Survey on wireless technology trade-offs for the industrial internet of things

Aside from vast deployment cost reduction, Industrial Wireless Sensor and Actuator Networks (IWSAN) introduce a new level of industrial connectivity. Wireless connection of sensors and actuators in industrial environments not only enables wireless monitoring and actuation, it also enables coordination of production stages, connecting mobile robots and autonomous transport vehicles, as well as localization and tracking of assets. All these opportunities already inspired the development of many wireless technologies in an effort to fully enable Industry 4.0. However, different technologies significantly differ in performance and capabilities, none being capable of supporting all industrial use cases. When designing a network solution, one must be aware of the capabilities and the trade-offs that prospective technologies have. This paper evaluates the technologies potentially suitable for IWSAN solutions covering an entire industrial site with limited infrastructure cost and discusses their trade-offs in an effort to provide information for choosing the most suitable technology for the use case of interest. The comparative discussion presented in this paper aims to enable engineers to choose the most suitable wireless technology for their specific IWSAN deployment

Distributed scheduling algorithms for LoRa-based wide area cyber-physical systems

Low Power Wide Area Networks (LPWAN) are a class of wireless communication protocols that work over long distances, consume low power and support low datarates. LPWANs have been designed for monitoring applications, with sparse communication from nodes to servers and sparser from servers to nodes. Inspite of their initial design, LPWANs have the potential to target applications with higher and stricter requirements like those of Cyber-Physical Systems (CPS). Due to their long-range capabilities, LPWANs can specifically target CPS applications distributed over a wide-area, which is referred to as Wide-Area CPS (WA-CPS). Augmenting WA-CPSs with wireless communication would allow for more flexible, low-cost and easily maintainable deployment. However, wireless communications come with problems like reduced reliability and unpredictable latencies, making them harder to use for CPSs. With this intention, this thesis explores the use of LPWANs, specifically LoRa, to meet the communication and control requirements of WA-CPSs. The thesis focuses on using LoRa due to its high resilience to noise, several communication parameters to choose from and a freely modifiable communication stack and servers making it ideal for research and deployment. However, LoRaWAN suffers from low reliability due to its ALOHA channel access method. The thesis posits that "Distributed algorithms would increase the protocol's reliability allowing it to meet the requirements of WA-CPSs". Three different application scenarios are explored in this thesis that leverage unexplored aspects of LoRa to meet their requirements. The application scenarios are delay-tolerant vehicular networks, multi-stakeholder WA-CPS deployments and water distribution networks. The systems use novel algorithms to facilitate communication between the nodes and gateways to ensure a highly reliable system. The results outperform state-of-art techniques to prove that LoRa is currently under-utilised and can be used for CPS applications.Open Acces

LoRa Enabled Smart Inverters for Microgrid Scenarios with Widespread Elements

The introduction of low-power wide-area networks (LPWANs) has changed the image of smart systems, due to their wide coverage and low-power characteristics. This category of communication technologies is the perfect candidate to be integrated into smart inverter control architectures for remote microgrid (MG) applications. LoRaWAN is one of the leading LPWAN technologies, with some appealing features such as ease of implementation and the possibility of creating private networks. This study is devoted to analyze and evaluate the aforementioned integration. Initially, the characteristics of different LPWAN technologies are introduced, followed by an in-depth analysis of LoRa and LoRaWAN. Next, the role of communication in MGs with widespread elements is explained. A point-by-point LoRa architecture is proposed to be implemented in the grid-feeding control structure of smart inverters. This architecture is experimentally evaluated in terms of latency analysis and externally generated power setpoint, following smart inverters in different LoRa settings. The results demonstrate the effectiveness of the proposed LoRa architecture, while the settings are optimally configured. Finally, a hybrid communication system is proposed that can be effectively implemented for remote residential MG management

Impact of EU duty cycle and transmission power limitations for sub-GHz LPWAN SRDs : an overview and future challenges

Long-range sub-GHz technologies such as LoRaWAN, SigFox, IEEE 802.15.4, and DASH7 are increasingly popular for academic research and daily life applications. However, especially in the European Union (EU), the use of their corresponding frequency bands are tightly regulated, since they must confirm to the short-range device (SRD) regulations. Regulations and standards for SRDs exist on various levels, from global to national, but are often a source of confusion. Not only are multiple institutes responsible for drafting legislation and regulations, depending on the type of document can these rules be informational or mandatory. Regulations also vary from region to region; for example, regulations in the United States of America (USA) rely on electrical field strength and harmonic strength, while EU regulations are based on duty cycle and maximum transmission power. A common misconception is the presence of a common 1% duty cycle, while in fact the duty cycle is frequency band-specific and can be loosened under certain circumstances. This paper clarifies the various regulations for the European region, the parties involved in drafting and enforcing regulation, and the impact on recent technologies such as SigFox, LoRaWAN, and DASH7. Furthermore, an overview is given of potential mitigation approaches to cope with the duty cycle constraints, as well as future research directions

LoRaWAN Performance evaluation

The Internet of Things (IoT) is expected to grow in the upcoming years. LoRaWAN is one promising Low Power Wide Area Network (LPWAN) standard proposed for IoT widely adopted across the world. It runs on unlicensed spectrum and was designed to carry sporadic traffic. This dissertation analyses the performance of LoRaWAN in extreme conditions, where peak traffic loads occur in the network. It starts by evaluating the Network Simulator 3 (ns- 3) LoRaWAN module, identifying and correcting their implementation. In a second phase, it evaluates the limitations of the class A LoRaWAN access protocol during synchronized peaks of traffic, and proposes a new access algorithm to improve the reliability and reduce the latency

A smartwater metering deployment based on the fog computing paradigm

In this paper, we look into smart water metering infrastructures that enable continuous, on-demand and bidirectional data exchange between metering devices, water flow equipment, utilities and end-users. We focus on the design, development and deployment of such infrastructures as part of larger, smart city, infrastructures. Until now, such critical smart city infrastructures have been developed following a cloud-centric paradigm where all the data are collected and processed centrally using cloud services to create real business value. Cloud-centric approaches need to address several performance issues at all levels of the network, as massive metering datasets are transferred to distant machine clouds while respecting issues like security and data privacy. Our solution uses the fog computing paradigm to provide a system where the computational resources already available throughout the network infrastructure are utilized to facilitate greatly the analysis of fine-grained water consumption data collected by the smart meters, thus significantly reducing the overall load to network and cloud resources. Details of the system's design are presented along with a pilot deployment in a real-world environment. The performance of the system is evaluated in terms of network utilization and computational performance. Our findings indicate that the fog computing paradigm can be applied to a smart grid deployment to reduce effectively the data volume exchanged between the different layers of the architecture and provide better overall computational, security and privacy capabilities to the system

Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios

Connectivity is probably the most basic building block of the Internet of Things (IoT) paradigm. Up to know, the two main approaches to provide data access to the \emph{things} have been based either on multi-hop mesh networks using short-range communication technologies in the unlicensed spectrum, or on long-range, legacy cellular technologies, mainly 2G/GSM, operating in the corresponding licensed frequency bands. Recently, these reference models have been challenged by a new type of wireless connectivity, characterized by low-rate, long-range transmission technologies in the unlicensed sub-GHz frequency bands, used to realize access networks with star topology which are referred to a \emph{Low-Power Wide Area Networks} (LPWANs). In this paper, we introduce this new approach to provide connectivity in the IoT scenario, discussing its advantages over the established paradigms in terms of efficiency, effectiveness, and architectural design, in particular for the typical Smart Cities applications

EnerMon: IoT power monitoring system for smart environments

In this research work, we describe the development and subsequent validation of EnerMon a flexible, efficient, edge-computing based IoT LoRa System to monitor power consumption. This system provides real-time information and a descriptive analytics process to provide a ‘big picture’ about energy consumption over time and identify energetic waste. The solution is based on Arduinos, Current Transformer Sensors, Raspberry PI as an application server and LoRa communication alongside a description and information on what is to be expected of it. It describes the development process from the Design phase to the Validation phase with all the steps in between. Due to LoRa low debit communication, an edge computing approach was implemented to create a real-time monitoring process based on this technology. This solution, with the help of descriptive analysis, allows the creation of an energetic local footprint, using a low-cost developed solution for less than 80€ per three-phases monitoring device. It also allows for an easy installation without communication range and obstacles limitations making it easy to be used in a different set of situations from big complex building to smaller consumers, such as electric boilers, or simply to measure the energetic footprint of tourists in a small local tourist apartment.O presente estudo, realizado no âmbito da tese de mestrado, descreve o desenvolvimento e subsequente validação de EnerMon, um sistema IoT(Internet of Things / Internet das Coisas) LoRa flexível, eficiente e baseado em edge-computing capaz de monitorizar consumo de energia em tempo real. Através de processos de análise descritiva é também apresentada uma visão geral sobre o consumo energético ao longo do tempo com a identificação de desperdícios de energia. Neste trabalho o leitor irá tomar conhecimento do processo de desenvolvimento completo do sistema, desde a fase de design à fase de testes, criado com o uso de Arduinos, Sensores de transformadores de corrente e Raspberry PIs como servidores aplicacionais, bem como informação relacionada com a comunicação LoRa e o que lhe é expectável. Esta solução, com a ajuda de analíticas descritivas, permitem a identificação de pegadas energéticas locais, usando materiais de baixo custo por menos de 80€ por sensor de monitorização de três fases. Permite também a fácil instalação sem limitações de alcance e obstáculos na comunicação, simplificando a sua utilização em diferentes ambientes desde edifícios complexos a consumidores energéticos mais pequenos, como caldeiras elétricas ou simplesmente medir a pegada energética de turistas em alojamento local