45,848 research outputs found

    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

    Fog-supported delay-constrained energy-saving live migration of VMs over multiPath TCP/IP 5G connections

    Get PDF
    The incoming era of the fifth-generation fog computing-supported radio access networks (shortly, 5G FOGRANs) aims at exploiting computing/networking resource virtualization, in order to augment the limited resources of wireless devices through the seamless live migration of virtual machines (VMs) toward nearby fog data centers. For this purpose, the bandwidths of the multiple wireless network interface cards of the wireless devices may be aggregated under the control of the emerging MultiPathTCP (MPTCP) protocol. However, due to the fading and mobility-induced phenomena, the energy consumptions of the current state-of-the-art VM migration techniques may still offset their expected benefits. Motivated by these considerations, in this paper, we analytically characterize and implement in software and numerically test the optimal minimum-energy settable-complexity bandwidth manager (SCBM) for the live migration of VMs over 5G FOGRAN MPTCP connections. The key features of the proposed SCBM are that: 1) its implementation complexity is settable on-line on the basis of the target energy consumption versus implementation complexity tradeoff; 2) it minimizes the network energy consumed by the wireless device for sustaining the migration process under hard constraints on the tolerated migration times and downtimes; and 3) by leveraging a suitably designed adaptive mechanism, it is capable to quickly react to (possibly, unpredicted) fading and/or mobility-induced abrupt changes of the wireless environment without requiring forecasting. The actual effectiveness of the proposed SCBM is supported by extensive energy versus delay performance comparisons that cover: 1) a number of heterogeneous 3G/4G/WiFi FOGRAN scenarios; 2) synthetic and real-world workloads; and, 3) MPTCP and wireless connections

    Making Heat Visible: Promoting Energy Conservation Behaviors Through Thermal Imaging

    Get PDF
    Householders play a role in energy conservation through the decisions they make about purchases and installations such as insulation, and through their habitual behavior. The present U.K. study investigated the effect of thermal imaging technology on energy conservation, by measuring the behavioral effect after householders viewed images of heat escaping from or cold air entering their homes. In Study 1 (n = 43), householders who received a thermal image reduced their energy use at a 1-year follow-up, whereas householders who received a carbon footprint audit and a non-intervention control demonstrated no change. In Study 2 (n = 87), householders were nearly 5 times more likely to install draught proofing measures after seeing a thermal image. The effect was especially pronounced for actions that addressed an issue visible in the images. Findings indicate that using thermal imaging to make heat loss visible can promote energy conservation

    Asian Energy and Environmental Policy: Promoting Growth While Preserving the Environment

    Get PDF
    Asia has truly experienced spectacular economic growth over the past 15 years. However, this economic progress has come at a high cost. It has led to unprecedented environmental consequences. The ecological footprint shows that, despite the fact that one-fifth of the population in Asia still lives on less than US$ 1 per day (PPP-adjusted), the region is already living beyond its ecological carrying capacity. The region is facing a dilemma. On the one hand, continued economic growth is needed to alleviate the poverty of the two-thirds of the world’s poor living in this region. On the other hand, that economic growth will further place tremendous strains on the natural environment. In order to extricate itself from this difficult position, the region needs to shift the conventional pattern of “develop first and then treat the pollution” to a different trajectory of sustainable development. To that end, this paper examines a variety of policy responses at national, regional and international levels to deal with growing concerns about the environmental challenges in Asia in order to help to put the region on a more sustainable development path. In the context of national responses, special attention is paid to the following issues: coordination between the central and local governments, market-based environmental instruments and industrial policies, tougher emissions standards for mobile and stationary sources and for fuel quality, policies to promote energy efficiency and the use of clean energy and biofuels, the integration of environmental policies with economic and sectoral policies, and engagement of the private sector through e.g., ecolabelling, green government procurement, corporate ratings and disclosure programs, and drawing the support of financial institutions to promote improved corporate environmental performance. It is concluded that having the right policy mix, coupled with strengthened cooperation at national, local and regional levels, will ensure continuing economic growth in the region without compromising its limited ecological carrying capacity and environmental quality.Energy policy; Market-based environmental instruments; Asia

    Climate Change and Individual Decision Making: An Examination of Knowledge, Risk Perception, Self-interest and Their Interplay

    Get PDF
    In this essay, three separate yet interconnected components of pro-environmental decision making are considered: (a) knowledge, in the form of basic scientific understanding and procedural knowledge, (b) risk perception, as it relates to an individual’s direct experience of climate change and (c) self-interest, either monetary or status-driven. Drawing on a variety of sources in public policy, psychology, and economics, I examine the role of these concepts in inducing or discouraging pro-environmental behavior. Past researches have often overemphasized the weight of just one of those variables in the decision making. I argue, instead, that none of them alone is capable of bringing about the behavioral change required by the environmental crisis. Evidence shows that increasing the public’s scientific knowledge of climate change cannot unilaterally bring about a strong behavioral change. The same can be noticed even when knowledge is joined by risk-perception: deep psychological mechanisms may steer people towards inaction and apathy, despite their direct experience of the detrimental effects of climate change on their lives. Focusing on self-interest alone is similarly unable to induce pro-environmental behavior, due to a host of psychological factors. Instead, in all of the above cases an important missing ingredient may be found in providing the public with locally contextualized procedural knowledge in order to translate its knowledge and concern into action. The importance of this kind of practical knowledge has solid empirical and theoretical underpinnings, and is often overlooked in the climate-change debate that tends to focus on more high-level issues. Yet, for all its essential simplicity, it may carry important public-policy implications.Individual Behavior, Climate-Change, Psychology, Uncertainty

    Ecodriving and Carbon Footprinting: Understanding How Public Education Can Reduce Greenhouse Gas Emissions and Fuel Use

    Get PDF
    Ecodriving is a collection of changes to driving behavior and vehicle maintenance designed to impact fuel consumption and greenhouse gas (GHG) emissions in existing vehicles. Because of its promise to improve fuel economy within the existing fleet, ecodriving has gained increased attention in North America. One strategy to improve ecodriving is through public education with information on how to ecodrive. This report provides a review and study of ecodriving from several angles. The report offers a literature review of previous work and programs in ecodriving across the world. In addition, researchers completed interviews with experts in the field of public relations and public message campaigns to ascertain best practices for public campaigns. Further, the study also completed a set of focus groups evaluating consumer response to a series of websites that displayed ecodriving information. Finally, researchers conducted a set of surveys, including a controlled stated-response study conducted with approximately 100 University of California, Berkeley faculty, staff, and students, assessing the effectiveness of static ecodriving web-based information as well as an intercept clipboard survey in the San Francisco Bay Area. The stated-response study consisted of a comparison of the experimental and control groups. It found that exposure to ecodriving information influenced people’s driving behavior and some maintenance practices. The experimental group’s distributional shift was statistically significant, particularly for key practices including: lower highway cruising speed, driving behavior adjustment, and proper tire inflation. Within the experimental group (N = 51), fewer respondents significantly changed their maintenance practices (16%) than the majority that altered some driving practices (71%). This suggests intentionally altering driving behavior is easier than planning better maintenance practices. While it was evident that not everyone modifies their behavior as a result of reviewing the ecodriving website, even small shifts in behavior due to inexpensive information dissemination could be deemed cost effective in reducing fuel consumption and emissions

    A low-energy rate-adaptive bit-interleaved passive optical network

    Get PDF
    Energy consumption of customer premises equipment (CPE) has become a serious issue in the new generations of time-division multiplexing passive optical networks, which operate at 10 Gb/s or higher. It is becoming a major factor in global network energy consumption, and it poses problems during emergencies when CPE is battery-operated. In this paper, a low-energy passive optical network (PON) that uses a novel bit-interleaving downstream protocol is proposed. The details about the network architecture, protocol, and the key enabling implementation aspects, including dynamic traffic interleaving, rate-adaptive descrambling of decimated traffic, and the design and implementation of a downsampling clock and data recovery circuit, are described. The proposed concept is shown to reduce the energy consumption for protocol processing by a factor of 30. A detailed analysis of the energy consumption in the CPE shows that the interleaving protocol reduces the total energy consumption of the CPE significantly in comparison to the standard 10 Gb/s PON CPE. Experimental results obtained from measurements on the implemented CPE prototype confirm that the CPE consumes significantly less energy than the standard 10 Gb/s PON CPE

    Is It Fair to Treat China as a Christmas Tree to Hang Everybody’s Complaints? Putting its Own Energy Saving into Perspective

    Get PDF
    China had been the world’s second largest carbon emitter for years. However, recent studies show that China had overtaken the U.S. as the world’s largest emitter in 2007. This has put China on the spotlight, just at a time when the world community starts negotiating a post-Kyoto climate regime under the Bali roadmap. China seems to become such a Christmas tree on which everybody can hang his/her complaints. This paper first discusses whether such a critics is fair by examining China’s own efforts towards energy saving, the widespread use of renewable energy and participation in clean development mechanism. Next, the paper puts carbon reductions of China’s unilateral actions into perspective by examining whether the estimated greenhouse gas emission reduction from meeting the country’s national energy saving goal is achieved from China’s unilateral actions or mainly with support from the clean development mechanism projects. Then the paper discusses how far developing country commitments can go in an immediate post-2012 climate regime, thus pointing out the direction and focus of future international climate negotiations. Finally, emphasizing that China needs to act as a large and responsible developing country and take due responsibilities and to set a good example to the majority of developing countries, the paper articulates what can be expected from China to illustrate that China can be a good partner in combating global climate change.Energy Saving, Renewable Energy, Post-Kyoto Climate Negotiations, Clean Development Mechanism, China, USA
    corecore