University of Southern California

Displaying 1-40 of 192 results

  • White Papers // Aug 2012

    Scaling Behaviors of Wireless Device-to-Device Communications With Distributed Caching

    The authors analyze a novel architecture for caching popular video content to enable wireless device-to-device collaboration. They focus on the asymptotic scaling characteristics and show how they depends on video content popularity statistics. They identify a fundamental conflict between collaboration distance and interference and show how to optimize the transmission...

    Provided By University of Southern California

  • White Papers // May 2012

    Bipartite Index Coding

    The authors analyze a generalized index coding problem that allows multiple users to request the same packet. For this problem they introduce a novel coding scheme called partition multicast. Their scheme can be seen as a natural generalization of clique cover for directed index coding problems. Further, partition multicast corresponds...

    Provided By University of Southern California

  • White Papers // May 2012

    Feedback in the K-User Interference Channel

    A traditional viewpoint on feedback capacity has been pessimistic over the past few decades. This is mainly due to Shannon's original result which shows that feedback provides no increase in capacity for discrete memory-less point-to-point channels. Although feedback can indeed increase the capacity of multiple access channels, the increase in...

    Provided By University of Southern California

  • White Papers // May 2012

    Locally Repairable Codes

    One main challenge in the design of distributed storage codes is the Exact Repair Problem: if a node storing encoded information fails, to maintain the same level of reliability, the authors need to exactly regenerate what was lost in a new node. A major open problem in this area has...

    Provided By University of Southern California

  • White Papers // May 2012

    vCRIB: Virtualized Rule Management in the Cloud

    Cloud operators increasingly need many fine-grained rules to better control individual network flows for various management tasks. While previous approaches have advocated placing rules either on hypervisors or switches, the authors argue that future data centers would benefit from leveraging rule processing capabilities at both for better scalability and performance....

    Provided By University of Southern California

  • White Papers // May 2012

    Wireless Device-to-Device Communications With Distributed Caching

    The authors introduce a novel wireless Device-To-Device (D2D) collaboration architecture that exploits distributed storage of popular content to enable frequency reuse. They identify a fundamental conflict between collaboration distance and interference and show how to optimize the transmission power to maximize frequency reuse. Their analysis depends on the user content...

    Provided By University of Southern California

  • White Papers // Feb 2012

    Wireless Peer-to-Peer Scheduling in Mobile Networks

    This paper considers peer-to-peer scheduling for a network with multiple wireless devices. A subset of the devices are mobile users that desire specific files. Each user may already have certain popular files in its cache. The remaining devices are access points that typically have access to a larger set of...

    Provided By University of Southern California

  • White Papers // Feb 2012

    Repairable Fountain Codes

    This paper is eligible for the student paper award. The authors introduce a new family of fountain codes that are systematic and also have sparse parities. Although this is impossible if they require the code to be MDS, they show it can be achieved if they relax their requirement into...

    Provided By University of Southern California

  • White Papers // Feb 2012

    Allocations for Heterogeneous Distributed Storage

    The authors study the problem of storing a data object in a set of data nodes that fail independently with given probabilities. Their problem is a natural generalization of a homogenous storage allocation problem where all the nodes had the same reliability and is naturally motivated for peer-to-peer and cloud...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Power-Aware Topology Control for Wireless Ad-Hoc Networks

    In this paper, the authors examine the problem of power-aware topology control for wireless ad-hoc networks. The reliance on wireless multihop communications to maintain connectivity among nodes adds new complexity on the design and operation of the wireless ad-hoc networks. In particular, the lack of a physical backbone infrastructure poses...

    Provided By University of Southern California

  • White Papers // Jan 2012

    ELECTION: Energy-Efficient and Low-LatEncy SCheduling Technique for WIreless Sensor Networks

    The authors propose ELECTION, a new sleep scheduling scheme that adaptively schedules the sleep cycles of both communication radios and sensors in wireless active sensor networks. Taking advantage of spatial and temporal correlations in the underlying physical phenomenon, their scheme controls sleeping schedules of radios and sensors, and adaptively meets...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Automatic Request Categorization in Internet Services

    Modeling system performance and workload characteristics has become essential for efficiently provisioning Internet services and for accurately predicting future resource requirements on anticipated workloads. The accuracy of these models benefits substantially by differentiating among categories of requests based on their resource usage characteristics. However, categorizing requests and their resource demands...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Energy-Optimal and Energy-Balanced Sorting in a Single-Hop Wireless Sensor Network

    A large number of sensors networked together form self-organizing pervasive systems that provide the basis for implementation of several applications involving distributed, collaborative computations. Energy dissipation is a critical issue for these networks, as their life-time is limited by the battery power of the sensors. In this paper, the authors...

    Provided By University of Southern California

  • White Papers // Jan 2012

    MIND: A Distributed Multi-Dimensional Indexing System for Network Diagnosis

    Detecting coordinated attacks on Internet resources requires a distributed network monitoring infrastructure. Such an infrastructure will have two logically distinct elements: distributed monitors that continuously collect traffic information, and a distributed query system that allows network operators to efficiently correlate information from different monitors in order to detect anomalous traffic...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Communication Models for Algorithm Design in Wireless Sensor Networks

    With continuing advancements in sensor node design and increasingly complex applications for Wireless Sensor Networks (WSNs), formal communication models are needed for either fair comparison between various algorithms or the development of design automation in WSNs. Toward such a goal, the authors formally define two link-wise communication models, namely, the...

    Provided By University of Southern California

  • White Papers // Nov 2011

    Dynamic Index Coding for Wireless Broadcast Networks

    The authors consider a wireless broadcast station that transmits packets to multiple users. The packet requests for each user may overlap, and some users may already have certain packets. This presents a problem of broadcasting in the presence of side information, and is a generalization of the well known (and...

    Provided By University of Southern California

  • White Papers // Oct 2011

    Performance Analysis of Vertex-Centric Graph Algorithms on the Azure Cloud Platform

    Finding key vertices in large graphs is an important problem in many applications such as social networks, bioinformatics, and distribution networks. Betweenness centrality is a popular algorithm for finding such vertices and has been studied extensively, yielding several parallel formulations suitable to supercomputers and clusters. In this paper, the authors...

    Provided By University of Southern California

  • White Papers // Sep 2011

    Designing a Secure Storage Repository for Sharing Scientific Datasets Using Public Clouds

    As Cloud platforms gain increasing traction among scientific and business communities for outsourcing storage, computing and content delivery, there is also growing concern about the associated loss of control over private data hosted in the Cloud. In this paper, the authors present an architecture for a secure data repository service...

    Provided By University of Southern California

  • White Papers // Sep 2011

    MCC: A High-Throughput Multi-Channel Data Collection Protocol for Wireless Sensor Networks

    The authors present the design and implementation of MCC, the first high-rate multi-channel time-scheduled protocol for fair, real-time data collection in Wireless Sensor Networks. MCC incorporates sophisticated mechanisms for balanced routing tree formation, multiple frequency channel allocation and globally synchronized TDMA scheduling. Through systematic experiments with real WSN hardware(Tmote Sky),...

    Provided By University of Southern California

  • White Papers // Aug 2011

    On Hardness of Multiflow Transmission in Delay Constrained Cooperative Wireless Networks

    The authors consider the problem of energy-efficient transmission in multi-flow multi-hop cooperative wireless networks. Although the performance gains of cooperative approaches are well known, the combinatorial nature of these schemes makes it difficult to design efficient polynomial-time algorithms for joint routing, scheduling and power control. This becomes more so when...

    Provided By University of Southern California

  • White Papers // Jul 2011

    Decentralized Online Learning Algorithms for Opportunistic Spectrum Access

    The fundamental problem of multiple secondary users contending for opportunistic spectrum access over multiple channels in cognitive radio networks has been formulated recently as a Decentralized Multi-Armed Bandit (D-MAB) problem. In a D-MAB problem there are M users and N arms (channels) that each offer i.i.d. stochastic rewards with unknown...

    Provided By University of Southern California

  • White Papers // Jul 2011

    Wireless Body Area Networks: Where Does Energy Go?

    Wireless Body Area Networks (WBANs) promise to revolutionize health care in the near future. By integrating bio-sensors with a mobile phone it is possible to monitor an individual's health and related behaviors. Monitoring is done by analyzing the sensor data either on a mobile phone or on a remote server...

    Provided By University of Southern California

  • White Papers // Jun 2011

    Distributed Storage Codes Reduce Latency in Vehicular Networks

    The authors investigate the benefits of distributed storage using erasure codes for file sharing in vehicular networks through both analysis and realistic trace-based simulations. They show that the key parameter affecting the file download latency is the ratio of file size to download bandwidth. When this ratio is small so...

    Provided By University of Southern California

  • White Papers // Jun 2011

    Distributed Storage Codes Through Hadamard Designs

    In distributed storage systems that employ erasure coding, the issue of minimizing the total repair bandwidth required to exactly regenerate a storage node after a failure arises. This repair bandwidth depends on the structure of the storage code and the repair strategies used to restore the lost data. Minimizing it...

    Provided By University of Southern California

  • White Papers // May 2011

    An Analysis of Security and Privacy Issues in Smart Grid Software Architectures on Clouds

    Power utilities globally are increasingly upgrading to Smart Grids that use bi-directional communication with the consumer to enable an information-driven approach to distributed energy management. Clouds offer features well suited for Smart Grid software platforms and applications, such as elastic resources and shared services. However, the security and privacy concerns...

    Provided By University of Southern California

  • White Papers // May 2011

    Multi-Dimensional SLA-Based Resource Allocation for Multi-Tier Cloud Computing Systems

    With increasing demand for computing and memory, distributed computing systems have attracted a lot of attention. Resource allocation is one of the most important challenges in the distributed systems specially when the clients have Service Level Agreements (SLAs) and the total profit in the system depends on how the system...

    Provided By University of Southern California

  • White Papers // Mar 2011

    Maximizing Profit in Cloud Computing System Via Resource Allocation

    With increasing demand for high performance computing and data storage, distributed computing systems have attracted a lot of attention. Resource allocation is one of the most important challenges in the distributed systems specially when the clients have some Service Level Agreements (SLAs) and the total profit in the system depends...

    Provided By University of Southern California

  • White Papers // Mar 2011

    LIFO-Backpressure Achieves Near Optimal Utility-Delay Tradeoff

    Recent developments in stochastic network optimization theory have yielded a very general framework that solves a large class of networking problems of the following form: the authors are given a discrete time stochastic network. The network state, which describes the current realization of the underlying network randomness, such as the...

    Provided By University of Southern California

  • White Papers // Mar 2011

    Semi-Markovian State Estimation and Policy Optimization for Energy Efficient Mobile Sensing

    User context monitoring on mobile devices benefits end-users by providing information support to various kinds of mobile applications. A pervasive question, however, is how the sensors on the mobile device could be scheduled energy efficiently without sacrificing too much detection accuracy. In this paper, the authors formulate the user state...

    Provided By University of Southern California

  • White Papers // Mar 2011

    Reliability Aware Exceptions for Software Directed Fault Handling

    Today reliability emerges as a first order design constraint. Faults encountered in a chip can be classified into three categories: transient, intermittent and permanent. Fault classification allows a chip designer to provide the appropriate corrective action for each fault type. However, fault classification and correction are expensive mechanisms to implement...

    Provided By University of Southern California

  • White Papers // Mar 2011

    Optimal Power Cost Management Using Stored Energy in Data Centers

    Since the electricity bill of a data center constitutes a significant portion of its overall operational costs, reducing this has become important. The authors investigate cost reduction opportunities that arise by the use of Uninterrupted Power Supply (UPS) units as energy storage devices. This represents a deviation from the usual...

    Provided By University of Southern California

  • White Papers // Feb 2011

    On the Economics of Cloud Markets

    Cloud computing is a paradigm that has the potential to transform and revolutionalize the next generation IT industry by making software available to end-users as a service. A cloud, also commonly known as a cloud network, typically comprises of hardware (network of servers) and a collection of software that is...

    Provided By University of Southern California

  • White Papers // Feb 2011

    A Framework for Quantitative Analysis of Cascades on Networks

    How does information flow in online social networks? How does the structure and size of the information cascade evolve in time? How can people efficiently mine the information contained in cascade dynamics? The authors approach these questions empirically and present an efficient and scalable mathematical framework for quantitative analysis of...

    Provided By University of Southern California

  • White Papers // Feb 2011

    Adaptive Rate Stream Processing for Smart Grid Applications on Clouds

    The growing deployment of smart meters to continuously measure power usage by consumers as part of a smarter power grid is resulting in the need for utilities to process and analyze thousands of data streams in near real-time to detect system overload. The authors describe the use of Cloud platforms...

    Provided By University of Southern California

  • White Papers // Feb 2011

    Towards Autonomous Wireless Backbone Deployment in Highly-Obstructed Environments

    In a setting that lacks infrastructure e.g., urban search and rescue, a team of networked mobile robots can provide a communication substrate by acting as routers in a wireless mesh network. The authors study the problem of determining the minimum number of robots, and how to position them, so that...

    Provided By University of Southern California

  • White Papers // Feb 2011

    Household Location And Race: A Twenty-Year Retrospective

    In a paper published in The Review of Economics and Statistics some 20 years ago, the authors sought to assess the disparate residential location choices of black and white households in the Washington, D.C. metropolitan area (Gabriel and Rosenthal [1989]). The paper showed that simulated closure of large socio-economic gaps...

    Provided By University of Southern California

  • White Papers // Jan 2011

    Optimizing Information Credibility in Social Swarming Applications

    With the advent of smartphone technology, it has become possible to conceive of entirely new classes of applications. Social swarming, in which users armed with smartphones are directed by a central director to report on events in the physical world, has several real-world applications. In this paper, the authors focus...

    Provided By University of Southern California

  • White Papers // Jan 2011

    Energy Routing on the Future Grid: A Stochastic Network Optimization Approach

    Population expansion and broad deployment of wind and solar renewable power generation has highlighted concerns over the long-standing strategy for grid deployment, expansion and upgrade. Due to their stochastic and often volatile nature, these renewable sources are difficult to integrate into the grid in its current power-on-demand paradigm. In this...

    Provided By University of Southern California

  • White Papers // Jan 2011

    Delay Constrained Minimum Energy Broadcast in Cooperative Wireless Networks

    The authors formulate the problem of delay constrained energy-efficient broadcast in cooperative multihop wireless networks. The authors show that this important problem is not only NP-complete, but also o(log(n)) inapproximable. They derive approximation results and an analytical lower-bound for this problem. They break this NP hard problem into three parts:...

    Provided By University of Southern California

  • White Papers // Jan 2011

    Opportunistic Scheduling With Worst Case Delay Guarantees in Single and Multi-Hop Networks

    The authors first consider a multi-user, single-hop wireless network with arbitrarily varying (and possibly non-ergodic) arrivals and channels. They design an opportunistic scheduling algorithm that guarantees all sessions have a bounded worst case delay. The algorithm has no knowledge of the future, but yields throughput-utility that is close to (or...

    Provided By University of Southern California

  • White Papers // Jun 2010

    Efficient Algorithms for Renewable Energy Allocation to Delay Tolerant Consumers

    The authors investigate the problem of allocating energy from renewable sources to flexible consumers in electricity markets. They assume there is a renewable energy supplier that provides energy according to a time-varying (and possibly unpredictable) supply process. The plant must serve consumers within a specified delay window, and incurs a...

    Provided By University of Southern California

  • White Papers // May 2012

    vCRIB: Virtualized Rule Management in the Cloud

    Cloud operators increasingly need many fine-grained rules to better control individual network flows for various management tasks. While previous approaches have advocated placing rules either on hypervisors or switches, the authors argue that future data centers would benefit from leveraging rule processing capabilities at both for better scalability and performance....

    Provided By University of Southern California

  • White Papers // Aug 2008

    A Graph-Based Approach to Multi-Cell OFDMA Downlink Resource Allocation

    A novel, practical and low-complexity multi-cell OFDMA downlink channel assignment method using a graph-based approach is proposed in this paper. The Inter-Cell Interference (ICI) information is obtained through inference from the diversity set of Mobile Stations (MSs) and presented in the form of an interference graph. The proposed downlink channel...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Power-Aware Topology Control for Wireless Ad-Hoc Networks

    In this paper, the authors examine the problem of power-aware topology control for wireless ad-hoc networks. The reliance on wireless multihop communications to maintain connectivity among nodes adds new complexity on the design and operation of the wireless ad-hoc networks. In particular, the lack of a physical backbone infrastructure poses...

    Provided By University of Southern California

  • White Papers // Aug 2008

    Mobile Video Processing for Visual Saliency Map Determination

    The visual saliency map represents the most attractive regions in video. Automatic saliency map determination is important in mobile video applications such as auto-focusing in video capturing. It is well known that motion plays a critical role in visual attention modeling. Motion in video consists of camera's motion and foreground...

    Provided By University of Southern California

  • White Papers // Jun 2010

    The Application of Cloud Computing to the Creation of Image Mosaics and Management of Their Provenance

    The authors have used the Montage image mosaic engine to investigate the cost and performance of processing images on the Amazon EC2 cloud, and to inform the requirements that higher-level products impose on provenance management technologies. They will present a detailed comparison of the performance of Montage on the cloud...

    Provided By University of Southern California

  • White Papers // Feb 2011

    Adaptive Rate Stream Processing for Smart Grid Applications on Clouds

    The growing deployment of smart meters to continuously measure power usage by consumers as part of a smarter power grid is resulting in the need for utilities to process and analyze thousands of data streams in near real-time to detect system overload. The authors describe the use of Cloud platforms...

    Provided By University of Southern California

  • White Papers // Jul 2010

    An Uncertain Control Framework of Cloud Model

    The mathematical representation of a concept with uncertainty is one of the foundations of Artificial Intelligence. Uncertain Control has been the core in VSC systems and nonlinear control systems, as the representation of Uncertainty is required. Cloud Model represents the uncertainty with expectation Ex, entropy En and Hyper-entropy He by...

    Provided By University of Southern California

  • White Papers // Jan 2012

    ELECTION: Energy-Efficient and Low-LatEncy SCheduling Technique for WIreless Sensor Networks

    The authors propose ELECTION, a new sleep scheduling scheme that adaptively schedules the sleep cycles of both communication radios and sensors in wireless active sensor networks. Taking advantage of spatial and temporal correlations in the underlying physical phenomenon, their scheme controls sleeping schedules of radios and sensors, and adaptively meets...

    Provided By University of Southern California

  • White Papers // Aug 2012

    Scaling Behaviors of Wireless Device-to-Device Communications With Distributed Caching

    The authors analyze a novel architecture for caching popular video content to enable wireless device-to-device collaboration. They focus on the asymptotic scaling characteristics and show how they depends on video content popularity statistics. They identify a fundamental conflict between collaboration distance and interference and show how to optimize the transmission...

    Provided By University of Southern California

  • White Papers // Oct 2008

    Static Replication Strategies for Content Availability in Vehicular Ad-Hoc Networks

    This paper investigates replication strategies for reducing latency to desired content in a vehicular peer-to-peer network. The authors provide a general constrained optimization formulation for efficient replication and study it via analysis and simulations employing a discrete random walk mobility model for the vehicles. Their solution space comprises of a...

    Provided By University of Southern California

  • White Papers // Jan 2009

    Dynamic MIPS Rate Stabilization in Out-of-Order Processors

    Today's micro-processor cores reach high performance levels not only by their high clock rate but also by the concurrent execution of a large number of instructions. Because of the relationship between power and frequency, it becomes attractive to run an OoO (Out-of-Order) processor at a frequency lower than its nominal...

    Provided By University of Southern California

  • White Papers // Feb 2009

    Link Scheduling in a Single Broadcast Domain Underwater Networks

    Because radio waves decay rapidly in sea water, acoustic communication is the most popular choic for underwater sensor networks. However, since the propagation speed of acoustic waves are 3 orders slower than radio waves, scheduling techniques designed for radio-based communication systems may not be suitable for underwater use. The authors...

    Provided By University of Southern California

  • White Papers // Feb 2009

    Sub-Carrier Allocation in OFDM Systems: Complexity, Approximability and Algorithms

    Orthogonal Frequency Division Multiplexing (OFDM) has become the de facto standard for fourth generation wireless networks. In such a network, the frequency band is divided into numerous orthogonal sub-carriers. In each time-slot, disjoint sets of sub-carriers can be assigned to users based on some target objective. The users in turn...

    Provided By University of Southern California

  • White Papers // Jun 2009

    Coordinated Sampling in Communication Constrained Sensor Networks Using Markov Decision Processes

    The paper describes a Markov Decision Process (MDP) framework for coordinated sensing and adaptive communication in embedded sensor networks. The technique enables distributed sensor nodes to adapt their sampling rates in response to changing event criticality and the availability of resources (energy) at each node. The relationship between energy consumption,...

    Provided By University of Southern California

  • White Papers // Jul 2010

    A Privacy Mechanism for Mobile-Based Urban Traffic Monitoring

    Participatory sensing is a paradigm that allows each participant to sense, collect and transmit information about their surroundings to either other members in the group or to a centralized server. The information that is provided by the community of users is then combined to provide a useful service to all...

    Provided By University of Southern California

  • White Papers // Jun 2010

    Tag Spotting: Communicating Beyond Carrier Sense

    A fundamental difference between wireless and wired networks is the presence of interference among wireless links, which introduces dependencies among flows that do not share a link or node. As a result, when designing a resource allocation scheme, be it a medium access scheduler or a flow rate controller, one...

    Provided By University of Southern California

  • White Papers // Feb 2010

    Optimizing Content Dissemination in Heterogeneous Vehicular Networks

    Disseminating shared information to many vehicles could incur significant access fees if it relies only on unicast cellular communications. The authors consider the problem of efficient content dissemination over a heterogeneous vehicular network, in which vehicles are equipped with two kinds of radios: a high-cost low-bandwidth, long-range cellular radio, and...

    Provided By University of Southern California

  • White Papers // Dec 2009

    Continuous Reliability Monitoring Using Adaptive Critical Path Testing

    As processor reliability becomes a first order design constraint, this research argues for a need to provide continuous reliability monitoring. The authors present an adaptive critical path monitoring architecture which provides accurate and real-time measure of the processor's timing margin degradation. Special test patterns check a set of critical paths...

    Provided By University of Southern California

  • White Papers // Aug 2010

    On the Performance of Multiuser MIMO Mesh Networks

    Over the last five years both the academia and the industry have produced evidence that wireless multi-hopping suffers from low performance. Even putting real-world constraints aside and assuming deployment of optimal schedulers and rate controllers, the fact of the matter is that wireless multi-hop networks are severely constrained by interference....

    Provided By University of Southern California

  • White Papers // Dec 2010

    Combinatorial Network Optimization With Unknown Variables: Multi-Armed Bandits With Linear Rewards

    In the classic multi-armed bandits problem, the goal is to have a policy for dynamically operating arms that each yield stochastic rewards with unknown means. The key metric of interest is regret, defined as the gap between the expected total reward accumulated by an omniscient player that knows the reward...

    Provided By University of Southern California

  • White Papers // Dec 2010

    On the Combinatorial Multi-Armed Bandit Problem with Markovian Rewards

    Multi-armed bandit problems provide a fundamental approach to learning under stochastic rewards, and find rich applications in a wide range of networking contexts, from Internet advertising to medium access in cognitive radio networks. In the simplest, classic non-Bayesian version of the problem, studied by Lai and Robbins, there are K...

    Provided By University of Southern California

  • White Papers // Mar 2011

    Semi-Markovian State Estimation and Policy Optimization for Energy Efficient Mobile Sensing

    User context monitoring on mobile devices benefits end-users by providing information support to various kinds of mobile applications. A pervasive question, however, is how the sensors on the mobile device could be scheduled energy efficiently without sacrificing too much detection accuracy. In this paper, the authors formulate the user state...

    Provided By University of Southern California

  • White Papers // Mar 2011

    Reliability Aware Exceptions for Software Directed Fault Handling

    Today reliability emerges as a first order design constraint. Faults encountered in a chip can be classified into three categories: transient, intermittent and permanent. Fault classification allows a chip designer to provide the appropriate corrective action for each fault type. However, fault classification and correction are expensive mechanisms to implement...

    Provided By University of Southern California

  • White Papers // Jun 2011

    Distributed Storage Codes Reduce Latency in Vehicular Networks

    The authors investigate the benefits of distributed storage using erasure codes for file sharing in vehicular networks through both analysis and realistic trace-based simulations. They show that the key parameter affecting the file download latency is the ratio of file size to download bandwidth. When this ratio is small so...

    Provided By University of Southern California

  • White Papers // Sep 2011

    MCC: A High-Throughput Multi-Channel Data Collection Protocol for Wireless Sensor Networks

    The authors present the design and implementation of MCC, the first high-rate multi-channel time-scheduled protocol for fair, real-time data collection in Wireless Sensor Networks. MCC incorporates sophisticated mechanisms for balanced routing tree formation, multiple frequency channel allocation and globally synchronized TDMA scheduling. Through systematic experiments with real WSN hardware(Tmote Sky),...

    Provided By University of Southern California

  • White Papers // Jul 2011

    Wireless Body Area Networks: Where Does Energy Go?

    Wireless Body Area Networks (WBANs) promise to revolutionize health care in the near future. By integrating bio-sensors with a mobile phone it is possible to monitor an individual's health and related behaviors. Monitoring is done by analyzing the sensor data either on a mobile phone or on a remote server...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Automatic Request Categorization in Internet Services

    Modeling system performance and workload characteristics has become essential for efficiently provisioning Internet services and for accurately predicting future resource requirements on anticipated workloads. The accuracy of these models benefits substantially by differentiating among categories of requests based on their resource usage characteristics. However, categorizing requests and their resource demands...

    Provided By University of Southern California

  • White Papers // Jan 2009

    A Federated Experiment Environment for Emulab-Based Testbeds

    The authors describe an architecture for creating experimental environments across multiple cooperating Emulab-based testbeds, called the DETER Federation Architecture (DFA). The system uses cooperative resource allocation and multiple-level testbed access to create a cohesive environment for experimentation. Testbeds that contribute resources continue to exert their own resource allocation and access...

    Provided By University of Southern California

  • White Papers // Jan 2010

    Performance of Round Robin Policies for Dynamic Multichannel Access

    The authors consider two simple round-robin sensing policies for dynamic multi-channel access in cognitive radio networks - one in which channel switching takes place when the primary user is sensed to be present, and one in which a channel switching takes place when the primary user is sensed to be...

    Provided By University of Southern California

  • White Papers // Feb 2012

    Wireless Peer-to-Peer Scheduling in Mobile Networks

    This paper considers peer-to-peer scheduling for a network with multiple wireless devices. A subset of the devices are mobile users that desire specific files. Each user may already have certain popular files in its cache. The remaining devices are access points that typically have access to a larger set of...

    Provided By University of Southern California

  • White Papers // Jan 2012

    Energy-Optimal and Energy-Balanced Sorting in a Single-Hop Wireless Sensor Network

    A large number of sensors networked together form self-organizing pervasive systems that provide the basis for implementation of several applications involving distributed, collaborative computations. Energy dissipation is a critical issue for these networks, as their life-time is limited by the battery power of the sensors. In this paper, the authors...

    Provided By University of Southern California

  • White Papers // Jan 2012

    MIND: A Distributed Multi-Dimensional Indexing System for Network Diagnosis

    Detecting coordinated attacks on Internet resources requires a distributed network monitoring infrastructure. Such an infrastructure will have two logically distinct elements: distributed monitors that continuously collect traffic information, and a distributed query system that allows network operators to efficiently correlate information from different monitors in order to detect anomalous traffic...

    Provided By University of Southern California

  • White Papers // May 2012

    Wireless Device-to-Device Communications With Distributed Caching

    The authors introduce a novel wireless Device-To-Device (D2D) collaboration architecture that exploits distributed storage of popular content to enable frequency reuse. They identify a fundamental conflict between collaboration distance and interference and show how to optimize the transmission power to maximize frequency reuse. Their analysis depends on the user content...

    Provided By University of Southern California

  • White Papers // Feb 2012

    Repairable Fountain Codes

    This paper is eligible for the student paper award. The authors introduce a new family of fountain codes that are systematic and also have sparse parities. Although this is impossible if they require the code to be MDS, they show it can be achieved if they relax their requirement into...

    Provided By University of Southern California

  • White Papers // May 2012

    Bipartite Index Coding

    The authors analyze a generalized index coding problem that allows multiple users to request the same packet. For this problem they introduce a novel coding scheme called partition multicast. Their scheme can be seen as a natural generalization of clique cover for directed index coding problems. Further, partition multicast corresponds...

    Provided By University of Southern California

  • White Papers // May 2012

    Feedback in the K-User Interference Channel

    A traditional viewpoint on feedback capacity has been pessimistic over the past few decades. This is mainly due to Shannon's original result which shows that feedback provides no increase in capacity for discrete memory-less point-to-point channels. Although feedback can indeed increase the capacity of multiple access channels, the increase in...

    Provided By University of Southern California

  • White Papers // Feb 2012

    Allocations for Heterogeneous Distributed Storage

    The authors study the problem of storing a data object in a set of data nodes that fail independently with given probabilities. Their problem is a natural generalization of a homogenous storage allocation problem where all the nodes had the same reliability and is naturally motivated for peer-to-peer and cloud...

    Provided By University of Southern California

  • White Papers // May 2012

    Locally Repairable Codes

    One main challenge in the design of distributed storage codes is the Exact Repair Problem: if a node storing encoded information fails, to maintain the same level of reliability, the authors need to exactly regenerate what was lost in a new node. A major open problem in this area has...

    Provided By University of Southern California

  • White Papers // Jun 2011

    Distributed Storage Codes Through Hadamard Designs

    In distributed storage systems that employ erasure coding, the issue of minimizing the total repair bandwidth required to exactly regenerate a storage node after a failure arises. This repair bandwidth depends on the structure of the storage code and the repair strategies used to restore the lost data. Minimizing it...

    Provided By University of Southern California