Gerhard P. Hancke

Smart Grid Technologies: Communication Technologies and Standards

For 100 years, there has been no change in the basic structure of the electrical power grid. Experiences have shown that the hierarchical, centrally controlled grid of the 20th Century is ill-suited to the needs of the 21st Century. To address the challenges of the existing power grid, the new concept of smart grid has emerged. The smart grid can be considered as a modern electric power grid infrastructure for enhanced efficiency and reliability through automated control, high-power converters, modern communications infrastructure, sensing and metering technologies, and modern energy management techniques based on the optimization of demand, energy and network availability, and so on. While current power systems are based on a solid information and communication infrastructure, the new smart grid needs a different and much more complex one, as its dimension is much larger. This paper addresses critical issues on smart grid technologies primarily in terms of information and communication technology (ICT) issues and opportunities. The main objective of this paper is to provide a contemporary look at the current state of the art in smart grid communications as well as to discuss the still-open research issues in this field. It is expected that this paper will provide a better understanding of the technologies, potential advantages and research challenges of the smart grid and provoke interest among the research community to further explore this promising research area.

Industrial Wireless Sensor Networks: Challenges, Design Principles, and Technical Approaches

In todays competitive industry marketplace, the companies face growing demands to improve process efficiencies, comply with environmental regulations, and meet corporate financial objectives. Given the increasing age of many industrial systems and the dynamic industrial manufacturing market, intelligent and low-cost industrial automation systems are required to improve the productivity and efficiency of such systems. The collaborative nature of industrial wireless sensor networks (IWSNs) brings several advantages over traditional wired industrial monitoring and control systems, including self-organization, rapid deployment, flexibility, and inherent intelligent-processing capability. In this regard, IWSN plays a vital role in creating a highly reliable and self-healing industrial system that rapidly responds to real-time events with appropriate actions. In this paper, first, technical challenges and design principles are introduced in terms of hardware development, system architectures and protocols, and software development. Specifically, radio technologies, energy-harvesting techniques, and cross-layer design for IWSNs have been discussed. In addition, IWSN standards are presented for the system owners, who plan to utilize new IWSN technologies for industrial automation applications. In this paper, our aim is to provide a contemporary look at the current state of the art in IWSNs and discuss the still-open research issues in this field and, hence, to make the decision-making process more effective and direct.

Opportunities and Challenges of Wireless Sensor Networks in Smart Grid

The collaborative and low-cost nature of wireless sensor networks (WSNs) brings significant advantages over traditional communication technologies used in todays electric power systems. Recently, WSNs have been widely recognized as a promising technology that can enhance various aspects of todays electric power systems, including generation, delivery, and utilization, making them a vital component of the next-generation electric power system, the smart grid. However, harsh and complex electric-power-system environments pose great challenges in the reliability of WSN communications in smart-grid applications. This paper starts with an overview of the application of WSNs for electric power systems along with their opportunities and challenges and opens up future work in many unexploited research areas in diverse smart-grid applications. Then, it presents a comprehensive experimental study on the statistical characterization of the wireless channel in different electric-power-system environments, including a 500-kV substation, an industrial power control room, and an underground network transformer vault. Field tests have been performed on IEEE 802.15.4-compliant wireless sensor nodes in real-world power delivery and distribution systems to measure background noise, channel characteristics, and attenuation in the 2.4-GHz frequency band. Overall, the empirical measurements and experimental results provide valuable insights about IEEE 802.15.4-compliant sensor network platforms and guide design decisions and tradeoffs for WSN-based smart-grid applications.

A Survey on Smart Grid Potential Applications and Communication Requirements

Information and communication technologies (ICT) represent a fundamental element in the growth and performance of smart grids. A sophisticated, reliable and fast communication infrastructure is, in fact, necessary for the connection among the huge amount of distributed elements, such as generators, substations, energy storage systems and users, enabling a real time exchange of data and information necessary for the management of the system and for ensuring improvements in terms of efficiency, reliability, flexibility and investment return for all those involved in a smart grid: producers, operators and customers. This paper overviews the issues related to the smart grid architecture from the perspective of potential applications and the communications requirements needed for ensuring performance, flexible operation, reliability and economics.

An RFID Distance Bounding Protocol

Radio-frequency identification tokens, such as contactless smartcards, are vulnerable to relay attacks if they are used for proximity authentication. Attackers can circumvent the limited range of the radio channel using transponders that forward exchanged signals over larger distances. Cryptographic distance-bounding protocols that measure accurately the round-trip delay of the radio signal provide a possible countermeasure. They infer an upper bound for the distance between the reader and the token from the fact that no information can propagate faster than at the speed of light. We propose a new distance-bounding protocol based on ultra-wideband pulse communication. Aimed at being implementable using only simple, asynchronous, low-power hardware in the token, it is particularly well suited for use in passive low-cost tokens, noisy environments and high-speed applications.

Introduction to Industrial Control Networks

An industrial control network is a system of interconnected equipment used to monitor and control physical equipment in industrial environments. These networks differ quite significantly from traditional enterprise networks due to the specific requirements of their operation. Despite the functional differences between industrial and enterprise networks, a growing integration between the two has been observed. The technology in use in industrial networks is also beginning to display a greater reliance on Ethernet and web standards, especially at higher levels of the network architecture. This has resulted in a situation where engineers involved in the design and maintenance of control networks must be familiar with both traditional enterprise concerns, such as network security, as well as traditional industrial concerns such as determinism and response time. This paper highlights some of the differences between enterprise and industrial networks, presents a brief history of industrial networking, gives a high level explanation of some operations specific to industrial networks, provides an overview of the popular protocols in use and describes current research topics. The purpose of this paper is to serve as an introduction to industrial control networks, aimed specifically at those who have had minimal exposure to the field, but have some familiarity with conventional computer networks.

The Role of Advanced Sensing in Smart Cities

In a world where resources are scarce and urban areas consume the vast majority of these resources, it is vital to make cities greener and more sustainable. Advanced systems to improve and automate processes within a city will play a leading role in smart cities. From smart design of buildings, which capture rain water for later use, to intelligent control systems, which can monitor infrastructures autonomously, the possible improvements enabled by sensing technologies are immense. Ubiquitous sensing poses numerous challenges, which are of a technological or social nature. This paper presents an overview of the state of the art with regards to sensing in smart cities. Topics include sensing applications in smart cities, sensing platforms and technical challenges associated with these technologies. In an effort to provide a holistic view of how sensing technologies play a role in smart cities, a range of applications and technical challenges associated with these applications are discussed. As some of these applications and technologies belong to different disciplines, the material presented in this paper attempts to bridge these to provide a broad overview, which can be of help to researchers and developers in understanding how advanced sensing can play a role in smart cities.

So near and yet so far: distance-bounding attacks in wireless networks

Distance-bounding protocols aim to prevent an adversary from pretending that two parties are physically closer than they really are. We show that proposed distance-bounding protocols of Hu, Perrig and Johnson (2003), Sastry, Shankar and Wagner (2003), and Capkun and Hubaux (2005, 2006) are vulnerable to a guessing attack where the malicious prover preemptively transmits guessed values for a number of response bits. We also show that communication channels not optimized for minimal latency imperil the security of distance-bounding protocols. The attacker can exploit this to appear closer himself or to perform a relaying attack against other nodes. We describe attack strategies to achieve this, including optimizing the communication protocol stack, taking early decisions as to the value of received bits and modifying the waveform of transmitted bits. We consider applying distance-bounding protocols to constrained devices and evaluate existing proposals for distance bounding in ad hoc networks.

Comparison of two routing metrics in OLSR on a grid based mesh network

Predicting the performance of ad hoc networking protocols for mesh networks has typically been performed by making use of software based simulation tools. Experimental study and validation of such predictions is a vital to obtaining more realistic results, but may not be possible under the constrained environment of network simulators. This paper presents an experimental comparison of OLSR using the standard hysteresis routing metric and the ETX metric in a 7 by 7 grid of closely spaced Wi-Fi nodes to obtain more realistic results. The wireless grid is first modelled to extract its ability to emulate a real world multi-hop ad hoc network. This is followed by a detailed analysis of OLSR in terms of hop count, routing traffic overhead, throughput, delay, packet loss and route flapping in the wireless grid using the hysteresis and ETX routing metric. It was discovered that the ETX metric which has been extensively used in mesh networks around the world is fundamentally flawed when estimating optimal routes in real mesh networks and that the less sophisticated hysteresis metric shows better performance in large dense mesh networks.

A Distributed Topology Control Technique for Low Interference and Energy Efficiency in Wireless Sensor Networks

Topology control plays an important role in the design of wireless ad hoc and sensor networks; it is capable of constructing networks that have desirable characteristics such as sparser connectivity, lower transmission power, and a smaller node degree. In this research, a new distributed topology control technique is presented that enhances energy efficiency and reduces radio interference in wireless sensor networks. Each node in the network makes local decisions about its transmission power and the culmination of these local decisions produces a network topology that preserves global connectivity. Central to this topology control technique is the novel Smart Boundary Yao Gabriel Graph (SBYaoGG) and optimizations to ensure that all links in the network are symmetric and energy efficient. Simulation results are presented demonstrating the effectiveness of this new technique as compared to other approaches to topology control.