE 802.15.4 amb una completa avaluació del rendiment amb la qual el correcte funcionament queda validat. Degut a que no existien resultats pràctics sobre l'ús d'aquest protocol per aplicacions de control, presentem un pendol invertit per mostrar els beneficis del control sense fils de processos utilitzant el IEEE 802.15.4 en un llaç de control. Els resultats experimentals mostren les pèrdues de paquets i retards, factors determinants per garantir l'estabilitat del sistema. D'altra banda, també demostrem i analitzem els beneficis d'aquest protocol aplicat a una xarxa intel·ligent (Smart Grid).Castellano: Considerando los potenciales beneficios de las redes inalámbricas de sensores (WSN), se están convirtiendo en una interesante tecnología para procesos, producción, y el control industrial así como para redes inteligentes. Estas aplicaciones motivan a otras compañías, comunidades industriales y a las universidades a centrar la investigación en esta dirección. El IEEE 802.15.4 es un estándar propuesto para ser utilizado en comunicaciones de bajo consumo donde las WSNs forman parte. A pesar de que existen muchas implementaciones de dicho estándar para el sistema operativo seleccionado, TinyOS, no están completamente validadas o completamente implementadas. Además, a pesar de la existencia de estudios que utilizan este protocolo, no hay un análisis suficiente del rendimiento de este estándar en una implementación real. En este proyecto, se comparan dos implementaciones a través de diferentes experimentos para comprobar la validez de dichas implementaciones. Debido al hecho de la implementación seleccionada no incluye el mecanismo Guaranteed Time Slots (GTSs), en este proyecto se proporcionan todos los mecanismo necesarios para transmitir durante el Contention-Free Period (CFP): asignación, expiación, re-asignación y de-asignación. De esta manera, proporcionamos la implementación del IEEE 802.15.4 con una completa evaluación del rendimiento con el cual su correcto comportamiento queda validado. Debido a que no existían resultados prácticos del uso de este protocolo para aplicaciones de control, presentamos un péndulo invertido para mostrar también los beneficios del control inalámbrico de procesos utilizando el IEEE 802.15.4 en un lazo de control. Los resultados experimentales muestran las perdidas de paquetes y retrasos, factores determinantes para garantizar la estabilidad del sistema. Además, demostramos y analizamos los beneficios de este protocolo aplicado a una red inteligente (Smart Grid).English: Considering the potential benefits offered by Wireless Sensor Networks (WSNs), they have been becoming an interesting technology for process, manufacturing, and industrial control and Smart Grid applications. These applications motivate many companies, industrial communities and academy to focus and research in this direction. The IEEE 802.15.4 is the standard proposed to be use in low-power communication of which WSN is part. Even though there are many implementations of the standard for the selected operating system, TinyOS, they are not fully validated or fully implemented. Moreover, in spite of the existence of previous studies using the protocol, there is no sufficient analysis of the performance of this standard. In this thesis, a comparison between the two main implementations is done through the experiments to validate the feasibility of the implementations. Because of the fact that the selected implementation does not have the Guaranteed Time Slots (GTSs) mechanism developed, in this thesis are provided all the mechanisms necessary to transmit during the Contention-Free Period (CFP): allocation, expiration, reallocation and deallocation. Hence, a IEEE 802.15.4 implementation is provided with a comprehensive evaluation with which the behaviour is proven. The implementation is validated in terms of packet delivery rate and delay for different network configurations and different parameters. Owing to no practical results for the use of this protocol in control applications, a inverted pendulum process is introduced to show the benefits in wireless process control by using the IEEE 802.15.4 in a real-time control loop process. The extensive experimental results show that packets losses and delays are the essential factors to guarantee the stability of the system. Furthermore, we also demonstrate and analyse the benefits of using this protocol in a Home Smart Grid setup

On the use of IEEE 802.15.4/ZigBee as federating communication protocols for Wireless Sensor Networks

Tese de mestrado. Redes e Serviços de Comunicação. Faculdade de Engenharia. Universidade do Porto, Instituto Superior de Engenharia. 200

Innovative energy-efficient wireless sensor network applications and MAC sub-layer protocols employing RTS-CTS with packet concatenation

of energy-efficiency as well as the number of available applications. As a consequence there are challenges that need to be tackled for the future generation of WSNs. The research work from this Ph.D. thesis has involved the actual development of innovative WSN applications contributing to different research projects. In the Smart-Clothing project contributions have been given in the development of a Wireless Body Area Network (WBAN) to monitor the foetal movements of a pregnant woman in the last four weeks of pregnancy. The creation of an automatic wireless measurement system for remotely monitoring concrete structures was an contribution for the INSYSM project. This was accomplished by using an IEEE 802.15.4 network enabling for remotely monitoring the temperature and humidity within civil engineering structures. In the framework of the PROENEGY-WSN project contributions have been given in the identification the spectrum opportunities for Radio Frequency (RF) energy harvesting through power density measurements from 350 MHz to 3 GHz. The design of the circuits to harvest RF energy and the requirements needed for creating a WBAN with electromagnetic energy harvesting and Cognitive Radio (CR) capabilities have also been addressed. A performance evaluation of the state-of-the art of the hardware WSN platforms has also been addressed. This is explained by the fact that, even by using optimized Medium Access Control (MAC) protocols, if the WSNs platforms do not allow for minimizing the energy consumption in the idle and sleeping states, energy efficiency and long network lifetime will not be achieved. The research also involved the development of new innovative mechanisms that tries and solves overhead, one of the fundamental reasons for the IEEE 802.15.4 standard MAC inefficiency. In particular, this Ph.D. thesis proposes an IEEE 802.15.4 MAC layer performance enhancement by employing RTS/CTS combined with packet concatenation. The results have shown that the use of the RTS/CTS mechanism improves channel efficiency by decreasing the deferral time before transmitting a data packet. In addition, the Sensor Block Acknowledgment MAC (SBACK-MAC) protocol has been proposed that allows the aggregation of several acknowledgment responses in one special Block Acknowledgment (BACK) Response packet. Two different solutions are considered. The first one considers the SBACK-MAC protocol in the presence of BACK Request (concatenation) while the second one considers the SBACK-MAC in the absence of BACK Request (piggyback). The proposed solutions address a distributed scenario with single-destination and single-rate frame aggregation. The throughput and delay performance is mathematically derived under both ideal conditions (a channel environment with no transmission errors) and non ideal conditions (a channel environment with transmission errors). An analytical model is proposed, capable of taking into account the retransmission delays and the maximum number of backoff stages. The simulation results successfully validate our analytical model. For more than 7 TX (aggregated packets) all the MAC sub-layer protocols employing RTS/CTS with packet concatenation allows for the optimization of channel use in WSNs, v8-48 % improvement in the maximum average throughput and minimum average delay, and decrease energy consumption

Analysis of Jamming Attacks on Wireless Sensor Networks

Wireless Sensor Network (WSN) is a wireless-oriented form of communication largely used for outdoor applications, such as environmental monitoring and military surveillance. Therefore, a jamming attack is one of the denial of service attacks (DOS) that may take place by jamming the communication channel, making communication between genuine sensor nodes difficult or even impossible. Several studies have been carried out to develop countermeasures against jamming attacks, utilising parameters such as Packet Delivery Ratio (PDR), Packet Send Ratio (PSR), Received Signal Strength Indication (RSSI) and Clear Channel Assessment (CCA). The accuracy of the parameters used is very important for developing successful countermeasures against jamming attacks. Consequently, the focus in this study is to examine the effect of a jamming attack that was generated by one or more wireless sensor network nodes on PDR, PSR and RSSI, and look at the enhancements that can be made on Packet Delivery Ratio by altering the value of CCA on sender nodes. The experiment was performed using XBee RF and K-mote devices configured as jammers by disabling the CSMA protocol. It was performed in a non-isolated room in order to emulate a real-life environment. Two scenarios were carried out in this study. The first scenario aimed to study RSSI, PSR and PDR values with a fixed CCA value, and the second scenario studied the effect of CCA on PDR value. The experiment showed that the RSSI value measured by XBee RF inflated in the presence of noise. This fact has to be considered when RSSI is utilised in jamming attack counter measures. Further, it has been observed that the PDR value is distressed by jamming because genuine packets collide with jammers’ packets and increase the power of the sent packets without considering that the distance will not be enough to enhance the PDR value. This study demonstrates that changing the CCA threshold value on the XBee RF module influences the Packet Delivery Ratio (PDR) value in the presence of jamming

On the use of IEEE 802.15.4/Zigbee for time-sensitive wireless sensor network applications

Mestrado em Engenharia Electrotécnica e de ComputadoresRecent advancements in information and communication technologies are paving the way for new paradigms in embedded computing systems. This, allied with an increasing eagerness for monitoring and controlling everything, everywhere, is pushing forward the design of new Wireless Sensor Network (WSN) infrastructures that will tightly interact with the physical environment, in a ubiquitous and pervasive fashion. Such cyber-physical systems require a rethinking of the usual computing and networking concepts, and given that the computing entities closely interact with their environment, timeliness is of increasing importance. This Thesis addresses the use of standard protocols, particularly IEEE 802.15.4 and ZigBee, combined with commercial technologies as a baseline to enable WSN infrastructures capable of supporting the Quality of Service (QoS) requirements (specially timeliness and system lifetime) that future large-scale networked embedded systems will impose. With this purpose, in this Thesis we start by evaluating the network performance of the IEEE 802.15.4 Slotted CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism for different parameter settings, both through simulation and through an experimental testbed. In order to improve the performance of these networks (e.g. throughput, energyefficiency, message delay) against the hidden-terminal problem, a mechanism to mitigate it was implemented and experimentally validated. The effectiveness of this mechanism was also demonstrated in a real application scenario, featuring a target tracking application. A methodology for modelling cluster-tree WSNs and computing the worst-case endto-end delays, buffering and bandwidth requirements was tested and validated experimentally. This work is of paramount importance to understand the behaviour of WSNs under worst-case conditions and also to make the appropriate network settings. Our experimental work enabled us to identify a number of technological constrains, namely related to hardware/software and to the Open-ZB implementation in TinyOS. In this line, a new implementation effort was triggered to port the Open-ZB IEEE 802.15.4/ZigBee protocol stack to the ERIKA real-time operating system. This implementation was validated experimentally and its behaviour compared with the TinyOS–based implementation.Os últimos avanços nas tecnologias de informação e comunicação (ICTs) estão a abrir caminho para novos paradigmas de sistemas computacionais embebidos. Este facto, aliado à tendência crescente em monitorizar e controlar tudo, em qualquer lugar, está a alimentar o desenvolvimento de novas infra-estruturas de Redes de Sensores Sem Fios (WSNs), que irão interagir intimamente com o mundo físico de uma forma ubíqua. Este género de sistemas ciber-físicos de grande escala, requer uma reflexão sobre os conceitos de redes e de computação tradicionais, e tendo em conta a proximidade que estas entidades partilham com ambiente envolvente, o seu comportamento temporal é de acrescida importância. Esta Tese endereça a utilização de protocolos normalizados, em particular do IEEE 802.15.4 e ZigBee em conjunto com tecnologias comerciais, para desenvolver infraestruturas WSN capazes de responder aos requisitos de Qualidade de Serviço (QoS) (especialmente em termos de comportamento temporal e tempo de vida do sistema), que os futuros sistemas embebidos de grande escala deverão exigir. Com este propósito, nesta Tese começamos por analisar a performance do mecanismo de Slotted CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) do IEEE 802.15.4 para diferentes parâmetros, através de simulação e experimentalmente. De modo a melhorar a performance destas redes (ex. throughput, eficiência energética, atrasos) em cenários que contenham nós escondidos (hidden-nodes), foi implementado e validado experimentalmente um mecanismo para eliminar este problema. A eficácia deste mecanismo foi também demonstrada num cenário aplicacional real. Foi testada e validada uma metodologia para modelizar uma WSN em cluster-tree e calcular os piores atrasos das mensagens, necessidades de buffering e de largura de banda. Este trabalho foi de grande importância para compreender o comportamento deste tipo de redes para condições de utilização limite e para as configurar a priori. O nosso trabalho experimental permitiu identificar uma série de limitações tecnológicas, nomeadamente relacionadas com hardware/software e outras relacionadas com a implementação do Open-ZB em TinyOS. Isto desencadeou a migração da pilha protocolar IEEE 802.15.4/ZigBee Open-ZB para o ERIKA, um sistema operativo de tempo-real. Esta implementação foi validada experimentalmente e o seu comportamento comparado com o da implementação baseada em TinyOS

Deploying RIOT operating system on a reconfigurable Internet of Things end-device

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e ComputadoresThe Internet of Everything (IoE) is enabling the connection of an infinity of physical objects to the Internet, and has the potential to connect every single existing object in the world. This empowers a market with endless opportunities where the big players are forecasting, by 2020, more than 50 billion connected devices, representing an 8 trillion USD market. The IoE is a broad concept that comprises several technological areas and will certainly, include more in the future. Some of those already existing fields are the Internet of Energy related with the connectivity of electrical power grids, Internet of Medical Things (IoMT), for instance, enables patient monitoring, Internet of Industrial Things (IoIT), which is dedicated to industrial plants, and the Internet of Things (IoT) that focus on the connection of everyday objects (e.g. home appliances, wearables, transports, buildings, etc.) to the Internet. The diversity of scenarios where IoT can be deployed, and consequently the different constraints associated to each device, leads to a heterogeneous network composed by several communication technologies and protocols co-existing on the same physical space. Therefore, the key requirements of an IoT network are the connectivity and the interoperability between devices. Such requirement is achieved by the adoption of standard protocols and a well-defined lightweight network stack. Due to the adoption of a standard network stack, the data processed and transmitted between devices tends to increase. Because most of the devices connected are resource constrained, i.e., low memory, low processing capabilities, available energy, the communication can severally decrease the device’s performance. Hereupon, to tackle such issues without sacrificing other important requirements, this dissertation aims to deploy an operating system (OS) for IoT, the RIOT-OS, while providing a study on how network-related tasks can benefit from hardware accelerators (deployed on reconfigurable technology), specially designed to process and filter packets received by an IoT device.O conceito Internet of Everything (IoE) permite a conexão de uma infinidade de objetos à Internet e tem o potencial de conectar todos os objetos existentes no mundo. Favorecendo assim o aparecimento de novos mercados e infinitas possibilidades, em que os grandes intervenientes destes mercados preveem até 2020 a conexão de mais de 50 mil milhões de dispositivos, representando um mercado de 8 mil milhões de dólares. IoE é um amplo conceito que inclui várias áreas tecnológicas e irá certamente incluir mais no futuro. Algumas das áreas já existentes são: a Internet of Energy relacionada com a conexão de redes de transporte e distribuição de energia à Internet; Internet of Medical Things (IoMT), que possibilita a monotorização de pacientes; Internet of Industrial Things (IoIT), dedicada a instalações industriais e a Internet of Things (IoT), que foca na conexão de objetos do dia-a-dia (e.g. eletrodomésticos, wearables, transportes, edifícios, etc.) à Internet. A diversidade de cenários à qual IoT pode ser aplicado, e consequentemente, as diferentes restrições aplicadas a cada dispositivo, levam à criação de uma rede heterogénea composto por diversas tecnologias de comunicação e protocolos a coexistir no mesmo espaço físico. Desta forma, os requisitos chave aplicados às redes IoT são a conectividade e interoperabilidade entre dispositivos. Estes requisitos são atingidos com a adoção de protocolos standard e pilhas de comunicação bem definidas. Com a adoção de pilhas de comunicação standard, a informação processada e transmitida entre dispostos tende a aumentar. Visto que a maioria dos dispositivos conectados possuem escaços recursos, i.e., memória reduzida, baixa capacidade de processamento, pouca energia disponível, o aumento da capacidade de comunicação pode degradar o desempenho destes dispositivos. Posto isto, para lidar com estes problemas e sem sacrificar outros requisitos importantes, esta dissertação pretende fazer o porting de um sistema operativo IoT, o RIOT, para uma solução reconfigurável, o CUTE mote. O principal objetivo consiste na realização de um estudo sobre os benefícios que as tarefas relacionadas com as camadas de rede podem ter ao serem executadas em hardware via aceleradores dedicados. Estes aceleradores são especialmente projetados para processar e filtrar pacotes de dados provenientes de uma interface radio em redes IoT periféricas

Development of a long range wireless sensor platform

Wireless Sensor Networks have emerged as an exciting field in recent years. There have been numerous studies on how to improve and standardise different aspects of wireless sensor networks. This paper aims to develop a wireless sensor network suitable for environmental monitoring applications. More specifically this paper aims to address the limited communication range of the existing wireless sensor technology. In order to achieve the desired objectives, we have initially developed a hardware platform and then integrated the hardware with a long range RF radio module to achieve the goals. The system is further enhanced with mesh networking capabilities to increase the communication range and overall reliability of the network. The developed wireless sensor network is composed of sensors, microcontroller, RF radio module, antenna and expansion connectors for additional sensors and peripheral devices. The developed wireless sensor network has been rigorously tested under three different scenarios to ensure the correct operation of the mesh network, communication range and effect of environmental obstacles such as vegetation and trees. The developed wireless sensor network has been proven to be a suitable platform for environmental monitoring applications and the modular design has made it very easy to optimise it for different applications

Wireless Process Control using IEEE 802.15.4 Protocol

Projecte final de carrera fet en col.laboració amb KTH Royal Institute of TechnologyCatalà:: Considerant els beneficis potencials de les xarxes sense fils de sensors (WSNs), s'estan convertint en una interessant tecnologia tant per processos com per al control industrial així com per xarxes intel·ligents. Aquestes aplicacions motiven altres companyies, comunitats industrials i a universitats a centrar la investigació en aquesta direcció. El IEEE 802.15.4 és un estàndard proposat per ser utilitzat en comunicacions de baix consum energètic on les WSNs formen part. Malgrat l'existència de moltes implementacions d'aquests estàndard per el nostre sistema operatiu, TinyOS, no estan completament validats o no existeix un anàlisi suficient del rendiment de l'estàndard en una implementació real. En aquest projecte, es compara dues implementacions a través de diferents experiments per comprovar la validesa de les implementacions. Però la implementació seleccionada no incorpora el mecanisme de Guaranteed Time Slots (GTSs), es per això, que en aquest projecte es proporcionen tots els mecanismes necessaris per transmetre durant el Contention-Free Period (CFP): assignació, expiració, reassignació i deassignació. D'aquesta manera proporcionem la implementació del IEEE 802.15.4 amb una completa avaluació del rendiment amb la qual el correcte funcionament queda validat. Degut a que no existien resultats pràctics sobre l'ús d'aquest protocol per aplicacions de control, presentem un pendol invertit per mostrar els beneficis del control sense fils de processos utilitzant el IEEE 802.15.4 en un llaç de control. Els resultats experimentals mostren les pèrdues de paquets i retards, factors determinants per garantir l'estabilitat del sistema. D'altra banda, també demostrem i analitzem els beneficis d'aquest protocol aplicat a una xarxa intel·ligent (Smart Grid).Castellano: Considerando los potenciales beneficios de las redes inalámbricas de sensores (WSN), se están convirtiendo en una interesante tecnología para procesos, producción, y el control industrial así como para redes inteligentes. Estas aplicaciones motivan a otras compañías, comunidades industriales y a las universidades a centrar la investigación en esta dirección. El IEEE 802.15.4 es un estándar propuesto para ser utilizado en comunicaciones de bajo consumo donde las WSNs forman parte. A pesar de que existen muchas implementaciones de dicho estándar para el sistema operativo seleccionado, TinyOS, no están completamente validadas o completamente implementadas. Además, a pesar de la existencia de estudios que utilizan este protocolo, no hay un análisis suficiente del rendimiento de este estándar en una implementación real. En este proyecto, se comparan dos implementaciones a través de diferentes experimentos para comprobar la validez de dichas implementaciones. Debido al hecho de la implementación seleccionada no incluye el mecanismo Guaranteed Time Slots (GTSs), en este proyecto se proporcionan todos los mecanismo necesarios para transmitir durante el Contention-Free Period (CFP): asignación, expiación, re-asignación y de-asignación. De esta manera, proporcionamos la implementación del IEEE 802.15.4 con una completa evaluación del rendimiento con el cual su correcto comportamiento queda validado. Debido a que no existían resultados prácticos del uso de este protocolo para aplicaciones de control, presentamos un péndulo invertido para mostrar también los beneficios del control inalámbrico de procesos utilizando el IEEE 802.15.4 en un lazo de control. Los resultados experimentales muestran las perdidas de paquetes y retrasos, factores determinantes para garantizar la estabilidad del sistema. Además, demostramos y analizamos los beneficios de este protocolo aplicado a una red inteligente (Smart Grid).English: Considering the potential benefits offered by Wireless Sensor Networks (WSNs), they have been becoming an interesting technology for process, manufacturing, and industrial control and Smart Grid applications. These applications motivate many companies, industrial communities and academy to focus and research in this direction. The IEEE 802.15.4 is the standard proposed to be use in low-power communication of which WSN is part. Even though there are many implementations of the standard for the selected operating system, TinyOS, they are not fully validated or fully implemented. Moreover, in spite of the existence of previous studies using the protocol, there is no sufficient analysis of the performance of this standard. In this thesis, a comparison between the two main implementations is done through the experiments to validate the feasibility of the implementations. Because of the fact that the selected implementation does not have the Guaranteed Time Slots (GTSs) mechanism developed, in this thesis are provided all the mechanisms necessary to transmit during the Contention-Free Period (CFP): allocation, expiration, reallocation and deallocation. Hence, a IEEE 802.15.4 implementation is provided with a comprehensive evaluation with which the behaviour is proven. The implementation is validated in terms of packet delivery rate and delay for different network configurations and different parameters. Owing to no practical results for the use of this protocol in control applications, a inverted pendulum process is introduced to show the benefits in wireless process control by using the IEEE 802.15.4 in a real-time control loop process. The extensive experimental results show that packets losses and delays are the essential factors to guarantee the stability of the system. Furthermore, we also demonstrate and analyse the benefits of using this protocol in a Home Smart Grid setup