University of Texas

Displaying 241-277 of 277 results

  • White Papers // Jul 2009

    Calculating, Creating, And Claiming Value In Business Markets: Status And Research Agenda

    B2B markets offer challenges that differ from those in B2C markets in addressing these issues (e.g., Anderson, Narus, and Narayandas 2009; Dwyer and Tanner 2008). These challenges stem from the fact that most B2B markets (relative to B2C markets) are characterized by a far fewer buyers who buy in much...

    Provided By University of Texas

  • White Papers // Jul 2009

    An Optimal Boundary-Fair Scheduling Algorithm for Multiprocessor Real-Time Systems

    Although the scheduling problem for multiprocessor real-time systems has been studied for decades, it is still an evolving research field with many open problems. In this paper, focusing on periodic real-time tasks, the authors propose a novel optimal scheduling algorithm, namely Boundary fair (Bfair), which follows the same line of...

    Provided By University of Texas

  • White Papers // Jul 2009

    Block Diagonalization in the MIMO Broadcast Channel With Delayed CSIT

    This paper investigates the impact of delayed Channel State Information at the Transmitter (CSIT) on the MIMO broadcast channel with Block Diagonalization (BD) pre-coding. First, an upper bound for the achievable throughput is provided, which shows that BD is more robust to imperfect CSIT than zero-forcing pre-coding as it has...

    Provided By University of Texas

  • White Papers // Jul 2009

    Position Paper for Workshop on Future Directions in Cyber-Physical Systems Security

    Cyber-Physical System (CPS) security presents new problems inasmuch as cyber-physical systems are different from either information systems (IS) or Physical Control Systems (PCS) in that there are interactions between the information processing elements and the physical control elements that neither IS nor PCS alone may incur. In computational terms, CPS...

    Provided By University of Texas

  • White Papers // Jul 2009

    Transfer Learning From Minimal Target Data by Mapping Across Relational Domains

    A central goal of transfer learning is to enable learning when training data from the domain of interest is limited. Yet, work on transfer across relational domains has so far focused on the case where there is a significant amount of target data. This paper bridges this gap by studying...

    Provided By University of Texas

  • White Papers // Jun 2009

    PAQ: Adapting Query Fidelity in Dynamic Networks

    Ubiquitous computing applications have been enabled by a tight embedding of computation to the environment, support for dynamic networks, and the physical distribution of application components. Applications respond to frequent changes, detected through persistent monitoring of the environment in domains such as construction sites, where maintaining safety is essential; in...

    Provided By University of Texas

  • White Papers // Jun 2009

    Towards Adaptive Resource-Driven Routing

    In pervasive computing environments, applications find themselves in constantly changing operating conditions. Such applications often need to discover locally available resources on-demand. Communication protocols have been developed that base discovery not on the unique address of the destination but on application-level characteristics of the destination host. Previous work has focused...

    Provided By University of Texas

  • White Papers // Jun 2009

    Resolving and Mediating Ambiguous Contexts for Pervasive Care Environments

    Ubiquitous (or smart) healthcare applications envision sensor rich computing and networking environments that can capture various types of contexts of patients (or inhabitants of the environment), such as their location, activities and vital signs. Such context information is useful in providing health related and wellness management services in an intelligent...

    Provided By University of Texas

  • White Papers // Jun 2009

    Web 2.0 and Semantic Web Portal for Annotation and Discovery of Web Services in Geosciences

    With the rapid development of e-Science and scientific workflow technologies, geosciences Web portals are becoming even more important to support geoscientists in their research and discovery. While existing portals provide convenient means for humans to share and search for scientific data and services, they provide little support for automated agents...

    Provided By University of Texas

  • White Papers // Jun 2009

    A Location-Determination Application in WirelessHART

    WirelessHART is an emerging wireless communication standard that is targeted at the real-time process control industry. An example application of wireless communication in an industrial process control plant is the location of field engineers. The capability to locate personnel is a safety critical issue in process control plants because of...

    Provided By University of Texas

  • White Papers // Jun 2009

    A Framework for Modeling Security Measures

    This paper introduces a framework that provides a model for describing security measures and their relative effectiveness as well as importance. This model enhances computer security training and educational curriculum by providing experimental data and analysis to educators and students. Business environments will benefit from this model by enabling more...

    Provided By University of Texas

  • White Papers // Jun 2009

    Graphical Models of Separation Logic

    Graphs are used to model control and data flow among events occurring in the execution of a concurrent program. The authors' treatment of data flow covers both shared storage and external communication. Nevertheless, the laws of Hoare and Jones correctness reasoning remain valid when interpreted in this general model. In...

    Provided By University of Texas

  • White Papers // May 2009

    Security Threat and Vulnerability Mitigation Patterns: A Case of Credit Card Theft Mitigation

    Most attacks on computer and software systems are caused by threats to known vulnerabilities. Part of the reason is that one needs a lot of knowledge in developing secure systems, but it is difficult to obtain sufficient knowledge and use it correctly as security incident reports and security standards are...

    Provided By University of Texas

  • White Papers // May 2009

    On the Secrecy Rate of Interference Networks Using Structured Codes

    This paper shows that structured transmission schemes are a good choice for secret communication over interference networks with an eavesdropper. Structured transmission is shown to exploit channel asymmetries and thus perform better than randomly generated codebooks for such channels. For a class of interference channels, the authors show that an...

    Provided By University of Texas

  • White Papers // May 2009

    ODON: An On-Demand Security Overlay for Mission-Critical Applications

    In this paper, the authors consider the construction of a large-scale, highly available and secure overlay network to enable mission-critical communication between emergency personnel at a disaster area and their coordinating agencies across the Internet. This network is designed to be secure against network-based failures and external attacks including Denial...

    Provided By University of Texas

  • White Papers // May 2009

    Coverage in Multi-Antenna Two-Tier Networks

    In two-tier networks comprising a conventional cellular network overlaid with shorter range hotspots (e.g. femtocells, distributed antennas, or wired relays)with universal frequency reuse, the near-far effect from cross-tier interference creates dead spots where reliable coverage cannot be guaranteed to users in either tier. Equipping the macrocell and femtocells with multiple...

    Provided By University of Texas

  • White Papers // May 2009

    SOAR: Simple Opportunistic Adaptive Routing Protocol for Wireless Mesh Networks

    Multihop wireless mesh networks are becoming a new attractive communication paradigm owing to their low cost and ease of deployment. Routing protocols are critical to the performance and reliability of wireless mesh networks. Traditional routing protocols send traffic along predetermined paths and face difficulties in coping with unreliable and unpredictable...

    Provided By University of Texas

  • White Papers // May 2009

    Target Debt Ratios, Adverse Selection Costs, And Equity Mis-Pricing

    Previous studies disagree on the speed at which firms adjust their leverage toward a target. The authors argue that a portion of this variance is caused by two factors. First, firms face a 'Hard' boundary when over levered. This is due to the present value of bankruptcy costs increasing at...

    Provided By University of Texas

  • White Papers // Apr 2009

    Quicklink Selection for Navigational Query Results

    Quicklinks for a website are navigational shortcuts displayed below the website homepage on a search results page, and that let the users directly jump to selected points inside the website. Since the real-estate on a search results page is constrained and valuable, picking the best set of quicklinks to maximize...

    Provided By University of Texas

  • White Papers // Apr 2009

    Inputs of Coma: Static Detection of Denial-of-Service Vulnerabilities

    As networked systems grow in complexity, they are increasingly vulnerable to Denial-of-Service (DoS) attacks involving resource exhaustion. A single malicious input of coma can trigger high-complexity behavior such as deep recursion in a carelessly implemented server, exhausting CPU time or stack space and making the server unavailable to legitimate clients....

    Provided By University of Texas

  • White Papers // Apr 2009

    Mode Switching for the Multi-Antenna Broadcast Channel Based on Delay and Channel Quantization

    Imperfect channel state information degrades the performance of Multiple-Input Multiple-Output (MIMO) communications; its effects on Single-User (SU) and MultiUser (MU) MIMO transmissions are quite different. In particular, MU-MIMO suffers from residual interuser interference due to imperfect channel state information while SU-MIMO only suffers from a power loss. This paper compares...

    Provided By University of Texas

  • White Papers // Apr 2009

    Images Of Europeans: In-Group Trust And Support For European Integration

    Prior research on citizen support for European integration does not consider how individuals' evaluations of European nationalities are associated with support. This paper fills this gap by developing a political cohesion model based on social identity theory. The author claims that the probability of supporting integration increases with greater levels...

    Provided By University of Texas

  • White Papers // Apr 2009

    Enforcing IRM Security Policies: Two Case Studies

    SPoX (Security Policy XML) is a declarative language for specifying application security policies for enforcement by In-lined Reference Monitors. Two case studies are presented that demonstrate how this language can be used to effectively enforce application-specific security policies for untrusted Java applications in the absence of source code. In-lined Reference...

    Provided By University of Texas

  • White Papers // Apr 2009

    Social Network Classification Incorporating Link Type Values

    Classification of nodes in a social network and its applications to security informatics have been extensively studied in the past. However, previous paper generally does not consider the types of links (e.g., whether a person is friend or a close friend) that connect social networks members for classification purposes. Here,...

    Provided By University of Texas

  • White Papers // Mar 2009

    PADS: A Policy Architecture for Distributed Storage Systems

    This paper presents PADS, a policy architecture for building distributed storage systems. A policy architecture has two aspects. First, a common set of mechanisms that allow new systems to be implemented simply by defining new policies. Second, a structure for how policies, themselves, should be specified. In the case of...

    Provided By University of Texas

  • White Papers // Mar 2009

    Detection and Prevention Methods of Botnet-Generated Spam

    Although anti-spam measures are improving, the spam volume is increasing due to the use of Botnets. Botnets facilitate an efficient generation and guaranteed delivery of large volumes of spam. Spambots, or spam-generating bots, use different transmission methods based on the network settings of the infected host. These methods include relaying,...

    Provided By University of Texas

  • White Papers // Mar 2009

    Tactical Synthesis of Efficient Global Search Algorithms

    Algorithm synthesis transforms a formal specification into an efficient algorithm to solve a problem. Algorithm synthesis in Specware combines the formal specification of a problem with a high-level algorithm strategy. To derive an efficient algorithm, a developer must define operators that refine the algorithm by combining the generic operators in...

    Provided By University of Texas

  • White Papers // Mar 2009

    Synthesis of Fast Programs for Maximum Segment Sum Problems

    It is well-known that a naive algorithm can often be turned into an efficient program by applying appropriate semantic spreserving transformations. This technique has been used to derive programs to solve a variety of maximum-sum programs. One problem with this approach is that each problem variation requires a new set...

    Provided By University of Texas

  • White Papers // Mar 2009

    DexterNet: An Open Platform for Heterogeneous Body Sensor Networks and Its Applications

    The authors present an open-source platform for wireless body sensor networks called DexterNet. The system supports real-time, persistent human monitoring in both indoor and outdoor environments. The platform utilizes a three-layer architecture to control heterogeneous body sensors. The first layer called the Body Sensor Layer (BSL) deals with design of...

    Provided By University of Texas

  • White Papers // Feb 2009

    Auction Pricing: A Case Study Assessing The Price Elasticity Of Demand Based On Supply And The Revenue Equivalence Theorem

    This paper addresses the price elasticity of demand related to various categories of goods sold within the consignment auction-marketing environment. An actual ongoing non-traditional business organization specializing in the nation-wide distribution of merchandise via consignment auctions provides data for this case study. Originally developed and initiated in 1993 in response...

    Provided By University of Texas

  • White Papers // Nov 2008

    Using Anonymized Data for Classification

    In recent years, anonymization methods have emerged as an important tool to preserve individual privacy when releasing privacy sensitive data sets. This interest in anonymization techniques has resulted in a plethora of methods for anonymizing data under different privacy and utility assumptions. At the same time, there has been little...

    Provided By University of Texas

  • White Papers // Aug 2008

    An Asynchronous Neighbor Discovery Algorithm for Cognitive Radio Networks

    Cognitive Radio (CR) technology is a promising emerging technology that enables a more efficient usage of already assigned spectrum. However, before CR networks can be deployed, new algorithms and protocols need to be developed. When forming an ad-hoc Cognitive Radio Network (CRN), one of the fundamental tasks is to determine...

    Provided By University of Texas

  • White Papers // Apr 2007

    Enforcing Honesty in Assured Information Sharing within a Distributed System

    The growing number of distributed information systems such as the internet has created a need for security in data sharing. When several autonomous parties attempt to share data, there is not necessarily any guarantee that the participants will share data truthfully. In fact, there is often a large incentive to...

    Provided By University of Texas

  • White Papers // Feb 2007

    Sustainable IT Outsourcing Success: Let Enterprise Architecture Be Your Guide

    This paper explores the relationship between IT outsourcing and enterprise architecture. In an earlier paper which described four stages of architecture maturity (business silos, standardized technology, rationalized process, and business modularity). In this paper it is concluded that three different outsourcing arrangements support transitions from one stage to another. Firms...

    Provided By University of Texas

  • White Papers // Jan 2007

    Disclosure Quality And Its Effect On Litigation Risk

    This paper examines the relationship between the quality of disclosure in companies' 10-K filings and the risk of securities class action litigation. The author uses a dataset containing 10-K documents filed electronically with the SEC in the period 1996-2005. Using two content analysis software programs that analyze the categories of...

    Provided By University of Texas

  • White Papers // Feb 2006

    Sovereign Joins

    The authors present a secure network service for sovereign information sharing whose only trusted component is an off-the shelf secure coprocessor. The participating data providers send encrypted relations to the service that sends the encrypted results to the recipients. The technical challenge in implementing such a service arises from the...

    Provided By University of Texas

  • White Papers // Jul 2001

    Product Costing And Pricing Under Long Term Capacity Commitment

    This white paper discusses about a model that is developed to analyze optimal product costing and pricing decisions when a firm must make long term commitments to some activity resource capacities. The problem is complex because of interactions between the initial capacity choices and adjustments in product costs and prices...

    Provided By University of Texas

  • White Papers // Jan 2012

    XML Query Routing in Structured P2P Systems

    This paper addresses the problem of data placement, indexing, and querying large XML data repositories distributed over an existing P2P service infrastructure. The authors' architecture scales gracefully to the network and data sizes, is fully distributed, fault tolerant and self-organizing, and handles complex queries efficiently, even those queries that use...

    Provided By University of Texas

  • White Papers // Jan 2011

    A Fully Pipelined XQuery Processor

    The authors present a high-performance, pull-based streaming processor for XQuery, called XQPull, that can handle many essential features of the language, including general predicates, recursive queries, backward axis steps, and function calls, using a very small amount of caching. Their framework is based on a new type of event streams,...

    Provided By University of Texas

  • White Papers // Sep 2011

    Supervised Learning for Insider Threat Detection Using Stream Mining

    Insider threat detection requires the identification of rare anomalies in contexts where evolving behaviors tend to mask such anomalies. This paper proposes and tests an ensemble-based stream mining algorithm based on supervised learning that addresses this challenge by maintaining an evolving collection of multiple models to classify dynamic data streams...

    Provided By University of Texas

  • White Papers // Nov 2011

    Insider Threat Detection Using Stream Mining and Graph Mining

    Evidence of malicious insider activity is often buried within large data streams, such as system logs accumulated over months or years. Ensemble-based stream mining leverages multiple classification models to achieve highly accurate anomaly detection in such streams even when the stream is unbounded, evolving, and unlabeled. This makes the approach...

    Provided By University of Texas

  • White Papers // Apr 2011

    Towards Security-Aware Program Visualization for Analyzing In-Lined Reference Monitors

    In-lined Reference Monitoring frameworks are an emerging technology for enforcing security policies over untrusted, mobile, binary code. However, formulating correct policy specifications for such frameworks to enforce remains a daunting undertaking with few supporting tools. A visualization approach is proposed to aid in this task; preliminary results are presented in...

    Provided By University of Texas

  • White Papers // Sep 2010

    Challenges and Future Directions of Software Technology: Secure Software Development

    Developing large scale software systems has major security challenges. This paper describes the issues involved and then addresses two topics: formal methods for emerging secure systems and secure services modeling. Large scale software development is one of the biggest challenges faced by corporations. Incorporating security into the software development process...

    Provided By University of Texas

  • White Papers // Oct 2009

    Model-Checking In-Lined Reference Monitors

    A technique for elegantly expressing In-lined Reference Monitor (IRM) certification as model-checking is presented and implemented. In-lined Reference Monitors (IRM's) enforce software security policies by in-lining dynamic security guards into untrusted binary code. Certifying IRM systems provide strong formal guarantees for such systems by verifying that the instrumented code produced...

    Provided By University of Texas

  • White Papers // Apr 2009

    Enforcing IRM Security Policies: Two Case Studies

    SPoX (Security Policy XML) is a declarative language for specifying application security policies for enforcement by In-lined Reference Monitors. Two case studies are presented that demonstrate how this language can be used to effectively enforce application-specific security policies for untrusted Java applications in the absence of source code. In-lined Reference...

    Provided By University of Texas

  • White Papers // Jan 2010

    Logical Concurrency Control From Sequential Proofs

    The authors are interested in identifying and enforcing the isolation requirements of a concurrent program, i.e., concurrency control that ensures that the program meets its specification. This can be done systematically starting from a sequential proof, i.e., a proof of correctness of the program in the absence of concurrent inter-leavings....

    Provided By University of Texas

  • White Papers // Jan 2012

    Identifying Failure-Inducing Combinations in a Combinatorial Test Set

    A t-way combinatorial test set is designed to detect failures that are triggered by combinations involving no more than t parameters. Assume that the authors have executed a t-way test set and some tests have failed. A natural question to ask is: what combinations have caused these failures? Identifying such...

    Provided By University of Texas

  • White Papers // Aug 2011

    The CleanJava Language for Functional Program Verification

    Unlike Hoare-style program verification, functional program verification supports forward reasoning by viewing a program as a mathematical function from one program state to another and proving its correctness by essentially comparing two mathematical functions, the function computed by the program and its specification. Since it requires a minimal mathematical background...

    Provided By University of Texas

  • White Papers // Nov 2011

    Functional Verification of Class Invariants in CleanJava

    In Cleanroom-style functional program verification, a program is viewed as a mathematical function from one program state to another, and the program is verified by comparing two functions, the implemented and the expected behaviors of a program. The technique requires a minimal mathematical background and supports forward reasoning, but it...

    Provided By University of Texas

  • White Papers // Jul 2011

    Multiuser Zero-Forcing Beamforming With Limited Feedback in Wireless Ad Hoc Networks

    The effect of limited feedback on point-to-multipoint communication is investigated in multi-antennas wireless ad hoc networks. The authors consider zero-forcing beamforming with quantized channel direction information and derive new closed-form expressions for the outage probability, throughput, transmission capacity, and average user rate. Expressions for the performance degradation due to finite...

    Provided By University of Texas

  • White Papers // Jul 2011

    Downlink Femtocell Networks: Open or Closed?

    A fundamental choice in femtocell deployments is the set of users which are allowed to access each femtocell. Closed access restricts the set to specifically registered users, while open access allows any mobile subscriber to use any femtocell. The main results of the paper are lemmas which provide expressions for...

    Provided By University of Texas

  • White Papers // Mar 2011

    A New Way of Computing Rate in Cellular Networks

    It is common practice to model the Base Station (BS) locations in a cellular system by a grid, such as a hexagonal or square lattice. This model is usually analytically intractable as well as quite idealized. Therefore, system designers resort to complex simulations to evaluate network performance. In this paper,...

    Provided By University of Texas

  • White Papers // Sep 2010

    On the Accuracy of the Wyner Model in Downlink Cellular Networks

    Compared to real cellular systems where users are spatially distributed and interference levels vary by several orders of magnitude over a cell, in the Wyner model user locations are fixed and the interference intensity is characterized by a single fixed parameter. Although it is a fairly extreme simplification, the Wyner...

    Provided By University of Texas

  • White Papers // Sep 2010

    The Effect of Interference Cancellation on Spectrum-Sharing Transmission Capacity

    The efficiency of spectrum sharing can be improved by interference suppression and/or cancellation. This paper analyzes the performance of spectrum sharing networks with Interference Cancellation (IC) based on the Spectrum-sharing Transmission Capacity (S-TC), defined as the number of successful transmissions per unit area while guaranteeing all target outage probabilities of...

    Provided By University of Texas

  • White Papers // Feb 2011

    Ergodic Spatial Throughput of Wireless Ad Hoc Networks With Markovian Fading Channels

    Most work on wireless network throughput ignores the temporal correlation inherent to wireless channels, due to trouble with tractability. In order to better capture the temporal variations of wireless network throughput, this paper introduces the metric of Ergodic Spatial Throughput (EST), which includes spatial and temporal ergodicity. All transmitters in...

    Provided By University of Texas

  • White Papers // Jun 2011

    A Tractable Framework for Coverage and Outage in Heterogeneous Cellular Networks

    The authors develop a tractable, flexible, and accurate model for downlink heterogeneous cellular networks. It consists of K tiers of randomly-located Base Stations (BSs), where each tier may differ in terms of the average transmit power, the supported data rate and the BS density. This allows elements spanning traditional, micro,...

    Provided By University of Texas

  • White Papers // Mar 2010

    A Graphical Model Approach to Downlink Cooperative MIMO Systems

    The authors propose a new method for computing transmit beamforming vectors for downlink multi-cell Multiple-Input Multiple-Output (MIMO) networks. The key novelty of the work is the application of graphical model theory to the intercell interference problem. An index restriction beamforming strategy is adopted to mitigate intercell interference, and is implemented...

    Provided By University of Texas

  • White Papers // Jul 2010

    Femtocell Access Control in the TDMA/OFDMA Uplink

    This paper investigates open vs. closed access in the uplink of femtocell networks, for the particular case of orthogonal multiple access protocols like TDMA or OFDMA. Open access reduces near-far interference and provides an inexpensive way to expand the capacity of the operator's network. Additionally, with a cap on the...

    Provided By University of Texas

  • White Papers // Aug 2010

    CDMA Uplink Capacity in Both Open and Closed Access Two-Tier Femtocell Networks

    Femtocells are assuming an increasingly important role in cellular coverage. Femtocells can be configured to be either open access or closed access. Seemingly, the network operator would prefer an open access deployment since this provides an inexpensive way to expand their network capabilities, whereas the femtocell owner would prefer closed...

    Provided By University of Texas

  • White Papers // Sep 2010

    Comparison of Fractional Frequency Reuse Approaches in the OFDMA Cellular Downlink

    Fractional Frequency Reuse (FFR) is an interference coordination technique well-suited to OFDMA based wireless networks wherein cells are partitioned into spatial regions with different frequency reuse factors. This paper focuses on evaluating the two main types of FFR deployments: strict FFR and Soft Frequency Reuse (SFR). Relevant metrics are discussed,...

    Provided By University of Texas

  • White Papers // Mar 2010

    Analog Equalization for Low Power 60 GHz Receivers in Realistic Multipath Channels

    Multi-gigabit per second wireless network devices are emerging for Personal Area Networks (PAN) in the 60 GHz band. Such devices are typically power hungry, largely due to the requisite high speed Analog to Digital Converters (ADCs) that can consume hundreds of milliwatts of power. This paper studies the use of...

    Provided By University of Texas

  • White Papers // Jun 2011

    Fundamentals of Inter-Cell Overhead Signaling in Heterogeneous Cellular Networks

    Heterogeneous base stations (e.g. picocells, microcells, femtocells and distributed antennas) will become increasingly essential for cellular network capacity and coverage. Up until now, little basic research has been done on the fundamentals of managing so many infrastructures - much of it unplanned - together with the carefully planned macrocellular network....

    Provided By University of Texas

  • White Papers // Jul 2011

    Heterogeneous Cellular Networks With Flexible Cell Association: A Comprehensive Downlink SINR Analysis

    In this paper, the authors develop a tractable framework for SINR analysis in downlink Heterogeneous Cellular Networks (HCNs) with flexible cell association policies. The HCN is modeled as a multi-tier cellular network where each tier's Base Stations (BSs) are randomly located and have a particular transmit power, path loss exponent,...

    Provided By University of Texas

  • White Papers // Jul 2011

    Distributed SIR-Aware Scheduling in Large-Scale Wireless Networks

    Opportunistic scheduling and routing can in principle greatly increase the throughput of decentralized wireless networks, but to be practical such algorithms must do so with small amounts of timely side information. In this paper, the authors propose three related techniques for low-overhead Distributed Opportunistic Scheduling (DOS) and precisely determine their...

    Provided By University of Texas

  • White Papers // May 2011

    Broadcast Channels With Delayed Finite-Rate Feedback: Predict or Observe?

    Most multiuser pre-coding techniques require accurate Transmitter Channel State Information (CSIT) to maintain orthogonality between the users. Such techniques have proven quite fragile in time-varying channels because the CSIT is inherently imperfect due to estimation and feedback delay, as well quantization noise. An alternative approach recently proposed by Maddah-Ali and...

    Provided By University of Texas

  • White Papers // May 2011

    Characterizing Decentralized Wireless Networks With Temporal Correlation in the Low Outage Regime

    Communication in decentralized wireless networks is limited by interference. Because transmissions typically last for more than a single contention time slot, interference often exhibits strong statistical dependence over time that results in temporally correlated communication performance. The temporal dependence in interference increases as user mobility decreases and/or the total transmission...

    Provided By University of Texas

  • White Papers // Mar 2011

    Ergodic Transmission Capacity of Wireless Ad Hoc Networks With Interference Management

    Most work on wireless network throughput ignores the temporal correlation inherent to wireless channels because it degrades tractability. To better model and quantify the temporal variations of wireless network throughput, this paper introduces a metric termed Ergodic Transmission Capacity (ETC), which includes spatial and temporal ergodicity. All transmitters in the...

    Provided By University of Texas

  • White Papers // Nov 2010

    Cooperative Spectral Covariance Sensing Under Correlated Shadowing

    This paper investigates the theoretical limits of white space sensing in a Cognitive Radio (CR) network limited by channel correlation. In a log-normal shadowing channel, the received signal power is correlated based on the distance between the sensors and this makes sensing the presence of a signal difficult, even with...

    Provided By University of Texas

  • White Papers // Apr 2010

    An Upper Bound on Multi-Hop Transmission Capacity With Dynamic Multipath Routing

    This paper develops upper bounds on the end-to-end transmission capacity of multi-hop wireless networks. Potential source-destination paths are dynamically selected from a pool of randomly located relays, from which a closed-form lower bound on the outage probability is derived in terms of the expected number of potential paths. This is...

    Provided By University of Texas

  • White Papers // Jul 2011

    Capacity Bounds on Multiuser MIMO Transmission in Random Wireless Networks

    The authors consider a large wireless ad hoc network in which each multi-antenna transmitting node sends multiple independent streams to different receivers in a Poisson field of interferers. They provide exact expressions and simplified approximations on the outage probability, contention density, and transmission capacity for dirty paper coding with perfect...

    Provided By University of Texas

  • White Papers // Mar 2011

    Outage Probability for Heterogeneous Cellular Networks With Biased Cell Association

    In this paper, the authors develop a tractable framework for SINR analysis in downlink Heterogeneous Cellular Networks (HCNs) with flexible cell association policies. The HCN is modeled as a multi-tier cellular network where each tier's BSs are randomly located and have a unique transmit power, path loss exponent, spatial density,...

    Provided By University of Texas

  • White Papers // Jun 2011

    Coverage in Two-Tier Cellular Networks With Fractional Frequency Reuse

    Fractional Frequency Reuse (FFR) is an interference management technique well-suited to OFDMA-based cellular networks wherein the cells are partitioned into spatial regions with different frequency reuse factors. These techniques are of further relevance when considered in the context of heterogeneous networks whose performance is often limited by intercell and inter-tier...

    Provided By University of Texas

  • White Papers // Feb 2011

    A New Model for Coverage With Fractional Frequency Reuse in OFDMA Cellular Networks

    Fractional Frequency Reuse (FFR) is an interference management technique well-suited to OFDMA-based cellular networks wherein the cells are partitioned into spatial regions with different frequency reuse factors. To date, FFR techniques have been typically been evaluated through system-level simulations using a hexagonal grid for the base station locations. This paper...

    Provided By University of Texas

  • White Papers // Nov 2011

    Leakage - Delay Tradeoff in Wide-Bit Nanoscale CMOS Adders

    The scaling of nanometer technology has had a major impact on the power dissipation of CMOS circuits. As transistor size decreases it has become apparent that leakage power is becoming a dominant fighting force against future technology. In this paper, the importance of static power consumption on the design of...

    Provided By University of Texas