University of Notre Dame

Displaying 1-40 of 215 results

  • White Papers // Mar 2012

    Fine-Grained Access Control in the Chirp Distributed File System

    Although the distributed file-system is a widely used technology in local area networks, it has seen less use on the wide area networks that connect clusters, clouds, and grids. One reason for this is access control: existing file-system technologies require either the client machine to be fully trusted, or the...

    Provided By University of Notre Dame

  • White Papers // Mar 2012

    Applying DDDAS Principles to Command, Control and Mission Planning for UAV Swarms

    Government agencies predict ever-increasing inventories of Unmanned Aerial Vehicles (UAVs). Sizes will vary from current manned aircraft scales to miniature, micro, millimeter scales or smaller. Missions for UAVs will increase, especially for the 3-D missions: dull, dirty, and dangerous. As their numbers and missions increase, three important challenges will emerge...

    Provided By University of Notre Dame

  • White Papers // Feb 2012

    Secondary Access Policies With Imperfect Sensing in Dynamic Spectrum Access Networks

    The authors consider secondary access policies with imperfect sensing in sensing-based dynamic spectrum access networks. Interference caused by both missed detections as well as the primary user's return to the channel during the secondary transmission are explored. They allow arbitrary distributions for the primary ON/OFF intervals and expand each interval...

    Provided By University of Notre Dame

  • White Papers // Feb 2012

    Low Latency Relaying Schemes for Next-Generation Cellular Networks

    The reduction in both user and control plane latency is a major goal for next generation (4G) cellular networks, specifically the Long Term Evolution-Advanced (LTE-A) standard. At the same time, relay stations, which introduce additional latency into transmissions, are seen as a potential means to improve cell spectral efficiency and...

    Provided By University of Notre Dame

  • White Papers // Feb 2012

    Multiaccess Communication in the Finite Blocklength Regime

    Although real-world communication networks employ coding schemes with blocklengths as low as several hundred symbols, classical coding theorems of information theory rely on blocklengths approaching infinity. Following a recent line of work on channel dispersion in the finite blocklength regime, the authors use first- and second-order statistics to characterize low-complexity...

    Provided By University of Notre Dame

  • White Papers // Jan 2012

    Method for Privacy-Protecting Display and Exchange of Emergency Information on Mobile Devices

    First responders and emergency care providers make life or death decisions with little to no information about patient's medical problems. Access to a person's medical record could greatly improve the medical care they receive. Challenges to proving this information include finding the correct platform and protecting the patient's privacy. Current...

    Provided By University of Notre Dame

  • White Papers // Jan 2012

    Swarming Under Perfect Consensus Using Integral Action

    Swarming is a collective behavior in which a group of distinct dynamical agents begin to move as a single entity. Swarming behavior has fascinated those interested in how collective actions can emerge from the selfish behavior of individuals in the group. Early examples may be found in physics and biology....

    Provided By University of Notre Dame

  • White Papers // Jan 2012

    Sensorless Sensing in Wireless Networks: Implementation and Measurements

    Multipath fading and shadowing are usually regarded as negative phenomena hindering proper radio communication. Adopting a completely different stance, this paper illustrates that such phenomena enable information harvesting from received signal strength leading to a number of original applications requiring no conventional sensing hardware. The radio itself, provided that it...

    Provided By University of Notre Dame

  • White Papers // Dec 2011

    Emergency Response in Smartphone-Based Mobile Ad-Hoc Networks

    Today's modern mobile devices (e.g., smartphones and tablets) present great potential for building large-scale mobile sensing and information sharing systems which can be highly beneficial to minimize the fatalities of human lives during emergency response. This paper presents a framework, called BREathing rate MONitoring (BREMON) that allows paramedics to monitor...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Random Power Control in Poisson Networks

    This paper studies power control strategies in interference-limited wireless networks with Poisson distributed nodes. The authors concentrate on two sets of strategies: Single-Node Optimal Power Control (SNOPC) strategies and Nash Equilibrium Power Control (NEPC) strategies. SNOPC strategies maximize the expected throughput of the power controllable link given that all the...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Work Queue + Python: A Framework for Scalable Scientific Ensemble Applications

    Even with the increase in the number and variety of computer resources available to research scientists today, it is still challenging to construct scalable distributed applications. To address this issue, the authors developed Work Queue, a flexible master/- worker framework for building large scale scientific ensemble applications that span many...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Converting a High Performance Application to an Elastic Cloud Application

    Over the past decade, high performance applications have embraced parallel programming and computing models. While parallel computing offers advantages such as good utilization of dedicated hardware resources, it also has several drawbacks such as poor fault-tolerance, scalability, and ability to harness available resources during run-time. The advent of cloud computing...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Seamless Dynamic Runtime Reconfiguration in a Software-Defined Radio

    The authors discuss implementation aspects of a software-defined radio system that allows for dynamic waveform reconfiguration during runtime without interrupting data-flow processing. Traditional software-defined radio systems execute a waveform statically, exactly as it is programmed. Reconfiguration is provided by executing a different waveform, which requires the system to stop processing...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Communications Overhead as the Cost of Constraints

    This paper speculates on a perspective for studying overhead in communication systems that contrasts the traditional viewpoint that overhead is the "Non-data" portion of transmissions. By viewing overhead as the cost of constraints imposed on a system, information-theoretic techniques can be used to obtain fundamental limits on overhead information, and...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    On the Use of an Algebraic Language Interface for Waveform Definition

    The authors discuss implementation aspects of a software-defined radio system that allows the user to define waveforms using an algebraic language interface, currently as an extension to C++. Current software-defined radio systems provide waveform definitions through a combination of a graphical interface, markup language, interpreted script, and compiled code. No...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Interference in Ad Hoc Networks With General Motion-Invariant Node Distributions

    In this paper, the authors derive the tail properties of interference for any stationary and isotropic spatial distribution of transmitting nodes. Previously the properties of interference were known only when the nodes are distributed as a homogeneous Poisson point process on the plane. They show the effect of a singular...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Bounds on Information Propagation Delay in Interference-Limited ALOHA Networks

    In a wireless network the set of transmitting nodes changes frequently because of the MAC scheduler and the traffic load. Analyzing the connectivity of such a network using static graphs would lead to pessimistic performance results. In this paper, the authors consider an ad hoc network with half-duplex radios that...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Path Loss Exponent Estimation in Large Wireless Networks

    In wireless channels, the Path Loss Exponent (PLE) has a strong impact on the quality of the links, and hence, it needs to be accurately estimated for the efficient design and operation of wireless networks. This paper addresses the problem of PLE estimation in large wireless networks, which is relevant...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Effect of Network Geometry and Interference on Consensus in Wireless Networks

    The authors study the convergence of the average consensus algorithm in wireless networks in the presence of interference. It is well-known that convergence of the consensus algorithm improves with network connectivity. However, from a networking standpoint, highly connected wireless networks may have lower throughput because of increased interference. This raises...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    On Consensus Over Stochastically Switching Directed Topologies

    The authors consider average consensus algorithms executed over stochastically varying communication topologies that may be unbalanced. It is known that the state values will reach consensus, under fairly weak conditions. However, the consensus value is a random variable. They provide concentration bounds for the distance of the state vector from...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Dynamic Connectivity and Packet Propagation Delay in ALOHA Wireless Networks

    The authors consider an ad hoc network which uses multihop and slotted ALOHA for its MAC contention. They then formulate the minimum time required for a packet to reach the destination from the origin. They define this delay as the minimum time required for a causal path to form between...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Geometry, Connectivity, and Broadcast Transport Capacity of Random Networks With Fading

    In ad hoc networks with random node distribution, the underlying point process model and the channel fading process are usually considered separately. The authors provide a unified framework for the geometric characterization of fading by incorporating the fading process into the point process model. Concretely, assuming nodes are distributed in...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    On Stability Across a Gaussian Product Channel

    The authors present sufficient conditions for stabilizing a scalar discrete-time LTI plant in the mean squared sense when a sensor transmits the plant state information to a remotely placed controller across a Gaussian product channel. The Gaussian product channel models a continuous-time waveform Gaussian channel, where the encoder transmits information...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Secure and Verifiable Outsourcing of Large-Scale Biometric Computations

    Cloud computing services are becoming prevalent and readily available today, bringing to one economies of scale and making large scale computation feasible. Security and privacy considerations, however, stand on the way of fully utilizing the benefits of such services and architectures. In this paper, the authors address the problem of...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Achieving Full Security in Privacy-Preserving Data Mining

    "In privacy-preserving data mining, a number of parties would like to jointly learn a function of their private data sets in a way that no information about their inputs, beyond the output itself, is revealed as a result of such computation. The researcher 2010 showed that several popular data mining...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Superposition Coding Strategies: Design and Experimental Evaluation

    The authors design and implement a software-radio system for Superposition Coding (SC), a multiuser transmission scheme that deliberately introduces interference among user signals at the transmitter, using a library of off-the-shelf point-to-point channel codes. They experimentally determine the set of rate-pairs achieved by this transmission scheme under a packet-error constraint....

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Notre Dame Marketing Professor Recognized With Lifetime Achievement Award

    The author has spent much of his 35-year academic career researching and teaching in the area of ethical concerns in marketing, publishing research papers and books about sustainability and corporate social responsibility as far back as the 1970s. The University of Notre Dame professor recently was honored for his contributions...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    On the Optimal Block Length for Joint Channel and Network Coding

    Channel coding alone is not sufficient to reliably transmit a message of finite length from a source to one or more destinations. To ensure that no data is lost, channel coding on the physical layer needs to be combined with rateless erasure correcting schemes such as Automatic Repeat reQuest (ARQ)...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Flying Bosses: New Study Highlights Why CEO Pilots Make Good Leaders

    The kind of risk-seeking behavior that motivates certain people to fly personal aircraft may also make them effective corporate leaders, according to a new study co-authored by professors from the University of Notre Dame and the University of Oregon. Merging finance and psychology research to explore the role that genetics...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Research Shows Men Get Ahead For Being "Disagreeable" In The Workplace; Women Don't

    In the workplace they do, according to new research co-authored by University of Notre Dame Management Professor Timothy Judge. The paper shows a strong negative relationship between agreeableness and earnings for men. The more agreeable a man is, the less he will earn. For women, there is essentially no relationship...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Interference and Outage in Mobile Random Networks: Expectation, Distribution, and Correlation

    In mobile networks, distance variations caused by node mobility generate fluctuations in the channel gains. Such fluctuations can be treated as another type of fading besides multi-path effects. In this paper, the interference statistics in mobile random networks are characterized by mapping the distance variations of mobile nodes to the...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Percolation in the Secrecy Graph

    Secrecy graphs model the connectivity of wireless networks under secrecy constraints. Directed edges in the graph are present whenever a node can talk to another node securely in the presence of eavesdroppers. In the case of infinite networks, a critical parameter is the maximum density of eavesdroppers that can be...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Notre Dame MBA Joins Fort? Foundation To Support Women In Business

    The University of Notre Dame MBA, a leading graduate business program located in the Mendoza College of Business, has joined Fort? Foundation, a consortium of leading multinational corporations, the Graduate Management Admission Council? (GMAC?) and top global business schools. The Fort? Foundation is the leading organization that provides a national...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    News Corp. Phone Hacking Scandal Now Political

    The author says the phone hacking scandal surrounding Rupert Murdoch's News Corporation has become more of a political story than a business story. "What's been exposed here is the overly-cozy relationship between senior political figures, the metropolitan police and the tabloid press in London," the author says. "The usual forms...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Consider Yourself Ethical? Think Again, Says New Research

    When confronted with an ethical dilemma, most of us like to think we would stand up for our principles. But we are not as ethical as we think we are, according to the author, the Rex and Alice A. Martin Professor of Business Ethics at the University of Notre Dame's...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Improving Control-Performance Across AWGN Channels Using a Relay Node

    Consider an unstable linear time invariant system in which the sensor transmits information to a controller across an additive white Gaussian noise channel. The designer can optionally utilize a relay node to assist the controller; however the total transmission power consumed by the sensor and the relay node is constant....

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Executive Education Awards Recognize Corporate Partners, Faculty

    An orthopedic manufacturer, an improve group and a CEO from an investment bank in Puerto Rico were among the diverse group of award recipients during the annual Notre Dame Executive Education awards banquet, held June 14 inside Purcell Pavilion at the Joyce Center at the University of Notre Dame. "The...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Low-Complexity Incremental Use of Multiple Transmitters in Wireless Communication Systems

    In this paper, the authors develop and analyze low-complexity approaches that they call incremental Multiple-Input Multiple-Output (IMIMO) for exploiting multiple antennas for reliable high-rate communications in wireless systems. The proposed schemes leverage consecutive uses of a single transmit antenna combined with Automatic Repeat reQuest (ARQ) feedback, possibly with multiple receive...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Service Sharing in Mobile Sensing Systems

    Today's modern mobile devices, (such as smartphones and tablets) present great potential for growth of many novel, powerful, but also highly demanding applications. However, most mobile devices/users operate in isolation from one another, i.e., they are not aware of the presence of other devices in their proximity. There are numerous...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Former Naval Officer Will Head Notre Dame Business Undergrad Program

    The author, formerly a professor of Naval Science at the University of Notre Dame, will become the senior director of Undergraduate Studies at the Mendoza College of Business as of July 1. A graduate of the United States Naval Academy, the author earned a Master of Science degree in Management...

    Provided By University of Notre Dame

  • White Papers // Jun 2011

    An Online Holistic Scheduling Framework for Energy-Constrained Wireless Real-Time Systems

    The authors consider wireless real-time systems that execute computationally-intensive applications and must transmit packets over the network in a timely manner. Existing methods do not consider the importance (i.e., urgency) of a packet as perceived by end users in conjunction with energy consumption, real-time task deadlines, and packet deadlines, inadvertently...

    Provided By University of Notre Dame

  • White Papers // Oct 2010

    An Integrated Monitoring System for Smartphones

    Much work has been done in the area of monitoring on traditional systems, such as servers, workstations and laptops. User and application behavior has also been studied on a wide range of platforms. Recently, smartphones have seen a dramatic increase in availability and adoption. New monitoring tools are needed to...

    Provided By University of Notre Dame

  • White Papers // Jan 2010

    Local Delay in Static and Highly Mobile Poisson Networks With ALOHA

    Communication between two neighboring nodes is the most basic operation in wireless networks. Yet very little research has focused on the local delay, defined as the mean time it takes a node to connect to its nearest neighbor. In this paper, the authors derive the local delay in Poisson networks...

    Provided By University of Notre Dame

  • White Papers // Sep 2009

    Implementation and Experimental Results of Superposition Coding on Software Radio

    In theory, multi-user techniques such as Super-Position Coding (SPC) are known to improve throughput in wireless networks. However, in order to understand their practical limitations, it is imperative to actually implement and experiment with such techniques in a realistic setting. In this paper, the authors present the design of a...

    Provided By University of Notre Dame

  • White Papers // Mar 2012

    Fine-Grained Access Control in the Chirp Distributed File System

    Although the distributed file-system is a widely used technology in local area networks, it has seen less use on the wide area networks that connect clusters, clouds, and grids. One reason for this is access control: existing file-system technologies require either the client machine to be fully trusted, or the...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Converting a High Performance Application to an Elastic Cloud Application

    Over the past decade, high performance applications have embraced parallel programming and computing models. While parallel computing offers advantages such as good utilization of dedicated hardware resources, it also has several drawbacks such as poor fault-tolerance, scalability, and ability to harness available resources during run-time. The advent of cloud computing...

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Work Queue + Python: A Framework for Scalable Scientific Ensemble Applications

    Even with the increase in the number and variety of computer resources available to research scientists today, it is still challenging to construct scalable distributed applications. To address this issue, the authors developed Work Queue, a flexible master/- worker framework for building large scale scientific ensemble applications that span many...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Achieving Full Security in Privacy-Preserving Data Mining

    "In privacy-preserving data mining, a number of parties would like to jointly learn a function of their private data sets in a way that no information about their inputs, beyond the output itself, is revealed as a result of such computation. The researcher 2010 showed that several popular data mining...

    Provided By University of Notre Dame

  • White Papers // Apr 2011

    GridSpace Scripting Environment - From Common Component Architecture to Cloud Components

    This paper presents an overview of the experience from investigating various approaches to component-based scientific applications on grids and clouds. The developed frameworks include the MOCCA component framework based on Common Component Architecture (CCA) standard, as well as GridSpace virtual laboratory and workbench for script-based programming and running distributed collaborative...

    Provided By University of Notre Dame

  • White Papers // Jun 2009

    Mispricing Of Dual-Class Shares: Profit Opportunities, Arbitrage, And Trading

    This is the first paper to examine the microstructure of how mispricing is created and resolved. The authors study an easily observable type of mispricing, i.e. dual class-shares with equal cash-flow rights but different prices, and show that a simple trading strategy creates abnormal profits that survive transactions costs and...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Secure and Verifiable Outsourcing of Large-Scale Biometric Computations

    Cloud computing services are becoming prevalent and readily available today, bringing to one economies of scale and making large scale computation feasible. Security and privacy considerations, however, stand on the way of fully utilizing the benefits of such services and architectures. In this paper, the authors address the problem of...

    Provided By University of Notre Dame

  • White Papers // Jan 2011

    Lessons Learned Building TeamTrak: An Urban/Outdoor Mobile Testbed

    Much research in mobile networks relies on the use of simulations for evaluation purposes. While a number of powerful simulation tools have been developed for this purpose, only recently has the need for physical implementations of mobile systems and applications been widely accepted in the literature. In recognition of this...

    Provided By University of Notre Dame

  • White Papers // Nov 2010

    Balancing Broadcast Reliability and Transmission Range in VANETs

    In this paper, a novel transmits power control protocol for Vehicular Ad-hoc NETworks (VANETs) is proposed that aims to improve the reliability of safety-critical broadcasts while also maximizing the transmission range. Large transmission ranges are often desirable in order to ensure that safety-critical messages reach as many vehicles as possible,...

    Provided By University of Notre Dame

  • White Papers // Jan 2011

    On Improving Dynamic Source Routing for Intermittently Available Nodes in MANETs

    Previous work on routing in MANETs has resulted in numerous routing protocols that aim at satisfying constraints such as minimum hop or low energy. Existing routing protocols often fail to discover stable routes between source and sink when route availability is transient, i.e., due to mobile devices switching their network...

    Provided By University of Notre Dame

  • White Papers // Jun 2010

    On Improving the Agility and Quality of Adaptation in QoS-Aware Routing

    Adaptation in QoS-aware routing is a process where an individual system (node, route, or network) responds to a change in its environment. This paper introduces a method to improve the agility and quality of adaptation in QoS-aware routing using real-time applications with varying data rates. A target zone is established...

    Provided By University of Notre Dame

  • White Papers // May 2011

    Mobi-Sync: Configurable Time Synchronization for Mobile Multihop Networks

    Maintaining a common notion of time among communicating nodes in mobile multihop networks is crucial to the correctness of many distributed real-time applications such as target tracking, data fusion, and environmental monitoring. Achieving both synchronization accuracy and efficiency (in terms of communication and energy overheads) are important goals of a...

    Provided By University of Notre Dame

  • White Papers // Oct 2010

    Recommendations for Virtualization Technologies in High Performance Computing

    The benefits of virtualization are typically considered to be server consolidation (leading to the reduction of power and cooling costs), increased availability, isolation, ease of operating system deployment and simplified disaster recovery. High Performance Computing (HPC) environments pose one main challenge for virtualization: the need to maximize throughput with minimal...

    Provided By University of Notre Dame

  • White Papers // Jun 2009

    flockfs, a Moderated Group Authoring System for Wireless Workgroups

    This paper describes the design and implementation of a group authoring system for wireless users. The authors' analysis of the behavior of various groupware systems using wireless user availability traces showed that prior systems would have performed poorly, especially during peak availability durations when many group members were simultaneously available....

    Provided By University of Notre Dame

  • White Papers // Jan 2011

    Routing in Ad Hoc Networks - A Wireless Perspective

    Traditionally, the routing problem is addressed at the network layer, an approach that has been extended to the wireless realm. In wireless multi-hop networks, however, strict layer-base protocol design leads to substantial inefficiencies. This paper addresses the routing problem for large wireless ad hoc networks from a fundamental point of...

    Provided By University of Notre Dame

  • White Papers // Feb 2011

    Predictors of Short-Term Decay of Cell Phone Contacts in a Large Scale Communication Network

    In this paper, the authors explore the question of short-term decay of cell-phone contacts as a problem of decay/persistence prediction: determining what local structural features allow one to best determine whether certain dyads that are considered to be connected during a given time window will be disconnected during an immediately...

    Provided By University of Notre Dame

  • White Papers // Jan 2011

    Interference and Outage in Poisson Cognitive Networks

    Consider a cognitive radio network with two types of users: Primary Users (PUs) and Cognitive Users (CUs), whose locations follow two independent Poisson point processes. The cognitive users follow the policy that a cognitive transmitter is active only when it is outside the primary user exclusion regions. The authors found...

    Provided By University of Notre Dame

  • White Papers // Mar 2011

    Delay Characterization of Multi-Hop Transmission in a Poisson Field of Interference

    The authors evaluate the end-to-end delay of a multi-hop transmission scheme that includes a source, a number of relays and a destination, in the presence of interferers located according to a Poisson point process. The Medium-Access Control (MAC) protocol considered is a combination of TDMA and ALOHA, according to which...

    Provided By University of Notre Dame

  • White Papers // Feb 2011

    A Statistical Mechanics-Based Framework to Analyze Ad Hoc Networks With Random Access

    Characterizing the performance of ad hoc networks is one of the most intricate open challenges; conventional ideas based on information-theoretic techniques and inequalities have not yet been able to successfully tackle this problem in its generality. Motivated thus, the authors promote the Totally Asymmetric Simple Exclusion Process (TASEP), a particle...

    Provided By University of Notre Dame

  • White Papers // May 2011

    Incremental Use of Multiple Transmitters for Low-Complexity Diversity Transmission in Wireless Systems

    In this paper, the authors develop and analyze low-complexity approaches called Incremental Multiple-Input Multiple-Output (IMIMO) for exploiting multiple antennas for reliable high-rate communications. The proposed schemes leverage consecutive uses of a single transmit antenna combined with Automatic Repeat reQuest (ARQ) feedback. Unlike Multiple-Input Multiple-Output (MIMO) communications without feedback, the schemes...

    Provided By University of Notre Dame

  • White Papers // May 2011

    Secrecy From Resolvability

    The authors investigate an approach to physical-layer security based on the premise that the coding mechanism for secrecy over noisy channels is fundamentally tied to the notion of resolvability. Instead of considering capacity-based constructions, which associate to each message a sub-code whose rate approaches the capacity of the eavesdropper's channel,...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Improving Control-Performance Across AWGN Channels Using a Relay Node

    Consider an unstable linear time invariant system in which the sensor transmits information to a controller across an additive white Gaussian noise channel. The designer can optionally utilize a relay node to assist the controller; however the total transmission power consumed by the sensor and the relay node is constant....

    Provided By University of Notre Dame

  • White Papers // Oct 2011

    Seamless Dynamic Runtime Reconfiguration in a Software-Defined Radio

    The authors discuss implementation aspects of a software-defined radio system that allows for dynamic waveform reconfiguration during runtime without interrupting data-flow processing. Traditional software-defined radio systems execute a waveform statically, exactly as it is programmed. Reconfiguration is provided by executing a different waveform, which requires the system to stop processing...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    Superposition Coding Strategies: Design and Experimental Evaluation

    The authors design and implement a software-radio system for Superposition Coding (SC), a multiuser transmission scheme that deliberately introduces interference among user signals at the transmitter, using a library of off-the-shelf point-to-point channel codes. They experimentally determine the set of rate-pairs achieved by this transmission scheme under a packet-error constraint....

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Interference and Outage in Mobile Random Networks: Expectation, Distribution, and Correlation

    In mobile networks, distance variations caused by node mobility generate fluctuations in the channel gains. Such fluctuations can be treated as another type of fading besides multi-path effects. In this paper, the interference statistics in mobile random networks are characterized by mapping the distance variations of mobile nodes to the...

    Provided By University of Notre Dame

  • White Papers // Feb 2011

    Delay Analysis of Spatio-Temporal Channel Access for Cognitive Networks

    Most channel access schemes for cognitive radio only consider using the idle periods of the primary users. Such schemes are not using the spectrum efficiently, since transmission opportunities also arise when a primary transmitter is active but its corresponding primary receiver is far away from the cognitive user. By detecting...

    Provided By University of Notre Dame

  • White Papers // Jan 2011

    A Location-Based MAC Scheme for Random Wireless Network

    This paper proposes a Location-based MAC (LMAC) scheme for wireless networks with randomly placed nodes. This scheme regulates channel access by sharing local location information among transmitters. A lattice approximation approach is used to derive upper and lower bound for the success probability for a typical transmission attempt. Numerical results...

    Provided By University of Notre Dame

  • White Papers // Jan 2011

    Temporal Correlation of the Interference in Mobile Random Networks

    In wireless networks, network performance measured by, e.g., link outage, is mainly limited by interference. The characterization of the interference depends on the transmitters set, the fading and the path loss. In static networks, the distance between nodes stays constant over time, while in mobile networks, the random mobility of...

    Provided By University of Notre Dame

  • White Papers // Aug 2011

    On the Optimal Block Length for Joint Channel and Network Coding

    Channel coding alone is not sufficient to reliably transmit a message of finite length from a source to one or more destinations. To ensure that no data is lost, channel coding on the physical layer needs to be combined with rateless erasure correcting schemes such as Automatic Repeat reQuest (ARQ)...

    Provided By University of Notre Dame

  • White Papers // Jul 2011

    Percolation in the Secrecy Graph

    Secrecy graphs model the connectivity of wireless networks under secrecy constraints. Directed edges in the graph are present whenever a node can talk to another node securely in the presence of eavesdroppers. In the case of infinite networks, a critical parameter is the maximum density of eavesdroppers that can be...

    Provided By University of Notre Dame

  • White Papers // Feb 2012

    Secondary Access Policies With Imperfect Sensing in Dynamic Spectrum Access Networks

    The authors consider secondary access policies with imperfect sensing in sensing-based dynamic spectrum access networks. Interference caused by both missed detections as well as the primary user's return to the channel during the secondary transmission are explored. They allow arbitrary distributions for the primary ON/OFF intervals and expand each interval...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Interference in Ad Hoc Networks With General Motion-Invariant Node Distributions

    In this paper, the authors derive the tail properties of interference for any stationary and isotropic spatial distribution of transmitting nodes. Previously the properties of interference were known only when the nodes are distributed as a homogeneous Poisson point process on the plane. They show the effect of a singular...

    Provided By University of Notre Dame

  • White Papers // Sep 2009

    Implementation and Experimental Results of OFDM-Based Superposition Coding

    In theory, multi-user techniques such as Super-Position Coding (SPC) are known to improve throughput in wireless networks. However, in order to understand their practical limitations, it is imperative to actually implement and experiment with such techniques in a realistic setting. In this paper, the authors present the design of a...

    Provided By University of Notre Dame

  • White Papers // Mar 2010

    Control Design for Switched Systems Using Passivity Indices

    This paper presents a framework for control design of interconnected nonlinear switched systems using passivity and passivity indices. Background material is presented on the concept of passivity indices for continuously-varying systems. The passivity indices are then generalized to apply to switched systems to measure the level of passivity in a...

    Provided By University of Notre Dame

  • White Papers // Apr 2010

    Symmetry in the Design of Large-Scale Complex Control Systems: Some Initial Results Using Dissipativity and Lyapunov Stability

    In this paper, stability conditions for large-scale systems are derived by categorizing agents into symmetry groups and applying local control laws under limited interconnections with neighbors. Particularly, stability for dissipative systems is considered. It is assumed that subsystems are dissipative and stability is studied. Conditions are derived for the max...

    Provided By University of Notre Dame

  • White Papers // Sep 2011

    Bounds on Information Propagation Delay in Interference-Limited ALOHA Networks

    In a wireless network the set of transmitting nodes changes frequently because of the MAC scheduler and the traffic load. Analyzing the connectivity of such a network using static graphs would lead to pessimistic performance results. In this paper, the authors consider an ad hoc network with half-duplex radios that...

    Provided By University of Notre Dame