University of Calgary

Displaying 1-40 of 532 results

  • White Papers // Jan 2015

    Analyzing Tabular Requirements Specifications Using Infinite State Model Checking

    In this paper, the authors investigate the application of infinite state model checking to the formal analysis of requirements specifications in the SCR (Software Cost Reduction) tabular notation using Action Language Verifier (ALV). After reviewing the SCR method and tools and the Action Language, experimental results are presented of formally...

    Provided By University of Calgary

  • White Papers // Jan 2015

    Analyzing Conversations: Realizability, Synchronizability, and Verification

    Conversations provide an intuitive and simple model for analyzing interactions among composite web services. A conversation is the global sequence of messages exchanged among the peers participating to a composite web service. Interactions in a composite web service can be analyzed by investigating the temporal properties of its conversations. Conversations...

    Provided By University of Calgary

  • White Papers // Jan 2015

    Modular Verification of Synchronization with Reentrant Locks

    The authors present a modular approach for verification of synchronization behavior in concurrent programs that use reentrant locks. Their approach decouples the verification of the lock implementation from the verification of the threads that use the lock. This decoupling is achieved using lock interfaces that characterize the allowable execution order...

    Provided By University of Calgary

  • White Papers // Jan 2015

    Applying Infinite State Model Checking and Other Analysis Techniques to Tabular Requirements Specifications of Safety-Critical Systems

    Although it is most often applied to finite state models, in recent years, symbolic model checking has been extended to infinite state models using symbolic representations that encode infinite sets. This paper investigates the application of an infinite state symbolic model checker called Action Language Verifier (ALV) to formal requirements...

    Provided By University of Calgary

  • White Papers // Jan 2015

    Extended Interface Grammars for Automated Stub Generation

    An important challenge in software verification is the ability to verify different software components in isolation. Achieving modularity in software verification requires development of innovative interface specification languages. In this paper the authors focus on the idea of using grammars for specification of component interfaces. In earlier work, they investigated...

    Provided By University of Calgary

  • White Papers // Jan 2015

    Computing Real Time Jobs in P2P Networks

    In this paper, the authors present a distributed computing framework designed to support higher quality of service and fault tolerance for processing deadline-driven tasks in a P2P environment. Their proposed strategy strives to build an open infrastructure that is accessible by ordinary users for both cycle donation and consumption. For...

    Provided By University of Calgary

  • White Papers // Nov 2014

    To Go or Not to Go: On Energy-aware and Communication-aware Robotic Operation

    The authors consider the scenario where a mobile robot needs to visit a number of Points Of Interest (POIs) in a workspace, gather their generated bits of information, and successfully transmit them to a remote station, while operating in a realistic communication environment, minimizing its total energy consumption (including both...

    Provided By University of Calgary

  • White Papers // Sep 2014

    CloudTracker: Using Execution Provenance to Optimize the Cost of Cloud Use

    In this paper, the authors investigate tools that enable dollar cost optimization of scientific simulations using commercial clouds. They present a framework, called CloudTracker that transparently records information from a simulation that is executed in a commercial cloud so that it may be \"Replayed\" exactly to reproduce its results. Using...

    Provided By University of Calgary

  • White Papers // Jul 2014

    Automata-Based Symbolic String Analysis for Vulnerability Detection

    Verifying string manipulating programs is a crucial problem in computer security. String operations are used extensively within web applications to manipulate user input, and their erroneous use is the most common cause of security vulnerabilities in web applications. The authors present an automata-based approach for symbolic analysis of string manipulating...

    Provided By University of Calgary

  • White Papers // Jul 2014

    BareCloud: Bare-metal Analysis-based Evasive Malware Detection

    The volume and the sophistication of malware are continuously increasing and evolving. Automated dynamic malware analysis is a widely-adopted approach for detecting malicious software. However, many recent malware samples try to evade detection by identifying the presence of the analysis environment itself, and refraining from performing malicious actions. Because of...

    Provided By University of Calgary

  • White Papers // Jul 2014

    Hulk: Eliciting Malicious Behavior in Browser Extensions

    The authors present Hulk, a dynamic analysis system that detects malicious behavior in browser extensions by monitoring their execution and corresponding network activity. Hulk elicits malicious behavior in extensions in two ways. First, Hulk leverages HoneyPages, which are dynamic pages that adapt to an extension's expectations in web page structure...

    Provided By University of Calgary

  • White Papers // Jul 2014

    EmergeNet: Robust, Rapidly Deployable Cellular Networks

    Cellular phone networks are often paralyzed after a disaster, as damage to fixed infrastructure, loss of power, and increased demand degrade coverage and quality of service. To ensure disaster victims and first responders have access to reliable local and global communication, the authors propose EmergeNet, a portable, rapidly deployable, small...

    Provided By University of Calgary

  • White Papers // Jun 2014

    DRoP:DNS-based Router Positioning

    In this paper, the authors focus on geolocating Internet routers, using a methodology for extracting and decoding geography-related strings from fully qualified domain names (hostnames). They first compiled an extensive dictionary associating geographic strings (e.g., airport codes) with geophysical locations. They then searched a large set of router hostnames for...

    Provided By University of Calgary

  • White Papers // May 2014

    Asymptotically Optimal Sequential Tests for Anomaly Detection: Switching with Memory

    Each anomalous process incurs a cost per unit time until its anomaly is identified and fixed. Different anomalous processes may incur different costs depending on their criticality to the system. Switching between processes and state declarations are allowed at all times, while decisions are based on all past observations and...

    Provided By University of Calgary

  • White Papers // May 2014

    Empirically Characterizing Domain Abuse and the Revenue Impact of Blacklisting

    Using ground truth sales data for over 40K unlicensed prescription pharmaceuticals sites, the authors present an economic analysis of two aspects of domain abuse in the online counterfeit drug market. First, they characterize the nature of domains abused by affiliate spammers to monetize what is evidently an overwhelming demand for...

    Provided By University of Calgary

  • White Papers // May 2014

    Automatic and Portable Cloud Deployment for Scientific Simulations

    In this paper, the authors present CloudRunner, a framework that extracts arbitrary programs from a source code repository (e.g. GitHub), wraps them in a web service and tasking system, and deploys them over disparate cloud infrastructures and local clusters, automating their portability. In particular, CloudRunner automatically creates and configures virtual...

    Provided By University of Calgary

  • White Papers // May 2014

    Enhanced Lattice-Based Signatures on Reconfigurable Hardware

    The recent Bimodal LattIce Signature Scheme (BLISS) showed that lattice-based constructions have evolved to practical alternatives to RSA or ECC. Besides reasonably small signatures with 5600 bits for a 128-bit level of security, BLISS enables extremely fast signing and signature verification in software. However, due to the complex sampling of...

    Provided By University of Calgary

  • White Papers // May 2014

    A Sampling-Based Approach to Scalable Constraint Satisfaction in Linear Sampled-Data Systems - Part I: Computation

    Sampled-Data (SD) systems, which are composed of both discrete- and continuous-time components, are arguably one of the most common classes of cyber-physical systems in practice; most modern controllers are implemented on digital platforms while the plant dynamics that are being controlled evolve continuously in time. As with all cyber-physical systems,...

    Provided By University of Calgary

  • White Papers // May 2014

    Scalable Fault-Tolerant Data Feeds in AsterixDB

    In this paper, the authors describe the support for data feed ingestion in AsterixDB, an open-source Big Data Management System (BDMS) that provides a platform for storage and analysis of large volumes of semi-structured data. Data feeds are a mechanism for having continuous data arrive into a BDMS from external...

    Provided By University of Calgary

  • White Papers // May 2014

    ReDHiP: Recalibrating Deep Hierarchy Prediction for Energy Efficiency

    Recent hardware trends point to increasingly deeper cache hierarchies. In such hierarchies, accesses that lookup and miss in every cache involve significant energy consumption and degraded performance. To mitigate these problems, in this paper the authors propose Recalibrating Deep Hierarchy Prediction (ReDHiP), an architectural mechanism that predicts Last-Level Cache (LLC)...

    Provided By University of Calgary

  • White Papers // Apr 2014

    Multi-Level Coded Caching

    Recent work has demonstrated that for content caching, joint design of storage and delivery can yield significant benefits over conventional caching approaches. This is based on storing content in the caches, so as to create coded-multicast opportunities even amongst users with different demands. Such a coded-caching scheme has been shown...

    Provided By University of Calgary

  • White Papers // Apr 2014

    Towards Automatically Estimating Porting Effort Between Web Service APIs

    In this paper, the authors describe a new methodology for automatically quantifying the relative work required for a programmer to port an application from one web API to another, i.e. \"Porting effort\". Their approach defines a simple language (based on Python) with which API developers specify the semantics of API...

    Provided By University of Calgary

  • White Papers // Apr 2014

    SELFISHMIGRATE: A Scalable Algorithm for Non-Clairvoyantly Scheduling Heterogeneous Processors

    Many computer architects believe that architectures consisting of heterogeneous processors will be the dominant architectural design in the future: simulation studies indicate that, for a given area and power budget, heterogeneous multiprocessors can offer an order of magnitude better performance for typical workloads. Looking at the consequences of Moore's Law...

    Provided By University of Calgary

  • White Papers // Mar 2014

    Lithography-Induced Limits to Scaling of Design Quality

    Quality and value of an IC product are functions of power, performance, area, cost and reliability. The forthcoming 2013 ITRS roadmap observes that while manufacturers continue to enable potential Moore's Law scaling of layout densities, the \"Realizable\" scaling in competitive products has for some years been significantly less. In this...

    Provided By University of Calgary

  • White Papers // Mar 2014

    VANET via Named Data Networking

    Recently manufactured vehicles are equipped with not only computation powers but also a variety of wireless communication interfaces such as 3G/LTE, WiMAX, Wi-Fi, IEEE 1901 (power line communication), and 802.11p (DSRC/WAVE). In this paper, the authors apply the named data networking, a newly proposed Internet architecture, to networking vehicles on...

    Provided By University of Calgary

  • White Papers // Mar 2014

    Circuit Switching Under the Radar with REACToR

    The potential advantages of optics at high link speeds have led to significant interest in deploying optical switching technology in data-center networks. Initial efforts have focused on hybrid approaches that rely on millisecond-scale circuit switching in the core of the network, while maintaining the flexibility of electrical packet switching at...

    Provided By University of Calgary

  • White Papers // Feb 2014

    SENIC: Scalable NIC for End-Host Rate Limiting

    Rate limiting is an important primitive for managing server network resources. Unfortunately, software-based rate limiting suffers from limited accuracy and high CPU overhead, and modern NICs only support a handful of rate limiters. The authors present SENIC, a NIC design that can natively support 10s of thousands of rate limiters...

    Provided By University of Calgary

  • White Papers // Feb 2014

    SAFEDISPATCH: Securing C++ Virtual Calls from Memory Corruption Attacks

    Several defenses have increased the cost of traditional, low-level attacks that corrupt control data, e.g. return addresses saved on the stack, to compromise program execution. In response, creative adversaries have begun circumventing these defenses by exploiting programming errors to manipulate pointers to virtual tables, or vtables, of C++ objects. These...

    Provided By University of Calgary

  • White Papers // Feb 2014

    The Melbourne Shuffle: Improving Oblivious Storage in the Cloud

    The authors present a simple, efficient, and secure data-oblivious randomized shuffle algorithm. This is the first secure data-oblivious shuffle that is not based on sorting. Their method can be used to improve previous oblivious storage solutions for network-based outsourcing of data. One of the unmistakable recent trends in networked computation...

    Provided By University of Calgary

  • White Papers // Feb 2014

    Optimal Reliability-Constrained Overdrive Frequency Selection In Multicore Systems

    In leading-edge process technologies, reliability is a first-class constraint for both IC design and system operation. For multicore systems, reliability affects task scheduling decisions since it constrains both performance and throughput. Previous works on reliability-constrained task scheduling have two basic limitations: either they cannot guarantee lifetime (e.g., that the chip...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Automated Test Generation from Vulnerability Signatures

    Web applications need to validate and sanitize user inputs in order to avoid attacks such as Cross Site Scripting (XSS) and SQL injection. Writing string manipulation code for input validation and sanitization is an error-prone process leading to many vulnerabilities in real-world web applications. Automata-based static string analysis techniques can...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Cloud Platform Support for API Governance

    As scalable information technology evolves to a more cloud-like model, digital assets (code, data and software environments) increasingly require duration as web-accessible services. \"Service-izing\" digital assets consist of encapsulating assets in software that exposes them to web and mobile applications via well-defined yet flexible, network accessible, Application Programming Interfaces (APIs)....

    Provided By University of Calgary

  • White Papers // Jan 2014

    NOLO : A No-Loop, Predictive Useful Skew Methodology for Improved Timing in IC Implementation

    Useful skew is a well-known design technique that adjusts clock sink latencies to improve performance and/or robustness of high-performance IC designs. Current design methodologies apply useful skew after the netlist has been synthesized (e.g., with a uniform skew or clock uncertainty assumption on all flops), and after placement has been...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Timing Margin Recovery with Flexible Flip-Flop Timing Model

    In timing signoff for leading-edge SOCs, even few-picosecond timing violations will not only increase design turnaround time, but also degrade design quality (e.g., through power increase from insertion of extra buffers). Conventional flip-flop timing models have fixed values of setup/hold times and clock-to-q (c2q) delay, with some advanced \"Setup-Hold Pessimism...

    Provided By University of Calgary

  • White Papers // Jan 2014

    A Flexible, Syntax Independent Representation (SIR) for System Level Design Models

    System Level Design (SLD) is widely seen as a solution for bridging the gap between chip complexity and design productivity of Systems on Chip (SoC). SLD relieves the designer from detailed manual implementation by raising the level of abstraction in design models. There are many different modeling approaches to SLD....

    Provided By University of Calgary

  • White Papers // Jan 2014

    Introduction to Hardware-Dependent Software Design

    Microelectronics is ubiquitous and took over large parts of the people daily life. Together with an increasing profileration of such embedded systems, their complexities are growing exponentially. Due to the rapidly increasing software content in embedded systems, Hardware-dependent Software (HdS) has become a critical topic in system design. In this...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Creating Explicit Communication in SoC Models Using Interactive Re-Coding

    Communication exploration has become a critical step during SoC design. Researchers in the CAD community have proposed fast and efficient techniques for comprehensive design space exploration to expedite this critical design step. Although these advances have been helpful in reducing the design time significantly, the overall design time of the...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Power-Aware Register Renaming in High-Performance Processors Using Compiler Support

    Recently, energy consumption in embedded systems has become more and more important, mainly due to the fact that many systems are now being designed as mobile devices, i.e., they have to operate on battery power instead of using abundant power from wall sockets. One important aspect of such devices is...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Ubiquitous Access to Distributed Data in Large-Scale Sensor Networks through Decentralized Erasure Codes

    Consider a large-scale wireless sensor network of n nodes, where a fraction k out of n generates data packets of global interest. Assuming that the individual nodes have limited storage and computational capabilities, the authors address the problem of how to enable ubiquitous access to the distributed data packets. Specially,...

    Provided By University of Calgary

  • White Papers // Jan 2014

    Data Placement Based on the Seek Time Analysis of a MEMS-based Storage Device

    Reducing access times to secondary I/O devices has long been the focus of many systems researchers. With traditional disk drives, access time is the composition of transfer time, seek time and rotational latency, so many techniques as to minimize these factors, such as ordering I/O requests or intelligently placing data,...

    Provided By University of Calgary

  • White Papers // Jan 2005

    Revenues, Profitability, and Returns: Clinical Analysis of the Market for Mobster Films

    This paper analyzes empirically the revenues, profitability, and financial returns of mobster-related movies using data from worldwide theatrical exhibition, television syndication, and video rentals and sales. It quantifies the revenues across each window of exhibition in relation to subsequent windows and to the production budget. A regression model is used...

    Provided By University of Calgary

  • White Papers // Jan 2010

    A Case for Context-Aware TCP/IP

    This paper discusses the design and evaluation of CATNIP, a Context-Aware Transport/Network Internet Protocol for the Web. This integrated protocol uses application-layer knowledge (i.e.,Web document size) to provide explicit context information to the TCP and IP protocols. While this approach violates the traditional layered Internet protocol architecture, it enables informed...

    Provided By University of Calgary

  • White Papers // Jan 2010

    Downlink Performance for Mixed Web/VoIP Traffic in 1xEVDO Rev a Networks

    Current 3G cellular networks, such as those based on 1xEVDO Rev A, have several mechanisms to provide Quality of Service (QoS) to network applications. This paper investigates the performance for mixed Web/VoIP traffic on the downlink in 1xEVDO Rev A networks. The impacts from the mixed traffic are studied by...

    Provided By University of Calgary

  • White Papers // Jan 2010

    Improved Port Knocking With Strong Authentication

    Sometimes, it becomes necessary to let only the authorized external users access the open ports whereas closed ports may be accessible to all. The paper seeks to investigate various methods of authentication so as to keep data secure. It specifically focuses on 'Port Knocking' method and the procedure to implement...

    Provided By University of Calgary

  • White Papers // Jan 2012

    On the Performance of Redundant Traffic Elimination in WLANs

    Redundant Traffic Elimination (RTE) detects and removes repeated chunks of data across network flows, protocols, and applications, with the purpose of reducing bandwidth usage. In this paper, the authors explore the effectiveness of RTE in WLAN, compare it to RTE in Ethernet, and investigate specific issues affecting RTE in WLAN....

    Provided By University of Calgary

  • White Papers // Dec 2010

    Enhancing Redundant Network Traffic Elimination

    Protocol-independent Redundant Traffic Elimination (RTE) is a method to detect and remove redundant chunks of data from network-layer packets by using caching at both ends of a network link or path. In this paper, the authors propose a set of techniques to improve the effectiveness of packet-level RTE. In particular,...

    Provided By University of Calgary

  • White Papers // Jan 2011

    A Station-Based Adaptation Algorithm to Improve Robustness of IEEE 802.11

    This paper studies a Bad Apple phenomenon caused by Head-of-Line blocking in IEEE 802.11 networks. This problem can adversely affect the performance of wireless multimedia streaming. The authors summarize the characteristics of the Bad Apple problem, and then propose a Station-Based Adaptation (SBA) algorithm to solve it. SBA maintains per-station...

    Provided By University of Calgary

  • White Papers // Jan 2011

    Characterization of CDMA2000 Cellular Data Network Traffic

    This paper describes the analysis of low-level measurements from a CDMA2000 1x cellular data network. The network traces record detailed information about wireless Internet packet data call activity on the network, including mobile station identity, call initiation, burst behaviour, supplementary channel usage, soft handoffs, and call termination. The analysis in...

    Provided By University of Calgary

  • White Papers // Jan 2011

    Towards Stadium-Scale Wireless Media Streaming

    This paper proposes a scalable architecture for multimedia streaming in wireless LANs. Current IEEE 802.11 WLANs can support tens of media streaming users. The authors propose a hierarchical approach that can support over 1000 concurrent users. Their architecture exploits several existing technologies, including multi-channel WLANs, power control, and caching. The...

    Provided By University of Calgary

  • White Papers // Jan 2011

    On Effective Capacity in Time-Varying Wireless Networks

    In some networks, the physical transmission capacity can vary unpredictably with time. This stochastic variation may degrade system performance, reducing the effective capacity of the network. Traditional performance modeling ignoring this variation may overestimate system performance. In this paper, the authors investigate the impacts from stochastic capacity characteristics, using simulation....

    Provided By University of Calgary

  • White Papers // Nov 2009

    Auction Based On-Demand P2P Min-Cost Media Streaming With Network Coding

    Realizing on-demand media streaming in a Peer-To-Peer (P2P) fashion is more challenging than in the case of live media streaming, since only peers with close-by media play progresses may help each other in obtaining the media content. The situation is further complicated if the authors wish to pursue low aggregated...

    Provided By University of Calgary

  • White Papers // Feb 2011

    Strategyproof Mechanisms for Content Delivery Via Layered Multicast

    Layered multicast exploits the heterogeneity of user capacities, making it ideal for delivering content such as media streams over the Internet. In order to maximize either its revenue or the total utility of users, content providers employing layered multicast need to carefully choose a routing, layer allocation and pricing scheme....

    Provided By University of Calgary

  • White Papers // Aug 2011

    Cuckoo: Scaling Microblogging Services With Divergent Traffic Demands

    Today's microblogging services such as Twitter have long outgrown their initial designs as SMS-based social networks. Instead, a massive and steadily-growing user population of more than 100 million is using Twitter for everything from capturing the mood of the country to detecting earthquakes and Internet service failures. It is unsurprising...

    Provided By University of Calgary

  • White Papers // Jan 2012

    Localization With Witnesses

    Localization protocols enable an entity (called the verifier) to determine the physical location of another entity (called the prover), even if the prover maliciously advertises a false location or tries to corrupt the verifier's time measurements by time-shifting its responses. Unfortunately, the correctness of such protocols is critically dependent on...

    Provided By University of Calgary

  • White Papers // Jul 2011

    Bounding the Coding Advantage of Combination Network Coding in Undirected Networks

    The authors refer to network coding schemes in which information flows propagate along a combination network topology as Combination Network Coding (CNC). CNC and its variations are the first network coding schemes studied in the literature, and so far still represent arguably the most important class of known structures where...

    Provided By University of Calgary

  • White Papers // May 2012

    Bit-Interleaved Coded Multiple Beamforming With Perfect Coding

    When Channel State Information (CSI) is available at both the transmitter and the receiver, beamforming techniques exploiting Singular Value Decomposition (SVD) are applied in a Multiple-Input Multiple-Output (MIMO) system to achieve spatial multiplexing1 and thereby increase the data rate, or to enhance the performance. However, spatial multiplexing without channel coding...

    Provided By University of Calgary

  • White Papers // May 2012

    Outage Performance for Amplify-and-Forward Channels With an Unauthenticated Relay

    The authors investigate a relay network where the source can potentially utilize an unauthenticated Amplify-and-Forward (AF) relay to augment its direct transmission of a confidential message to the destination. Since the relay is unauthenticated, it is desirable to protect the confidential data from it while simultaneously making use of it...

    Provided By University of Calgary

  • White Papers // Sep 2012

    ACORN: An Auto-Configuration Framework for 802.11n WLANs

    The wide channels feature combines two adjacent channels to form a new, wider channel to facilitate high data rate transmissions in MIMO-based 802.11n networks. Using a wider channel can exacerbate interference effects. Furthermore, contrary to what has been reported by prior studies, the authors find that wide channels do not...

    Provided By University of Calgary

  • White Papers // Aug 2012

    Realizing the Benefits of Wireless Network Coding in Multi-Rate Settings

    Network coding has been proposed as a technique that can potentially increase the transport capacity of a wireless network via mixing data packets at intermediate routers. However, most previous studies either assume a fixed transmission rate or do not consider the impact of using diverse rates on the network coding...

    Provided By University of Calgary

  • White Papers // May 2012

    Combination Weights for Diffusion Strategies With Imperfect Information Exchange

    Adaptive networks rely on in-network and collaborative processing among distributed agents to deliver enhanced performance in estimation and inference tasks. Information is exchanged among the nodes, usually over noisy links. This paper first investigates the mean-square performance of adaptive diffusion algorithms in the presence of various sources of imperfect information...

    Provided By University of Calgary

  • White Papers // May 2012

    Distributed Throughput Optimization Over P2P Mesh Networks Using Diffusion Adaptation

    This work develops a decentralized adaptive strategy for throughput maximization over Peer-To-Peer (P2P) networks. The adaptive strategy can cope with changing network topologies, is robust to network disruptions, and does not rely on central processors. The algorithm is obtained as a special case of a more general diffusion strategy for...

    Provided By University of Calgary

  • White Papers // Oct 2012

    On Constant-Round Concurrent Zero-Knowledge From a Knowledge Assumption

    In this paper, the authors consider the long-standing open question of constructing constant-round concurrent zero-knowledge protocols in the plain model. Resolving this question is known to require non-black-box techniques. They consider non-black-box techniques for zero-knowledge based on knowledge assumptions, a line of thinking initiated by the work of Hada and...

    Provided By University of Calgary

  • White Papers // May 2012

    Protograph-Based Raptor-Like LDPC Codes With Low Thresholds

    This paper presents a new construction of Punctured-Node Protograph-Based Raptor-Like (PN-PBRL) codes that is suitable for long-blocklength applications. As with the Raptor codes, additional parity bits can be easily produced by exclusive-OR operations on the precoded bits, providing extensive rate compatibility. The new construction provides low iterative decoding thresholds that...

    Provided By University of Calgary

  • White Papers // May 2012

    Coded Path Protection: Efficient Conversion of Sharing to Coding

    Link failures in wide area networks are common and cause significant data losses. Mesh-based protection schemes offer high capacity efficiency but they are slow and require complex signaling. Additionally, real-time reconfiguration of a cross connect threatens their transmission integrity. On the other hand, coding-based protection schemes are proactive. Therefore, they...

    Provided By University of Calgary

  • White Papers // May 2012

    Cyclostationarity-Based Low Complexity Wideband Spectrum Sensing Using Compressive Sampling

    Detecting the presence of licensed users and avoiding interference to them is vital to the proper operation of a Cognitive Radio (CR) network. Operating in a wideband channel requires high Nyquist sampling rates, which is limited by the state-of-the-art A/D converters. Compressive sampling is a promising solution to reduce sampling...

    Provided By University of Calgary

  • White Papers // Sep 2012

    Towards Verifying Android Apps for the Absence of No-Sleep Energy Bugs

    The Android OS conserves battery life by aggressively turning off components, such as screen and GPS, while allowing application developers to explicitly prevent part of this behavior using the Wake-Lock API. Unfortunately, the inherent complexity of the Android programming model and developer errors often lead to improper use of Wake-Locks...

    Provided By University of Calgary

  • White Papers // May 2011

    Provenance Based Rebuild: Using Data Provenance to Improve Reliability

    Traditionally, data preservation and reliability have used Error Correcting Codes (ECCs) to ensure data safety. The development of general data provenance tracking systems provides a new opportunity for data reliability. The authors present a method that utilizes provenance to determine a datum's generating process and inputs, and then uses this...

    Provided By University of Calgary

  • White Papers // May 2011

    Tracking Emigrant Data via Transient Provenance

    Information leaks are a constant worry for companies and government organizations. After a leak occurs it is very important for the data owner to not only determines the extent of the leak, but who originally leaked the information. The authors propose a technique to extend data provenance to aid in...

    Provided By University of Calgary

  • White Papers // Aug 2012

    Evolving Landscape of Cellular Network Traffic

    Recent technological advances have resulted in a dramatic change in the market shares of cellular mobile devices. However, little is known about the impact of these changes on the landscape of cellular network traffic. Using anonymized traces from one million cellular subscribers, the authors conduct a comparative study of the...

    Provided By University of Calgary

  • White Papers // Nov 2012

    Simultaneous Information and Energy Transfer: A Two-User MISO Interference Channel Case

    This paper considers the sum rate maximization problem of a two-user multiple-input single-output interference channel with receivers that can scavenge energy from the radio signals transmitted by the transmitters. The authors first study the optimal transmission strategy for an ideal scenario where the two receivers can simultaneously decode the information...

    Provided By University of Calgary

  • White Papers // Jul 2012

    Cramer-Rao Bounds for Joint RSS/DoA-Based Primary-User Localization in Cognitive Radio Networks

    Knowledge about the location of licensed Primary-Users (PU) could enable several key features in Cognitive Radio (CR) networks including improved spatio-temporal sensing, intelligent location-aware routing, as well as aiding spectrum policy enforcement. In this paper, the authors consider the achievable accuracy of PU localization algorithms that jointly utilize Received-Signal-Strength (RSS)...

    Provided By University of Calgary

  • White Papers // Mar 2010

    Power Allocation for Beamforming Relay Networks Under Channel Uncertainties

    Power allocation strategies have attracted considerable attention in an effort to reduce the network power and/or improve the performance of the cooperative relay networks. In cooperative relay networks, multiple relays cooperate to retransmit data. In, power control factors are designed to maximize a Signal-to-Noise Ratio (SNR) upper bound. Under the...

    Provided By University of Calgary

  • White Papers // Jan 2013

    Content Based Traffic Engineering in Software Defined Information Centric Networks

    This paper describes a content centric network architecture which uses software defined networking principles to implement efficient metadata driven services by extracting content metadata at the network layer. The ability to access content metadata transparently enables a number of new services in the network. Specific examples discussed here include: a...

    Provided By University of Calgary

  • White Papers // Nov 2012

    Cooperative Beamforming in Multiuser MIMO Networks: Fast SINR Fairness Algorithms

    This paper studies efficient signal transmission strategies in a multiuser MIMO network where multiple source nodes form a large virtual MIMO array to perform cooperative beamforming. In order to reduce instantaneous feedback needs, the authors investigate joint power control and cooperative beamforming techniques to maximize the minimum weighted average SINR...

    Provided By University of Calgary

  • White Papers // Nov 2012

    Multi-User Detection for Asynchronous Space-Frequency Block Coded Schemes in Frequency Selective Environments

    Multi-user detection is an efficient approach proposed to boost the spectral efficiency of a wireless communication system. While multi-user detection in synchronous systems or in flat fading environments has been successfully addressed, it is still an open and challenging problem in the practical case of asynchronous MIMO systems employing space-frequency...

    Provided By University of Calgary

  • White Papers // Oct 2012

    Making the Internet More Evolvable

    Why is the Internet so hard to evolve? Some argue that the people require a radically different architecture to enable evolution. To the contrary, they contend that a simple re-engineering of the basic Internet interfaces to make them more modular and extensible - as one would in any software system...

    Provided By University of Calgary

  • White Papers // Sep 2012

    Macroscopically Sustainable Networking: An Internet Quine

    The Internet stands atop an unseen industrial system required for its continued growth, operation, and maintenance. While its scale could not have been achieved without this reliance, its dependencies - ranging from sophisticated manufacturing facilities to limited raw materials - make it vulnerable to disruptions. To achieve independence requires an...

    Provided By University of Calgary

  • White Papers // Nov 2012

    Linear Programming Based Joint Detection of LDPC Coded MIMO Systems

    Multiple-Input Multiple-Output (MIMO) communication systems can achieve higher throughput by exploiting diversity in multi-antenna wireless communications. Spatial multiplexing schemes attempts to take advantage of the increased Shannon capacity that grows linearly with the number of transceiver antennas. One can apply Maximum a Posteriori probability (MAP) detector and Minimum Mean Square...

    Provided By University of Calgary

  • White Papers // Nov 2012

    Spectrum Management in Heterogeneous Bandwidth Networks

    As optical network continues to evolve, lightpaths will take on different spectrum spaces as opposed to current uniform 50-GHz grid. While lightpaths of heterogeneous bandwidths co-exist, two factors emerge that will degrade the provisioning efficiency and negatively impact its sustainable evolution: unfairness of access among different bandwidth connections, and spectrum...

    Provided By University of Calgary

  • White Papers // Sep 2012

    Cloud Platform Datastore Support

    There are many datastore systems to choose from that differ in many ways including public versus private cloud support, data management interfaces, programming languages, supported feature sets, fault tolerance, consistency guarantees, configuration, and their deployment processes. In this paper, the authors focus on technologies for structured data access (database/datastore systems)...

    Provided By University of Calgary