University of Texas

Displaying 41-80 of 268 results

  • 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 // 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

    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 // 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 // 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 // Jun 2011

    Enhancing the Role of Inlining in Effective Interprocedural Parallelization

    The emergence of multi-core architectures makes it essential for optimizing compilers to automatically extract parallelism for large scientific applications composed of many subroutines residing in different files. Inlining is a well-known technique which can be used to erase procedural boundaries and enable more aggressive loop parallelization. However, conventional inlining cannot...

    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 // Jun 2011

    Average Rate Achievable in K-Tier Downlink Heterogeneous Cellular Networks

    Cellular networks are becoming increasingly heterogeneous due to the co-deployment of many disparate infrastructure elements, including micro, pico and femtocells, and distributed antennas. This introduces new challenges in the modeling, analysis, and design of these networks. While grid-based models have been quite popular in modeling classical macrocell networks, they are...

    Provided By University of Texas

  • White Papers // Jun 2011

    3G Meets the Internet: Understanding the Performance of Hierarchical Routing in 3G Networks

    The volume of Internet traffic over 3G wireless networks is sharply rising. In contrast to many Internet services utilizing replicated resources, such as Content Distribution Networks (CDN), the current 3G standard architecture employs hierarchical routing, where all user data traffic goes through a small number of aggregation points using logical...

    Provided By University of Texas

  • White Papers // Jun 2011

    Cloaking Malware With the Trusted Platform Module

    The Trusted Platform Module (TPM) is commonly thought of as hardware that can increase platform security. However, it can also be used for malicious purposes. The TPM, along with other hardware, can implement a cloaked computation, whose memory state cannot be observed by any other software, including the operating system...

    Provided By University of Texas

  • White Papers // Jun 2011

    A Framework for Resource-Aware Data Accumulation in Sparse Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) have become an enabling technology for a wide range of applications. In contrast, with traditional scenarios where static sensor nodes are densely deployed, a sparse WSN architecture can also be used in many cases. In a sparse WSN, special Mobile Data Collectors (MDCs) are used to...

    Provided By University of Texas

  • White Papers // Jun 2011

    XML Query Optimization in Map-Reduce

    The authors present a novel query language for large-scale analysis of XML data on a map-reduce environment, called MRQL, that is expressive enough to capture most common data analysis tasks and at the same time is amenable to optimization. The authors' evaluation plans are constructed using a small number of...

    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 // Jun 2011

    Network Control: A Rate-Distortion Perspective

    Today's networks are controlled assuming precompressed and packetized data. For video, this assumption of data packets abstracts out one of the key aspects - the lossy compression problem. Therefore, first, this paper develops a framework for network control that incorporates both source-rate and source-distortion. Next, it decomposes the network control...

    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 // 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

    EVE: Verifying Correct Execution of Cloud-Hosted Web Applications

    The authors present a new approach to verifying that a completely untrusted, Platform-as-a-Service cloud is correctly executing an outsourced web application. Web applications such as blogs, wikis, and online social networks are increasingly hosted on third-party, "Platform-as-a-Service" (PaaS) clouds. The owner outsources the execution of his application to a cloud...

    Provided By University of Texas

  • White Papers // May 2011

    Architecture and Abstractions for Environment and Traffic Aware System-Level Coordination of Wireless Networks

    This paper presents a system level approach to interference management in an infrastructure based wireless network with full frequency reuse. The key idea is to use loose base station coordination that is tailored to the spatial load distribution and the propagation environment to exploit the diversity in a user population's...

    Provided By University of Texas

  • White Papers // May 2011

    Practical Adaptive User Association Policies for Wireless Systems With Dynamic Interference

    The authors study the impact of user association policies on flow-level performance in interference-limited wireless networks. Most research in this area has used static interference models (neighboring base stations are always active) and resorted to intuitive objectives such as load balancing. In this paper, they show that this can be...

    Provided By University of Texas

  • White Papers // May 2011

    Secure Data Processing in a Hybrid Cloud

    Cloud computing has made it possible for a user to be able to select a computing service precisely when needed. However, certain factors such as security of data and regulatory issues will impact a user's choice of using such a service. A solution to these problems is the use of...

    Provided By University of Texas

  • White Papers // May 2011

    Regret-Freedom Isn't Free

    Cooperative, Peer-To-Peer (P2P) services-distributed systems consisting of participants from Multiple Administrative Domains (MAD)|must deal with the threat of arbitrary (Byzan-tine) failures while incentivizing the cooperation of potentially selfish (rational) nodes that such services rely on to function. Although previous work has generally agreed that these types of participants need to...

    Provided By University of Texas

  • White Papers // May 2011

    Consistency, Availability, and Convergence

    The authors examine the limits of consistency in fault-tolerant distributed storage systems. In particular, they identify fundamental tradeoffs among properties of consistency, availability, and convergence, and the authors close the gap between what is known to be impossible (i.e. CAP) and known systems that are highly-available but that provide weaker...

    Provided By University of Texas

  • White Papers // Apr 2011

    Mechanizing the Expert Dense Linear Algebra Developer

    Sustained high performance on the fastest computers in the world has traditionally been accomplished by experts who carefully hand-code key routines. This quickly becomes unmanageable for large bodies of software and/or as architectures change enough that entire libraries need to be rewritten. The authors believe the problem is that a...

    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 // Apr 2011

    Get Off My Prefix! the Need for Dynamic, Gerontocratic Policies in Inter-Domain Routing

    Inter-domain routing in today's Internet is plagued by security and reliability issues (e.g., prefix hijacking), which are often caused by malicious or Byzantine misbehavior. The authors argue that route selection policies must move beyond static preferences that select routes on the basis of static attributes such as route length or...

    Provided By University of Texas

  • White Papers // Apr 2011

    Combating Channel Impairments and Impulsive Noise in Local Utility Powerline Communications

    A smart grid intelligently monitors and controls energy flow in order to improve the efficiency and reliability of power delivery. This monitoring and control requires low-delay, real-time, highly reliable communications between customers, local utilities and regional utilities. This paper focuses on PowerLine Communications (PLC) from the customer power meters to...

    Provided By University of Texas

  • White Papers // Apr 2011

    Repair From a Chair: Computer Repair as an Untrusted Cloud Service

    Today, when people need their computers repaired, their process is not very different from hiring someone to fix a television: they either bring the computer to a repair service, or they call a technician (or family member) and ask for a house call. This process is inconvenient. It also risks...

    Provided By University of Texas

  • White Papers // Apr 2011

    Toward Practical and Unconditional Verification of Remote Computations

    This paper revisits a classic question: how can a machine specify a computation to another one and then, without executing the computation, check that the other machine carried it out correctly? The applications of such a primitive include cloud computing (a computationally limited device offloads processing to the cloud but...

    Provided By University of Texas

  • White Papers // Apr 2011

    The K-Observer Problem in Computer Networks

    For any non-negative integer K, a K-observer P of a network N is a set of nodes in N such that each message, that travels at least K hops in N, is handled (and so observed) by at least one node in P. A K-observer P of a network N...

    Provided By University of Texas

  • White Papers // Apr 2011

    Dynamic Focusing of Awareness in Fuzzy Control Systems

    Adaptive fuzzy logic control systems with Gaussian membership functions are described. A systematic simulation study of 'Dynamic focusing of awareness' in fuzzy logic control systems is provided. This study shows how the final steady-state values of the membership functions change in response to varying initial membership functions, changing desired trajectory,...

    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 // 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 // Mar 2011

    Secure Multidimensional Range Queries Over Outsourced Data

    In this paper the authors study the problem of supporting multidimensional range queries on encrypted data. The problem is motivated by secure data outsourcing applications where a client may store his/her data on a remote server in encrypted form and want to execute queries using server's computational capabilities. The solution...

    Provided By University of Texas

  • White Papers // Mar 2011

    Deterministic Public-Key Encryption Revisited

    One of the maxims of modern cryptography is that "Randomness is needed for good encryption," meaning the encryption algorithm of a scheme that should be randomized. Such an encryption scheme is called probabilistic. Indeed, probabilistic encryption is necessary to meet the fundamental notion of semantic security introduced by Goldwasser and...

    Provided By University of Texas

  • White Papers // Mar 2011

    Fuzzy Optimization for Mobile Ad Hoc Networks: A Bottom-up Cross-Layer Approach

    In this paper, the authors introduce a new method for cross-layer design in mobile ad hoc networks. They use Fuzzy Logic System (FLS) to coordinate physical layer, data-link layer and application layer for cross-layer design. Ground speed, average delay and packets successful transmission ratio are selected as antecedents for the...

    Provided By University of Texas

  • White Papers // Mar 2011

    Efficient Lattice (H)IBE in the Standard Model

    The authors construct an efficient identity based encryption system based on the standard Learning With Errors (LWE) problem. Their security proof holds in the standard model. The key step in the construction is a family of lattices for which there are two distinct trapdoors for finding short vectors. One trapdoor...

    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 // Mar 2011

    TPP: The Two-Way Password Protocol

    The need for secure communication in the Internet has led to the widespread deployment of secure application-level protocols. The current state-of-the-art is to use TLS, in conjunction with a password protocol. The password protocol, which the authors call a One-way Password Protocol (OPP), authenticates the client to the server, using...

    Provided By University of Texas

  • White Papers // Mar 2011

    Modeling and Analysis of K-Tier Downlink Heterogeneous Cellular Networks

    Cellular networks are in a major transition from a carefully planned set of large tower-mounted BaseStations (BSs) to an irregular deployment of heterogeneous infrastructure elements that often additionally includes micro, pico, and femtocells, as well as distributed antennas. In this paper, the authors develop a tractable, flexible, and accurate model...

    Provided By University of Texas

  • White Papers // Dec 2009

    Capacity Scaling of MIMO Broadcast Channels With Random User Distribution

    A novel capacity scaling law for Multiple-Input Multiple-Output (MIMO) broadcast channels is derived considering a random user distribution. The random locations cause unequal average SNRs amongst the users, whereas prior work typically assumes that all users have the same average SNR. Most centralized wireless networks, e.g. cellular systems, are more...

    Provided By University of Texas

  • White Papers // Jan 2010

    A New Method for Computing the Transmission Capacity of Non-Poisson Wireless Networks

    The relative locations of concurrent transmitting nodes play an important role in the performance of wireless networks because it largely determines their mutual interference. In most prior work the set of interfering transmitters has been modeled by a homogeneous Poisson distribution, which assumes independence in the transmitting node positions, and...

    Provided By University of Texas

  • White Papers // Dec 2009

    Multicast Capacity Scaling of Wireless Networks With Multicast Outage

    Multicast transmission has several distinctive traits as opposed to more commonly studied unicast networks. Specially, these include - identical packets must be delivered successfully to several nodes, outage could simultaneously happen at different receivers, and the multicast rate is dominated by the receiver with the weakest link in order to...

    Provided By University of Texas

  • White Papers // Jan 2010

    Spectral Covariance for Spectrum Sensing, With Application to IEEE 802.22

    Despite the shortage of available frequency spectrum, recent studies have shown that the actual usage of the allocated spectrum is scarce. The IEEE is developing the 802.22 standard for spectral reuse in TV bands that uses Cognitive Radio (CR) technology. One of the essential and challenging features of CR is...

    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 // Nov 2009

    A Simple Upper Bound on Random Access Transport Capacity

    The authors attempt to quantify end-to-end throughput in multi-hop wireless networks using a metric that measures the maximum density of source-destination pairs that can successfully communicate over a specified distance at certain data rate. They term this metric the random access transport capacity, since it is similar to transport capacity...

    Provided By University of Texas

  • White Papers // Apr 2011

    Combating Channel Impairments and Impulsive Noise in Local Utility Powerline Communications

    A smart grid intelligently monitors and controls energy flow in order to improve the efficiency and reliability of power delivery. This monitoring and control requires low-delay, real-time, highly reliable communications between customers, local utilities and regional utilities. This paper focuses on PowerLine Communications (PLC) from the customer power meters to...

    Provided By University of Texas

  • White Papers // Jan 2011

    Energy Efficient Schemes for Wireless Sensor Networks With Multiple Mobile Base Stations

    One of the main design issues for a sensor network is conservation of the energy available at each sensor node. The authors propose to deploy multiple, mobile base stations to prolong the lifetime of the sensor network. They split the lifetime of the sensor network into equal periods of time...

    Provided By University of Texas

  • White Papers // Nov 2010

    The Impact Of Bank Health On The Investment Of Its Corporate Borrowers

    This paper investigates the impact of changes in a bank's health on the investment behavior of its current borrowers for a panel of U.S. firms. The author finds that, after controlling for aggregate credit availability and the condition of outside banks, firms reduce their investment when the health of their...

    Provided By University of Texas

  • White Papers // May 2011

    Secure Data Processing in a Hybrid Cloud

    Cloud computing has made it possible for a user to be able to select a computing service precisely when needed. However, certain factors such as security of data and regulatory issues will impact a user's choice of using such a service. A solution to these problems is the use of...

    Provided By University of Texas

  • White Papers // Mar 2010

    Dynamic Connectivity in ALOHA Ad Hoc Networks

    In a wireless network the set of transmitting nodes changes frequently because of the MAC scheduler and the traffic load. Previously, connectivity in wireless networks was analyzed using static geometric graphs, and as the authors show leads to an overly constrained design criterion. The dynamic nature of the transmitting set...

    Provided By University of Texas

  • White Papers // Dec 2010

    Vertical Specialization, Intermediate Tariffs, And The Pattern Of Trade: Assessing The Role Of Tariff Liberalization To U.S.

    How important are intermediate tariffs in determining trade patterns? Empirical work measuring the impact of tariff liberalization most commonly focuses on the effects of barriers imposed by importers, but exporter trade policy should also matter when exports are produced with imported intermediates. Guided by extensions of the Eaton and Kortum...

    Provided By University of Texas

  • White Papers // Jan 2011

    Lightweight Distributed Selective Re-Execution and Its Implications for Value Speculation

    In this paper, the authors describe a lightweight protocol to support selective re-execution on the TRIPS processor. The protocol permits multiple waves of speculation to be traversing a dataflow graph simultaneously and in any order, with a cleanup "Commit" wave propagating as well to determine completion of a group of...

    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 // Feb 2010

    Understanding Transactional Memory Performance

    This paper introduces Syncchar, a novel method and tool for reasoning about the performance of transactional memory. The authors have validated Syncchar's performance predictions and demonstrated its usefulness in guiding performance tuning on the TxLinux kernel. This paper also presents a detailed characterization of how the whole system, including architecture,...

    Provided By University of Texas

  • White Papers // May 2010

    Foreign Portfolio Investment Inflows To The United States: The Impact Of Investor Risk Aversion And US Stock Market Performance

    This paper examines the relationship of net foreign portfolio investment inflows, namely corporate bonds and stocks, to two pull factors; investor risk aversion and the US stock market. Using a vector autoregressive model, we find that positive shocks to the stock market elicit an insignificant response to the net corporate...

    Provided By University of Texas

  • White Papers // Aug 2010

    POET: A Scripting Language for Applying Parameterized Source-to-Source Program Transformations

    The authors present POET, a scripting language designed for applying advanced program transformations to code in arbitrary programming languages as well as building ad-hoc translators between these languages. The authors have used POET to support a large number of compiler optimizations, including loop interchange, parallelization, blocking, fusion/ fission, strength reduction,...

    Provided By University of Texas

  • White Papers // Apr 2010

    Automated Programmable Code Transformation for Portable Performance Tuning

    The authors present a framework which uses POET, an interpreted code transformation language, to effectively combine programmable control from developers, advanced optimizations by compilers, and flexible empirical tuning of optimizations to achieve portable high performance for scientific computing. The authors have extended ROSE, a C/C++/Fortran source-to-source compiler, to automatically analyze...

    Provided By University of Texas

  • White Papers // Jan 2010

    Energy Consumption in Wireless Sensor Networks Using GSP

    One of the main design issues for a sensor network is conservation of the energy available at each sensor node. The authors propose to deploy multiple, mobile base stations to prolong the lifetime of the sensor network. They split the lifetime of the sensor network into equal periods of time...

    Provided By University of Texas

  • White Papers // Sep 2010

    Depot: Cloud Storage With Minimal Trust

    The paper describes the design, implementation, and evaluation of Depot, a cloud storage system that minimizes trust assumptions. Depot tolerates buggy or malicious behavior by any number of clients or servers, yet it provides safety and liveness guarantees to correct clients. Depot provides these guarantees using a two-layer architecture. First,...

    Provided By University of Texas

  • White Papers // Dec 2009

    Edge-Based Cloud Computing as a Feasible Network Paradigm

    The term edge based cloud computing refers to a network of edge systems that provide the services currently provided by data center clouds. In this paper the authors present modifications to MRPerf, an existing tool used to simulate MapReduce in data center clouds, enabling it to simulate Hadoop MapReduce jobs...

    Provided By University of Texas

  • White Papers // Jan 2010

    IP Address Assignment in a Mobile Ad Hoc Network

    A Mobile Ad Hoc NETwork (MANET) consists of a set of identical mobile nodes communicating with each other via wireless links. The network's topology may change rapidly and unpredictably. Such networks may operate in a stand-alone fashion, or may be connected to the larger Internet. In traditional networks, hosts rely...

    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 // 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 // Jan 2010

    PeterNet : An Emergent Technology Based Radio Access Network Architecture for Next Generation Cellular Wireless Systems

    For next generation wireless cellular networks, the Radio Access Network (RAN) component is destined to evolve into a high-capacity, flexible and reconfigurable network architecture supporting smaller cell sites and newer technologies. Based on the well-known Petersen graph, in this paper the authors propose a RAN architecture, named PeterNet, that interconnects...

    Provided By University of Texas

  • White Papers // Jan 2010

    PeterNet: A Free Space Optics Based BackHaul Architecture for Next Generation Cellular Networks

    There has been an increasing demand for bandwidth-intensive services in mobile devices, such as streaming video and music, which bring about a paradigm shift in wireless cellular network architectures. Although various coding and modulation schemes are being adopted to address these requirements, a critical area of modification is the existing...

    Provided By University of Texas

  • White Papers // Feb 2011

    A Tractable Approach to Coverage and Rate in Cellular Networks

    Cellular networks are usually modeled by placing the base stations on a grid, with mobile users either randomly scattered or placed deterministically. These models have been used extensively but suffer from being both highly idealized and not very tractable, so complex system-level simulations are used to evaluate coverage/outage probability and...

    Provided By University of Texas

  • White Papers // Sep 2010

    Two-Way Transmission Capacity of Wireless Ad-Hoc Networks

    The transmission capacity of an ad-hoc network is the maximum density of active transmitters per unit area, given an outage constraint at each receiver for a fixed rate of transmission. Most prior work on finding the transmission capacity of ad-hoc networks has focused only on one-way communication where a source...

    Provided By University of Texas

  • White Papers // Sep 2009

    Diversity-Multiplexing Tradeoff of Network Coding With Bidirectional Random Relaying

    This paper develops a Diversity-Multiplexing Tradeoff (DMT) over a bidirectional random relay set in a wireless network where the distribution of all nodes is a stationary Poisson point process. This is a nontrivial extension of the DMT because it requires consideration of the cooperation (or lack thereof) of relay nodes,...

    Provided By University of Texas

  • White Papers // Mar 2011

    A Generic Handover Decision Management Framework for Next Generation Networks

    Next generation networks are defined to be packet based networks that provide telecommunication services to users by utilizing different transport technologies, wired and wireless. In this paper the authors provide a generic framework for handover decision management in next generation networks. They show that any handover decision algorithm can utilize...

    Provided By University of Texas

  • White Papers // Aug 2009

    Goal-Oriented Security Threat 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 it is difficult to possess necessary broad and deep knowledge of security related strategic knowledge to choose mitigating solutions suitable for a specific application or organization. This paper presents three...

    Provided By University of Texas

  • White Papers // Jan 2011

    Enhancing Both Network and User Performance for Networks Supporting Best Effort Traffic

    With a view on improving user perceived performance on networks supporting best effort flows, e.g., multimedia/data file transfers, the authors propose a family of bandwidth allocation criteria that depends on the residual work of on-going transfers. Analysis and simulations show that allocating bandwidth in this fashion can significantly improve the...

    Provided By University of Texas

  • White Papers // Mar 2011

    Downlink SDMA With Limited Feedback in Interference-Limited Wireless Networks

    The tremendous capacity gains promised by Space Division Multiple Access (SDMA) depend critically on the accuracy of the transmit channel state information. In the broadcast channel, even without any network interference, it is known that such gains collapse due to interstream interference if the feedback is delayed or low rate....

    Provided By University of Texas

  • White Papers // Mar 2011

    Modeling and Analysis of K-Tier Downlink Heterogeneous Cellular Networks

    Cellular networks are in a major transition from a carefully planned set of large tower-mounted BaseStations (BSs) to an irregular deployment of heterogeneous infrastructure elements that often additionally includes micro, pico, and femtocells, as well as distributed antennas. In this paper, the authors develop a tractable, flexible, and accurate model...

    Provided By University of Texas

  • White Papers // Apr 2011

    Dynamic Focusing of Awareness in Fuzzy Control Systems

    Adaptive fuzzy logic control systems with Gaussian membership functions are described. A systematic simulation study of 'Dynamic focusing of awareness' in fuzzy logic control systems is provided. This study shows how the final steady-state values of the membership functions change in response to varying initial membership functions, changing desired trajectory,...

    Provided By University of Texas

  • White Papers // Jul 2010

    On the Insecurity of Parallel Repetition for Leakage Resilience

    A fundamental question in leakage-resilient cryptography is: Can leakage resilience always be amplified by parallel repetition? It is natural to expect that if people have leakage-resilient primitive tolerating nl bits of leakage, they can take n copies of it to form a system tolerating nl bits of leakage. In this...

    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 // Mar 2010

    Coding-Aware Multi-path Routing in Multi-Hop Wireless Networks

    To overcome the inherent lossy property of wireless links and increase network throughput, many multi-path routing protocols have been proposed to improve the reliability and latency of packet delivery in wireless networks. Multi-path routing protocols, however, do not take advantage of existing coding opportunities to maximize network throughput. In this...

    Provided By University of Texas

  • White Papers // Oct 2009

    Design of a Reliable Communication System for Grid-Style Traffic Control Networks

    This paper designs and analyzes the performance of a reliable communication scheme for the traffic control system built upon a wireless process control protocol, aiming at enhancing the robustness and timeliness of the safety critical control applications. Focusing on the slot-based predictable access and the grid topology of urban area...

    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