University of California

Displaying 161-200 of 788 results

  • White Papers // Feb 2011

    Heuristic Evaluation of Programming Language Features

    Usability is an important feature for programming languages. However, user studies which compare programming languages or systems are both very expensive and typically inconclusive. In this paper, the authors posit that discount usability methods can be successfully applied to programming languages concepts such as language features. They give examples of...

    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 // Feb 2011

    An Empirical Analysis of XSS Sanitization in Web Application Frameworks

    Filtering or sanitization is the predominant mechanism in today's applications to defend against cross-site scripting (XSS) attacks. XSS sanitization can be difficult to get right as it ties in closely with the parsing behavior of the browser. This paper explains some of the subtleties of ensuring correct sanitization, as well...

    Provided By University of California

  • White Papers // Feb 2011

    Peer-to-Peer Multimedia Sharing Based on Social Norms

    Empirical data shows that in the absence of incentives, a peer participating in a Peer-to-Peer (P2P) network wishes to download content, while avoiding to contribute content in return. This phenomenon, known as free-riding, has been actively studied in the literature and incentives have been proposed to compel self-interested peers to...

    Provided By University of California

  • White Papers // Feb 2011

    Towards a Societal Scale, Mobile Sensing System

    With the proliferation of sensor equipped smart phones, and augmented reality applications fast appearing, the mobile phone is becoming something much more than a scaled-down, connected IO and processing device. In addition to these standard PC traits, a cell phone is situated in an environment, mobile, and typically co-located with...

    Provided By University of California

  • White Papers // Feb 2011

    Reduced-Bandwidth Multithreaded Algorithms for Sparse Matrix-Vector Multiplication

    On multicore architectures, the ratio of peak memory bandwidth to peak floating-point performance (byte: flop ratio) is decreasing as core counts increase, further limiting the performance of bandwidth limited applications. Multiplying a sparse matrix (as well as its transpose in the un-symmetric case) with a dense vector is the core...

    Provided By University of California

  • White Papers // Jan 2011

    Traffic Characterization and Internet Usage in Rural Africa

    While Internet connectivity has reached a significant part of the world's population, those living in rural areas of the developing world are still largely disconnected. Recent efforts have provided Internet connectivity to a growing number of remote locations, yet Internet traffic demands cause many of these networks to fail to...

    Provided By University of California

  • White Papers // Jan 2011

    A Unified CAD-PLM Architecture for Improving Electronics Design Productivity Through Automation, Collaboration, and Cloud Computing

    In electronics design, Computer Aided Design (CAD) tools manage part data in a logical schematic view (a part symbol) and a physical PCB view (a part footprint). Yet, a part has a third view, which CAD tools ignore - its supply data (manufacturer part number, variant, distributor, etc). To manage...

    Provided By University of California

  • White Papers // Jan 2011

    PoX: Protecting Users From Malicious Facebook Applications

    Online social networks such as Facebook, MySpace, and Orkut store large amounts of sensitive user data. While a user can legitimately assume that a social network provider adheres to strict privacy standards, the authors argue that it is unwise to trust third-party applications on these platforms in the same way....

    Provided By University of California

  • White Papers // Jan 2011

    Temporal Traffic Dynamics Improve the Connectivity of Ad Hoc Cognitive Radio Networks

    In an ad hoc cognitive radio network, secondary users access channels temporarily unused by primary users and the existence of a communication link between two secondary users depends on the transmitting and receiving activities of nearby primary users. Using theories and techniques from continuum percolation and ergodicity, the authors analytically...

    Provided By University of California

  • White Papers // Jan 2011

    Enhancing Data Privacy in the Cloud

    Due to its low cost, robustness, flexibility and ubiquitous nature, cloud computing is changing the way entities manage their data. However, various privacy concerns arise whenever potentially sensitive data is outsourced to the cloud. This paper presents a novel approach for coping with such privacy concerns. The proposed scheme prevents...

    Provided By University of California

  • White Papers // Jan 2011

    Rubik's for Cryptographers

    Hard mathematical problems are at the core of security arguments in cryptography. In this paper, the authors study mathematical generalizations of the famous Rubik's cube puzzle, namely the factorization, representation and balance problems in non-Abelian groups. These problems arise naturally when describing the security of Cayley hash functions, a class...

    Provided By University of California

  • White Papers // Jan 2011

    The Theory of Intervention Games for Resource Sharing in Wireless Communications

    This paper develops a game-theoretic framework for the design and analysis of a new class of incentive schemes called intervention schemes. The authors formulate intervention games, propose a solution concept of intervention equilibrium, and prove its existence in a finite intervention game. They apply the framework to resource sharing scenarios...

    Provided By University of California

  • White Papers // Jan 2011

    The SQL-Based All-Declarative FORWARD Web Application Development Framework

    The vast majority of database-driven web applications perform, at a logical level, fundamentally simple Insert/Update/Delete commands. In response to a user action on the browser, the web application executes a program that transitions the old state to a new state. The state is primarily persistent and often captured in a...

    Provided By University of California

  • White Papers // Jan 2011

    Latin Square Based Channel Access Scheduling in Large-Scale WLAN Systems

    WLAN systems based on the IEEE 802.11 could contain hundreds even up to thousands of wireless access points nowadays. However, IEEE 802.11 MAC protocols, including DCF, PCF and EDCA mechanisms, are unable to meet the challenges to provide collision freedom, especially in distributed large scale WLAN systems. The authors propose...

    Provided By University of California

  • White Papers // Jan 2011

    Flow-Sensitive Pointer Analysis for Millions of Lines of Code

    Many program analyses benefit, both in precision and performance, from precise pointer analysis. An important dimension of pointer analysis precision is flow-sensitivity, which has been shown to be useful for applications such as program verification and static analysis of binary code, among many others. However, flow-sensitive pointer analysis has historically...

    Provided By University of California

  • White Papers // Jan 2011

    Sound and Complete Monitoring of Sequential Consistency for Relaxed Memory Models

    The authors present a technique for verifying that a program has no executions violating Sequential Consistency (SC) when run under the relaxed memory models Total Store Order (TSO) and Partial Store Order (PSO). The technique works by monitoring sequentially consistent executions of a program to detect if similar program executions...

    Provided By University of California

  • White Papers // Jan 2011

    Pseudo-IP: Providing a Thin Network Layer Protocol for Semi-IntelligentWireless 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

    Energy Conservation in Datacenters Through Cluster Memory Management and Barely-Alive Memory Servers

    As a result of current resource provisioning schemes in Internet services, servers end up less than 50% utilized almost all the time. At this level of utilization, the servers' energy efficiency is less than half their efficiency at peak utilization. A solution to this problem could be consolidating workloads into...

    Provided By University of California

  • White Papers // Jan 2011

    External Double Hashing With Choice

    A novel extension to external double hashing providing significant reduction to both successful and unsuccessful search lengths is presented. The experimental and analytical results demonstrate the reductions possible. This method does not restrict the hashing table configuration parameters and utilizes very little additional storage space per bucket. The runtime performance...

    Provided By University of California

  • White Papers // Jan 2011

    Looking for Diamonds in the Desert - Extending Automatic Protocol Generation to Three-Party Authentication and Key Agreement Protocols

    The current process of designing a security protocol is usually ad-hoc and involves little formalism and mechanical assistance. Such a design process is not only slow but also error-prone. Evidence shows that even when security protocols are designed with care and examined intensely,they can still be fundamentally flawed. A classic...

    Provided By University of California

  • White Papers // Jan 2011

    Timing Analysis of Keystrokes and Timing Attacks on SSH

    SSH is designed to provide a secure channel between two hosts. Despite the encryption and authentication mechanisms it uses, SSH has two weakness: First, the transmitted packets are padded only to an eight-byte boundary (if a block cipher is in use), which reveals the approximate size of the original data....

    Provided By University of California

  • White Papers // Jan 2011

    Routing and Multicast in Multihop, Mobile Wireless Networks

    In this paper, the authors present a multicast protocol which builds upon a cluster based wireless network infrastructure. First, they introduce the network infrastructure which includes several innovative features such as: minimum change cluster formation; dynamic priority token access protocol, and; distributed hierarchical routing. Then, for this infrastructure they propose...

    Provided By University of California

  • White Papers // Jan 2011

    Asymptotically Efficient Multi-Channel Estimation for Opportunistic Spectrum Access

    The problem of estimating the parameters of multiple independent continuous-time Markov on-off processes is considered. The objective is to minimize the total Mean Square Error (MSE) under a constraint on the total sensing time. The Fisher information matrix for the primary traffic model and the maximum likelihood estimator are obtained...

    Provided By University of California

  • White Papers // Jan 2011

    Spectrum Opportunity Detection: How Good Is Listen-Before-Talk?

    The authors consider spectrum opportunity detection in cognitive radio networks for spectrum overlay. They highlight the differences between detecting primary signals and detecting spectrum opportunities. They show that besides noise and fading, the geographic distribution and traffic pattern of primary users have significant impact on the performance of spectrum opportunity...

    Provided By University of California

  • White Papers // Jan 2011

    ASCENT: Adaptive Self-Configuring SEnsor Networks Topologies

    Advances in micro-sensor and radio technology will enable small but smart sensors to be deployed for a wide range of environmental monitoring applications. The low per-node cost will allow these wireless networks of sensors and actuators to be densely distributed. The nodes in these dense networks will coordinate to perform...

    Provided By University of California

  • White Papers // Jan 2011

    On the Throughput Capacity of Random Wireless Networks

    The authors consider the problem of how throughput in a wireless network with randomly located nodes scales as the number of users n grows. Their results rely on percolation theory arguments. When the node density is too high the network is fully connected but generates excessive interference. In the low...

    Provided By University of California

  • White Papers // Jan 2011

    Distributed Channel Access Scheduling for Ad Hoc Networks

    In this paper, the authors present and analyze protocols for Time-Division Multiple Access (TDMA) scheduling in ad hoc networks with omni-directional antennas. These protocols use a Neighbor-aware Contention Resolution (NCR) algorithm to elect deterministically one or multiple winners in a given contention context based on the topology information within two...

    Provided By University of California

  • White Papers // Jan 2011

    Joint Design of Scheduling and Routing Based on Connected Coverage for Optimal Sensor Network Lifetime

    The authors consider information retrieval in a wireless sensor network deployed to monitor a spatially corrected random led. The measured data are sent to an access point through multi-hop transmissions. They address the joint design of sensor scheduling and information routing in each data collection to optimize a performance measure:...

    Provided By University of California

  • White Papers // Jan 2011

    Coverage-Based Information Retrieval for Lifetime Maximization in Sensor Networks

    The authors consider information retrieval in a wireless sensor network deployed to monitor a spatially correlated random field. They address sensor scheduling in each data collection under the performance measure of network lifetime. They formulate this problem as an energy constrained coverage problem and proposal a scheduling algorithm based on...

    Provided By University of California

  • White Papers // Jan 2011

    A Self-Healing and Optimizing Routing Technique for Ad Hoc Networks

    On demand routing protocols provide scalable and cost-effective solutions for packet routing in wireless ad hoc networks. The paths generated by these protocols may deviate far from the optimal because of the lack of knowledge about the global topology and the mobility of nodes. Routing optimality affects network performance, especially...

    Provided By University of California

  • White Papers // Jan 2011

    Cryptographic Voting Protocols: A Systems Perspective

    Cryptographic voting protocols offer the promise of verifiable voting without needing to trust the integrity of any software in the system. However, these cryptographic protocols are only one part of a larger system composed of voting machines, software implementations, and election procedures, and they must analyze their security by considering...

    Provided By University of California

  • White Papers // Jan 2011

    Distillation Codes and Applications to DoS Resistant Multicast Authentication

    The authors introduce distillation codes, a method for streaming and storing data. Like erasure codes, distillation codes allow information to be decoded from a sufficiently large quorum of symbols. In contrast to erasure codes, distillation codes are robust against pollution attacks, a powerful class of Denial of Service (DoS) attacks...

    Provided By University of California

  • White Papers // Jan 2011

    Hidden Markov Model Cryptanalysis

    The authors present HMM attacks, a new type of cryptanalysis based on modeling randomized side channel countermeasures as Hidden Markov Models (HMM's). They also introduce Input Driven Hidden Markov Models (IDHMM's), a generalization of HMM's that provides a powerful and unified cryptanalytic framework for analyzing countermeasures whose operational behavior can...

    Provided By University of California

  • White Papers // Jan 2011

    Detecting MAC Layer Back-Off Timer Violations in Mobile Ad Hoc Networks

    In IEEE 802.11 based ad hoc networks, by simply manipulating the back-off timers and/or wait times prior to transmission, malicious nodes can cause a drastically reduced allocation of bandwidth to well-behaved nodes. This can result in causing bandwidth starvation and hence, a denial of service to legitimate nodes. The authors...

    Provided By University of California

  • White Papers // Jan 2011

    Layered Media Multicast Control (LMMC): Real-Time Error Control

    The authors study the problem of real-time error control in layered and replicated media systems. They formulate an optimization problem aimed at minimizing a cost metric defined over the wasted bandwidth of redundancy in such systems. They also provide an analytical solution to the problem in the context of Layered...

    Provided By University of California

  • White Papers // Jan 2011

    Power Conservation and Quality of Surveillance in Target Tracking Sensor Networks

    Target tracking is an important application of wireless sensor networks. In this application, the sensor nodes collectively monitor and track the movement of an event or target object. The network operations have two states: the surveillance state during the absence of any event of interest, and the tracking state which...

    Provided By University of California

  • White Papers // Jan 2011

    Comparison: ASR is a Variant of ANODR

    Recently, on-demand routing approach has been embraced by several anonymous routing schemes to protect Mobile Ad hoc NETworks (MANETs) from traffic analysts' attacks. ANODR is the first in literature an on-demand anonymous routing protocol proposed for MANETs, followed by SDAR, ASR and MASK which use the same on-demand approach. While...

    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 // Apr 2009

    Authentication Without Elision

    Specification documents for real-world authentication protocols typically mandate some aspects of a protocol's behavior but leave other features optional or undefined. In addition, real-world schemes often include parameter negotiations, authenticate associated data, and support a multiplicity of options. The cryptographic community has routinely elided such matters from the authors' definitions,...

    Provided By University of California

  • White Papers // Apr 2009

    A Secure Cryptographic Token Interface

    Cryptographic keys must be protected from exposure. In real-world applications, they are often guarded by cryptographic tokens that employ sophisticated hardware-security measures. Several logical attacks on the key management operations of cryptographic tokens have been reported in the past, which allowed exposing keys merely by exploiting the token API in...

    Provided By University of California

  • White Papers // Feb 2010

    Structural Change And Growth In India

    This paper examines the link between structural change and growth in India. It constructs indices of structural change, and performs a time series analysis of the data. It finds that 1988 marks a break in the time series of growth and structural change. There is one-way causality from structural change...

    Provided By University of California

  • White Papers // Nov 2008

    Understanding West German Economic Growth In The 1950s

    The authors evaluate explanations for why Germany grew so quickly in the 1950s. The recent literature has emphasized convergence, structural change and institutional shake-up while minimizing the importance of the postwar shock. They show that this shock and its consequences were more important than neoclassical convergence and structural change in...

    Provided By University of California

  • White Papers // Jun 2011

    Vintage Capital Growth Theory: Three Breakthroughs

    Vintage capital growth models have been at the heart of growth theory in the 60s. This research line collapsed in the late 60s with the so-called embodiment controversy and the technical sophistication of the vintage models. This paper analyzes the astonishing revival of this literature in the 90s. In particular,...

    Provided By University of California

  • White Papers // Jun 2010

    Multinational Firms And Trade: Gravity Versus Market Power In A Ricardian World

    Are multinational firms good for consumer welfare? The authors build a model of foreign direct investment and trade that exploits both firm heterogeneity and strategic pricing behavior, embodying direct exporting and multinational production for both export and local sale in one framework. They show that improved efficiency in target firms...

    Provided By University of California

  • White Papers // Nov 2009

    Kicking The Bad Apples Out: Tariff Liberalization And Bilateral Trade

    In this paper, the author presents a simple model in which liberalization of a Most-Favored Nation (MFN) tariff need not increase bilateral imports from all MFN sources. While liberalization must increase imports from high price MFN sources, it may decrease imports from low price MFN sources. This has stark implications...

    Provided By University of California

  • White Papers // Jan 2010

    Business Travel As An Input To International Trade

    The importance of business and social networks in generating trade is becoming increasingly recognized in the international economics literature. An important way in which people build and maintain networks is through face-to-face meetings. The author proposes an empirical model in which business travel helps to overcome informational asymmetries in international...

    Provided By University of California

  • White Papers // Jul 2010

    Knowledge Transfers From Multinational To Domestic Firms: Evidence From Worker Mobility

    Labor turnover is a commonly-cited mechanism for the transmission of technology from multinational to domestic firms, but until now there has been little direct evidence for this mechanism. Using a novel matched establishment-worker database from Brazil, the author presents evidence consistent with the existence of positive multinational wage spillovers through...

    Provided By University of California

  • White Papers // Sep 2009

    Foreign Direct Investment In Cross-Border Infrastructure

    In this paper, the authors critically review the relevant information and literature and that can enhance the feasibility and the successful implementation of cross-border infrastructure projects. They provide detailed information concerning FDI into the major emerging regions: East Asia/Pacific, Latin America and Eastern Europe. They also discuss the theoretical and...

    Provided By University of California

  • White Papers // Feb 2009

    From New Deal Institutions To Capital Markets: Commercial Consumer Risk Scores And The Making Of Subprime Mortgage Finance

    At the tail end of 2006, the 'Subprime' hit the news with a bang when default rates shot up in a segment of mortgage finance that had previously received little attention in mainstream reporting. Against rising central bank interest rates, and following the collapse of the housing bubble, borrowers bearing...

    Provided By University of California

  • White Papers // Feb 2009

    Racial Exclusion And The Political Economy Of The Subprime Crisis

    This paper develops a political economic explanation of the 2007-09 US subprime crisis which focuses on one of its central causes: the transformation of racial exclusion in US mortgage markets. Until the early 1990s, racial minorities were systematically excluded from mortgage finance due to bank redlining and discrimination. But then...

    Provided By University of California

  • White Papers // Apr 2011

    Illiquid Financial Markets And Monetary Policy

    This paper analyzes the role of money in markets where financial investment takes place in a decentralized fashion. A key methodological contribution is the development of a dynamic framework that brings together a model for illiquid assets a la Duffie et al. and a monetary framework a la Lagos and...

    Provided By University of California

  • White Papers // Dec 2008

    A Dynamic Model Of Entrepreneurship With Borrowing Constraints: Theory And Evidence

    Does wealth beget wealth and entrepreneurship, or is entrepreneurship mainly determined by an individual's ability? A large literature studies the relationship between wealth and entry to entrepreneurship to inform this question. This paper shows that in a dynamic model, the existence of financial constraints to the creation of businesses implies...

    Provided By University of California

  • White Papers // Jun 2009

    Fuzzy Math, Disclosure Regulation And Credit Market Outcomes: Evidence From Truth-In-Lending Reform

    Consumer installment lenders prefer to market "Low monthly payments" and shroud interest rates. Why not voluntarily disclose rates? The authors show that when an interest rate is not disclosed, most consumers substantially underestimate it using information on the monthly payment, loan principal and maturity. This "Fuzzy math" or "Payment/interest bias"...

    Provided By University of California

  • White Papers // Apr 2011

    Financial Crises, Credit Booms, And External Imbalances: 140 Years Of Lessons

    Do external imbalances increase the risk of financial crises? In this paper, the authors study the experience of 14 developed countries over 140 years (1870{2008). They exploit their long-run dataset in a number of different ways. First, they apply new statistical tools to describe the temporal and spatial patterns of...

    Provided By University of California

  • White Papers // Aug 2009

    Modeling and Characterizing User Experience in a Cloud Server Based Mobile Gaming Approach

    With the evolution of mobile devices and networks, and the growing trend of mobile Internet access, rich, multi-player gaming using mobile devices, similar to PC-based Internet games, has tremendous potential and interest. However, the current client-server architecture for PC-based Internet games, where most of the storage and computational burden of...

    Provided By University of California

  • White Papers // May 2011

    The Effects Of Monetary Policy "News" And "Surprises"

    There is substantial agreement in the monetary policy literature over the effects of exogenous monetary policy shocks. The shocks that are investigated, however, almost exclusively represent unanticipated changes in policy, which surprise the private sector and which are typically found to have a delayed and sluggish effect on output. In...

    Provided By University of California

  • White Papers // May 2011

    Heterogeneity-Aware Resource Allocation and Scheduling in the Cloud

    Data analytics are key applications running in the cloud computing environment. To improve performance and cost-effectiveness of a data analytics cluster in the cloud, the data analytics system should account for heterogeneity of the environment and workloads. In addition, it also needs to provide fairness among jobs when multiple jobs...

    Provided By University of California

  • White Papers // Feb 2009

    Bank Competition And Economic Stability: The Role Of Monetary Policy

    This paper analyzes the dual role of monetary policy for economic efficiency and stability in a model of endogenous bank competition. Multiple equilibria emerge from the complementarity between bank and non-financial firm decisions. Adverse aggregate or idiosyncratic liquidity shocks may cause a breakdown in which the economy collapses into no-production...

    Provided By University of California

  • White Papers // Jul 2009

    SenSearch: GPS and Witness Assisted Tracking for Delay Tolerant Sensor Networks

    This paper describes the design, implementation and performance evaluation of SenSearch, an outdoors, GPS assisted personnel tracking system using MICA motes. SenSearch is a mobile wireless ad-hoc network comprised of sensor nodes worn by users. These nodes store and forward information about the location of other nodes in an environment...

    Provided By University of California

  • White Papers // Dec 2010

    Good Neighbor: Secure Pairing of Nearby Wireless Devices by Multiple Antennas

    The proliferation of personal wireless devices requires secure connection between them. While it is easy to securely pair electronic devices by wires, it is very challenging to pair them wirelessly when they have no prior association. The authors propose Good Neighbor, a novel scheme that securely pairs nearby wireless devices...

    Provided By University of California

  • White Papers // Aug 2008

    The Effect of Link Churn on Wireless Routing

    In this paper, the authors examine the spatiotemporal dynamics of wireless links and evaluate their effect on routing. They ran several experiments using a testbed consisting of 57 MicaZ motes, and collected data on link behavior over one entire day. They use this data to observe the overall network connectivity...

    Provided By University of California

  • White Papers // Aug 2009

    Evaluation of Traffic Data Obtained Via GPS-Enabled Mobile Phones: The Mobile Century Field Experiment

    The growing need of the driving public for accurate traffic information has spurred the deployment of large scale dedicated monitoring infrastructure systems, which mainly consist in the use of inductive loop detectors and video cameras. On-board electronic devices have been proposed as an alternative traffic sensing infrastructure, as they usually...

    Provided By University of California

  • White Papers // Jan 2011

    Power Conservation and Quality of Surveillance in Target Tracking Sensor Networks

    Target tracking is an important application of wireless sensor networks. In this application, the sensor nodes collectively monitor and track the movement of an event or target object. The network operations have two states: the surveillance state during the absence of any event of interest, and the tracking state which...

    Provided By University of California

  • White Papers // Jan 2011

    Comparison: ASR is a Variant of ANODR

    Recently, on-demand routing approach has been embraced by several anonymous routing schemes to protect Mobile Ad hoc NETworks (MANETs) from traffic analysts' attacks. ANODR is the first in literature an on-demand anonymous routing protocol proposed for MANETs, followed by SDAR, ASR and MASK which use the same on-demand approach. While...

    Provided By University of California

  • White Papers // Aug 2011

    Linear-Feedback Sum-Capacity for Gaussian Multiple Access Channels

    The capacity region of the N-sender Gaussian multiple access channel with feedback is not known in general. This paper studies the class of linear-feedback codes that includes (non-linear) non-feedback codes at one extreme and the linear-feedback codes by Schalkwijk and Kailath, Ozarow, and Kramer at the other extreme. In particular,...

    Provided By University of California

  • White Papers // Jan 2009

    Delay-Optimal Server Allocation in Multi-Queue Multi-Server Systems With Time-Varying Connectivities

    This paper considers the problem of optimal server allocation in a time-slotted system with N statistically symmetric queues and K servers when the arrivals and channels are stochastic and time-varying. In this setting, the authors identify two classes of ?Desirable? policies with potentially competing goals of maximizing instantaneous throughput versus...

    Provided By University of California

  • White Papers // Sep 2008

    High-SNR Analysis of Outage-Limited Communications With Bursty and Delay-Limited Information

    This paper analyzes the high-SNR asymptotic error performance of outage-limited communications with fading, where the number of bits that arrive at the transmitter during any timeslot is random but the delivery of bits at the receiver must adhere to a strict delay limitation. Specifically, bit errors are caused by erroneous...

    Provided By University of California

  • White Papers // Feb 2010

    NEW: A Channel Management Strategy for IEEE 802.11n

    IEEE 802.11n is a newly emerging wireless standard which, relative to former 802.11 protocols, such as 802.11a/b/g, has a number of new mechanisms that enable multi-fold increases in transmission speeds. These new mechanisms include Multiple-Input-Multiple-Output (MIMO) transmission schemes as well as the option for channel bonding two 20MHz channels into...

    Provided By University of California

  • White Papers // Feb 2010

    Anycast Cloud Routing for Wireless Networks

    The authors envision the present and future topologies of wireless networks to include complex hierarchies of infrastructured, and semi-infrastructured multihop networks using a variety of connection technologies. In this hierarchy the weakest component is the wireless multihop network. Wireless connections are known to experience unpredictable packet loss. This loss pattern...

    Provided By University of California

  • White Papers // Feb 2010

    Analysis of Internet Usage in a Rural Wireless Network

    There have been a number of rural wireless network proving Internet access operating since 2005. But little is known about how the Internet is being used on these networks and whether it follows similar trends to Internet usage patterns in developed regions. It is clear that certain commonly accepted content...

    Provided By University of California

  • White Papers // Feb 2010

    IMOP: Improving Multicast Only Performance in Layer 2 Access Networks

    One of multicast's greatest success stories to date has been service providers' deployment of IPTV. A common thread among IPTV solutions is an attempt to improve perception of channel changes for broadcast television through the use of unicast "Bursts" intended to supplement the streaming media contained in multicast groups during...

    Provided By University of California

  • White Papers // Feb 2010

    Power Guru: Implementing Smart Power Management on the Android Platform

    Improving battery life in mobile devices has become a very important area of research. Other components like the CPU, has had some major upgrades while batteries? development has lacked the same progression. The authors? goal is to implement a smart power management system that looks at the currently running applications...

    Provided By University of California

  • White Papers // Feb 2010

    Mobile Device Theft Recovery Applicaiton

    The constant access to information and computing resources brought by mobile devices had changed the nature of computing and communication experience. With more and more cell phones and laptops sold every year, stolen and lost devices have become a rising concern. Several theft recovery applications have been developed targeted specifically...

    Provided By University of California

  • White Papers // Jan 2010

    Energy Efficient Throughput Optimization in Multi-Hop Wireless Networks

    Throughput, fairness, and energy consumption are often conflictly objectives in multi-hop wireless networks. In this paper, the authors propose the notion of lexicographical maxmin energy efficiency throughput fairness that achieves throughput fairness per unit energy. Compared with maxmin throughput fairness and maxmin time fairness, the proposed scheme allocates more bandwidth...

    Provided By University of California

  • White Papers // Jan 2011

    Temporal Traffic Dynamics Improve the Connectivity of Ad Hoc Cognitive Radio Networks

    In an ad hoc cognitive radio network, secondary users access channels temporarily unused by primary users and the existence of a communication link between two secondary users depends on the transmitting and receiving activities of nearby primary users. Using theories and techniques from continuum percolation and ergodicity, the authors analytically...

    Provided By University of California

  • White Papers // Sep 2009

    Minimum-Energy Multicast Tree in Cognitive Radio Networks

    The authors address the multicast problem in cognitive radio networks, where secondary users exploit channels temporarily unused by primary users (i.e., spectrum opportunities). The existence of a communication link between two secondary users depends not only on the transmission power of the secondary transmitter and the distance between these two...

    Provided By University of California

  • White Papers // Mar 2009

    Preamble Design for Non-Contiguous Spectrum Usage in Cognitive Radio Networks

    Cognitive radios can significantly improve spectrum efficiency by using locally available spectrum. The efficiency, however, depends heavily on their transceiver design. In particular, being able to use non-contiguously aligned spectrum bands simultaneously is a critical requirement. Prior work in this area requires a control channel so that transmitter/receiver pairs can...

    Provided By University of California

  • White Papers // Oct 2008

    Traffic-Aware Dynamic Spectrum Access

    Demand-driven spectrum allocation can drastically improve performance for Wi-Fi access points struggling under increasing user demands. While their frequency agility makes cognitive radios ideal for this challenge, performing adaptive spectrum allocation is a complex and difficult process. In this paper, the authors propose FLEX, an efficient spectrum allocation architecture that...

    Provided By University of California