Utilização do protocolo IEC 61850 sobre redes de telecomunicações IP

We live in an era where the consumption of energy rises to an almost immeasurable level, jeopardizing the balance of systems when a power failure in the electrical grid occurs. This brought the necessity of making it safer and intelligent, hence emerging the concept of Smart Grid. The IEC 61850 standard was initially designed to operate within substations, yet other potential developments glimpsed to operate not only within substations but also to the outside of them. Based on several communications protocols, including MMS, GOOSE and SV, the IEC 61850 provides the possibility of real-time data exchange, leading to cost savings, increased security and interoperability between different vendors’ devices. Addressing this issue, together with EFACEC and the Institute of Telecommunications of Aveiro, a key question emerged: What are the requirements for the communication between devices in different substations? This MSc dissertation aims to answer this question, as well as to analyse other possible technologies that are suitable at the time of its implementation. With this analysis, a specific technology stands out, the 4G-LTE. A study was conducted recurring to temporal diagrams of the messages, performing with both approaches as described in the standard. Either using the IP or VPN approach, different technologies such as ADSL, Optical Fibre, and the previously referred 4G-LTE were tested. Thereafter, the results of the study are analysed, obtaining this way the conclusions for each one of the approaches, as well for each of the different technologies studied. Last but not least, it is analysed which of the approaches will be more beneficial in the long-term, as well as the necessary future work that must be developed in the different areas of the presented standard.Vivemos numa era em que o consumo de energia cresce a um nível quase imensurável, colocando em causa o equilíbrio de um sistema aquando a ocorrência de uma falha na rede elétrica. Isto trouxe a necessidade de a tornar numa rede mais segura e inteligente, surgindo então o conceito de Smart Grid. O standard IEC 61850 foi inicialmente concebido para operar dentro das subestações, contudo vislumbraram-se outras potencialidades para o aplicar não só dentro, mas também para fora das mesmas. Assente em vários protocolos de comunicação, entre os quais MMS, GOOSE e SV, o IEC 61850 oferece a possibilidade de troca de dados em tempo real, levando a uma redução de custos, um aumento da segurança bem como a interoperabilidade entre os equipamentos dos diferentes vendedores. Abordando este tema em conjunto com a EFACEC e o Instituto de Telecomunicações de Aveiro, houve uma questão se levantou: Quais são as condições requeridas para a comunicação entre os equipamentos das diferentes subestações? Esta dissertação de mestrado visa dar resposta a esta questão, assim como analisar outras possíveis tecnologias a utilizar no momento da sua implementação. Realizada essa análise, houve uma tecnologia que se evidenciou, o 4G-LTE. Foi elaborado um estudo com recurso a diagramas temporais de mensagens, utilizando as duas abordagens descritas no standard. Quer utilizando a abordagem por IP quer utilizando a abordagem por VPN, foram testados em ambos os cenários diferentes tecnologias como a ADSL, Fibra Ótica, bem como o já referido, 4G-LTE. De seguida, são analisados os resultados do estudo, obtendo as devidas conclusões para cada uma das abordagens bem como para cada uma das diferentes tecnologias. Por fim, é analisada qual das abordagens será mais proveitosa a longo prazo, assim como qual o trabalho futuro que deverá ser desenvolvido no que diz respeito às diferentes áreas do standard apresentado.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

On Statistical QoS Provisioning for Smart Grid

Current power system is in the transition from traditional power grid to Smart Grid. A key advantage of Smart Grid is its integration of advanced communication technologies, which can provide real-time system-wide two-way information links. Since the communication system and power system are deeply coupled within the Smart Grid system, it makes Quality of Service (QoS) performance analysis much more complex than that in either system alone. In order to address this challenge, the effective rate theory is studied and extended in this thesis, where a new H transform based framework is proposed. Various scenarios are investigated using the new proposed effective rate framework, including both independent and correlated fading channels. With the effective rate as a connection between the communication system and the power system, an analysis of the power grid observability under communication constraints is performed. Case studies show that the effective rate provides a cross layer analytical framework within the communication system, while its statistical characterisation of the communication delay has the potential to be applied as a general coupling point between the communication system and the power system, especially when real-time applications are considered. Besides the theoretical QoS performance analysis within Smart Grid, a new Software Defined Smart Grid testbed is proposed in this thesis. This testbed provides a versatile evaluation and development environment for Smart Grid QoS performance studies. It exploits the Real Time Digital Simulator (RTDS) to emulate different power grid configurations and the Software Defined Radio (SDR) environment to implement the communication system. A data acquisition and actuator module is developed, which provides an emulation of various Intelligent Electronic Devices (IEDs). The implemented prototype demonstrates that the proposed testbed has the potential to evaluate real time Smart Grid applications such as real time voltage stability control

Industrial networks and IIoT: Now and future trends

Connectivity is the one word summary for Industry 4.0 revolution. The importance of Internet of Things (IoT) and Industrial IoT (IIoT) have been increased dramatically with the rise of industrialization and industry 4.0. As new opportunities bring their own challenges, with the massive interconnected devices of the IIoT, cyber security of those networks and privacy of their users have become an important aspect. Specifically, intrusion detection for industrial networks (IIoT) has great importance. For instance, it is a key factor in improving the safe operation of the smart grid systems yet protecting the privacy of the consumers at the same time. In the same manner, data streaming is a valid option when the analysis is to be pushed from the cloud to the fog for industrial networks to provide agile response, since it brings the advantage of fast action on intrusion detection and also can buy time for intrusion mitigation. In order to dive deep in industrial networks, basic ground needs to be settled. Hence, this chapter serves in this manner, by presenting basic and emerging technologies along with ideas and discussions: First, an introduction of semiconductor evolution is provided along with the up-to-date hi-tech wired/wireless communication solutions for industrial networks. This is followed by a thorough representation of future trends in industrial environments. More importantly, enabling technologies for industrial networks is also presented. Finally, the chapter is concluded with a summary of the presentations along with future projections of IIoT networks

Design of Real-Time Simulation Testbed for Advanced Metering Infrastructure (Ami) Network

Conventional power grids are being superseded by smart grids, which have smart meters as one of the key components. Currently, for the smart metering communication, wireless technologies have predominantly replaced the traditional Power Line Communication (PLC). Different vendors manufacture smart meters using different wireless communication technologies. For example, some vendors use WiMAX, others prefer Low-Power Wireless Personal Area Networks (Lo-WPAN) for the Media Access Control (MAC) and physical layer of the smart meter network, also known as Advanced Metering Infrastructure (AMI) network. Different communication techniques are used in various components of an AMI network. Thus, it is essential to create a testbed to evaluate the performance of a new wireless technology or a novel protocol to the network. It is risky to study cyber-security threats in an operational network. Hence, a real-time simulation testbed is considered as a substitute to capture communication among cyber-physical subsystems. To design the communication part of our testbed, we explored a Cellular Internet of Things (CIoT) : Co-operative Ultra NarrowBand (C-UNB) technology for the physical and the MAC layer of the Neighborhood Area Network (NAN) of the AMI. After successful evaluation of its performance in a Simpy python simulator, we integrated a module into Network Simulator-3 (NS-3). As NS-3 provides a platform to incorporate real-time traffic to the AMI network, we can inject traffic from power simulators like Real Time Digital Simulator (RTDS). Our testbed was used to make a comparative study of different wireless technologies such as IEEE 802.11ah, WiMAX, and Long Term Evolution (LTE). For the traffic, we used HTTP and Constrained Application Protocol (CoAP), a widely used protocol in IoT. Additionally, we integrated the NS-3 module of Device Language Message Specification - Companion Specification for Energy Metering (DLMS-COSEM), that follows the IEC 62056 standards for electricity metering data exchange. This module which comprises of application and transport layers works in addition with the physical and MAC layer of the ii C-UNB module. Since wireless communication is prone to eavesdropping and information leakages, it is crucial to conduct security studies on these networks. Hence, we performed some cyber-attacks such as Denial of Service (DoS), Address Resolution Protocol (ARP) spoofing and Man-in-the-Middle (MiTM) attacks in the testbed, to analyze their impact on normal operation of AMI network. Encryption techniques can alleviate the issue of data hijacking, but makes the network traffic invisible, which prevents conventional Intrusion Detection Systems (IDS) from undertaking packet-level inspection. Thus, we developed a Bayesian-based IDS for ARP spoof detection to prevent rogue smart meters from modifying genuine data or injecting false data. The proposed real time simulation testbed is successfully utilized to perform delay and throughput analysis for the existing wireless technologies alongwith the evaluation of the novel features of C-UNB module in NS-3. This module can be used to evaluate a broad range of traffic. Using the testbed we also validated our IDS for ARP spoofing attack. This work can be further utilized by security researchers to study different cyber attacks in the AMI network and propose new attack prevention and detection solution. Moreover, it can also allow wireless communication researchers to improve our C-UNB module for NS-3

Low-latency Networking: Where Latency Lurks and How to Tame It

While the current generation of mobile and fixed communication networks has been standardized for mobile broadband services, the next generation is driven by the vision of the Internet of Things and mission critical communication services requiring latency in the order of milliseconds or sub-milliseconds. However, these new stringent requirements have a large technical impact on the design of all layers of the communication protocol stack. The cross layer interactions are complex due to the multiple design principles and technologies that contribute to the layers' design and fundamental performance limitations. We will be able to develop low-latency networks only if we address the problem of these complex interactions from the new point of view of sub-milliseconds latency. In this article, we propose a holistic analysis and classification of the main design principles and enabling technologies that will make it possible to deploy low-latency wireless communication networks. We argue that these design principles and enabling technologies must be carefully orchestrated to meet the stringent requirements and to manage the inherent trade-offs between low latency and traditional performance metrics. We also review currently ongoing standardization activities in prominent standards associations, and discuss open problems for future research

Real-time wireless networks for industrial control systems

The next generation of industrial systems (Industry 4.0) will dramatically transform manyproductive sectors, integrating emerging concepts such as Internet of Things, artificialintelligence, big data, cloud robotics and virtual reality, to name a few. Most of thesetechnologies heavily rely on the availability of communication networks able to offernearly–istantaneous, secure and reliable data transfer. In the industrial sector, these tasks are nowadays mainly accomplished by wired networks, that combine the speed ofoptical fiber media with collision–free switching technology. However, driven by the pervasive deployment of mobile devices for personal com-munications in the last years, more and more industrial applications require wireless connectivity, which can bring enormous advantages in terms of cost reduction and flex-ibility. Designing timely, reliable and deterministic industrial wireless networks is a complicated task, due to the nature of the wireless channel, intrinsically error–prone andshared among all the devices transmitting on the same frequency band. In this thesis, several solutions to enhance the performance of wireless networks employed in industrial control applications are proposed. The presented approaches differ in terms of achieved performance and target applications, but they are all characterized by an improvement over existing industrial wireless solutions in terms of timeliness, reliability and determinism. When possible, an experimental validation of the designed solutions is provided. The obtained results prove that significant performance improvements are already possible, often using commercially available devices and preserving compliance to existing standards. Future research efforts, combined with the availability of new chipsets and standards, could lead to a world where wireless links effectively replace most of the existing cables in industrial environments, as it is already the case in the consumer market

Improving the Reliability of Optimised Link State Routing Protocol in Smart Grid’s Neighbour Area Network

A reliable and resilient communication infrastructure that can cope with variable application traffic types and delay objectives is one of the prerequisites that differentiates a Smart Grid from the conventional electrical grid. However, the legacy communication infrastructure in the existing electrical grid is insufficient, if not incapable of satisfying the diverse communication requirements of the Smart Grid. The IEEE 802.11 ad hoc Wireless Mesh Network (WMN) is re-emerging as one of the communication networks that can significantly extend the reach of Smart Grid to backend devices through the Advanced Metering Infrastructure (AMI). However, the unique characteristics of AMI application traffic in the Smart Grid poses some interesting challenges to conventional communication networks including the ad hoc WMN. Hence, there is a need to modify the conventional ad hoc WMN, to address the uncertainties that may exist in its applicability in a Smart Grid environment. This research carries out an in-depth study of the communication of Smart Grid application traffic types over ad hoc WMN deployed in the Neighbour Area Network (NAN). It begins by conducting a critical review of the application characteristics and traffic requirements of several Smart Grid applications and highlighting some key challenges. Based on the reviews, and assuming that the application traffic types use the internet protocol (IP) as a transport protocol, a number of Smart Grid application traffic profiles were developed. Through experimental and simulation studies, a performance evaluation of an ad hoc WMN using the Optimised Link State Routing (OLSR) routing protocol was carried out. This highlighted some capacity and reliability issues that routing AMI application traffic may face within a conventional ad hoc WMN in a Smart Grid NAN. Given the fact that conventional routing solutions do not consider the traffic requirements when making routing decisions, another key observation is the inability of link metrics in routing protocols to select good quality links across multiple hops to a destination and also provide Quality of Service (QoS) support for target application traffic. As with most routing protocols, OLSR protocol uses a single routing metric acquired at the network layer, which may not be able to accommodate different QoS requirements for application traffic in Smart Grid. To address these problems, a novel multiple link metrics approach to improve the reliability performance of routing in ad hoc WMN when deployed for Smart Grid is presented. It is based on the OLSR protocol and explores the possibility of applying QoS routing for application traffic types in NAN based ad hoc WMN. Though routing in multiple metrics has been identified as a complex problem, Multi-Criteria Decision Making (MCDM) techniques such as the Analytical Hierarchy Process (AHP) and pruning have been used to perform such routing on wired and wireless multimedia applications. The proposed multiple metrics OLSR with AHP is used to offer the best available route, based on a number of considered metric parameters. To accommodate the variable application traffic requirements, a study that allows application traffic to use the most appropriate routing metric is presented. The multiple metrics development is then evaluated in Network Simulator 2.34; the simulation results demonstrate that it outperforms existing routing methods that are based on single metrics in OLSR. It also shows that it can be used to improve the reliability of application traffic types, thereby overcoming some weaknesses of existing single metric routing across multiple hops in NAN. The IEEE 802.11g was used to compare and analyse the performance of OLSR and the IEEE 802.11b was used to implement the multiple metrics framework which demonstrate a better performance than the single metric. However, the multiple metrics can also be applied for routing on different IEEE wireless standards, as well as other communication technologies such as Power Line Communication (PLC) when deployed in Smart Grid NAN

Models and Methods for Network Selection and Balancing in Heterogeneous Scenarios

The outbreak of 5G technologies for wireless communications can be considered a response to the need for widespread coverage, in terms of connectivity and bandwidth, to guarantee broadband services, such as streaming or on-demand programs offered by the main television networks or new generation services based on augmented and virtual reality (AR / VR). The purpose of the study conducted for this thesis aims to solve two of the main problems that will occur with the outbreak of 5G, that is, the search for the best possible connectivity, in order to offer users the resources necessary to take advantage of the new generation services, and multicast as required by the eMBMS. The aim of the thesis is the search for innovative algorithms that will allow to obtain the best connectivity to offer users the resources necessary to use the 5G services in a heterogeneous scenario. Study UF that allows you to improve the search for the best candidate network and to achieve a balance that allows you to avoid congestion of the chosen networks. To achieve these two important focuses, I conducted a study on the main mathematical methods that made it possible to select the network based on QoS parameters based on the type of traffic made by users. A further goal was to improve the computational computation performance they present. Furthermore, I carried out a study in order to obtain an innovative algorithm that would allow the management of multicast. The algorithm that has been implemented responds to the needs present in the eMBMS, in realistic scenarios