North Carolina State University

Displaying 1-40 of 258 results

  • White Papers // Jun 2014

    ScalaJack: Customized Scalable Tracing with in-situ Data Analysis

    Root cause diagnosis of large-scale HPC applications often fails because tools, specifically trace-based ones, can no longer record all metrics they measure. The authors address this problems by combining customized tracing and providing support for in-situ data analysis via ScalaJack, a framework with customizable instrumentation and pluggable ex-tension capabilities for...

    Provided By North Carolina State University

  • White Papers // Mar 2014

    NoCMsg: Scalable NoC-Based Message Passing

    Current processor design with ever more cores may ensure that theoretical compute performance still follows past increases (resting from Moore's law), but they also increasingly present a challenge to hardware and software alike. As the core count increases, the Network-on-Chip (NoC) topology has changed from buses over rings and fully...

    Provided By North Carolina State University

  • White Papers // Feb 2014

    Tools for Simulation and Benchmark Generation at Exascale

    The path to exascale High-Performance Computing (HPC) poses several challenges related to power, performance, resilience, productivity, programmability, data movement, and data management. Investigating the performance of parallel applications at scale on future architectures and the performance impact of different architecture choices is an important component of HPC hardware/software co-design. Simulations...

    Provided By North Carolina State University

  • White Papers // Feb 2014

    Automatic Identification of Application I/O Signatures from Noisy Server-Side Traces

    Competing workloads on a shared storage system cause I/O resource contention and application performance vagaries. This problem is already evident in today's HPC storage systems and is likely to become acute at exascale. The authors need more interaction between application I/O requirements and system software tools to help alleviate the...

    Provided By North Carolina State University

  • White Papers // Feb 2014

    Understanding the Tradeoffs between Software- Managed vs. Hardware-Managed Caches in GPUs

    On-chip caches are commonly used in computer systems to hide long off-chip memory access latencies. To manage on-chip caches, either software-managed or hardware-managed schemes can be employed. State-of-art accelerators, such as the NVIDIA Fermi or Kepler GPUs and Intel's forthcoming MIC \"KNights Landing\" (KNL), support both software-managed caches, aka. shared...

    Provided By North Carolina State University

  • White Papers // Feb 2014

    Understanding the Tradeoffs Between Software-Managed Vs. Hardware-Managed Caches in GPUs

    On-chip caches are commonly used in computer systems to hide long off-chip memory access latencies. To manage on-chip caches, either software-managed or hardware-managed schemes can be employed. State-of-art accelerators, such as the NVIDIA Fermi or Kepler GPUs and Intel's forthcoming MIC \"KNights Landing\" (KNL), support both software-managed caches, aka. shared...

    Provided By North Carolina State University

  • White Papers // Jan 2014

    Warp-Level Divergence in GPUs: Characterization, Impact, and Mitigation

    High throughput architectures rely on high Thread-Level Parallelism (TLP) to hide execution latencies. In state-of-art Graphics Processing Units (GPUs), threads are organized in a grid of Thread Blocks (TBs) and each TB contains tens to hundreds of threads. With a TB-level resource management scheme, all the resource required by a...

    Provided By North Carolina State University

  • White Papers // Jan 2014

    Communication Characteristics of Large-Scale Scientific Applications for Contemporary Cluster Architectures

    In this paper, the authors examine the explicit communication characteristics of several sophisticated scientific applications, which, by themselves, constitute a representative suite of publicly available benchmarks for large cluster architectures. By focusing on the Message Passing Interface (MPI) and by using hardware counters on the microprocessor, they observe each application's...

    Provided By North Carolina State University

  • White Papers // Jan 2014

    Soft Error Protection via Fault-Resilient Data Representations

    Embedded systems are increasingly deployed in harsh environments that their components were not necessarily designed for. As a result, systems may have to sustain transient faults, i.e., both single-bit soft errors caused by radiation from space and transient errors caused by lower signal/noise ratio in smaller fabrication sizes. Hardware can...

    Provided By North Carolina State University

  • White Papers // Jan 2014

    IPSec/VPN Security Policy: Correctness, Conflict Detection and Resolution

    IPSec (Internet Security Protocol suite) functions will be executed correctly only if its policies are correctly specified and configured. Manual IPSec policy configuration is inefficient and error-prone. An erroneous policy could lead to communication blockade or serious security breach. In addition, even if policies are specified correctly in each domain,...

    Provided By North Carolina State University

  • White Papers // Jan 2014

    Fair Caching in a Chip Multiprocessor Architecture

    In this paper, the authors present a detailed study of fairness in cache sharing between threads in a Chip Multi-Processor (CMP) architecture. Prior work in CMP architectures has only studied throughput optimization techniques for a shared cache. The issue of fairness in cache sharing, and its relation to throughput, has...

    Provided By North Carolina State University

  • White Papers // Dec 2013

    Performance Assessment of A Multi-block Incompressible Navier-Stokes Solver using Directive-based GPU Programming in a Cluster Environment

    OpenACC, a directive-based GPU programming standard, is emerging as a promising technology for massively-parallel accelerators, such as General-Purpose computing on Graphics Processing Units (GPGPU), Accelerated Processing Unit (APU) and Many Integrated Core architecture (MIC). The heterogeneous nature of these accelerators call for careful designs of parallel algorithms and data management,...

    Provided By North Carolina State University

  • White Papers // Dec 2013

    Exploiting Data Representation for Fault Tolerance

    The authors explore the link between data representation and soft errors in dot products. They present an analytic model for the absolute error introduced should a soft error corrupt a bit in an IEEE-754 floating-point number. They show how this finding relates to the fundamental linear algebra concepts of normalization...

    Provided By North Carolina State University

  • White Papers // Nov 2013

    PAQO: Preference-Aware Query Optimization for Decentralized Database Systems

    The declarative nature of SQL has traditionally been a major strength. Users simply state what information they are interested in, and the database management system determines the best plan for retrieving it. A consequence of this model is that should a user ever want to specify some aspect of how...

    Provided By North Carolina State University

  • White Papers // Sep 2013

    WHYPER: Towards Automating Risk Assessment of Mobile Applications

    In this paper, the authors present the first step in addressing this challenge. Specifically, they focus on permissions for a given application and examine whether the application description provides any indication for: why the application needs permission. They present WHYPER, a framework using Natural Language Processing (NLP) techniques to identify...

    Provided By North Carolina State University

  • White Papers // Jul 2013

    A Unified View of Non-monotonic Core Selection and Application Steering in Heterogeneous Chip Multiprocessors

    A single-ISA Heterogeneous Chip Multi-Processor (HCMP) is an attractive substrate to improve single-thread performance and energy efficiency in the dark silicon era. The authors consider HCMPs comprised of non-monotonic core types where each core type is performance-optimized to different instruction level behavior and hence cannot be ranked - different program...

    Provided By North Carolina State University

  • White Papers // Jun 2013

    MetaSymploit: Day-One Defense Against Script-Based Attacks with Security-Enhanced Symbolic Analysis

    In this paper, the authors propose MetaSymploit, the first system of fast attack script analysis and automatic signature generation for a network Intrusion Detection System (IDS). As soon as a new attack script is developed and distributed, MetaSymploit uses security-enhanced symbolic execution to quickly analyze the script and automatically generate...

    Provided By North Carolina State University

  • White Papers // Mar 2013

    Reasonableness Meets Requirements: Regulating Security and Privacy in Software

    Software security and privacy issues regularly grab headlines amid fears of identity theft, data breaches, and threats to security. Policymakers have responded with a variety of approaches to combat such risk. Suggested measures include promulgation of strict rules, enactment of open-ended standards, and, at times, abstention in favor of allowing...

    Provided By North Carolina State University

  • White Papers // Feb 2013

    Taming Hosted Hypervisors With (Mostly) Deprivileged Execution

    Recent years have witnessed increased adoption of hosted hypervisors in virtualized computer systems. By non-intrusively extending commodity OSs, hosted hypervisors can effectively take advantage of a variety of mature and stable features as well as the existing broad user base of commodity OSs. However, virtualizing a computer system is still...

    Provided By North Carolina State University

  • White Papers // Feb 2013

    Adaptive Cache Bypassing for Inclusive Last Level Caches

    Cache hierarchy designs, including bypassing, replacement, and the inclusion property, have significant performance impact. Recent works on high performance caches have shown that cache bypassing is an effective technique to enhance the Last Level Cache (LLC) performance. However, commonly used inclusive cache hierarchy cannot benefit from this technique because bypassing...

    Provided By North Carolina State University

  • White Papers // Feb 2013

    Directory-Oblivious Capacity Sharing in Tiled CMPs

    In bus-based CMPs with private caches, Capacity Sharing is applied by spilling victim cache blocks from over-utilized caches to under-utilized ones. If a spilled block is needed, it can be retrieved by posting a miss on the bus. Prior work in this domain focused on Capacity Sharing design and put...

    Provided By North Carolina State University

  • White Papers // Jan 2013

    Flexible Capacity Partitioning in Many-Core Tiled CMPs

    Chip Multi-Processors (CMP) have become a mainstream computing platform. As transistor density shrinks and the number of cores increases, more scalable CMP architectures will emerge. Recently, tiled architectures have shown such scalable characteristics and been used in many industry chips. The memory hierarchy in tiled architectures presents interesting design challenges....

    Provided By North Carolina State University

  • White Papers // Jan 2013

    QuickSense: Fast and Energy-Efficient Channel Sensing for Dynamic Spectrum Access Networks

    Spectrum sensing, the task of discovering spectrum usage at a given location, is a fundamental problem in dynamic spectrum access networks. While sensing in narrow spectrum bands is well studied in previous work, wideband spectrum sensing is challenging since a wideband radio is generally too expensive and power consuming for...

    Provided By North Carolina State University

  • White Papers // Jan 2013

    Characterizing Link Connectivity for Opportunistic Mobile Networking: Does Mobility Suffice?

    With recent drastic growth in the number of users carrying smart mobile devices, it is not hard to envision opportunistic ad-hoc communications taking place with such devices carried by humans. This leads to, however, a new challenge to the conventional link-level metrics, solely defined based on user mobility, such as...

    Provided By North Carolina State University

  • White Papers // Jan 2013

    A Semantic Protocol-Based Approach for Developing Business Processes

    A (business) protocol is a modular, public specification of an interaction among different roles that achieves a desired purpose. The authors' model protocols in terms of the commitments of the participating roles. Commitments enable reasoning about actions, thus allowing the participants to comply with protocols while acting flexibly to exploit...

    Provided By North Carolina State University

  • White Papers // Jan 2013

    Modeling Flexible Business Processes

    Current approaches of designing business processes rely on traditional workflow technologies and thus take a logically centralized view of processes. Processes designed in that manner assume the participants will act as invoked, thus limiting their flexibility or autonomy. Flexibility is in conflict with both reusability and compliance. The authors propose...

    Provided By North Carolina State University

  • White Papers // Dec 2012

    Scheduling Cloud Capacity for Time-Varying Customer Demand

    As utility computing resources become more ubiquitous, service providers increasingly look to the cloud for an in-full or in-part infrastructure to serve utility computing customers on demand. Given the costs associated with cloud infrastructure, dynamic scheduling of cloud resources can significantly lower costs while providing an acceptable service level. The...

    Provided By North Carolina State University

  • White Papers // Dec 2012

    Auto-Generation and Auto-Tuning of 3D Stencil Codes on Homogeneous and Heterogeneous GPU Clusters

    In this paper, the authors develop and evaluates search and optimization techniques for auto-tuning 3D stencil (nearest-neighbor) computations on GPUs. Observations indicate that parameter tuning is necessary for heterogeneous GPUs to achieve optimal performance with respect to a search space. Their proposed framework takes a most concise specification of stencil...

    Provided By North Carolina State University

  • White Papers // Nov 2012

    On the Accurate Identification of Network Service Dependencies in Distributed Systems

    The automated identification of network service dependencies remains a challenging problem in the administration of large distributed systems. Advances in developing solutions for this problem have immediate and tangible benefits to operators in the field. When the dependencies of the services in a network are better-understood, planning for and responding...

    Provided By North Carolina State University

  • White Papers // Oct 2012

    HadISD: A Quality-Controlled Global Synoptic Report Database for Selected Variables at Long-Term Stations From 1973 - 2011

    In this paper, the authors describes the creation of HadISD: an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973 - 2011. The full dataset consists of over 6000 stations, with 3427 long-term stations deemed...

    Provided By North Carolina State University

  • White Papers // Sep 2012

    Collaborative Assessment of Functional Reliability in Wireless Networks

    Nodes that are part of a multi-hop wireless network, typically deployed in mission critical settings, are expected to perform specific functions. Establishing a notion of reliability of the nodes with respect to each function (referred to as Functional Reliability or FR) is essential for efficient operations and management of the...

    Provided By North Carolina State University

  • White Papers // Sep 2012

    Is Link Signature Dependable for Wireless Security?

    Link signature, which refers to the unique and reciprocal wireless channel between a pair of transceivers, has gained significant attentions recently due to its effectiveness in signal authentication and shared secret construction for various wireless applications. A fundamental assumption of this technique is that the wireless signals received at two...

    Provided By North Carolina State University

  • White Papers // Sep 2012

    An Efficient Algorithm for Solving Traffic Grooming Problems in Optical Networks

    The authors consider the Virtual Topology and Traffic Routing (VTTR) problem, a sub-problem of traffic grooming that arises as a fundamental network design problem in optical networks. The objective of VTTR is to determine the minimum number of light-paths so as to satisfy a set of traffic demands, and does...

    Provided By North Carolina State University

  • White Papers // Sep 2012

    Scalable Optimal Traffic Grooming in WDM Rings Incorporating Fast RWA Formulation

    The authors present a scalable formulation for the traffic grooming problem in WDM ring networks. Specifically, they modify the ILP formulation to replace the constraints related to Routing and Wavelength Assignment (RWA), typically based on a link approach, with a new set of constraints based on the Maximal Independent Set...

    Provided By North Carolina State University

  • White Papers // Sep 2012

    Reducing Data Movement Costs Using Energy-Efficient, Active Computation on SSD

    Modern scientific discovery often involves running complex application simulations on supercomputers, followed by a sequence of data analysis tasks on smaller clusters. This offline approach suffers from significant data movement costs such as redundant I/O, storage bandwidth bottleneck, and wasted CPU cycles, all of which contribute to increased energy consumption...

    Provided By North Carolina State University

  • White Papers // Aug 2012

    A Physical Design Study of FabScalar-generated Superscalar Cores

    FabScalar is a recently published toolset for automatically composing synthesizable Register-Transfer-Level (RTL) designs of diverse superscalar cores. FabScalar is a recently published tool for automatically generating superscalar cores, of different pipeline widths, depths and sizes. The output of FabScalar is a synthesizable Register-Transfer-Level (RTL) description of the desired core. While...

    Provided By North Carolina State University

  • White Papers // Aug 2012

    Network Virtualization: Technologies, Perspectives, and Frontiers

    Network virtualization refers to a broad set of technologies. Commercial solutions have been offered by the industry for years, while more recently the academic community has emphasized virtualization as an enabler for network architecture research, deployment, and experimentation. The authors review the entire spectrum of relevant approaches with the goal...

    Provided By North Carolina State University

  • White Papers // Aug 2012

    A Fast Path-Based ILP Formulation for Offline RWA in Mesh Optical Networks

    RWA is a fundamental problem in the design and control of optical networks. The authors introduce the concept of symmetric RWA solutions and present a new ILP formulation to construct optimally such solutions. The formulation scales to mesh topologies representative of backbone and regional networks. Numerical results demonstrate that the...

    Provided By North Carolina State University

  • White Papers // Jul 2012

    Tracking the Trackers: Fast and Scalable Dynamic Analysis of Web Content for Privacy Violations

    JavaScript-based applications are very popular on the web today. However, the lack of effective protection makes various kinds of privacy violation attack possible, including cookie stealing, history sniffing and behavior tracking. There have been studies of the prevalence of such attacks, but the dynamic nature of the JavaScript language makes...

    Provided By North Carolina State University

  • White Papers // Jun 2012

    Fixing Performance Bugs: An Empirical Study of Open-Source GPGPU Programs

    Given the extraordinary computational power of modern Graphics Processing Units (GPUs), general purpose computation on GPUs (GPGPU) has become an increasingly important platform for high performance computing. To better understand how well the GPU resource has been utilized by application developers and then to facilitate them to develop high performance...

    Provided By North Carolina State University

  • White Papers // May 2012

    Enabling Adaptive Rate and Relay Selection for 802.11 Mobile Ad Hoc Networks

    Mobile Ad hoc NETworks (MANETs) are self-configuring wireless networks that lack permanent infrastructure and are formed among mobile nodes on demand. Rapid node mobility results in dramatic channel variation, or fading, that degrades MANET performance. Employing Channel State Information (CSI) at the transmitter can improve the throughput of routing and...

    Provided By North Carolina State University

  • White Papers // May 2012

    An Algorithm for Joint Guidance and Power Control for Electric Vehicles in the Smart Grid

    A massive amount of energy consumption currently stems from the transportation sector. Therefore, improvements in power usage by commuting vehicles are being studied and becoming an increasingly popular research topic. In particular, there is a growing need to model the envisioned smart infrastructure, including charging stations, some of which might...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Energy Efficient Iterative Waterfilling for the MIMO Broadcasting Channels

    Optimizing Energy Efficiency (EE) for the MIMO Broadcasting Channels (BC) is considered in this paper, where a practical power model is taken into account. Although the EE of the MIMO BC is non-concave, the authors reformulate it as a quasi-concave function based on the uplink-downlink duality. After that, an energy...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Packet Aggregation Based Back-Pressure Scheduling in Multi-Hop Wireless Networks

    The back-pressure based scheduling policy originally proposed by Tassiulas et al. in has shown the potential of solving many fairness and network utilization related problems of wireless multi-hop networks. Recently, the scheduling policy has been adapted in random medium access protocols such as CSMA/CA using prioritization of MAC layer transmissions....

    Provided By North Carolina State University

  • White Papers // May 2009

    Improving the Availability of Supercomputer Job Input Data Using Temporal Replication

    Storage systems in supercomputers are a major reason for service interruptions. RAID solutions alone cannot provide sufficient protection as 1) growing average disk recovery times make RAID groups increasingly vulnerable to disk failures during reconstruction, and 2) RAID does not help with higher-level faults such failed I/O nodes. This paper...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Design and Applications of a Smooth Mobility Model for Mobile Ad Hoc Networks

    Existing mobility models used in the simulation tools have two major limitations. First, these models invoke unrealistic moving behaviors, such as sudden stop and sharp turn during the simulation. Hence, the study of Mobile Ad-hoc NETworks (MANETs) based on these models could lead to wrong conclusions. Second, because the node...

    Provided By North Carolina State University

  • White Papers // Jun 2009

    Towards Well-Behaved Schema Evolution

    The authors study the problem of schema evolution in the RDF data model. RDF and the RDFS schema language are W3C standards for flexibly modeling and sharing data on the web. Although schema evolution has been intensively studied in the database and knowledge-representation communities, only recently has progress been made...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    Towards Quantitative Analysis of Proofs of Authorization: Applications, Framework, and Techniques

    Although policy compliance testing is generally treated as a binary decision problem, the evidence gathered during the trust management process can actually be used to examine these outcomes within a more continuous space. In this paper, the authors develop a formal model that allows them to quantitatively reason about the...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    DARTS: Techniques and Tools for Predictably Fast Memory Using Integrated Data Allocation and Real-Time Task Scheduling

    Hardware-managed caches introduce large amounts of timing variability, complicating real-time system design. One alternative is a memory system with scratchpad memories which improve system performance while eliminating such timing variability. Prior work introduced the DARTS approach, which combines static allocation of data into scratchpad memories, with task scheduling for preemptive...

    Provided By North Carolina State University

  • White Papers // Feb 2009

    Mining Exception-Handling Rules as Sequence Association Rules

    Programming languages such as Java and C++ provide exception-handling constructs such as try-catch to handle exception conditions that arise during program execution. Under these exception conditions, programs follow paths different from normal execution paths; these additional paths are referred to as exception paths. Applications developed based on these programming languages...

    Provided By North Carolina State University

  • White Papers // May 2010

    Informative Middleman Service, Variety-Expansion And Long Run Growth

    In reality, the intermediate firms not only conduct R&D but also provide informative middleman services to overcome the information cost generated by technological advancements. The author incorporates the informative middleman services such as consulting, advertising, technical supporting, repair and maintenance into a variety-expansion model. The author finds that: Activities of...

    Provided By North Carolina State University

  • White Papers // May 2010

    Schumpeterian Growth, Trade, And Dynamic Comparative Advantage

    The authors study the effects of trade on economic growth in a Schumpeterian framework. The model excludes scale effects and technology transfer, the two usual channels in the literature through which trade affects growth, leaving only comparative advantage. Comparative advantage and the trading pattern are determined endogenously. Endogeneity of production...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Self-Sustaining, Efficient and Forward-Secure Cryptographic Constructions for Unattended Wireless Sensor Networks

    Unattended Wireless Sensor Networks (UWSNs) operating in hostile environments face great security and performance challenges due to the lack of continuous real-time communication with the final data receivers (e.g., mobile data collectors). The lack of real-time communication forces sensors to accumulate sensed data possibly for long time periods, along with...

    Provided By North Carolina State University

  • White Papers // Oct 2009

    BAF: An Efficient Publicly Verifiable Secure Audit Logging Scheme for Distributed Systems

    Audit logs, providing information about the current and past states of systems, are one of the most important parts of modern computer systems. Providing security for audit logs on an untrusted machine in a large distributed system is a challenging task, especially in the presence of active adversaries. In such...

    Provided By North Carolina State University

  • White Papers // May 2009

    Hash-Based Sequential Aggregate and Forward Secure Signature for Unattended Wireless Sensor Networks

    Unattended Wireless Sensor Networks (UWSNs) operating in hostile environments face great security and performance challenges due to the lack of continuous real-time communication between senders (sensors) and receivers (e.g., mobile data collectors, static sinks). The lack of real-time communication forces sensors to accumulate the sensed data possibly for long time...

    Provided By North Carolina State University

  • White Papers // Aug 2009

    Predictive Constrained Gain Scheduling for UGV Path Tracking in a Networked Control System

    This paper presents a predictive gain scheduler for path tracking control in a networked control system with variable delay. The controller uses the plant model to predict future position and find the amount of travel possible with the global path as a constraint. Based on variable network conditions and vehicle...

    Provided By North Carolina State University

  • White Papers // May 2009

    Analysis on the Kalman Filter Performance in GPS/INS Integration at Different Noise Levels, Sampling Periods and Curvatures

    Kalman Filters (KF) has been extensively used in the integration of Global Positioning System (GPS) and Inertial Navigation System (INS) data. Often, the GPS data is used as a benchmark to update the INS data. In this paper, an analysis of integration of GPS data with INS data using an...

    Provided By North Carolina State University

  • White Papers // May 2009

    Predictive Control of Multiple UGVs in a NCS With Adaptive Bandwidth Allocation

    In network based path tracking control of systems with multiple Unmanned Ground Vehicles (UGVs), performance can be affected by network constraints including time-varying network delays and bandwidth limitation. Network delay has previously been compensated for using smith predictor based techniques and gain scheduling to limit UGV motion. The predictive gain...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    A Survey of Network Design Problems and Joint Design Approaches in Wireless Mesh Networks

    Over the last decade, the paradigm of Wireless Mesh Networks (WMNs) has matured to a reasonably commonly understood one, and there has been extensive research on various areas related to WMNs such as design, deployment, protocols, performance, etc. The quantity of research being conducted in the area of wireless mesh...

    Provided By North Carolina State University

  • White Papers // Mar 2010

    CentMesh: Modular and Extensible Wireless Mesh Network Testbed

    In this paper, the authors present the design of their wireless mesh network testbed (CentMesh) which facilitates experimentation as a service. CentMesh differs from other testbeds in terms of its modular, flexible and extensible design. The CentMesh software suite provides a modular programming library using which users can implement their...

    Provided By North Carolina State University

  • White Papers // Nov 2009

    Impact of Power Control on Relay Load Balancing in Wireless Sensor Networks

    When shortest path routing is employed in large scale multi-hop wireless networks, nodes located near the center of the network have to perform disproportional amount of relaying for others. In energy-constrained networks like sensor, such unfair forwarding results into early depletion of batteries of these congested nodes. To solve the...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Efficient Distribution of Key Chain Commitments for Broadcast Authentication in Distributed Sensor Networks

    A distributed sensor network usually consists of one or several computationally powerful nodes called base stations and a large amount of inexpensive, low capacity nodes called sensors (or sensor nodes). The nodes in a distributed sensor network communicate through wireless communication, which is usually limited in bandwidth. Distributed sensor networks...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Topology Stability Analysis and Its Application in Hierarchical Mobile Ad Hoc Networks

    The hierarchical architecture has been proven effective for solving the scalability problems in large-scale ad hoc networks. The stability of the hierarchical architecture is a key factor in determining the network performance. Although many solutions have been proposed to construct stable clusters, the maximum stability achievable in the mobile environments...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    ART: An Asymmetric and Reliable Transport Mechanism for Wireless Sensor Networks

    Many applications developed for Wireless Sensor Networks (WSNs) demand for Reliable communication service, since majority of these applications are event-critical applications. There has been a vast body of knowledge on reliable data transfer in wireless networks; however, many of those solutions are not applicable to WSNs due to the fact...

    Provided By North Carolina State University

  • White Papers // Jan 2010

    On Order Gain of Backoff Misbehaving Nodes in CSMA/CA-Based Wireless Networks

    Backoff misbehavior, in which a wireless node deliberately manipulates its backoff time, can induce significant network problems, such as severe unfairness and denial-of-service. Although great progress has been made towards the design of countermeasures to backoff misbehavior, little attention has been focused on quantifying the gain of backoff misbehaviors. In...

    Provided By North Carolina State University

  • White Papers // Aug 2010

    Review and Evaluation of Security Threats on the Communication Networks in the Smart Grid

    The smart grid, generally referred to as the next-generation power electric system, relies on robust communication networks to provide efficient, secure, and reliable information delivery. Thus, the network security is of critical importance in the smart grid. In this paper, the authors aim at classifying and evaluating the security threats...

    Provided By North Carolina State University

  • White Papers // Mar 2011

    From Jammer to Gambler: Modeling and Detection of Jamming Attacks Against Time-Critical Traffic

    Time-critical wireless applications in emerging network systems, such as e-healthcare and smart grids, have been drawing increasing attention in both industry and academia. The broadcast nature of wireless channels unavoidably exposes such applications to jamming attacks. However, existing methods to characterize and detect jamming attacks cannot be applied directly to...

    Provided By North Carolina State University

  • White Papers // Jun 2009

    Super-Diffusive Behavior of Mobile Nodes and Its Impact on Routing Protocol Performance

    Mobility is the most important component in Mobile Ad-hoc NETworks (MANETs) and Delay Tolerant Networks (DTNs). In this paper, the authors first investigate numerous GPS mobility traces of human mobile nodes and observe super-diffusive behavior in all GPS traces, which is characterized by a 'Faster-than-linear' growth rate of the Mean...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Exploiting Heterogeneity to Prolong the Lifetime of Large-Scale Wireless Sensor Networks

    In Wireless Sensor Networks (WSNs), sensor nodes are typically power-constrained with limited lifetime, and thus it is necessary to know how long the network sustains its networking operations. The authors consider the network lifetime as the time until that a majority of functional nodes remains connected of one another, forming...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Smart Sleep: Sleep More to Reduce Delay in Duty-Cycled Wireless Sensor Networks

    A Simple Random Walk (SRW) has been considered as an effective forwarding method for many applications in Wireless Sensor Networks (WSNs) due to its desirable properties. However, a critical downside of SRW - slow diffusion or exploration over the space, typically leads to longer packet delay and undermines its own...

    Provided By North Carolina State University

  • White Papers // Jul 2010

    A Distributed Wake-Up Scheduling for Opportunistic Forwarding in Wireless Sensor Networks

    In Wireless Sensor Networks (WSNs), sensor nodes are typically subjected to energy constraints and often prone to topology changes. While duty cycling has been widely used for energy conservation in WSNs, random walks have been popular for many delay-tolerant applications in WSNs due to their many inherent desirable properties. In...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    Exploiting Heterogeneity in Mobile Opportunistic Networks: An Analytic Approach

    Heterogeneity arises in a wide range of scenarios in mobile opportunistic networks and is one of key factors that govern the performance of packet forwarding algorithms. While the heterogeneity has been empirically investigated and exploited in the design of new forwarding algorithms, it has been typically ignored or marginalized when...

    Provided By North Carolina State University

  • White Papers // Jul 2011

    Optimal Max-Min Fair Resource Allocation in Multihop Relay-Enhanced WiMAX Networks

    In this paper, an optimal resource allocation scheme is proposed for WiMAX networks enhanced with non-transparent Relay Stations (RSs). The authors first focus on two-hop relaying networks, since this scenario has the largest throughput gain. Furthermore, many researchers have proposed different resource allocation schemes in two-hop relaying networks, and, thus,...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Transmission Throughput of Decentralized Overlaid Networks With Outage Constraints

    Overlaid networks, typically composed of primary and secondary networks, are emerging as a viable candidate to resolve the conflict between increasing demand for spectrum and spectrum shortage. The essential purpose of overlaid networks is to improve the network spectrum efficiency, which, however, may not be achieved if the secondary network...

    Provided By North Carolina State University

  • White Papers // Jun 2010

    Defending DSSS-Based Broadcast Communication Against Insider Jammers Via Delayed Seed-Disclosure

    Spread spectrum techniques such as Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping (FH) have been commonly used for anti-jamming wireless communication. However, traditional spread spectrum techniques require that sender and receivers share a common secret in order to agree upon, for example, a common hopping sequence (in FH) or...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    USD-FH: Jamming-Resistant Wireless Communication Using Frequency Hopping With Uncoordinated Seed Disclosure

    Spread spectrum techniques (e.g., Frequency Hopping (FH), Direct Sequence Spread Spectrum (DSSS)) have been widely used for anti-jamming wireless communications. Such techniques require that communicating devices agree on a shared secret before communication. However, it is non-trivial for two devices that do not share any secret to establish one in...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    Transport Capacity and Connectivity of Cognitive Radio Networks With Outage Constraint

    In this paper, the authors study two basic properties, capacity and connectivity, of Cognitive Radio networks. Their goal is to quantitatively characterize the relationship and tradeoff among key system parameters involved in these properties, incorporating channel randomness and interference into the performance analysis. In particular, they explore the characterization of...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    Authenticating Primary Users' Signals in Cognitive Radio Networks Via Integrated Cryptographic and Wireless Link Signatures

    To address the increasing demand for wireless bandwidth, Cognitive Radio Networks (CRNs) have been proposed to increase the efficiency of channel utilization; they enable the sharing of channels among secondary (unlicensed) and primary (licensed) users on a non-interference basis. A secondary user in a CRN should constantly monitor for the...

    Provided By North Carolina State University

  • White Papers // Jan 2010

    Distributed Network Decomposition: A Probabilistic Greedy Approach

    In this paper, the authors propose a novel distributed network decomposition algorithm with the aid of the factor graph model and the max-product algorithm, which aims to achieve minimum cut weight. Its effectiveness is testified for general graph partition as well as distributed inference in wireless networks. Their algorithm is...

    Provided By North Carolina State University

  • White Papers // Aug 2009

    Towards Efficient Designs for In-Network Computing With Noisy Wireless Channels

    In this paper, the authors study distributed function computation in a noisy multi-hop wireless network, in which n nodes are uniformly and independently distributed in a unit square. Each node holds an m-bit integer per instance and the computation is started after each node collects N readings. The goal is...

    Provided By North Carolina State University