University of California

Displaying 201-240 of 614 results

  • White Papers // Jan 2011

    The Cost Of Inflation: A Mechanism Design Approach

    A classical topic in monetary economics is measuring the burden that inflation imposes on society. The standard methodology, pioneered by Bailey (1956) and Friedman (1969) and reviewed in Lucas (2000), consists of estimating a reduced-form money demand function and measuring the welfare cost of inflation as the area underneath money...

    Provided By University of California

  • White Papers // Jan 2011

    Mobility Prediction and Routing in Ad Hoc Wireless Networks

    Wireless networks allow a more flexible model of communication than traditional networks since the user is not limited to a fixed physical location. Unlike cellular wireless networks, an ad hoc wireless network does not have any fixed communication infrastructure. For an active connection, the end host as well as the...

    Provided By University of California

  • White Papers // Jan 2011

    An Ad Hoc Network With Mobile Backbones

    A Mobile Ad Hoc NETwork (MANET) is usually assumed to be homogeneous, where each mobile node shares the same radio capacity. However, a homogeneous ad hoc network suffers from poor scalability. Recent research has demonstrated its performance bottleneck both theoretically and through simulation experiments and testbed measurement. Building a physically...

    Provided By University of California

  • White Papers // Jan 2011

    ChunkCast: An Anycast Service for Large Content Distribution

    Fast and efficient large content distribution is a challenge in the Internet due to its high traffic volume. In this paper, the authors propose ChunkCast, an anycast service that optimizes large content distribution. The authors present a distributed localityaware directory that supports an efficient query for large content. The system...

    Provided By University of California

  • White Papers // Jan 2011

    Host Multicast: A Framework for Delivering Multicast to End Users

    While the advantages of multicast delivery over multiple unicast deliveries is undeniable, the deployment of the IP multicast protocol has been limited to "Islands" of network domains under single administrative control. Deployment of inter-domain multicast delivery has been slow due to both technical and administrative reasons. In this paper the...

    Provided By University of California

  • White Papers // Jan 2011

    A Secure, Publisher-Centric Web Caching Infrastructure

    The current web caching infrastructure, though it has a number of performance benefits for clients and network providers, does not meet publishers' requirements. The authors argue that to satisfy these requirements, caches should be enhanced in both the data and control planes. In the data plane, caches will dynamically generate...

    Provided By University of California

  • White Papers // Jan 2011

    Data Mining by Navigation - An Experience with Systems Biology

    This paper proposes a navigational method for mining by collecting evidences from diverse data sources. Since the representation method and even semantics of data elements differ widely from one data source to the other, consolidation of data under a single platform doesn't become cost effective. Instead, this paper has proposed...

    Provided By University of California

  • White Papers // Jan 2011

    A Bayesian Network Framework for Reject Inference

    Most learning methods assume that the training set is drawn randomly from the population to which the learned model is to be applied. However in many applications this assumption is invalid. For example, lending institutions create models of who is likely to repay a loan from training sets consisting of...

    Provided By University of California

  • White Papers // Jan 2011

    Generating Tests From Counterexamples

    The authors have extended the software model checker BLAST to automatically generate test suites that guarantee full coverage with respect to a given predicate. More precisely, given a C program and a target predicate, BLAST determines the set of program locations which program execution can reach with true, and automatically...

    Provided By University of California

  • White Papers // Jan 2011

    Optimal Communication Complexity of Generic Multicast Key Distribution

    The authors prove a tight lower bound for generic protocols for secure multicast key distribution where the messages sent by the group manager are obtained by arbitrarily nested application of a symmetric encryption scheme, with random or pseudorandom keys. The lower bound shows that for any group of size n,...

    Provided By University of California

  • White Papers // Jan 2011

    Soundness of Formal Encryption in the Presence of Active Adversaries

    Cryptographic protocols are a fundamental tool in the design of secure distributed computing systems, but they are also extremely hard to design and validate. The difficulty of designing valid cryptographic protocols stems mostly from the fact that security properties should remain valid even when the protocol is executed in an...

    Provided By University of California

  • White Papers // Jan 2011

    IPv4 Address Allocation and the BGP Routing Table Evolution

    The IP address consumption and the global routing table size are two of the vital parameters of the Internet growth. This paper quantitatively characterize the IPv4 ad-dress allocations made over the past six years and the global BGP routing table size changes during the same period of time. About 63,000...

    Provided By University of California

  • White Papers // Jan 2011

    Exploring the Feasibility of Proactive Reputations

    Reputation mechanisms help peers in a Peer-To-Peer (P2P) system avoid unreliable or malicious peers. In application level networks, however, short peer lifetimes mean reputations are often generated from a small number of past transactions. These reputation values are less "Reliable,? and more vulnerable to badmouthing or collusion attacks. The authors...

    Provided By University of California

  • White Papers // Jan 2011

    The Y-Architecture for On-Chip Interconnect: Analysis and Methodology

    The Y-architecture for on-chip interconnect is based on pervasive use of 0-, 120-, and 240-degree oriented semi-global and global wiring. Its use of three uniform directions exploits on-chip routing resources more efficiently than traditional Manhattan wiring architecture. This paper gives in-depth analysis of deployment issues associated with the Y-architecture. The...

    Provided By University of California

  • White Papers // Jan 2011

    Contour Maps: Monitoring and Diagnosis in Sensor Networks

    Large-scale sensor networks impose energy and communication constraints, thus it is difficult to collect data from each individual sensor node and process it at the sink. In this paper, the authors propose an efficient data-collection scheme that can be used for event monitoring or network-wide diagnosis. The scheme relies on...

    Provided By University of California

  • White Papers // Jan 2011

    Dynamic Right-Sizing in TCP

    With the widespread arrival of bandwidth-intensive applications such as bulk-data transfer, multi-media web streaming and computational grids for high-performance computing, networking performance over the wide-area network has become a critical component in the infrastructure. Tragically, operating systems are still tuned for yesterday's WAN speeds and network applications. As a result,...

    Provided By University of California

  • White Papers // Jan 2011

    Query Selection Techniques for Efficient Crawling of Structured Web Sources

    The high quality, structured data from Web structured sources is invaluable for many applications. Hidden Web databases are not directly crawlable by Web search engines and are only accessible through Web query forms or via Web service interfaces. Recent research efforts have been focusing on understanding these Web query forms....

    Provided By University of California

  • White Papers // Jan 2011

    Optimization of SiGe VCOs for Wireless Applications

    This paper describes the optimization of phase noise performance in fully integrated SiGe HBT differential LC-tuned Voltage Controlled Oscillators (VCOs) for wireless applications. An accurate expression for phase noise in SiGe HBT LC-tuned VCOs is presented which takes the non-linear operation of the oscillator into account. The expression is derived...

    Provided By University of California

  • White Papers // Jan 2011

    Efficient Replica Maintenance for Distributed Storage Systems

    This paper considers replication strategies for storage systems that aggregate the disks of many nodes spread over the Internet. Maintaining replication in such systems can be prohibitively expensive, since every transient network or host failure could potentially lead to copying a server's worth of data over the Internet to maintain...

    Provided By University of California

  • White Papers // Jan 2011

    Chord: A Scalable Peer-to-Peer Lookup Protocol for Internet Applications

    A fundamental problem that confronts peer-to-peer applications is the efficient location of the node that stores a desired data item. This paper presents Chord, a distributed lookup protocol that addresses this problem. Chord provides support for just one operation: given a key, it maps the key onto a node. Data...

    Provided By University of California

  • White Papers // Jan 2011

    The P2P War: Someone Is Monitoring Your Activities!

    In an effort to prosecute P2P users, RIAA and MPAA have reportedly started to create decoy users: they participate in P2P networks in order to identify illegal sharing of content. This has reportedly scared some users who are afraid of being caught. The question the authors attempt to answer is...

    Provided By University of California

  • White Papers // Jan 2011

    Representative Multiprogram Workloads for Multithreaded Processor Simulation

    Almost all new consumer-grade processors are capable of executing multiple programs simultaneously. The analysis of multiprogrammed workloads for multicore and SMT processors is challenging and time-consuming because there are many possible combinations of benchmarks to execute and each combination may exhibit several different interesting behaviors. Missing particular combinations of program...

    Provided By University of California

  • White Papers // Jan 2011

    Dynamic Resource Discovery for Wireless Sensor Networks

    As sensor networks mature and are increasingly deployed, they will play an integral role in everyday life as the interface between the physical and digital worlds. In contrast to the current generation of sensor networks that are application-specific and exposed only to a limited set of users, heterogeneous sensor networks...

    Provided By University of California

  • White Papers // Jan 2011

    Visualizing Online News Reporting For Public Display

    The authors describe the iterative design and implementation of "Spheres of Influence," an interactive digital multimedia installation in a public space that visualizes the spatial, temporal, and semantic dimensions of online international news reporting. The installation invites the casual passerby to explore a continually growing collection of up-to-the-minute news reports...

    Provided By University of California

  • White Papers // Jan 2011

    Degenerate 3D Tensors

    Topological analysis of 3D tensor fields starts with the identification of degeneracies in the tensor field. In this paper, the authors present a new, intuitive and numerically stable method for finding degenerate tensors in symmetric second order 3D tensors. This method is formulated based on a description of a tensor...

    Provided By University of California

  • White Papers // Jan 2011

    Balancing Computation and Code Distribution Costs: The Case for Hybrid Execution in Sensor Networks

    Virtual Machines (VM) are promising as system software in networks of embedded systems and pervasive computing spaces. VMs facilitate the development of platform-independent applications with small footprints to enable low cost application distribution and evolution. A major impediment to their more widespread acceptance is the performance overhead of interpretation. Compiling...

    Provided By University of California

  • White Papers // Jan 2011

    Remote Incremental Linking for Energy-Efficient Reprogramming of Sensor Networks

    With sensor networks expected to be deployed for long periods of time, the ability to reprogram them remotely is necessary for providing new services, fixing bugs, and enhancing applications and system software. Given the envisioned scales of future sensor network deployments, their restricted accessibility, and the limited energy and computing...

    Provided By University of California

  • White Papers // Jan 2011

    The Case for Efficient File Access Pattern Modeling

    Most modern I/O systems treat each file access independently. However, events in a computer system are driven by programs. Thus, accesses to files occur in consistent patterns and are by no means independent. The result is that modern I/O systems ignore useful information. Using traces of file system activity the...

    Provided By University of California

  • White Papers // Jan 2011

    SARA: Combining Stack Allocation and Register Allocation

    Commonly-used memory units enable a processor to load and store multiple registers in one instruction. The authors showed in 2003 how to extend gcc with a Stack-Location-Allocation (SLA) phase that reduces memory traffic by rearranging the stack and replacing some load/store instructions with load/store-multiple instructions. While speeding up the target...

    Provided By University of California

  • White Papers // Jan 2011

    Application-Specific Garbage Collection

    Prior work, including the own, shows that application performance in garbage collected languages is highly dependent upon the application behavior and on underlying resource availability. The authors show that given a wide range of diverse Garbage Collection (GC) algorithms, no single system performs best across programs and heap sizes. They...

    Provided By University of California

  • White Papers // Jan 2011

    HPS: Hybrid Profiling Support

    Key to understanding and optimizing complex applications, is the ability to dynamically monitor executing programs with low overhead and high accuracy. Toward this end, the authors present HPS, a Hybrid Profiling Support system. HPS employs a hardware/software approach to program sampling that transparently, efficiently, and dynamically samples an executing instruction...

    Provided By University of California

  • White Papers // Jan 2011

    Efficient and General On-Stack Replacement for Aggressive Program Specialization

    Efficient invalidation and dynamic replacement of executing code - On-Stack Replacement (OSR), is necessary to facilitate effective, aggressive, specialization of object-oriented programs that are dynamically loaded, incrementally compiled, and garbage collected. Extant OSR mechanisms restrict the performance potential of program specialization since their implementations are special-purpose and restrict compiler optimization....

    Provided By University of California

  • White Papers // Jan 2011

    Using Adaptive Optimization Techniques to Teach Mobile Java Computing

    Dynamic, adaptive optimization is quickly becoming vital to the future of high-performance, mobile computing using Java. These compilation environments have the potential to enable ubiquitous computing on resources that together represent greater computing power than that which can be extracted from existing supercomputers. As a result, the authors believe that...

    Provided By University of California

  • White Papers // Jan 2011

    Evaluating the Performance Impact of Xen on MPI and Process Execution for HPC Systems

    Virtualization has become increasingly popular for enabling full system isolation, load balancing, and hardware multiplexing for high-end server systems. Virtualizing software has the potential to benefit HPC systems similarly by facilitating efficient cluster management, application isolation, full-system customization, and process migration. However, virtualizing software is not currently employed in HPC...

    Provided By University of California

  • White Papers // Jan 2011

    Language and Virtual Machine Support for Efficient Fine-Grained Futures in Java

    In this work, the authors investigate the implementation of futures in Java J2SE v5.0. Java 5.0 provides an interface-based implementation of futures that enables users to encapsulate potentially asynchronous computation and to define their own execution engines for futures. Although this methodology decouples thread scheduling from application logic, for applications...

    Provided By University of California

  • White Papers // Jan 2011

    An Observation of Fine-Grain Usage Patterns for Two Configuration Management Tools

    This paper presents the results of a survey of employees from one company that uses different configuration management tools and processes for the development of two separate products. Results from this study suggest that workspace semantics, and build semantics both have a significant impact on the fine grain use pattern...

    Provided By University of California

  • White Papers // Jan 2011

    Pseudo-IP: Providing a Thin Network Layer Protocol for Semi-Intelligent Wireless Devices

    In the near future users will be able to move freely and still have seamless network and Internet connectivity. The authors envision that the Internet of the future will interconnect mobile or stationary clouds into the existing IP infrastructure. While many of the Internet protocols are immensely successful in traditional...

    Provided By University of California

  • White Papers // Jan 2011

    Paravirtualization for HPC Systems

    In this work, the authors investigate the efficacy of using paravirtualizing software for performance-critical HPC kernels and applications. They present a comprehensive performance evaluation of Xen, a low-overhead, Linux-based, virtual machine monitor, for paravirtualization of HPC cluster systems at LLNL. They investigate subsystem and overall performance using a wide range...

    Provided By University of California

  • White Papers // Jan 2011

    Energy Efficient Data Collection in Distributed Sensor Environments

    Sensors are typically deployed to gather data about the physical world and its artifacts for a variety of purposes that range from environment monitoring, control, to data analysis. Since sensors are resource constrained, often sensor data is collected into a sensor database that resides at (more powerful) servers. A natural...

    Provided By University of California

  • White Papers // Jan 2011

    Control Plane for Advance Bandwidth Scheduling in Ultra High-Speed Networks

    An increasing number of large-scale science and commercial applications are producing colossal amounts of data, on the order of terabytes currently and petabytes in the near future. Since the data providers and consumers in these applications are often geographically distributed over a wide area environment, ultra high-speed dedicated connections are...

    Provided By University of California

  • White Papers // Jul 2010

    A Novel Delay-And Reliability-Aware Inter-Vehicle Routing Protocol

    Intelligent transportation systems could improve transportation safety, driving assistance and traffic management system. Vehicular Ad hoc NETwork (VANET) is an emerging field of technology, embedding wireless communication networks into vehicles to achieve intelligent transportation systems. The development of such systems pose many unique challenges like designing routing protocols that not...

    Provided By University of California

  • White Papers // Jan 2012

    On Wormhole Attacks in Under-Water Sensor Networks: A Two-Tier Localization Approach

    Under-Water Sensor Network (UWSN) is a novel networking paradigm to explore the uninhabited oceans. However, the characteristics of this new network, such as huge propagation delay, floating node mobility, and limited acoustic link capacity, are significantly different from land-based sensor networks. In this paper, the authors show that underwater denial-of-service...

    Provided By University of California

  • White Papers // Jan 2012

    Formal Notions of Anonymity for Peer-to-Peer Networks

    Providing anonymity support for Peer-To-Peer (P2P) overlay networks is critical. Otherwise, potential privacy attacks (e.g., network address trace-back) may deter a storage source from providing the needed data. In this paper, the authors use this practical application scenario to verify their observation that network-based anonymity can be modeled as a...

    Provided By University of California

  • White Papers // Jun 2011

    Memory-Side Acceleration for XML Parsing

    As Extensible Markup Language (XML) becomes prevalent in cloud computing environments, it also introduces significant performance overheads. In this paper, the authors analyze the performance of XML parsing, identify that a significant fraction of the performance overhead is indeed incurred by memory data loading. To address this problem, they propose...

    Provided By University of California

  • White Papers // Apr 2011

    In-Situ MapReduce for Log Processing

    Log analytics are a bedrock component of running many of today's Internet sites. Application and click logs form the basis for tracking and analyzing customer behaviors and preferences, and they form the basic inputs to ad-targeting algorithms. Logs are also critical for performance and security monitoring, debugging, and optimizing the...

    Provided By University of California

  • White Papers // Jun 2010

    Organizing Large Scale Hacking Competitions

    Computer security competitions and challenges are a way to foster innovation and educate students in a highly-motivating setting. In recent years, a number of different security competitions and challenges were carried out, each with different characteristics, configurations, and goals. From 2003 to 2007, the authors carried out a number of...

    Provided By University of California

  • White Papers // Mar 2012

    Primary User Traffic Estimation for Dynamic Spectrum Access

    Accurate estimation of licensed channel Primary User's (PU) temporal statistics is important for Dynamic Spectrum Access (DSA) systems. With accurate estimation of the mean duty cycle, u, and the mean off- and on-times of PUs, DSA systems can more efficiently assign PU resources to its subscribers, thus, increasing channel utilization....

    Provided By University of California

  • White Papers // Jun 2009

    Future Directions in Cognitive Radio Network Research

    Wireless technology is proliferating rapidly, and the vision of pervasive wireless computing and communications offers the promise of many societal and individual benefits. While consumer devices such as cell phones, PDAs and laptops receive a lot of attention, the impact of wireless technology is much broader, e.g., through sensor networks...

    Provided By University of California

  • White Papers // Feb 2012

    Mitigate Funnel Effect in Sensor Networks With Multi-Interface Relay Nodes

    Overlay network architectures that use orthogonal channels have been known to provide effective additional resources to underlying networks in high demand. Overlays are composed of relay nodes provided with rich computational resources and multiple wireless interfaces that make them capable of establishing several non-interfering networks. These networks can be used...

    Provided By University of California

  • White Papers // Aug 2011

    Timely and Robust Key Establishment Under Jamming Attack in Critical Wireless Networks

    Jamming attacks are security threats disrupting RF communications in wireless networks. Traditionally, spread spectrum has been proposed as a countermeasure. However, spread spectrum requires secure pre-key establishment before data transmission, with considerable time investment and thus limited functionality. This paper proposes a Frequency Quorum Rendezvous (FQR) scheme. In FQR, nodes...

    Provided By University of California

  • White Papers // Aug 2011

    MPR-Aware Performance Improvement for Inter-Domain Routing in MANETs

    Inter-domain routing for MANETs (Mobile Ad Hoc NETworks) draws increasing attention in military and civil application. It works on heterogeneous networking protocols, including different MAC layer protocols and routing layer protocols. It elects gateways within each domain, which in turn connect to other domains. In this paper, the authors propose...

    Provided By University of California

  • White Papers // Apr 2012

    Automated MAC Protocol Generation With Multiple Neighborhoods and Acknowledgments Based on Symbolic Monte Carlo Simulation

    The authors present a framework for automated Medium Access Control (MAC) protocol generation based on a model that incorporates multiple MAC neighborhoods as well as acknowledgments. Both the advertisement and acknowledgment packets are automatically generated by an optimization program that is built based on symbolic Monte Carlo simulation. The design...

    Provided By University of California

  • White Papers // Jun 2009

    Static Enforcement of Web Application Integrity Through Strong Typing

    Security vulnerabilities continue to plague web applications, allowing attackers to access sensitive data and co-opt legitimate web sites as a hosting ground for malware. Accordingly, researchers have focused on various approaches to detecting and preventing common classes of security vulnerabilities in web applications, including anomaly-based detection mechanisms, static and dynamic...

    Provided By University of California

  • White Papers // May 2011

    Performance Evaluation of Secure Network Coding Using Homomorphic Signature

    Network coding has gained significant attention by improving throughput and reliability in disruptive MANETs. Yet, it is vulnerable to attacks from malicious nodes. In order to prevent malicious attacks, the authors have explored the use of secure network coding schemes based on homomorphic properties of cryptographic systems. While homomorphic methods,...

    Provided By University of California

  • White Papers // Sep 2009

    Scalable Emulation of TinyOS Applications in Heterogeneous Network Scenarios

    Simulating the behavior of sensor applications in a heterogeneous network or under diverse environmental conditions is particularly challenging. In this paper, the authors present the design and implementation of TiQy, a scalable framework that allows unmodified TinyOS applications to be evaluated in a diverse set of operating conditions, including heterogeneous...

    Provided By University of California

  • White Papers // Aug 2011

    Towards Personal Content Networking

    Recent advances of technology in consumer electronics have promoted a lifestyle where people live with convenience and ease by accessing any kind of information at their finger tips. These devices also allow people to generate/share a sheer amount of personal content such as photos, videos, and documents. However, personal content...

    Provided By University of California

  • White Papers // Oct 2011

    ILS: Instant Localization Scheme for Underwater Mobile Networks

    Mobile underwater networks have recently been proposed as a way to explore and observe the ocean with a wide area coverage at reasonable cost when compared to traditional tethered approaches (e.g., seabed sensors). To achieve this goal, a swarm of mobile sensors, e.g., Autonomous Underwater Vehicles (AUVs) such as REMUS...

    Provided By University of California

  • White Papers // Jan 2012

    Routing Mechanisms for Mobile Ad Hoc Networks Based on the Energy Drain Rate

    Untethered nodes in mobile ad-hoc networks strongly depend on the efficient use of their batteries. In this paper, the authors propose a new metric, the drain rate, to forecast the lifetime of nodes according to current traffic conditions. This metric is combined with the value of the remaining battery capacity...

    Provided By University of California

  • White Papers // Jun 2009

    P2P Streaming Systems: A Survey and Experiments

    The great success of P2P systems for the purpose of file-sharing has set the path to likely be the next killer-app over the Internet, once the video streaming technology matures. Although solving scalability issues, P2P technology experiences problems of long start-time and churn-induced instability which can heavily affect the user...

    Provided By University of California

  • White Papers // Jul 2010

    On Developing Smart Applications for VANETs: Where Are We Now? Some Insights on Technical Issues and Open Problems

    The advances in research on ad hoc networks, the availability of cheap radio interfaces (e.g. Wi-Fi) and the increasing amount of electronic devices installed in vehicles have set the path for vehicular ad hoc networks. In the past few years, Vehicular Ad hoc NETwork (VANET) research has addressed all layers,...

    Provided By University of California

  • White Papers // Jun 2012

    Cooperative Localization Using Angle of Arrival Measurements: Sequential Algorithms and Non-Line-of-Sight Suppression

    The authors investigate localization of a source based on Angle of Arrival (AoA) measurements made at a geographically dispersed network of cooperating receivers. The goal is to efficiently compute accurate estimates despite outliers in the AoA measurements due to multipath reflections in Non-Line-Of-Sight (NLOS) environments. Maximal Likelihood (ML) location estimation...

    Provided By University of California

  • White Papers // Mar 2012

    Efficient and Optimally Secure Key-Length Extension for Block Ciphers Via Randomized Cascading

    The authors consider the question of efficiently extending the key length of block ciphers. To date, the approach providing highest security is triple encryption (used e.g., in Triple-DES), which was proved to have roughly k + minfn=2; k=2g bits of security when instantiated with ideal block ciphers with key length...

    Provided By University of California

  • White Papers // Mar 2009

    Online Learning in Autonomic Multi-Hop Wireless Networks for Transmitting Mission-Critical Applications

    In this paper, the authors study how to optimize the transmission decisions of nodes aimed at supporting mission-critical applications, such as surveillance, security monitoring, and military operations, etc. They focus on a network scenario where multiple source nodes transmit simultaneously mission-critical data through relay nodes to one or multiple destinations...

    Provided By University of California

  • White Papers // Mar 2012

    Opportunistic Routing With Congestion Diversity in Wireless Ad-Hoc Networks

    The authors consider the problem of routing packets across a multi-hop network consisting of multiple sources of traffic and wireless links while ensuring bounded expected delay. Each packet transmission can be overheard by a random subset of receiver nodes among which the next relay is selected opportunistically. The main challenge...

    Provided By University of California

  • White Papers // Feb 2012

    Multiflow Transmission in Delay Constrained Cooperative Wireless Networks

    This paper considers 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 California

  • White Papers // Aug 2010

    Interactive Visual Analysis of Hierarchical Enterprise Data

    In this paper, the authors present an interactive visual technique for analyzing and understanding hierarchical data, which they have applied to analyzing a corpus of technical reports produced by a corporate research laboratory. The analysis begins by selecting a known entity, such as a topic, a report, or a person,...

    Provided By University of California

  • White Papers // Dec 2010

    SUDOKU: Secure and Usable Deployment of Keys on Wireless Sensors

    Initial deployment of secrets plays a crucial role in any security design, but especially in hardware constrained wireless sensor networks. Many key management schemes assume either manually pre-installed shared secrets or keys authenticated with the aid of out-of-band channels. While manually installing secret keys affects the practicability of the key...

    Provided By University of California

  • White Papers // Jan 2012

    The Selective Intermediate Nodes Scheme for Ad Hoc On-Demand Routing Protocols

    The on-demand routing schemes in mobile ad hoc networks are appealing because of the lower routing overhead, compared with traditional proactive schemes. The on-demand routing protocols introduce routing overhead only in the presence of data packets that need routes. However, the control overhead of on-demand routing schemes increases with node...

    Provided By University of California

  • White Papers // Jun 2012

    Collaborative High Accuracy Localization in Mobile Multipath Environments

    The authors study the problem of high accuracy localization of mobile nodes in a multipath-rich environment where sub-meter accuracies are required. They employ a peer-to-peer framework where the vehicles/nodes can get pair-wise multipath-degraded ranging estimates in local neighborhoods together with a fixed number of anchor nodes. The challenge is to...

    Provided By University of California

  • White Papers // Apr 2010

    Covariance Based Signaling and Feedback Data Parameterization for the TimeVarying MIMO Broadcast Channel

    Linear precoding (beamforming) techniques that maximize the sum rate in the multi-antenna broadcast channel often suffer severe performance degradation when the channel state information at the transmitter is erroneous or outdated. This paper presents a linear precoding algorithm that uses the channel statistics rather than channel state to provide more...

    Provided By University of California

  • White Papers // Nov 2011

    How to Lower Congestion With Cross-Layer MPR-PHY/MAC Design?

    In this paper, the authors introduce a cross-layer design between PHY and MAC for Multiple Packet Reception (MPR). Based on the simulation results, three phases of operation has been identified for MPR-PHY/MAC design depending on the offered load to the network. The design is suitable for multihop ad-hoc networks. The...

    Provided By University of California

  • White Papers // Oct 2011

    CLA-MAC: A Cooperative Extension of Load Adaptive MAC Protocol

    The use of cooperative communications techniques has proven to significantly improve network performance via cooperation among network nodes. In this paper, the authors propose a cooperative extension of Load Adaptive MAC (LA-MAC) protocol proposed earlier by one as a hybrid CSMA-TDMA protocol for MANETs. They describe the design and GNU...

    Provided By University of California

  • White Papers // Jan 2012

    The Impacts of Physical Layer Parameters on the Connectivity of Ad-Hoc Networks

    The authors study the effects of physical layer parameters on the connectivity of fading wireless ad-hoc networks. Relying on a symbol error rate connectivity metric for wireless ad-hoc networks, they assume a pair of nodes are connected if their bidirectional measure of connectivity satisfies a given threshold. They investigate the...

    Provided By University of California

  • White Papers // Jan 2012

    A Constrained Resource Allocation Study for LOS MIMO Fading Ad-Hoc Networks

    The authors study constrained resource allocation problems for MIMO wireless ad-hoc networks under LOS fading. By considering the tradeoff between the aggregate consumed power and throughput of such networks, they investigate the performance characteristics of a number of MIMO coding techniques, namely MRC, STBCs, and orthogonal STTCs. Their study shows...

    Provided By University of California

  • White Papers // Jun 2011

    Fisher-Information-Matrix Based Analysis of Semiblind MIMO Frequency Selective Channel Estimation

    The authors present a study of Semi-Blind (SB) estimation for a Frequency-Selective (FS) Multiple-Input Multiple-Output (MIMO) wireless channel using a novel Fisher-Information Matrix (FIM) based approach. The frequency selective MIMO system is modeled as a matrix Finite Impulse Response (FIR) channel, and the transmitted data symbols comprise of a sequence...

    Provided By University of California

  • White Papers // Jan 2012

    PLASMA: A New Routing Paradigm for Wireless Multihop Networks

    In this paper, the authors present a new routing paradigm for wireless multi-hop networks. In plasma routing, each packet is delivered over the best available path to one of the gateways. The choice of the path and gateway for each packet is not made beforehand by the source node, but...

    Provided By University of California

  • White Papers // Feb 2011

    A Stateless Traceback Technique for Identifying the Origin of Attacks From a Single Packet

    Anonymity is one of the main motivations for conducting denial-of-service attacks. Currently, there is no mechanism to either identify the true source of an IP packet or to prove its authenticity. In this paper, the authors propose a stateless IP traceback technique that identifies the origin network of each individual...

    Provided By University of California

  • White Papers // Jan 2012

    Pricing and Revenue Sharing Strategies for Internet Service Providers

    One of the challenges facing the networking industry today is to increase the profitability of Internet services. This calls for economic mechanisms that can enable providers to charge more for better services and collect a fair share of the increased revenues. In this paper, the authors present a generic model...

    Provided By University of California

  • White Papers // Jan 2012

    Proactive Resource Provisioning

    Allocating resources in communication networks to QoS flows can require an undesirable delay or cost. As demand churns readjusting wavelength allocation in optical networks, Label Switched Path (LSP) reservations in MPLS networks, QoS connections in two-tier ad hoc networks, and Service Level Agreements (SLAs) between peering autonomous systems are just...

    Provided By University of California

  • White Papers // Jan 2012

    Effective and Efficient Localization of Multiple Faults Using Value Replacement

    The authors previously presented a fault localization technique called Value Replacement that repeatedly alters the state of an executing program to locate a faulty statement. The technique searches for program statements involving values that can be altered during runtime to cause the incorrect output of a failing run to become...

    Provided By University of California