Rice University

Displaying 1-40 of 78 results

  • White Papers // Apr 2012

    Synergy2Cloud: Introducing Cross-Sharing of Application Experiences Into the Cloud Management Cycle

    Automatically managing collocated cloud applications for improved performance is a hard problem due to the unprecedented scale and the dynamics of the multiplexed cloud environment. Compounding the problem, today's approaches to cloud application management are too limited in the way they acquire information. Monitoring performed by the operator is too...

    Provided By Rice University

  • White Papers // Jan 2012

    ADAM: An Adaptive Beamforming System for Multicasting in Wireless LANs

    The authors present the design and implementation of ADAM, the first adaptive beamforming based multicast system and experimental framework for indoor wireless environments. ADAM addresses the joint problem of adaptive beamformer design at the PHY layer and client scheduling at the MAC layer by proposing efficient algorithms that are amenable...

    Provided By Rice University

  • White Papers // Jan 2012

    STROBE: Actively Securing Wireless Communications Using Zero-Forcing Beamforming

    The authors present the design and experimental evaluation of Simultaneous TRansmission with Orthogonally Blinded Eavesdroppers (STROBE). STROBE is a cross-layer approach that exploits the multi-stream capabilities of existing technologies such as 802.11n and the upcoming 802.11ac standard where multi-antenna APs can construct simultaneous data streams using Zero-Forcing Beam-Forming (ZFBF). Instead...

    Provided By Rice University

  • White Papers // Jan 2012

    Closed-Form Throughput Expressions for CSMA Networks With Collisions and Hidden Terminals

    The authors present a novel modeling approach to derive closed-form throughput expressions for CSMA networks with hidden terminals. The key modeling principle is to break the interdependence of events in a wireless network using conditional expressions that capture the effect of a specific factor each, yet preserve the required dependences...

    Provided By Rice University

  • White Papers // Jan 2012

    Maestro: A System for Scalable OpenFlow Control

    The fundamental feature of an OpenFlow network is that the controller is responsible for the initial establishment of every flow by contacting related switches. Thus, the performance of the controller could be a bottleneck. This paper shows how this fundamental problem is addressed by parallelism. The state of the art...

    Provided By Rice University

  • White Papers // Jan 2012

    Caching Dynamic Web Content: Designing and Analysing an Aspect-Oriented Solution

    Caching dynamic web content is an effective approach to reduce Internet latency and server load. An ideal caching solution is one that can be added transparently by the developers and provides complete consistency of the cached documents, while minimizing false cache invalidations. In this paper, the authors design and implement...

    Provided By Rice University

  • White Papers // Dec 2011

    Maestro: Balancing Fairness, Latency and Throughput in the OpenFlow Control Plane

    The fundamental feature of an OpenFlow network is that the controller is responsible for the configuration of switches for every traffic flow. This feature brings programmability and flexibility, but also puts the controller in a critical role in the performance of an Open-Flow network. To fairly service requests from different...

    Provided By Rice University

  • White Papers // Nov 2011

    Analysis of Hadoop's Performance Under Failures

    Failures are common in today's data center environment and can significantly impact the performance of important jobs running on top of large scale computing frameworks. In this paper, the authors analyze Hadoop's behavior under compute node and process failures. Surprisingly, they find that even a single failure can have a...

    Provided By Rice University

  • White Papers // Aug 2011

    Inferring a Network Congestion Map With Zero Traffic Overhead

    This paper proposes a purely passive method for inferring a congestion map of a network. The congestion map is computed using the congestion markings carried in existing traffic, and is continuously updated as traffic is received. Consequently, congestion changes can be tracked in a real-time fashion with zero traffic overhead....

    Provided By Rice University

  • White Papers // Aug 2011

    A Scalability Study of Enterprise Network Architectures

    The largest enterprise networks already contain hundreds of thousands of hosts. Enterprise networks are composed of Ethernet subnets interconnected by IP routers. These routers require expensive configuration and maintenance. If the Ethernet subnets are made more scalable, the high cost of the IP routers can be eliminated. Unfortunately, it has...

    Provided By Rice University

  • White Papers // Jul 2011

    Experiment-Driven Characterization of Full-Duplex Wireless Systems

    Current deployed wireless communication systems employ either a time-division or frequency division approach to bidirectional communication. This requires dividing the temporal and/or spectral resources into orthogonal resources and results in half-duplex wireless communication systems. The key deterrent in implementing a full-duplex wireless communication system, which consists on same band simultaneous...

    Provided By Rice University

  • White Papers // Jul 2011

    Pushing the Limits of Full-duplex: Design and Real-time Implementation

    Recent work has shown the feasibility of single-channel fullduplex wireless physical layer, allowing nodes to send and receive in the same frequency band at the same time. In this paper, the authors first design and implement a real-time 64- subcarrier 10 MHz full-duplex OFDM physical layer, FDPHY. The proposed FD-PHY...

    Provided By Rice University

  • White Papers // May 2011

    Smoothing a Program Soundly and Robustly

    The authors study the foundations of smooth interpretation, a recently-proposed program approximation scheme that facilitates the use of local numerical search techniques (e.g., gradient descent) in program analysis and synthesis. While the popular techniques for local optimization works well only on relatively smooth functions, functions encoded by real-world programs are...

    Provided By Rice University

  • White Papers // Apr 2011

    MIDAS: Inference and Mitigation of Hindering Transmissions in Managed 802.11 Wireless Networks

    In 802.11 managed wireless networks, the manager can address under-served links by rate-limiting the conflicting nodes. In order to determine to what extent each conflicting node is responsible for the poor performance, the manager needs to understand the coordination among conflicting nodes' transmissions. In this paper, the authors present a...

    Provided By Rice University

  • White Papers // Apr 2011

    MOMMIE Knows Best: Systematic Optimizations for Verifiable Distributed Algorithms

    Complex distributed algorithms become running systems through an integration with optimizations that target the system's deployment environment. Although expedient, this approach has disadvantages. First, this often makes implementing the algorithm difficult, since its logic must be composed with the optimizations. Second, proving the guarantees of the implementation is tedious, because...

    Provided By Rice University

  • White Papers // Mar 2011

    Transparent Programming of Heterogeneous Smartphones for Sensing

    Sensing on smartphones is known to be power-hungry. It has been shown that this problem can be solved by adding an ultra low-power processor to execute simple, frequent sensor data processing. While very effective in saving energy, this resulting heterogeneous, distributed architecture poses a significant challenge to application development. The...

    Provided By Rice University

  • White Papers // Mar 2011

    Deterministic Reductions in an Asynchronous Parallel Language

    Reduction operations are a common and important feature in many parallel programming models. In this paper, the authors present a new reduction construct for Concurrent Collections (CnC). CnC is a deterministic, asynchronous parallel programming model in which data production and reduction can overlap. While reductions are most frequently incorporated in...

    Provided By Rice University

  • White Papers // Mar 2011

    Tax-Benefit Incidence Of Value Added Tax On Food And Medicine To Fund Progressive Social Expenditure

    In 2009, the Mexican Congress received a proposal of a generalized 2% increase in the statutory VAT rate, including currently untaxed food and medicine. Whereas opponents emphasized the regressive effect, supporters argued that progressivity of the compensatory expenditures included in the bill more than compensated the bottom income quintiles. In...

    Provided By Rice University

  • White Papers // Feb 2011

    QUIRE: Lightweight Provenance for Smart Phone Operating Systems

    Smartphone apps often run with full privileges to access the network and sensitive local resources, making it difficult for remote systems to have any trust in the provenance of network connections they receive. Even within the phone, different apps with different privileges can communicate with one another, allowing one app...

    Provided By Rice University

  • White Papers // Jan 2011

    PW-MAC: An Energy-Efficient Predictive-Wakeup MAC Protocol for Wireless Sensor Networks

    This paper presents PW-MAC (Predictive-Wakeup MAC), a new energy-efficient MAC protocol based on asynchronous duty cycling. In PW-MAC, nodes each wake up to receive at randomized, asynchronous times. PW-MAC minimizes sensor node energy consumption by enabling senders to predict receiver wakeup times; to enable accurate predictions, PW-MAC introduces an on-demand...

    Provided By Rice University

  • White Papers // Jan 2011

    Experimental Evaluation of Optimal CSMA

    By 'Optimal CSMA' the authors denote a promising approach to maximize throughput-based utility in wireless networks without message passing or synchronization among nodes. Despite the theoretical guarantees on the performance of these protocols, their evaluation in real networking scenarios has been preliminary. In this paper, they propose a methodical approach...

    Provided By Rice University

  • White Papers // Jan 2011

    LiveLab: Measuring Wireless Networks and Smartphone Users in the Field

    The authors present LiveLab, a methodology to measure real-world smartphone usage and wireless networks with a reprogrammable in-device logger designed for long-term user studies. They discuss the challenges of privacy protection and power impact in LiveLab and offer the solutions. This paper presents an iPhone 3GS based deployment of LiveLab...

    Provided By Rice University

  • White Papers // Jan 2011

    A Resource Management Framework for Predictable Quality of Service in Web Servers

    This paper presents a resource management framework for providing predictable quality of service in Web servers. The framework allows Web server and proxy operators to ensure a minimal quality of service, expressed as an average request rate or average response time, for a certain class of requests (called a service),...

    Provided By Rice University

  • White Papers // Jan 2011

    Adding Capacity Points to a Wireless Mesh Network Using Local Search

    Wireless mesh network deployments are popular as a cost-effective means to provide broadband connectivity to large user populations. As the network usage grows, network planners need to evolve an existing mesh network to provide additional capacity. In this paper, the authors study the problem of adding new capacity points (e.g.,...

    Provided By Rice University

  • White Papers // Jan 2011

    The Case for Byzantine Fault Detection

    Distributed systems are subject to a variety of faults and attacks. In this paper, the authors consider general (Byzantine) faults, i.e. a faulty node may exhibit arbitrary behavior. In particular, a faulty node may corrupt its local state and send arbitrary messages, including specific messages aimed at subverting the system....

    Provided By Rice University

  • White Papers // Jan 2011

    Performance Analysis of TLSWeb Servers

    TLS is the protocol of choice for securing today's e-commerce and online transactions, but adding TLS to a web server imposes a significant overhead relative to an insecure web server on the same platform. The authors perform a comprehensive study of the performance costs of TLS. The methodology is to...

    Provided By Rice University

  • White Papers // Jan 2011

    Experimenting With a Multi-Radio Mesh Networking Testbed

    Experimentation is an important next step to take in the study of multi-radio mesh networks, but it involves many obstacles preventing a stable and reproducible testbed environment. Using off-the-shelf equipment the authors demonstrate the impact that specific design choices for access points may have in the performance of a 2-hop...

    Provided By Rice University

  • White Papers // Jan 2011

    Secure Routing for Structured Peer-to-Peer Overlay Networks

    Structured peer-to-peer overlay networks provide a substrate for the construction of large-scale, decentralized applications, including distributed storage, group communication, and content distribution. These overlays are highly resilient; they can route messages correctly even when a large fraction of the nodes crash or the network partitions. But current overlays are not...

    Provided By Rice University

  • White Papers // Jan 2011

    RMAC: A Routing-Enhanced Duty-Cycle MAC Protocol for Wireless Sensor Networks

    Duty-cycle MAC protocols have been proposed to meet the demanding energy requirements of wireless sensor networks. Although existing duty-cycle MAC protocols such as S-MAC are power efficient, they introduce significant end-to-end delivery latency and provide poor traffic contention handling. In this paper, the authors present a new duty-cycle MAC protocol,...

    Provided By Rice University

  • White Papers // Jan 2011

    Puppeteer: Component-Based Adaptation for Mobile Computing

    Puppeteer is a system for adapting component-based applications in mobile environments. Puppeteer takes advantage of the exported interfaces of these applications and the structured nature of the documents they manipulate to perform adaptation without modifying the applications. The system is structured in a modular fashion, allowing easy addition of new...

    Provided By Rice University

  • White Papers // Jan 2011

    COMPASS: An Adaptive Sensor Network Architecture for Multi-Scale Communication

    Sensor networks have emerged as a promising tool for monitoring and actuating the devices of physical world. It employs self-organizing networks of battery-powered wireless sensors that can sense, process, and communicate. Such networks can be rapidly deployed at low cost, enabling large-scale, on-demand monitoring and tracking over a wide area....

    Provided By Rice University

  • White Papers // Dec 2010

    Sesame: Self-Constructive System Energy Modeling for Battery-Powered Mobile Systems

    System energy models are important for energy optimization and management in mobile systems. However, existing system energy models are built in lab with the help from a second computer. Not only are they labor-intensive; but also they will not adequately account for the great diversity in the hardware and usage...

    Provided By Rice University

  • White Papers // Dec 2010

    Concurrent Collections

    The authors introduce the Concurrent Collections (CnC) programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism. CnC is implicitly parallel, with the user providing high-level operations along with semantic ordering constraints that together form a CnC graph. They formally describe the execution semantics of CnC...

    Provided By Rice University

  • White Papers // Dec 2010

    Seamless Flow Migration on Smartphones Without Network Support

    This paper addresses the following question: Is it possible to migrate TCP/IP flows between different networks on modern mobile devices, without infrastructure support or protocol changes? To answer this question, the authors make three research contributions. They report a comprehensive characterization of IP traffic on smartphones using traces collected from...

    Provided By Rice University

  • White Papers // Oct 2010

    Efficient Data Race Detection for Async-Finish Parallelism

    One of the major productivity hurdles for parallel programming is non-determinism - a parallel program may yield different results on different executions with the same input, depending on the order in which operations are interleaved. A major source of non-determinism is data races, and checking for the absence of data...

    Provided By Rice University

  • White Papers // Oct 2010

    Effectively Presenting Call Path Profiles of Application Performance

    Call path profiling is a scalable measurement technique that has been shown to provide insight into the performance characteristics of complex modular programs. However, poor presentation of accurate and precise call path profiles obscures insight. To enable rapid analysis of an execution's performance bottlenecks, the authors make the following contributions...

    Provided By Rice University

  • White Papers // Oct 2010

    Structure And Response In The World Trade Network

    The authors examine how the structure of the world trade network has been shaped by globalization and recessions over the last 40 years. They show that by treating the world trade network as an evolving system, theory predicts the trade network is more sensitive to evolutionary shocks and recovers more...

    Provided By Rice University

  • White Papers // Sep 2010

    Mobile TCP Usage Characteristics and the Feasibility of Network Migration Without Infrastructure Support

    In this poster the authors describe initial findings regarding Internet usage characteristics, in particular TCP flows from a field study with 25 iPhone users. The authors present details regarding their usage characteristics, and provide a solution for migrating flows between different networks and/or network interfaces without requiring infrastructure support or...

    Provided By Rice University

  • White Papers // Sep 2010

    mClock: Handling Throughput Variability for Hypervisor IO Scheduling

    Virtualized servers run a diverse set of Virtual Machines (VMs), ranging from interactive desktops to test and development environments and even batch workloads. Hypervisors are responsible for multiplexing the underlying hardware resources among VMs while providing them the desired degree of isolation using resource management controls. Existing methods provide many...

    Provided By Rice University

  • White Papers // Aug 2010

    Gleaning Network-Wide Congestion Information From Packet Markings

    Distributed control protocols routinely have to operate oblivious of dynamic network information for scalability or complexity reasons. However, more informed protocols are likely to make more intelligent decisions. The authors argue that protocols can leverage dynamic congestion information without suffering the mentioned penalties. In this paper they show that routers...

    Provided By Rice University

  • White Papers // Nov 2009

    Configurable and Scalable Turbo Decoder for 4G Wireless Receivers

    The increasing requirements of high data rates and Quality of Service (QoS) in Fourth-Generation (4G) wireless communication require the implementation of practical capacity approaching codes. In this paper, the application of Turbo coding schemes that have recently been adopted in the IEEE 802.16e WiMax standard and 3GPP Long Term Evolution...

    Provided By Rice University

  • White Papers // Dec 2009

    Routing Primitives for Wireless Mesh Networks: Design, Analysis and Experiments

    In this paper, the authors consider routing in multi-hop wireless mesh networks. They analyze three standardized and commonly deployed routing mechanisms that they term "Nodepair discovery" primitives. The authors show that use of these primitives inherently yields inferior route selection, irrespective of the protocol that implements them. This behavior originates...

    Provided By Rice University

  • White Papers // Jan 2010

    SEAD: Secure Efficient Distance Vector Routing for Mobile Wireless Ad Hoc Networks

    An ad hoc network is a collection of wireless computers (Nodes), communicating among themselves over possibly multihop paths, without the help of any infrastructure such as base stations or access points. Although many previous ad hoc network routing protocols have been based in part on distance vector approaches, they have...

    Provided By Rice University

  • White Papers // Jun 2009

    Forward Error Correction Decoding for WiMAX and 3GPP LTE Modems

    In this paper, the authors review the requirements for Forward Error Correction (FEC) decoding for next generation wireless modems - mobile Worldwide Interoperability for Microwave Access (WiMAX) and Third Generation Partnership Project long term evolution (3GPP LTE). FEC decoder consists of mainly three components: control channel decoder, data channel decoder,...

    Provided By Rice University

  • White Papers // Aug 2009

    Leadership Communication: A Communication Approach For Senior-Level Managers

    A leader must be able to communicate effectively. When CEOs and other senior executives in all industries and countries are asked to list the most important skills a manager must possess, the answer consistently includes - good communication skills. Managers spend most of their day engaged in communication; in fact,...

    Provided By Rice University

  • White Papers // Jun 2010

    Energy Policy In The Obama Administration

    Change and innovation are unfolding at a rapid pace in the energy sector propelled by an influx of new entrepreneurial players entering the marketplace with capital, novel investment and business models, and differing regulatory experiences than the traditional oil and gas industry practices. This new "Clean Tech" sector is being...

    Provided By Rice University

  • White Papers // Jan 2011

    A Resource Management Framework for Predictable Quality of Service in Web Servers

    This paper presents a resource management framework for providing predictable quality of service in Web servers. The framework allows Web server and proxy operators to ensure a minimal quality of service, expressed as an average request rate or average response time, for a certain class of requests (called a service),...

    Provided By Rice University

  • White Papers // Mar 2010

    Reflex: Managing Sensor Data Processing in Mobile Systems

    Many emerging mobile services leverage sensors available on mobile systems to acquire information regarding the physical world through sensory data processing, in order to serve human users intelligently and ubiquitously. While the sensors themselves can be quite low-power, sensor data processing has proven to be a key bottleneck in the...

    Provided By Rice University

  • White Papers // Jan 2011

    LiveLab: Measuring Wireless Networks and Smartphone Users in the Field

    The authors present LiveLab, a methodology to measure real-world smartphone usage and wireless networks with a reprogrammable in-device logger designed for long-term user studies. They discuss the challenges of privacy protection and power impact in LiveLab and offer the solutions. This paper presents an iPhone 3GS based deployment of LiveLab...

    Provided By Rice University

  • White Papers // May 2009

    A Longitudinal Study of Non-Voice Mobile Phone Usage by Teens From an Underserved Urban Community

    The authors report a user study of over four months on the non-voice usage of mobile phones by teens from an underserved urban community in the USA where a community-wide, open-access Wi-Fi network exists. They instrumented the phones to record quantitative information regarding their usage and location in a privacy-respecting...

    Provided By Rice University

  • White Papers // Dec 2009

    Elastic Rate Limiting for Spatially Biased Wireless Mesh Networks

    In this paper, the authors show that it is sufficient to rate limit the single-hop nodes in order to give transmission opportunities to all other nodes. Based on this observation, they develop a new rate limiting scheme for 802.11 mesh networks, which counters the spatial bias effect and does not...

    Provided By Rice University

  • White Papers // Jan 2011

    Adding Capacity Points to a Wireless Mesh Network Using Local Search

    Wireless mesh network deployments are popular as a cost-effective means to provide broadband connectivity to large user populations. As the network usage grows, network planners need to evolve an existing mesh network to provide additional capacity. In this paper, the authors study the problem of adding new capacity points (e.g.,...

    Provided By Rice University

  • White Papers // Sep 2010

    Mobile TCP Usage Characteristics and the Feasibility of Network Migration Without Infrastructure Support

    In this poster the authors describe initial findings regarding Internet usage characteristics, in particular TCP flows from a field study with 25 iPhone users. The authors present details regarding their usage characteristics, and provide a solution for migrating flows between different networks and/or network interfaces without requiring infrastructure support or...

    Provided By Rice University

  • White Papers // Mar 2011

    Tax-Benefit Incidence Of Value Added Tax On Food And Medicine To Fund Progressive Social Expenditure

    In 2009, the Mexican Congress received a proposal of a generalized 2% increase in the statutory VAT rate, including currently untaxed food and medicine. Whereas opponents emphasized the regressive effect, supporters argued that progressivity of the compensatory expenditures included in the bill more than compensated the bottom income quintiles. In...

    Provided By Rice University

  • White Papers // Jan 2011

    The Case for Byzantine Fault Detection

    Distributed systems are subject to a variety of faults and attacks. In this paper, the authors consider general (Byzantine) faults, i.e. a faulty node may exhibit arbitrary behavior. In particular, a faulty node may corrupt its local state and send arbitrary messages, including specific messages aimed at subverting the system....

    Provided By Rice University

  • White Papers // Jan 2011

    Experimental Evaluation of Optimal CSMA

    By 'Optimal CSMA' the authors denote a promising approach to maximize throughput-based utility in wireless networks without message passing or synchronization among nodes. Despite the theoretical guarantees on the performance of these protocols, their evaluation in real networking scenarios has been preliminary. In this paper, they propose a methodical approach...

    Provided By Rice University

  • White Papers // Dec 2009

    Deploying Mesh Nodes Under Non-Uniform Propagation

    Wireless mesh networks are popular as a cost-effective means to provide broadband connectivity to large user populations. A mesh network placement provides coverage, such that each target client location has a link to a deployed mesh node, and connectivity, such that each mesh node wirelessly connects directly to a gateway...

    Provided By Rice University

  • White Papers // Jan 2009

    Synchronized CSMA Contention: Model, Implementation and Evaluation

    A class of CSMA protocols used in a broad range of wireless applications uses synchronized contention where nodes periodically contend at intervals of fixed duration. While several models exist for asynchronous CSMA contention used in protocols like IEEE 802.11 MAC, no model exists for synchronized CSMA contention that also incorporates...

    Provided By Rice University

  • White Papers // Jan 2011

    Performance Analysis of TLSWeb Servers

    TLS is the protocol of choice for securing today's e-commerce and online transactions, but adding TLS to a web server imposes a significant overhead relative to an insecure web server on the same platform. The authors perform a comprehensive study of the performance costs of TLS. The methodology is to...

    Provided By Rice University

  • White Papers // Mar 2010

    Router Group Monitoring: Making Traffic Trajectory Error Detection More Efficient

    Detecting errors in traffic trajectories (i.e., packet forwarding paths) is important to operational networks. Several different traffic monitoring algorithms such as Trajectory Sampling, PSAMP, and Fatih can be used for traffic trajectory error detection. However, a straight-forward application of these algorithms will incur the overhead of simultaneously monitoring all network...

    Provided By Rice University

  • White Papers // Mar 2011

    Deterministic Reductions in an Asynchronous Parallel Language

    Reduction operations are a common and important feature in many parallel programming models. In this paper, the authors present a new reduction construct for Concurrent Collections (CnC). CnC is a deterministic, asynchronous parallel programming model in which data production and reduction can overlap. While reductions are most frequently incorporated in...

    Provided By Rice University

  • White Papers // Dec 2010

    Concurrent Collections

    The authors introduce the Concurrent Collections (CnC) programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism. CnC is implicitly parallel, with the user providing high-level operations along with semantic ordering constraints that together form a CnC graph. They formally describe the execution semantics of CnC...

    Provided By Rice University

  • White Papers // Nov 2008

    Lightweight Secure PUFs

    To ensure security and robustness of the next generation of Physically Unclonable Functions (PUFs), the authors have developed a new methodology for PUF design. The authors' approach employs integration of three key principles: inclusion of multiple delay lines for creation of each response bit; transformations and combination of the challenge...

    Provided By Rice University

  • White Papers // Aug 2011

    Inferring a Network Congestion Map With Zero Traffic Overhead

    This paper proposes a purely passive method for inferring a congestion map of a network. The congestion map is computed using the congestion markings carried in existing traffic, and is continuously updated as traffic is received. Consequently, congestion changes can be tracked in a real-time fashion with zero traffic overhead....

    Provided By Rice University

  • White Papers // Oct 2010

    Effectively Presenting Call Path Profiles of Application Performance

    Call path profiling is a scalable measurement technique that has been shown to provide insight into the performance characteristics of complex modular programs. However, poor presentation of accurate and precise call path profiles obscures insight. To enable rapid analysis of an execution's performance bottlenecks, the authors make the following contributions...

    Provided By Rice University

  • White Papers // Nov 2009

    Compressive Distilled Sensing: Sparse Recovery Using Adaptivity in Compressive Measurements

    The recently-proposed theory of distilled sensing establishes that adaptivity in sampling can dramatically improve the performance of sparse recovery in noisy settings. In particular, it is now known that adaptive point sampling enables the detection and/or support recovery of sparse signals that are otherwise too weak to be recovered using...

    Provided By Rice University

  • White Papers // May 2010

    Distilled Sensing: Adaptive Sampling for Sparse Detection and Estimation

    Adaptive sampling results in dramatic improvements in the recovery of sparse signals in white Gaussian noise. A sequential adaptive sampling-and-refinement procedure called Distilled Sensing (DS) is proposed and analyzed. DS is a form of multi-stage experimental design and testing. Because of the adaptive nature of the data collection, DS can...

    Provided By Rice University

  • White Papers // Jan 2012

    STROBE: Actively Securing Wireless Communications Using Zero-Forcing Beamforming

    The authors present the design and experimental evaluation of Simultaneous TRansmission with Orthogonally Blinded Eavesdroppers (STROBE). STROBE is a cross-layer approach that exploits the multi-stream capabilities of existing technologies such as 802.11n and the upcoming 802.11ac standard where multi-antenna APs can construct simultaneous data streams using Zero-Forcing Beam-Forming (ZFBF). Instead...

    Provided By Rice University

  • White Papers // Jan 2012

    Closed-Form Throughput Expressions for CSMA Networks With Collisions and Hidden Terminals

    The authors present a novel modeling approach to derive closed-form throughput expressions for CSMA networks with hidden terminals. The key modeling principle is to break the interdependence of events in a wireless network using conditional expressions that capture the effect of a specific factor each, yet preserve the required dependences...

    Provided By Rice University

  • White Papers // Apr 2011

    MIDAS: Inference and Mitigation of Hindering Transmissions in Managed 802.11 Wireless Networks

    In 802.11 managed wireless networks, the manager can address under-served links by rate-limiting the conflicting nodes. In order to determine to what extent each conflicting node is responsible for the poor performance, the manager needs to understand the coordination among conflicting nodes' transmissions. In this paper, the authors present a...

    Provided By Rice University

  • White Papers // Jan 2012

    ADAM: An Adaptive Beamforming System for Multicasting in Wireless LANs

    The authors present the design and implementation of ADAM, the first adaptive beamforming based multicast system and experimental framework for indoor wireless environments. ADAM addresses the joint problem of adaptive beamformer design at the PHY layer and client scheduling at the MAC layer by proposing efficient algorithms that are amenable...

    Provided By Rice University

  • White Papers // Apr 2012

    Synergy2Cloud: Introducing Cross-Sharing of Application Experiences Into the Cloud Management Cycle

    Automatically managing collocated cloud applications for improved performance is a hard problem due to the unprecedented scale and the dynamics of the multiplexed cloud environment. Compounding the problem, today's approaches to cloud application management are too limited in the way they acquire information. Monitoring performed by the operator is too...

    Provided By Rice University

  • White Papers // Dec 2011

    Maestro: Balancing Fairness, Latency and Throughput in the OpenFlow Control Plane

    The fundamental feature of an OpenFlow network is that the controller is responsible for the configuration of switches for every traffic flow. This feature brings programmability and flexibility, but also puts the controller in a critical role in the performance of an Open-Flow network. To fairly service requests from different...

    Provided By Rice University

  • White Papers // Nov 2011

    Analysis of Hadoop's Performance Under Failures

    Failures are common in today's data center environment and can significantly impact the performance of important jobs running on top of large scale computing frameworks. In this paper, the authors analyze Hadoop's behavior under compute node and process failures. Surprisingly, they find that even a single failure can have a...

    Provided By Rice University

  • White Papers // Jan 2012

    Maestro: A System for Scalable OpenFlow Control

    The fundamental feature of an OpenFlow network is that the controller is responsible for the initial establishment of every flow by contacting related switches. Thus, the performance of the controller could be a bottleneck. This paper shows how this fundamental problem is addressed by parallelism. The state of the art...

    Provided By Rice University

  • White Papers // Dec 2009

    On Constructing Efficient Shared Decision Trees for Multiple Packet Filters

    Multiple packet filters serving different purposes (e.g., firewalling, QoS) and different virtual routers are often deployed on a single physical router. The HyperCuts decision tree is one efficient data structure for performing packet filter matching in software. Constructing a separate HyperCuts decision tree for each packet filter is not memory...

    Provided By Rice University

  • White Papers // Apr 2011

    MOMMIE Knows Best: Systematic Optimizations for Verifiable Distributed Algorithms

    Complex distributed algorithms become running systems through an integration with optimizations that target the system's deployment environment. Although expedient, this approach has disadvantages. First, this often makes implementing the algorithm difficult, since its logic must be composed with the optimizations. Second, proving the guarantees of the implementation is tedious, because...

    Provided By Rice University

  • White Papers // Jan 2009

    EtherProxy: Scaling Ethernet by Suppressing Broadcast Traffic

    Ethernet is the dominant technology for local area networks. This is mainly because of its autoconfiguration capability and its cost effectiveness. Unfortunately, a single Ethernet network cannot scale to span a large enterprise network. A main reason for this is broadcast traffic resulting from many protocols running on top of...

    Provided By Rice University

  • White Papers // Jan 2010

    Optimizing Network Virtualization in Xen

    This paper reports on improvements to Xen's networking performance resulting from the re-design and the re-implementation of certain aspects of its network virtualization and better support for advanced, hardware memory management features. This design remains compatible with the basic Xen 2.0 architecture of locating device drivers in a privileged driver...

    Provided By Rice University

  • White Papers // Dec 2009

    The Impact of Virtualization on Network Performance of Amazon EC2 Data Center

    Cloud computing services allow users to lease computing resources from large scale data centers operated by service providers. Using cloud services, users can deploy a wide variety of applications dynamically and on-demand. Most cloud service providers use machine virtualization to provide flexible and cost-effective resource sharing. However, few studies have...

    Provided By Rice University