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Pedro Reviriego

Bio: Pedro Reviriego is an academic researcher from Charles III University of Madrid. The author has contributed to research in topics: Error detection and correction & Computer science. The author has an hindex of 25, co-authored 292 publications receiving 3006 citations. Previous affiliations of Pedro Reviriego include Complutense University of Madrid & Carlos III Health Institute.


Papers
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Journal ArticleDOI
TL;DR: The development of the EEE standard and how energy savings resulting from the adoption of EEE may exceed $400 million per year in the U.S. alone are described and results show that packet coalescing can significantly improve energy efficiency while keeping absolute packet delays to tolerable bounds are presented.
Abstract: Ethernet is the dominant wireline communications technology for LANs with over 1 billion interfaces installed in the U.S. and over 3 billion worldwide. In 2006 the IEEE 802.3 Working Group started an effort to improve the energy efficiency of Ethernet. This effort became IEEE P802.3az Energy Efficient Ethernet (EEE) resulting in IEEE Std 802.3az-2010, which was approved September 30, 2010. EEE uses a Low Power Idle mode to reduce the energy consumption of a link when no packets are being sent. In this article, we describe the development of the EEE standard and how energy savings resulting from the adoption of EEE may exceed $400 million per year in the U.S. alone (and over $1 billion worldwide). We also present results from a simulation-based performance evaluation showing how packet coalescing can be used to improve the energy efficiency of EEE. Our results show that packet coalescing can significantly improve energy efficiency while keeping absolute packet delays to tolerable bounds. We are aware that coalescing may cause packet loss in downstream buffers, especially when using TCP/IP. We explore the effects of coalescing on TCP/IP flows with an ns-2 simulation, note that coalescing is already used to reduce packet processing load on the system CPU, and suggest open questions for future work. This article will help clarify what can be expected when EEE is deployed.

345 citations

Journal ArticleDOI
TL;DR: Although EEE improves the energy efficiency, there is still potential for substantial further energy savings as in many cases most of the energy is wasted in waking up and sleeping the link.
Abstract: Until very recently, energy efficiency has received little attention in many wired communications environments. For example, in most current Ethernet standards the transmitter and receiver operate at full power even when no data is being sent. However, new upcoming energy-aware standards, such as Energy Efficient Ethernet (EEE), are addressing this issue by introducing a low power mode for idle link intervals. The future EEE standard defines the procedure to enter and exit the low power mode. With EEE the actual energy savings will depend on the amount of traffic and on the timing of the frame arrivals. In this paper the performance of EEE in terms of energy saving is evaluated. The results show that although EEE improves the energy efficiency, there is still potential for substantial further energy savings as in many cases most of the energy is wasted in waking up and sleeping the link.

144 citations

Journal ArticleDOI
TL;DR: For the first time, Network Interface Cards (NICs) that implement Energy Efficient Ethernet (EEE) are used to measure energy savings with real traffic, and results confirm that transition overheads can be significant, leading to almost full energy consumption even at low utilization levels.
Abstract: In September 2010, the Energy Efficient Ethernet (IEEE 802.3az) standard was officially approved. This new standard introduces a low power mode for the most common Ethernet physical layer standards and is expected to provide large energy savings. In this letter, for the first time, Network Interface Cards (NICs) that implement Energy Efficient Ethernet (EEE) are used to measure energy savings with real traffic. The data presented will be useful to better estimate the energy savings that can be achieved when EEE is deployed. Existing analysis of EEE based on simulations predict a large overhead due to mode transitions between active and low power modes. The experimental results confirm that transition overheads can be significant, leading to almost full energy consumption even at low utilization levels. Therefore traffic patterns will play a key role in the energy savings achieved by EEE as it becomes deployed in the field.

98 citations

Journal ArticleDOI
TL;DR: The proposed fault-detection method significantly reduces memory access time when there is no error in the data read and uses the majority logic decoder itself to detect failures, which makes the area overhead minimal and keeps the extra power consumption low.
Abstract: Nowadays, single event upsets (SEUs) altering digital circuits are becoming a bigger concern for memory applications. This paper presents an error-detection method for difference-set cyclic codes with majority logic decoding. Majority logic decodable codes are suitable for memory applications due to their capability to correct a large number of errors. However, they require a large decoding time that impacts memory performance. The proposed fault-detection method significantly reduces memory access time when there is no error in the data read. The technique uses the majority logic decoder itself to detect failures, which makes the area overhead minimal and keeps the extra power consumption low.

89 citations

Journal ArticleDOI
TL;DR: An initial evaluation shows that the additional savings in the scenarios considered range from 5 to 70 percent for conventional users and approximately 50 percent for large data centers.
Abstract: The proposed Energy-Efficient Ethernet (EEE) standard reduces energy consumption by defining two operation modes for transmitters and receivers: active and low power. Burst transmission can provide additional energy savings when EEE is used. Collecting data frames into large-sized data bursts for back-to-back transmission maximizes the time an EEE device spends in low power, thus making its consumption nearly proportional to its traffic load. An initial evaluation shows that the additional savings in the scenarios considered range from 5 to 70 percent for conventional users and approximately 50 percent for large data centers.

83 citations


Cited by
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Christopher M. Bishop1
01 Jan 2006
TL;DR: Probability distributions of linear models for regression and classification are given in this article, along with a discussion of combining models and combining models in the context of machine learning and classification.
Abstract: Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

10,141 citations

Proceedings Article
01 Jan 1994
TL;DR: The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images.
Abstract: MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.

2,134 citations

Book
01 Dec 1981

609 citations

22 Jun 2016
TL;DR: Shehabi, Arman; Smith, Sarah; Sartor, Dale; Brown, Richard; Herrlin, Magnus; Koomey, Jonathan; Masanet, Eric; Horner, Nathaniel; Azevedo, Ines; Lintner, William as discussed by the authors.
Abstract: Author(s): Shehabi, Arman; Smith, Sarah; Sartor, Dale; Brown, Richard; Herrlin, Magnus; Koomey, Jonathan; Masanet, Eric; Horner, Nathaniel; Azevedo, Ines; Lintner, William

606 citations

Journal ArticleDOI
01 Sep 1986
TL;DR: This chapter discusses algorithmics and modular computations, Theory of Codes and Cryptography (3), and the theory and practice of error control codes (3).
Abstract: algorithmics and modular computations, Theory of Codes and Cryptography (3).From an analytical 1. RE Blahut. Theory and practice of error control codes. eecs.uottawa.ca/∼yongacog/courses/coding/ (3) R.E. Blahut,Theory and Practice of Error Control Codes, Addison Wesley, 1983. QA 268. Cached. Download as a PDF 457, Theory and Practice of Error Control CodesBlahut 1984 (Show Context). Citation Context..ontinued fractions.

597 citations