A communication infrastructure is an essential part to the success of the emerging smart grid. A scalable and pervasive communication infrastructure is crucial in both construction and operation of a smart grid. In this paper, we present the background and motivation of communication infrastructures in smart grid systems. We also summarize major requirements that smart grid communications must meet. From the experience of several industrial trials on smart grid with communication infrastructures, we expect that the traditional carbon fuel based power plants can cooperate with emerging distributed renewable energy such as wind, solar, etc, to reduce the carbon fuel consumption and consequent green house gas such as carbon dioxide emission. The consumers can minimize their expense on energy by adjusting their intelligent home appliance operations to avoid the peak hours and utilize the renewable energy instead. We further explore the challenges for a communication infrastructure as the part of a complex smart grid system. Since a smart grid system might have over millions of consumers and devices, the demand of its reliability and security is extremely critical. Through a communication infrastructure, a smart grid can improve power reliability and quality to eliminate electricity blackout. Security is a challenging issue since the on-going smart grid systems facing increasing vulnerabilities as more and more automation, remote monitoring/controlling and supervision entities are interconnected.

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1315&context=electricalengineeringfacpub

A Survey on Smart Grid CommunicationInfrastructures: Motivations, Requirements andChallenges

Internet of Things (IoT) is a term used to describe an environment where billions of objects, constrained in terms of resources (“things”), are connected to the Internet, and interacting autonomously. With so many objects connected in IoT solutions, the environment in which they are placed becomes smarter. A software, called middleware, plays a key role since it is responsible for most of the intelligence in IoT, integrating data from devices, allowing them to communicate, and make decisions based on collected data. Then, considering requirements of IoT platforms, a reference architecture model for IoT middleware is analyzed, detailing the best operation approaches of each proposed module, as well as proposes basic security features for this type of software. This paper elaborates on a systematic review of the related literature, exploring the differences between the current Internet and IoT-based systems, presenting a deep discussion of the challenges and future perspectives on IoT middleware. Finally, it highlights the difficulties for achieving and enforcing a universal standard. Thus, it is concluded that middleware plays a crucial role in IoT solutions and the proposed architectural approach can be used as a reference model for IoT middleware.

A Reference Model for Internet of Things Middleware

Low power and long range machine-to-machine (M2M) communication techniques are expected to provide ubiquitous connections for the wireless devices. In this paper, three major low power and long range M2M solutions are surveyed. The first type of solutions is referred to as the low power wide area (LPWA) network. The design of the LPWA techniques features low cost, low data rate, long communication range, and low power consumption. The second type of solutions is the IEEE 802.11ah which features higher data rates using a wider bandwidth than the LPWA-based solutions. The third type of solutions is operated under the cellular network infrastructure. Based on the analysis of the pros and cons of the enabling technologies of the surveyed M2M solutions, as well as the corresponding deployment strategies, the gaps in knowledge are identified. The paper also presents a summary of the research directions for improving the performance of the surveyed low power and long range M2M communication technologies.

A Survey of Enabling Technologies of Low Power and Long Range Machine-to-Machine Communications

The concept of a “digital twin” as a model for data-driven management and control of physical systems has emerged over the past decade in the domains of manufacturing, production, and operations. In the context of buildings and civil infrastructure, the notion of a digital twin remains ill-defined, with little or no consensus among researchers and practitioners of the ways in which digital twin processes and data-centric technologies can support design and construction. This paper builds on existing concepts of Building Information Modeling (BIM), lean project production systems, automated data acquisition from construction sites and supply chains, and artificial intelligence to formulate a mode of construction that applies digital twin information systems to achieve closed loop control systems. It contributes a set of four core information and control concepts for digital twin construction (DTC), which define the dimensions of the conceptual space for the information used in DTC workflows. Working from the core concepts, we propose a DTC information system workflow—including information stores, information processing functions, and monitoring technologies—according to three concentric control workflow cycles. DTC should be viewed as a comprehensive mode of construction that prioritizes closing the control loops rather than an extension of BIM tools integrated with sensing and monitoring technologies.

/pdf/construction-with-digital-twin-information-systems-2t1lu4831u.pdf

Construction with digital twin information systems

Russell Kenley and Olli Seppanen, Spon Press, London, 2009, 336 pp., ISBN 978 0 415 37050 9, £90 I found this book to be a very well‐researched and written summary of prevalent construction industr...

Location‐Based Management for Construction: Planning, Scheduling and Control

IEEE 802.11ah task group is working on a new amendment of the IEEE 802.11 standard, suitable for high density WLAN networks in the sub 1 GHz band. It is expected to be the prevalent standard in many Internet of Things (IoT) and Machine to Machine (M2M) applications where it will support long-range and energy-efficient communication in dense network environments. Therefore, significant changes in the legacy 802.11 standards have been proposed to improve the network performance in high contention scenarios, most important of which is the Restricted Access Window (RAW) mechanism described in the amendment. In this paper we analyze the performance of the RAW mechanism in the Non-Cross Slot Boundary case under various possible holding schemes. We propose new holding schemes as well as a new grouping scheme for RAW mechanism based on backoff states of the stations. The proposed schemes are shown to improve the saturation throughput and energy efficiency of the network through extensive simulations. These schemes can therefore be adapted in practical deployment scenarios of the IEEE 802.11ah use cases to improve the overall network performance. Overall, these advanced features make 802.11ah standard a true IoT-enabling technology towards seamless integration of massive amount of connected devices in the future.

Performance analysis of IoT-enabling IEEE 802.11ah technology and its RAW mechanism with non-cross slot boundary holding schemes

https://research.aalto.fi/files/33416685/1_s2.0_S0926580518306496_main.pdf

Real-time resource tracking for analyzing value-adding time in construction

Internet of Things (IoT) is expected to change the everyday life of its users by enabling data exchanges among pervasive things through the Internet. Such a broad aim, however, puts prohibitive constraints on applications demanding time-synchronized operation for the chronological ordering of information or synchronous execution of some tasks, since in general the networks are formed by entities of widely varying resources. On one hand, the existing contemporary solutions for time synchronization, such as Network Time Protocol, do not easily tailor to resource-constrained devices, and on the other, the available solutions for constrained systems do not extend well to heterogeneous deployments. In this article, the time synchronization problems for IoT deployments for applications requiring a coherent notion of time are studied. Detailed derivations of the clock model and various clock relation models are provided. The clock synchronization methods are also presented for different models, and their expected performance are derived and illustrated. A survey of time synchronization protocols is provided to aid the IoT practitioners to select appropriate components for a deployment. The clock discipline algorithms are presented in a tutorial format, while the time synchronization methods are summarized as a survey. Therefore, this paper is a holistic overview of the available time synchronization methods for IoT deployments.

https://www.mdpi.com/1424-8220/20/20/5928/pdf

Overview of time synchronization for iot deployments: Clock discipline algorithms and protocols

The Internet of Things (IoT) has recently revolutionized the concept of connectivity from humans to surrounding objects through the Internet infrastructure. To Enable the wide range of IoT use cases, several communication technologies are introduced. Among the others, short range radio technology is an essential part of IoT for enabling the local area networks. Bluetooth Low Energy (BLE) version 5 is recently developed by Bluetooth Special Interest Group (SIG) which claims to be better suit for IoT use cases. However, the complexity of BLE 5 protocol and the lack of system-level simulator hinder the detailed analytical study of this new technology. To this end, we develop comprehensive system-level tool for simulating BLE 5. Some of the most important features of BLE 5 are developed and results are investigated in this paper. We investigate the BLE 5 with new physical (PHY) layer from networking perspective by analyzing end-to-end delay, battery life time, packet error rate and throughput in open office environment. To this end, we investigate the scalability of the network for different PHYs. The results show that, in this case study, the coded PHYs have weaker performance when network becomes congested.

/pdf/on-the-system-level-performance-evaluation-of-bluetooth-5-in-5bvkjwqbee.pdf

On the System-level Performance Evaluation of Bluetooth 5 in IoT: Open Office Case Study

We analyze the performance of IEEE 802.11ah technology in an actuation use case for connected lighting from the perspective of latency and power consumption at the actuator in the downlink direction. The study includes network configurations with different beacon frame transmission intervals, channel bandwidths, group of stations in power-save mode as well as unicast-multicast transmissions using different modulation and coding schemes. The results show the existing trade off between the desired latency and power consumption at the actuator station as shorter beacon frame intervals are required to achieve lower latency. A system deployed using 2 MHz of channel bandwidth leads to lower transmission delays and power consumption compared to a 1 MHz system. Also, the study shows how grouping based on transmission indication map further affects latency and power consumption. Furthermore, addressing each actuator with a unicast transmission from the wireless access point limits the number of supported actuators and good latency performance is obtained when groups of actuators are commanded together utilizing broadcast-multicast transmissions with appropriate choice of modulation and coding scheme.

Behnam Badihi

Papers

Performance analysis of IoT-enabling IEEE 802.11ah technology and its RAW mechanism with non-cross slot boundary holding schemes

Real-time resource tracking for analyzing value-adding time in construction

Overview of time synchronization for iot deployments: Clock discipline algorithms and protocols

On the System-level Performance Evaluation of Bluetooth 5 in IoT: Open Office Case Study

Performance Evaluation of IEEE 802.11ah Actuators