240,714 research outputs found

    High Performance Wireless Sensor-Actuator Networks for Industrial Internet of Things

    Get PDF
    Wireless Sensor-Actuator Networks (WSANs) enable cost-effective communication for Industrial Internet of Things (IIoT). To achieve predictability and reliability demanded by industrial applications, industrial wireless standards (e.g., WirelessHART) incorporate a set of unique features such as a centralized management architecture, Time Slotted Channel Hopping (TSCH), and conservative channel selection. However, those features also incur significant degradation in performance, efficiency, and agility. To overcome these key limitations of existing industrial wireless technologies, this thesis work develops and empirically evaluates a suite of novel network protocols and algorithms. The primary contributions of this thesis are four-fold. (1) We first build an experimental testbed realizing key features of the WirelessHART protocol stack, and perform a series of empirical studies to uncover the limitations and potential improvements of existing network features. (2) We then investigate the impacts of the industrial WSAN protocol’s channel selection mechanism on routing and real-time performance, and present new channel and link selection strategies that improve route diversity and real-time performance. (3) To further enhance performance, we propose and design conservative channel reuse, a novel approach to support concurrent transmissions in a same wireless channel while maintaining a high degree of reliability. (4) Lastly, to address the limitation of the centralized architecture in handling network dynamics, we develop REACT, a Reliable, Efficient, and Adaptive Control Plane for centralized network management. REACT is designed to reduce the latency and energy cost of network reconfiguration by incorporating a reconfiguration planner to reduce a rescheduling cost, and an update engine providing efficient and reliable mechanisms to support schedule reconfiguration. All the network protocols and algorithms developed in this thesis have been empirically evaluated on the wireless testbed. This thesis represents a step toward next-generation IIoT for industrial automation that demands high-performance and agile wireless communication

    Public Sector Climate Leadership In Boston

    Get PDF
    The report discusses the important role the public sector is playing in achieving Boston's greenhouse gas emissions reduction targets. City, state, and federal agencies together own a large portion (more than 11%) of the city's building stock, and each level of government has committed to a goal of 25% reductions in GHG emissions by 2020. The report highlights four examples of action by public agencies in Boston that are going beyond pilot projects and are pursuing energy innovation on a portfolio-wide basis. These initiatives demonstrate how aggressive climate targets are both attainable and often beneficial for generating cost savings and helping streamline operations -- benefits that could be widely replicated in other sectors

    Sharpening the Cutting Edge: Corporate Action for a Strong, Low-Carbon Economy

    Get PDF
    Outlines lessons learned from early efforts to create a low-carbon economy, current and emerging best practices, and next steps, including climate change metrics, greenhouse gas reporting, effective climate policy, and long-term investment choices

    Named data networking for efficient IoT-based disaster management in a smart campus

    Get PDF
    Disasters are uncertain occasions that can impose a drastic impact on human life and building infrastructures. Information and Communication Technology (ICT) plays a vital role in coping with such situations by enabling and integrating multiple technological resources to develop Disaster Management Systems (DMSs). In this context, a majority of the existing DMSs use networking architectures based upon the Internet Protocol (IP) focusing on location-dependent communications. However, IP-based communications face the limitations of inefficient bandwidth utilization, high processing, data security, and excessive memory intake. To address these issues, Named Data Networking (NDN) has emerged as a promising communication paradigm, which is based on the Information-Centric Networking (ICN) architecture. An NDN is among the self-organizing communication networks that reduces the complexity of networking systems in addition to provide content security. Given this, many NDN-based DMSs have been proposed. The problem with the existing NDN-based DMS is that they use a PULL-based mechanism that ultimately results in higher delay and more energy consumption. In order to cater for time-critical scenarios, emergence-driven network engineering communication and computation models are required. In this paper, a novel DMS is proposed, i.e., Named Data Networking Disaster Management (NDN-DM), where a producer forwards a fire alert message to neighbouring consumers. This makes the nodes converge according to the disaster situation in a more efficient and secure way. Furthermore, we consider a fire scenario in a university campus and mobile nodes in the campus collaborate with each other to manage the fire situation. The proposed framework has been mathematically modeled and formally proved using timed automata-based transition systems and a real-time model checker, respectively. Additionally, the evaluation of the proposed NDM-DM has been performed using NS2. The results prove that the proposed scheme has reduced the end-to-end delay up from 2% to 10% and minimized up to 20% energy consumption, as energy improved from 3% to 20% compared with a state-of-the-art NDN-based DMS

    Climate-Related Investing Across Asset Classes

    Get PDF
    Responsible investment -- understood as the incorporation of environmental, social, and governance (ESG) information into investment analysis -- is a discipline that allows investors to:- Better assess long-term risks and opportunities in their portfolios; and- Better align their investment strategies with opportunities to create longterm wealth for investors and society alike.It is a tool for investors who seek to improve long-term financial returns through enhanced ESG analysis. It also appeals to mission or impact investors, who seek to achieve defined social and/or environmental goals while achieving targeted rates of return. In both cases, investors use responsible investment as a tool to improve their ability to achieve their goals.Climate change is among the most important issues addressed by today's responsible investment universe. The physical risks of climate change, the likelihood of major changes in political and regulatory investment environments as a result of climate change, the opportunities associated with a radical global transformation to a low-carbon economy -- these issues create far-reaching implications for investors as they make decisions about their investment strategies, and as they evaluate particular fund managers and investment opportunities. New ideas, products, and methods have entered the market to address the long-term implications of climate change.This short handbook takes as its premise that a climate lens reveals risks and opportunities across all elements of an investor's portfolio. Every asset class offers investors an opportunity to pursue climate-friendly investments, to mitigate exposure to climate risk, and to engage stakeholders to improve climate-related performance across the range of investment opportunities

    A Survey of Green Networking Research

    Full text link
    Reduction of unnecessary energy consumption is becoming a major concern in wired networking, because of the potential economical benefits and of its expected environmental impact. These issues, usually referred to as "green networking", relate to embedding energy-awareness in the design, in the devices and in the protocols of networks. In this work, we first formulate a more precise definition of the "green" attribute. We furthermore identify a few paradigms that are the key enablers of energy-aware networking research. We then overview the current state of the art and provide a taxonomy of the relevant work, with a special focus on wired networking. At a high level, we identify four branches of green networking research that stem from different observations on the root causes of energy waste, namely (i) Adaptive Link Rate, (ii) Interface proxying, (iii) Energy-aware infrastructures and (iv) Energy-aware applications. In this work, we do not only explore specific proposals pertaining to each of the above branches, but also offer a perspective for research.Comment: Index Terms: Green Networking; Wired Networks; Adaptive Link Rate; Interface Proxying; Energy-aware Infrastructures; Energy-aware Applications. 18 pages, 6 figures, 2 table

    Energy management in communication networks: a journey through modelling and optimization glasses

    Full text link
    The widespread proliferation of Internet and wireless applications has produced a significant increase of ICT energy footprint. As a response, in the last five years, significant efforts have been undertaken to include energy-awareness into network management. Several green networking frameworks have been proposed by carefully managing the network routing and the power state of network devices. Even though approaches proposed differ based on network technologies and sleep modes of nodes and interfaces, they all aim at tailoring the active network resources to the varying traffic needs in order to minimize energy consumption. From a modeling point of view, this has several commonalities with classical network design and routing problems, even if with different objectives and in a dynamic context. With most researchers focused on addressing the complex and crucial technological aspects of green networking schemes, there has been so far little attention on understanding the modeling similarities and differences of proposed solutions. This paper fills the gap surveying the literature with optimization modeling glasses, following a tutorial approach that guides through the different components of the models with a unified symbolism. A detailed classification of the previous work based on the modeling issues included is also proposed
    • …
    corecore