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Journal ArticleDOI

Non-Stationary Traffic Analysis and Its Implications on Multicore Platform Design

TL;DR: This work proposes a statistical physics inspired approach to capture the traffic dynamics in multicore systems and opens up new research directions into NoC optimization which require accurate models of time-dependent and space-dependent traffic behavior.
Abstract: Networks-on-chip (NoCs) have been proposed as a viable solution to solving the communication problem in multicore systems. In this new setup, mapping multiple applications on available computational resources leads to interaction and contention at various network resources. Consequently, taking into account the traffic characteristics becomes of crucial importance for performance analysis and optimization of the communication infrastructure, as well as proper resource management. Although queuing-based approaches have been traditionally used for performance analysis purposes, they cannot properly account for many of the traffic characteristics (e.g., non-stationarity, self-similarity) that are crucial for multicore platform design. To overcome these limitations, we propose a statistical physics inspired approach to capture the traffic dynamics in multicore systems. As shown later in this paper, this is of fundamental significance for re-thinking the very basis of multicore systems design; it also opens up new research directions into NoC optimization which require accurate models of time-dependent and space-dependent traffic behavior.
Citations
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Journal ArticleDOI
TL;DR: The aim of this survey is to enable researchers and system designers to get insights into the working and applications of CPSs and motivate them to propose novel solutions for making wide-scale adoption of CPS a tangible reality.
Abstract: Cyberphysical systems (CPSs) are new class of engineered systems that offer close interaction between cyber and physical components. The field of CPS has been identified as a key area of research, and CPSs are expected to play a major role in the design and development of future systems. In this paper, we survey recent advancements made in the development and applications of CPSs. We classify the existing research work based on their characteristics and identify the future challenges. We also discuss the examples of prototypes of CPSs. The aim of this survey is to enable researchers and system designers to get insights into the working and applications of CPSs and motivate them to propose novel solutions for making wide-scale adoption of CPS a tangible reality.

653 citations

Journal ArticleDOI
TL;DR: This paper presents a discrete particle swarm optimization (PSO)-based strategy to map applications on both 2-D and 3-D mesh-connected Networks-on-Chip, and its results are superior to those from reported techniques.
Abstract: This paper presents a discrete particle swarm optimization (PSO)-based strategy to map applications on both 2-D and 3-D mesh-connected Networks-on-Chip The basic PSO formulation has been augmented by: 1) running multiple PSOs and 2) deterministically generating a part of the initial population for PSO The mapping results, in terms of the overall communication metric, have been compared with well-known techniques reported in the literature and also with exact methods built around integer linear programming (ILP) Our PSO-based results are superior to those from reported techniques For smaller benchmarks, the results obtained are same as those corresponding to the ILP formulation, establishing the quality of the solution strategy

114 citations


Cites background from "Non-Stationary Traffic Analysis and..."

  • ...This has happened because of non stationarity with periods of high and low network loads [38]....

    [...]

Proceedings ArticleDOI
09 May 2012
TL;DR: This work proposes a new paradigm shift from power optimization based on linear models to control approaches based on fractal-state equations, and is the first to propose a controller for fractal workloads with precise constraints on state and control variables and specific time bounds.
Abstract: Reducing energy consumption in multi-processor systems-on-chip (MPSoCs) where communication happens via the network-on-chip (NoC) approach calls for multiple voltage/frequency island (VFI)-based designs. In turn, such multi-VFI architectures need efficient, robust, and accurate run-time control mechanisms that can exploit the workload characteristics in order to save power. Despite being tractable, the linear control models for power management cannot capture some important workload characteristics (e.g., fractality, non-stationarity) observed in heterogeneous NoCs, if ignored, such characteristics lead to inefficient communication and resources allocation, as well as high power dissipation in MPSoCs. To mitigate such limitations, we propose a new paradigm shift from power optimization based on linear models to control approaches based on fractal-state equations. As such, our approach is the first to propose a controller for fractal workloads with precise constraints on state and control variables and specific time bounds. Our results show that significant power savings (about 70%) can be achieved at run-time while running a variety of benchmark applications.

71 citations

Journal ArticleDOI
TL;DR: Four popular mathematical formalisms—queueing theory, network calculus, schedulability analysis, and dataflow analysis—and how they have been applied to the analysis of on-chip communication performance in Systems-on-Chip are reviewed.
Abstract: This article reviews four popular mathematical formalisms—queueing theory, network calculus, schedulability analysis, and dataflow analysis—and how they have been applied to the analysis of on-chip communication performance in Systems-on-Chip. The article discusses the basic concepts and results of each formalism and provides examples of how they have been used in Networks-on-Chip (NoCs) performance analysis. Also, the respective strengths and weaknesses of each technique and its suitability for a specific purpose are investigated. An open research issue is a unified analytical model for a comprehensive performance evaluation of NoCs. To this end, this article reviews the attempts that have been made to bridge these formalisms.

55 citations

Proceedings ArticleDOI
Li Zhou1, Avinash Kodi1
21 Apr 2013
TL;DR: The performance on synthetic and real traffic (PARSEC, Splash2) for 64-cores indicate that the proposed bandwidth scaling technique can reduce optical power by about 60% with at most 11% throughput penalty.
Abstract: Optical interconnect is a disruptive technology solution that can overcome the power and bandwidth limitations of traditional electrical Networks-on-Chip (NoCs). However, the static power dissipated in the external laser may limit the performance of future optical NoCs by dominating the stringent network power budget. From the analysis of real benchmarks for multicores, it is observed that high static power is consumed due to the external laser even for low channel utilization. In this paper, we propose PROBE: Prediction-based Optical Bandwidth Scaling for Energy-efficient NoCs by exploiting the latency/bandwidth trade-off to reduce the static power consumption by increasing the average channel utilization. With a lightweight prediction technique, we scale the bandwidth adaptively to the changing traffic demands while maintaining reasonable performance. The performance on synthetic and real traffic (PARSEC, Splash2) for 64-cores indicate that our proposed bandwidth scaling technique can reduce optical power by about 60% with at most 11% throughput penalty.

53 citations


Cites background from "Non-Stationary Traffic Analysis and..."

  • ...Second Predictor: However the traffic burstiness and sudden fluctuations will make the traffic trends hard to predict [17]....

    [...]

References
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Journal ArticleDOI
TL;DR: It is found that user-initiated TCP session arrivals, such as remote-login and file-transfer, are well-modeled as Poisson processes with fixed hourly rates, but that other connection arrivals deviate considerably from Poisson.
Abstract: Network arrivals are often modeled as Poisson processes for analytic simplicity, even though a number of traffic studies have shown that packet interarrivals are not exponentially distributed. We evaluate 24 wide area traces, investigating a number of wide area TCP arrival processes (session and connection arrivals, FTP data connection arrivals within FTP sessions, and TELNET packet arrivals) to determine the error introduced by modeling them using Poisson processes. We find that user-initiated TCP session arrivals, such as remote-login and file-transfer, are well-modeled as Poisson processes with fixed hourly rates, but that other connection arrivals deviate considerably from Poisson; that modeling TELNET packet interarrivals as exponential grievously underestimates the burstiness of TELNET traffic, but using the empirical Tcplib interarrivals preserves burstiness over many time scales; and that FTP data connection arrivals within FTP sessions come bunched into "connection bursts", the largest of which are so large that they completely dominate FTP data traffic. Finally, we offer some results regarding how our findings relate to the possible self-similarity of wide area traffic. >

3,915 citations

Journal ArticleDOI
TL;DR: Focusing on using probabilistic metrics such as average values or variance to quantify design objectives such as performance and power will lead to a major change in SoC design methodologies.
Abstract: On-chip micronetworks, designed with a layered methodology, will meet the distinctive challenges of providing functionally correct, reliable operation of interacting system-on-chip components. A system on chip (SoC) can provide an integrated solution to challenging design problems in the telecommunications, multimedia, and consumer electronics domains. Much of the progress in these fields hinges on the designers' ability to conceive complex electronic engines under strong time-to-market pressure. Success will require using appropriate design and process technologies, as well as interconnecting existing components reliably in a plug-and-play fashion. Focusing on using probabilistic metrics such as average values or variance to quantify design objectives such as performance and power will lead to a major change in SoC design methodologies. Overall, these designs will be based on both deterministic and stochastic models. Creating complex SoCs requires a modular, component-based approach to both hardware and software design. Despite numerous challenges, the authors believe that developers will solve the problems of designing SoC networks. At the same time, they believe that a layered micronetwork design methodology will likely be the only path to mastering the complexity of future SoC designs.

3,852 citations

Book
19 Dec 2003
TL;DR: In this article, the MPEG-4 and H.264 standards are discussed and an overview of the technologies involved in their development is presented. But the focus is on the performance and not the technical aspects.
Abstract: About the Author.Foreword.Preface.Glossary.1. Introduction.2. Video Formats and Quality.3. Video Coding Concepts.4. The MPEG-4 and H.264 Standards.5. MPEG-4 Visual.6. H.264/MPEG-4 Part 10.7. Design and Performance.8. Applications and Directions.Bibliography.Index.

2,491 citations

Posted Content
TL;DR: The principles of the complex organization and evolution of networks, natural and artificial, are discussed in this paper, which is addressed to all involved researchers and students, and the ideas are presented in a clear and a pedagogical way, with minimal mathematics, so even students without a deep knowledge of mathematics and statistical physics can rely on this as a reference.
Abstract: Only recently did mankind realise that it resides in a world of networks. The Internet and World Wide Web are changing our life. Our physical existence is based on various biological networks. We have recently learned that the term "network" turns out to be a central notion in our time, and the consequent explosion of interest in networks is a social and cultural phenomenon. The principles of the complex organization and evolution of networks, natural and artificial, are the topic of this book, which is written by physicists and is addressed to all involved researchers and students. The aim of the text is to understand networks and the basic principles of their structural organization and evolution. The ideas are presented in a clear and a pedagogical way, with minimal mathematics, so even students without a deep knowledge of mathematics and statistical physics will be able to rely on this as a reference. Special attention is given to real networks, both natural and artifical. Collected empirical data and numerous real applications of existing theories are discussed in detail, as well as the topical problems of communication networks. Available in OSO: http://www.oxfordscholarship.com/oso/public/content/physics/9780198515906/toc.html

1,906 citations

Journal ArticleDOI
01 Mar 1991
TL;DR: A compendium of recent theoretical results associated with using higher-order statistics in signal processing and system theory is provided, and the utility of applying higher- order statistics to practical problems is demonstrated.
Abstract: A compendium of recent theoretical results associated with using higher-order statistics in signal processing and system theory is provided, and the utility of applying higher-order statistics to practical problems is demonstrated. Most of the results are given for one-dimensional processes, but some extensions to vector processes and multichannel systems are discussed. The topics covered include cumulant-polyspectra formulas; impulse response formulas; autoregressive (AR) coefficients; relationships between second-order and higher-order statistics for linear systems; double C(q,k) formulas for extracting autoregressive moving average (ARMA) coefficients; bicepstral formulas; multichannel formulas; harmonic processes; estimates of cumulants; and applications to identification of various systems, including the identification of systems from just output measurements, identification of AR systems, identification of moving-average systems, and identification of ARMA systems. >

1,854 citations