A survey of communication protocols for internet of things and related challenges of fog and cloud computing integration

The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This article surveys e application layer communication protocols to fulfill the IoT communication requirements, and their potential for implementation in fog- and cloud-based IoT systems. To this end, the article first briefly presents potential protocol candidates, including request-reply and publish-subscribe protocols. After that, the article surveys these protocols based on their main characteristics, as well as the main performance issues, including latency, energy consumption, and network throughput. These findings are thereafter used to place the protocols in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their choice, interoperability, and wider system integration. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture.Peer ReviewedPostprint (author's final draft

Managing Mobility for Distributed Smart Cities Services

The IoT refers to the idea of internetworking physical devices, vehicles, buildings, and any other item embedded with the appropriate electronics, software, sensors, actuators, and network connectivity to allows them to interchange data and to provide highly effective new services. In this thesis we focus on the communications issues of the IoT in relation to mobility and we provide different solutions to alleviate the impact of these potential problems and to guarantee the information delivery in mobile scenarios. Our reference context is a Smart City where various mobile devices collaboratively participate, periodically sending information from their sensors. We assume that these services are located in platforms based in cloud infrastructures where the information is protected through the use of virtualisation ensuring their security and privacy. This thesis is structured into seven chapters. We first detail our objectives and identify the current problems we intend to address. Next, we provide a thorough review of the state of the art of all the areas involved in our work, highlighting how we improved the existing solutions with our research. The overall approach of the solutions we propose in this thesis use prototypes that encompasses and integrates different technologies and standards in a small infrastructure, using real devices in real scenarios with two of the most commonly used networks around the world: WiFi and 802.15.4 to efficiently solve the problems we originally identified. We focussed on protocols based on a producer/consumer paradigm, namely AMQP and particularly MQTT. We observed the behaviour of these protocols using in lab experiments and in external environments, using a mesh wireless network as the backbone network. Various issues raised by mobility were taken into consideration, and thus, we repeated the tests with different messages sizes and different inter-message periodicity, in order to model different possible applications. We also present a model for dimensioning the number of sources for mobile nodes and calculating the number of buffers required in the mobile node as a function of the number of sources and the size of the messages. We included a mechanism for avoiding data loss based on intermediate buffering adapted to the MQTT protocol that, in conjunction with the use of an alternative to the Network Manager in certain contexts, improves the connection establishment for wireless mobile clients. We also performed a detailed study of the jitter behaviour of a mobile node when transmitting messages with this proposal while moving through a real outdoor scenario. To emulate simple IoT networks we used the Cooja simulator to study and determine the effects on the probability of delivering messages when both publishers and subscribers were added to different scenarios. Finally we present an approach that combines the MQTT protocol with DTN which we specifically designed for constrained environments and guarantees that important information will never be lost. The advantage of our proposed solutions is that they make an IoT system more resilient to changes in the point of attachment of the mobile devices in an IoT network without requiring IoT application & service developers to explicitly consider this issue. Moreover, our solutions do not require additional support from the network through protocols such as MobileIP or LISP. We close the thesis by providing some conclusions, and identifying future lines of work which we unable to address here.Internet de las cosas (IoT) se refiere a la idea de interconectar sensores, actuadores, dispositivos físicos, vehículos, edificios y cualquier elemento dotado de la electrónica, así como del software y de la conectividad de red que los hace capaces de intercambiar datos para proporcionar servicios altamente efectivos. En esta tesis nos centramos en temas relacionados con la comunicación de sistemas IoT, específicamente en situaciones de movilidad y en los problemas que esto conlleva. Con este fin ofrecemos diferentes soluciones que alivian su impacto y garantizan la entrega de información en estas situaciones. El contexto de referencia es una ciudad inteligente donde varios dispositivos móviles participan de forma colaborativa enviando periódicamente información desde sus sensores hacia servicios ubicados en plataformas en la nube (cloud computing) donde mediante el uso de virtualización, la información está protegida garantizando su seguridad y privacidad. Las soluciones propuestas en esta tesis se enfocan en probar sobre una pequeña infraestructura un prototipo que abarca e integra diferentes tecnologías y estándares para resolver eficientemente los problemas previamente identificados. Hemos enfocado nuestro esfuerzo en el uso de dispositivos sobre escenarios reales con dos de las redes más extendidas en todo el mundo: WiFi y enlaces 802.15.4. Nos enfocamos en protocolos que ofrecen el paradigma productor/consumidor como el protocolo avanzado de colas de mensajes (AMQP) y particularmente el protocolo de transporte de mensajes telemétricos (MQTT), observamos su comportamiento a través de experimentos en laboratorio y en pruebas al aire libre, repitiendo las pruebas con diferentes tamaños de mensajes y diferente periodicidad entre mensajes. Para modelar las diferentes posibles aplicaciones de la propuesta, se tomaron en consideración varias cuestiones planteadas por la movilidad, resultando en un modelo para dimensionar eficientemente el número de fuentes para un nodo móvil y para calcular el tamaño requerido del buffer, en función del número de fuentes y del tamaño de los mensajes. Proponemos un mecanismo adaptado al protocolo MQTT que evita la pérdida de datos en clientes móviles, basado en un buffer intermedio entre la producción y publicación de mensajes que, en conjunto con el uso de una alternativa al gestor de conexiones inalámbricas "Network Manager", en ciertos contextos mejora el establecimiento de las conexiones. Para la evaluación de esta propuesta se presenta un estudio detallado de un nodo móvil que se mueve en un escenario real al aire libre, donde estudiamos el comportamiento del jitter y la transmisión de mensajes. Además, hemos utilizado emuladores de redes IoT para estudiar y determinar los efectos sobre la probabilidad de entrega de mensajes, cuando se agregan tanto publicadores como suscriptores a diferentes escenarios. Finalmente, se presenta una solución totalmente orientada a entornos con dispositivos de recursos limitados que combina los protocolos MQTT con redes tolerantes a retardos (DTN) para garantizar la entrega de información. La ventaja de las soluciones que proponemos reside en el hecho de que los sistemas IoT se vuelven resilientes a la movilidad y a los cambios de punto de acceso, permitiendo así que los desarrolladores creen fácilmente aplicaciones y servicios IoT evitando considerar estos problema. Otra ventaja de nuestras soluciones es que no necesitan soporte adicional de la red como sucede con protocolos como MobileIP o el protocolo que separa el identificador del localizador (LISP). Se destaca cómo hemos mejorado las soluciones existentes hasta el momento de la escritura de esta disertación, y se identifican futuras líneas de actuación que no han sido contempladas.Internet de les coses (IoT) es refereix a la idea d'interconnectar sensors, actuadors, dispositius físics, vehicles, edificis i qualsevol element dotat de l'electrònica, així com del programari i de la connectivitat de xarxa que els fa capaces d'intercanviar dades per proporcionar serveis altament efectius. En aquesta tesi ens centrem en temes relacionats amb la comunicació de sistemes IoT, específicament en situacions de mobilitat i en els problemes que això comporta. A aquest efecte oferim diferents solucions que alleugeren el seu impacte i garanteixen el lliurament d'informació en aquestes situacions. El context de referència és una ciutat intel·ligent on diversos dispositius mòbils participen de forma col·laborativa enviant periòdicament informació des dels seus sensors cap a serveis situats en plataformes en el núvol (cloud computing) on mitjançant l'ús de virtualització, la informació està protegida garantint la seva seguretat i privadesa. Les solucions proposades en aquesta tesi s'enfoquen a provar sobre una xicoteta infraestructura un prototip que abasta i integra diferents tecnologies i estàndards per a resoldre eficientment els problemes prèviament identificats. Hem enfocat el nostre esforç en l'ús de dispositius sobre escenaris reals amb dos de les xarxes més esteses a tot el món: WiFi i enllaços 802.15.4. Ens enfoquem en protocols que ofereixen el paradigma productor/consumidor com el protocol avançat de cues de missatges (AMQP) i particularment el protocol de transport de missatges telemètrics (MQTT), observem el seu comportament a través d'experiments en laboratori i en proves a l'aire lliure, repetint les proves amb diferents grandàries de missatges i diferent periodicitat entre missatges. Per a modelar les diferents possibles aplicacions de la proposta, es van prendre en consideració diverses qüestions plantejades per la mobilitat, resultant en un model per a dimensionar eficientment el nombre de fonts per a un node mòbil i per a calcular la grandària requerida del buffer, en funció del nombre de fonts i de la grandària dels missatges. Proposem un mecanisme adaptat al protocol MQTT que evita la pèrdua de dades per a clients mòbils, basat en un buffer intermedi entre la producció i publicació de missatges que en conjunt amb l'ús d'una alternativa al gestor de connexions sense fils "Network Manager'', en certs contextos millora l'establiment de les connexions. Per a l'avaluació d'aquesta proposta es presenta un estudi detallat d'un node mòbil que es mou en un escenari real a l'aire lliure, on estudiem el comportament del jitter i la transmissió de missatges. A més, hem utilitzat emuladors de xarxes IoT per a estudiar i determinar els efectes sobre la probabilitat de lliurament de missatges, quan s'agreguen tant publicadors com subscriptors a diferents escenaris. Finalment, es presenta una solució totalment orientada a entorns amb dispositius de recursos limitats que combina els protocols MQTT amb xarxes tolerants a retards (DTN) per a garantir el lliurament d'informació. L'avantatge de les solucions que proposem resideix en el fet que els sistemes IoT es tornen resilients a la mobilitat i als canvis de punt d'accés, permetent així que els desenvolupadors creuen fàcilment aplicacions i serveis IoT evitant considerar aquests problema. Un altre avantatge de les nostres solucions és que no necessiten suport addicional de la xarxa com succeeix amb protocols com MobileIP o el protocol que separa l'identificador del localitzador (LISP). Es destaca com hem millorat les solucions existents fins al moment de l'escriptura d'aquesta dissertació, i s'identifican futures línies d'actuació que no han sigut contemplades.Luzuriaga Quichimbo, JE. (2017). Managing Mobility for Distributed Smart Cities Services [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84744TESI

Adaptive Quality of Service Control for MQTT-SN

Internet of Things and wireless sensor networks applications are becoming more and more popular nowadays, supported by new communication technologies and protocols tailored to their specific requirements. This paper focuses on improving the performance of a Wireless Sensor Network operated by the MQTT-SN protocol, one of the most popular publish/subscribe protocols for IoT applications. In particular, we propose a dynamic Quality of Service (QoS) controller for the MQTT-SN protocol, capable of evaluating the status of the underlying network in terms of end-to-end delay and packet error rate, reacting consequently by assigning to a node the best QoS value. We design and implement the QoS controller in a simulated environment based on the ns-3 network emulator and we perform extensive experiments to prove its effectiveness compared to a non-controlled scenario. The reported results show that, by controlling the Quality of Service, it is possible to manage effectively the number of packets successfully received by each device and their average latency, to improve the quality of the communication of each end node

Wireless communication technologies for the Internet of Things

Internet of Things (IoT) is the inter-networking paradigm based on many processes such as identifying, sensing, networking and computation. An IoT technology stack provides seamless connectivity between various physical and virtual objects. The increasing number of IoT applications leads to the issue of transmitting, storing, and processing a large amount of data. Therefore, it is necessary to enable a system capable to handle the growing traffic requirements with the required level of QoS (Quality of Service). IoT devices become more complex due to the various components such as sensors and network interfaces. The IoT environment is often demanding for mobile power source, QoS, mobility, reliability, security, and other requirements. Therefore, new IoT technologies are required to overcome some of these issues. In recent years new wireless communication technologies are being developed to support the development of new IoT applications. This paper provides an overview of some of the most widely used wireless communication technologies used for IoT applications

Infraestruturas de rede para a indústria 4.0: implementação em IoT 2020

Industry 4.0 aims to integrate the Internet of Things (IoT) into industrial environments creating Industrial Internet of Things (IIoT). Industry 4.0 brings ample value to businesses' production systems to tackle current and future challenges and competition in the marketplace. Portuguese companies are aiming to adopt Industry 4.0 in their current manufacturing facilities in order to make their companies more competitive in national and international marketplaces. In this dissertation two use cases are presented that illustrate a snapshot of the current industry architecture. One is a production line in a car factory where the raw material undergoes two distinct processes. The second is the manufacturing line in a Portuguese ornamental stone factory where a raw stone is processed into stone ready to be applied in facades of buildings. As part of the Industry 4.0 adoption process, the creation of cyber-physical systems (CPS) is required. A CPS is the integration and coordination between computational and physical resources and requires the sensorization of everything that is to become part of it, such as industrial machines and transport systems. Since this sensorization requires the deployment of several new sensors, actuators and IoT gateways a cheaper alternative is studied in this work. The next part of this dissertation is the creation of a demonstrator with IoT 2020. This is a cheaper alternative for an IoT gateway that runs a distribution of Linux and can be programmed using a transversal programming language like C and C++. In this demonstrator an IoT 2020 is connected to sensors, actuators and to the network using MQTT. A Node-RED dashboard is used in order to interact with the system. The results show that IoT 2020 is able to receive and execute commands from the network. It takes about 12 milliseconds to acquire the values of four sensors and publish them to the network. This dissertation work is part in a funded project called Produtech. Produtech aims to enable the transformation of the Portuguese industry in order to embrace Industry 4.0.A Indústria 4.0 visa integrar a Internet das Coisas (IoT) em ambientes industriais, criando a Internet das Coisas Industrial (IIoT). A Indústria 4.0 adiciona amplo valor aos sistemas de produção das empresas de modo a enfrentar os desafios atuais e futuros assim como a concorrência no mercado. As empresas portuguesas pretendem adotar a Indústria 4.0 nas suas atuais instalações de manufatura, a fim de as tornar mais competitivas nos mercados nacionais e internacionais. Neste trabalho, são estudados dois casos práticos. O primeiro é uma linha de produção na fábrica automóvel, onde a matéria-prima passa por dois processos distintos e o outro é a linha de fabricação numa fábrica de produção de pedras ornamentais portuguesa, onde uma pedra bruta é processada em pedra pronta para ser aplicada nas fachadas dos edifícios. Esses casos práticos são estudados de modo a elaborar a arquitetura atual da indústria. Como parte do processo de adoção da Indústria 4.0, é necessário criar sistemas ciber-físicos (CPS). Um CPS é a integração e coordenação entre recursos físicos e computacionais. Um requisito de um CPS é a sensorização de tudo o que se tornará parte do CPS, como máquinas industriais e sistemas de transporte. Como essa sensorização requer a implantação de vários novos sensores, atuadores e gateways de IoT, uma alternativa mais barata é estudada neste trabalho. A próxima parte desta dissertação é a criação de um demonstrador com o IoT 2020, que é uma alternativa mais barata para um gateway de IoT que corre uma distribuição de Linux e pode ser programado usando uma linguagem de programação transversal como C e C ++. Neste demonstrador, um IoT 2020 é conectado a sensores, atuadores e à rede utilizando MQTT. Um painel de controlo Node-RED é utilizado para interagir com o sistema. Os resultados mostram que, o IoT 2020 é capaz de receber e executar comandos vindos da rede. Para adquirir os valores de quatro sensores e publicá-los na rede, demora cerca de 12 milissegundos. Este trabalho de dissertação está inserido num programa mobilizador financiado chamado Produtech. Produtech tem como objetivo viabilizar a transformação da indústria portuguesa de modo abranger a Indústria 4.0.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

A real time demonstrative analysis of lightweight payload encryption in resource constrained devices based on mqtt

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Kısıtlı cihazların kaynakları, yani bellek (ROM ve RAM), CPU ve pil ömrü (varsa) sınırlıdır. Genellikle, veri toplayan sensörler, makinadan makineye (M2M) veya servisleri ve elektrikli ev aletlerini kontrol eden akıllı cihazlar için puanlar. Bu tür aygıtlar bir ağa bağlandığında "nesnelerin Internet'i" nin (IoT) bir parçasını oluştururlar. Message Queue Telemetry Transport (yani MQTT), hafif, açık, basit, istemci-sunucu yayın/abone mesajlaşma taşıma protokolüdür. Güvenilir iletişim için üç Hizmet Kalitesi (QoS) seviyesini destekleyen çoğu kaynak kısıtlamalı IoT cihazı için kullanışlıdır ve verimlidir. Cihazdan Cihaza (D2D) ve nesnelerin Internet'i (IoT) bağlamları gibi kısıtlı ortamlarda iletişim için gerekli olan bir protokoldür. MQTT protokolü, güvenli soket katmanı (SSL) sertifikalarına dayalı taşıma katmanı güvenliği (TLS) dışında somut güvenlik mekanizmalarından yoksundur. Bununla birlikte, bu güvenlik protokollerinin en hafif değildir ve özellikle kısıtlı cihazlar için ağ yüklerini artırır. IoT cihazlarının yaklaşık %70'inde özellikle de istemci tarafında veri şifrelemesi yoktur ve TLS için mükemmel bir alternatif olabilir. Bu tezde, farklı Hizmet Kalitesi (QoS) ve veri yüklerin değişken boyutu için kısıtlı bir cihaz üzerinde MQTT protokolünün ağ performansı üzerindeki etkisini göstermek için bir deney düzeneği tasarlanmıştır. Bu çalışmanın yeni kısmı, yüklerin istemci tarafında şifrelenmesini ve ağ performansı üzerindeki etkisini kapsıyor. Denemelerde, verilere 128-bits ileileri şifreleme standardı (AES) hafif bir şifreleme uygulanmıştır. Mesajlar, farklı yük boyutlarına dayanan bir komisyoncu sunucusu aracılığıyla gerçek kablolu alt uçtakı yayıncılık istemcisi ve düşük uçtakı abone istemcisi üzerinden MQTT'deki üç farklı QoS seviyesini kullanarak aktarılır. Paketler, şifreleme ve şifre çözme işlem süresinin ölçülmesiyle birlikte uçtan uca gecikme, verimlilik ve mesaj kaybı analiz etmek için yakalanır. Deney sonuçlarına göre, şifrelenmemiş (şifresiz metin) yükün daha düşük bir ağ yük etkisine sahip olduğu ve bu nedenle, yüzde kaybı ve mesaj tesliminde, şifreli yüke göre MQTT'yi kullanarak nispeten daha iyi bir ağ performansı ürettiği sonucuna varılmıştır.Constrained devices are limited in resources namely, memory (ROM and RAM), CPU and battery life (if available). They are often used as sensors that collects data, machine to machine (M2M) or smart devices that control services and electrical appliances. When such devices are connected to a network they form what is called "things" and in a whole, they form part of the "Internet of Things" (IoT). Message Queue Telemetry Transport (MQTT) is a common light weight, open, simple, client-server publish/subscribe messaging transport protocol useful and efficient for most resource constrained IoT devices that supports three Quality of Service (QoS) levels for reliable communication. It is an essential protocol for communication in constrained environments such as Device to Device (D2D) and Internet of Things (IoT) contexts. MQTT protocol is devoid of concrete security mechanisms apart from Transport Layer Security (TLS) based on Secure Socket Layer (SSL) certificates. However, this is not the lightest of security protocols and increases network overheads especially for constrained devices. About 70 % of most ordinary IoT devices also lack data encryption especially at the client-end which could have been a perfect alternative for TLS. In this thesis, an experimental setup is designed to demonstrate the effect on network performance of MQTT protocol on a constrained device for different Quality of Service (QoS) and variable size of payloads. The novel part of this study covers client-side encryption of payloads and its effect over network performance. In the experiments, a lightweight encryption of 128-bits Advanced Encryption Standard (AES) is applied on the data. The messages are transferred using the three different QoS levels in MQTT over real wired low-end publish client and low-end subscriber client via a broker server based on different payload sizes. The packets are captured to analyze end-to-end latency, throughput and message loss along with the measurement of encryption and decryption processing time. According to the results of the experiment, it was concluded that, non-encrypted (plaintext) payload have a lower network load effect and hence produces a relatively better network performance using MQTT in terms of percentage loss and message delivery than the encrypted payload

Designing and implementing a GPS-based vehicle navigation application for Eclipse Kuksa

Abstract. With the development of the Internet of Things (IoT), connected cars are rapidly becoming an essential milestone in the design of intelligent transportation systems and a key element in smart city design. Connected cars use a three-layer client-connection-cloud architecture, and car sensors are located at the client layer. This architecture provides the driver with a large amount of data about the external environment, which reduces the number of traffic accidents and helps the car drive safely. Driving safety is the most critical design factor for next-generation vehicles. The future vision of the automotive industry is self-driving cars. However, it faces some challenges. Eclipse Kuksa provides solutions to challenges in the field of connected cars. A comprehensive ecosystem includes a complete tool stack for connected vehicles, including a vehicle platform, a cloud platform, and an application development Integrated Development Environment (IDE). Its essential function is to collect, store, and analyze vehicle data and transmit various information in the cloud. This master’s thesis aims to investigate a Global Positioning System (GPS) -based vehicle navigation application on the vehicle and cloud platforms of Eclipse Kuksa, understand how to develop a GPS-based vehicle navigation application using the Eclipse Kuksa software platform, and discuss the advantages and challenges of using Eclipse Kuksa to develop vehicle applications. The research methods are Design Science Research (DSR) and literature review. System development is carried out following the Design Science Research Methodology (DSRM) Process, developed and evaluated on the vehicle navigation application. The application artifact consists of the Eclipse Kuksa vehicle platform and cloud platform. The steps described in this paper can be used to build vehicle applications in Eclipse Kuksa. This paper also explains the benefits and challenges of using Eclipse Kuksa to develop vehicle applications. The main benefit is that open source solutions break the long-term closed development model of the automotive industry and establish a vehicle-to-cloud solution standard to meet the IoT challenges to the automotive industry. Simultaneously the challenge of using Eclipse Kuksa is the complexity of environment construction and the software and hardware compatibility