University of Toronto

Displaying 1-40 of 175 results

  • White Papers // Jan 2015

    A System Design Methodology for Reducing System Integration Time and Facilitating Modular Design Verification

    In this paper, the authors provide a realistic case study of using the previously introduced SIMPPL system architectural model, which fixes the physical interface and communication protocols between Processing Elements (PEs) using PE-specific SIMPPL controllers. The implementation of a real-time MPEG-1 video decoder using SIMPPL provides a practical demonstration of...

    Provided By University of Toronto

  • White Papers // May 2014

    Value Cocreation Modeling: Supporting the Analysis and Design of B2B Service Engagements Through Agent Orientation and Business Intelligence

    Current modeling approaches for designing services do not address the characteristics of collaborative Business-To-Business (B2B) service engagements. Yet, these types of service engagements, for example R&D services and other knowledge-intensive business services, are key components of industrialized economies. The authors identify the requirements of a modeling technique able to support...

    Provided By University of Toronto

  • White Papers // Apr 2014

    SleepScale: Runtime Joint Speed Scaling and Sleep States Management for Power Efficient Data Centers

    Power consumption in data centers has been growing significantly in recent years. To reduce power, servers are being equipped with increasingly sophisticated power management mechanisms. Different mechanisms offer dramatically different trade-offs between power savings and performance penalties. Considering the complexity, variety, and temporally varying nature of the applications hosted in...

    Provided By University of Toronto

  • White Papers // Jun 2012

    Cost Efficient Datacenter Selection for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, in a cost efficient manner. Previous work focused mostly on the electricity cost of datacenters. The approaches favor datacenters...

    Provided By University of Toronto

  • White Papers // May 2012

    MixApart: Decoupled Analytics for Shared Storage Systems

    Data analytics and enterprise applications have very different storage functionality requirements. For this reason, enterprise deployments of data analytics are on a separate storage silo. This may generate additional costs and inefficiencies in data management, e.g., whenever data needs to be archived, copied, or migrated across silos. The authors introduce...

    Provided By University of Toronto

  • White Papers // May 2012

    Oruta: Privacy-Preserving Public Auditing for Shared Data in the Cloud

    With cloud storage services, it is commonplace for data to be not only stored in the cloud, but also shared across multiple users. However, public auditing for such shared data - while preserving identity privacy - remains to be an open challenge. In this paper, the authors propose the first...

    Provided By University of Toronto

  • White Papers // May 2012

    A General and Practical Datacenter Selection Framework for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, depending on factors including performance, cost, etc. Previous work focused on efficiency and invariably considered the simple objective of...

    Provided By University of Toronto

  • White Papers // May 2012

    Mining for Data: Assessing the Use of Online Research

    In this paper, the authors provide evidence on the way that people use research resources posted on websites. Although the Internet is now 'The' main point of access to research findings, little is known about how it is used to this end. The paper reported here has gradually developed some...

    Provided By University of Toronto

  • White Papers // Apr 2012

    Postcard: Minimizing Costs on Inter-Datacenter Traffic With Store-and-Forward

    It is typical for cloud providers to operate a number of geographically distributed datacenters, where inter-datacenter traffic constitutes a large portion of a cloud provider's traffic demand over the Internet. Though such inter-datacenter traffic incurs substantial operational costs that are charged by ISPs, it varies significantly across different overlay links,...

    Provided By University of Toronto

  • White Papers // Apr 2012

    Towards Optimal Capacity Segmentation With Hybrid Cloud Pricing

    Cloud resources are usually priced in multiple markets with different service guarantees. For example, Amazon EC2 prices virtual instances under three pricing schemes - the subscription option (a.k.a., Reserved Instances), the pay-as-you-go offer (a.k.a., On-Demand Instances), and an auction-like spot market (a.k.a., Spot Instances) - simultaneously. There arises a new...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Bargaining Towards Maximized Resource Utilization in Video Streaming Datacenters

    Datacenters can be used to host large-scale video streaming services with better operational efficiency, as the multiplexing achieved by virtualization technologies allows different videos to share resources at the same physical server. Live migration of videos from servers that are overloaded to those that are under-utilized may be a solution...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Distributional Measures of Semantic Distance: A Survey

    The ability to mimic human notions of semantic distance has widespread applications. Some measures rely only on raw text (distributional measures) and some rely on knowledge sources such as WordNet. Although extensive studies have been performed to compare WordNet-based measures with human judgment, the use of distributional measures as proxies...

    Provided By University of Toronto

  • White Papers // Feb 2012

    Maximizing Revenue With Dynamic Cloud Pricing: The Infinite Horizon Case

    The authors study the infinite horizon dynamic pricing problem for an infrastructure cloud provider in the emerging cloud computing paradigm. The cloud provider, such as Amazon, provides computing capacity in the form of virtual instances and charges customers a time-varying price for the period they use the instances. The provider's...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Quality-Assured Cloud Bandwidth Auto-Scaling for Video-on-Demand Applications

    There has been a recent trend that Video-on-Demand (VoD) providers such as Netflix are leveraging resources from cloud services for multimedia streaming. In this paper, the authors consider the scenario that a VoD provider can make reservations for bandwidth guarantees from cloud service providers to guarantee the streaming performance in...

    Provided By University of Toronto

  • White Papers // Jan 2012

    A Theory of Cloud Bandwidth Pricing for Video-on-Demand Providers

    Current-generation cloud computing is offered with usage-based pricing, with no bandwidth capacity guarantees, which is however unappealing to bandwidth-intensive applications such as Video-on-Demand (VoD). The authors consider a new type of service where VoD providers, such as Netflix and Hulu, make reservations for bandwidth guarantees from the cloud at negotiable...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Jointly Optimal Bit Loading, Channel Pairing and Power Allocation for Multi-Channel Relaying

    The authors aim to enhance the end-to-end rate of a general dual-hop relay network with multiple channels and finite modulation formats, by jointly optimizing channel pairing, power allocation, and integer bit loading. Such an optimization problem has both a discrete feasible region, due to the combinatoric nature of channel pairing,...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Truthful Spectrum Auction Design for Secondary Networks

    Opportunistic wireless channel access by non-licensed users has emerged as a promising solution for addressing the bandwidth scarcity challenge. Auctions represent a natural mechanism for allocating the spectrum, generating an economic incentive for the licensed user to relinquish channels. A severe limitation of existing spectrum auction designs lies in the...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Supporting Efficient Collective Communication in NoCs

    Across many architectures and parallel programming paradigms, collective communication plays a key role in performance and correctness. Hardware support is necessary to prevent important collective communication from becoming a system bottleneck. Support for multicast communication in Networks-on-Chip (NoCs) has achieved substantial throughput improvements and power savings. In this paper, the...

    Provided By University of Toronto

  • White Papers // Jan 2012

    MANET Extensions to Ns2

    This is a set of software modules providing additional models for the simulation of multi-hop Mobile Ad hoc NETworks (MANETs) in the ns2 simulator. The authors provide implementations of the CM and Shell mobility models, and the AF and LOS radio propagation models described in. They also provide instrumentation tools...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Automated Data Analysis Techniques for a Modern Silicon Debug Environment

    With the growing size of modern designs and more strict time-to-market constraints, design errors unavoidably escape pre-silicon verification and reside in silicon prototypes. As a result, silicon debug has become a necessary step in the digital integrated circuit design flow. Although embedded hardware blocks, such as scan chains and trace...

    Provided By University of Toronto

  • White Papers // Jan 2012

    From RTL to Silicon: The Case for Automated Debug

    Computer-aided design tools are continuously improving their scalability and efficiency to mitigate the high cost associated with designing and fabricating modern VLSI systems. A key step in the design process is the root-cause analysis of detected errors. Debugging may take months to close, introduce high cost and uncertainty ultimately jeopardizing...

    Provided By University of Toronto

  • White Papers // Jan 2012

    A High-Throughput Overlay Multicast Infrastructure With Network Coding

    Network coding has been recently proposed in information theory as a new dimension of the information multicast problem that helps achieve optimal transmission rate or cost. End hosts in overlay networks are natural candidates to perform network coding, due to its available computational capabilities. In this paper, the authors seek...

    Provided By University of Toronto

  • White Papers // Jan 2012

    SFlow: Towards Resource-Efficient and Agile Service Federation in Service Overlay Networks

    Existing research work towards the composition of complex federated services has assumed that service requests and deliveries flow through a particular service path or tree. In this paper, the authors extend such a service model to a directed acyclic graph, allowing services to be delivered via parallel paths and interleaved...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Linear Processing for the Downlink in Multiuser MIMO Systems With Multiple Data Streams

    In this paper, the authors solve the problem of linear precoding for the downlink in multiuser Multiple-Input Multiple-Output (MIMO) systems. The transmitter and the receivers may be equipped with multiple antennas and each user may receive multiple data streams. Their objective is to jointly optimize the power allocation and transmit-receive...

    Provided By University of Toronto

  • White Papers // Jan 2012

    ToX - The Toronto XML Engine

    The authors present ToX - the Toronto XML Engine - a repository for XML data and metadata, which supports real and virtual XML documents. Real documents are stored as files or mapped into relational or object databases, depending on their structuredness; indices are defined according to the storage method used....

    Provided By University of Toronto

  • White Papers // Dec 2011

    Distributed Optimal TXOP Control for Throughput Requirements in IEEE 802.11e Wireless LAN

    This paper designs a distributed Transmission OPportunity (TXOP) adaptation algorithm for IEEE802.11e Enhanced Distributed Channel Access (EDCA). Each node measures its throughput in a window and compares it with a target value. If the measured throughput is higher than the target value, the node reduces its TXOP, otherwise if the...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Non-Solution Implications Using Reverse Domination in a Modern SAT-Based Debugging Environment

    With the growing complexity of VLSI designs, functional debugging has become a bottleneck in modern CAD flows. To alleviate this cost, various SAT-based techniques have been developed to automate bug localization in the RTL. In this paper, dominance relationships between circuit blocks have been recently shown to reduce the number...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Leveraging Reconfigurability to Raise Productivity in FPGA Functional Debug

    The authors propose new hardware and software techniques for FPGA functional debug that leverage the inherent re-configurability of the FPGA fabric to reduce functional debugging time. The functionality of an FPGA circuit is represented by a programming bit-stream that specifies the configuration of the FPGA's internal logic and routing. The...

    Provided By University of Toronto

  • White Papers // Nov 2011

    On Error Tolerance and Engineering Change With Partially Programmable Circuits

    The growing size, density and complexity of modern VLSI chips are contributing to an increase in hardware faults and design errors in the silicon, decreasing manufacturing yield and increasing the design cycle. The use of Partially Programmable Circuits (PPCs) has been recently proposed for yield enhancement with very small overhead....

    Provided By University of Toronto

  • White Papers // Nov 2011

    Joint Power Control and Beamforming Codebook Design for MISO Channels under the Outage Criterion

    This paper investigates the joint design of power control and beamforming codebooks for limited-feedback Multiple-Input Single-Output (MISO) wireless systems. The problem is formulated as the minimization of the outage probability subject to the transmit power constraint and cardinality constraints on the beamforming and power codebooks. The authors show that the...

    Provided By University of Toronto

  • White Papers // Nov 2011

    Efficient Debugging of Multiple Design Errors

    After functional verification detects a failure, design debugging aims to find all locations in the design that could be responsible for the observed error. The task of debugging becomes more difficult in modern designs because of the presence of multiple design errors. Multiple design errors exponentially increase the solution space...

    Provided By University of Toronto

  • White Papers // Oct 2011

    Propelling SAT-Based Debugging Using Reverse Domination

    With the growing complexity of VLSI designs, functional debugging has become a bottleneck in modern CAD flows. To alleviate this cost, various SAT-based techniques have been developed to automate bug localization in the RTL. In this paper, dominance relationships between circuit blocks have been recently shown to reduce the number...

    Provided By University of Toronto

  • White Papers // Sep 2011

    Modeling on Quicksand

    Researchers studying the inter-domain routing system, its properties and new protocols, face many challenges in performing realistic evaluations and simulations. Modeling decisions with respect to AS-level topology, routing policies and traffic matrices are complicated by a dearth of ground truth for each of these components. Moreover, scalability is-sues arise when...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Collaborative Caching for Video Streaming Among Selfish Wireless Service Providers

    Video streaming is now at the fingertips of mobile users with recent advances in wireless communications and mobile networking. Caching has been widely deployed by Wireless Service Providers (WSPs) to facilitate video content dissemination. Yet, capacity provisioning of cache servers is challenging given dynamic user demands and limited wireless bandwidth...

    Provided By University of Toronto

  • White Papers // Jul 2011

    YMMV: Multiple Session Multicast With MIMO

    Multicast is an important application in cellular networks. The 4G technologies, including WiMAX and LTE, invariably adopt Multiple-Input-Multiple-Output (MIMO) to facilitate spatial multiplexing and fundamentally increase channel capacity. However, state-of-the-art multicast protocols are designed to perform in single-hop mode with a single session, leading to under-utilization of the scarce spectrum...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Completion Delay Reduction in Lossy Feedback Scenarios for Instantly Decodable Network Coding

    In this paper, the authors study the effect of packet feedback loss events on the broadcast completion delay performance of instantly decodable network coding. These feedback loss events result in a continuous lack of knowledge about the reception status at different subsets of receivers. This lack of knowledge creates a...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Jointly Optimal Channel Pairing and Power Allocation for Multi-Channel Multi-Hop Relaying

    The authors study the problem of channel pairing and power allocation in a multi-channel multi-hop relay network to enhance the end-to-end data rate. Both Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying strategies are considered. Given fixed power allocation to the channels, they show that channel pairing over multiple hops can be...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Latch-Based Performance Optimization for FPGAs

    The authors explore using pulsed latches for timing optimization - a first in the FPGA community. Pulsed latches are transparent latches driven by a clock with a non-standard (non-50%) duty cycle. They exploit existing functionality within commercial FPGA chips to implement latch-based optimizations that do not have the power or...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Usury, Calvinism, And Credit In Protestant England: From The Sixteenth Century To The Industrial Revolution

    This paper analyzes the impact of Protestantism on interest rates in England from the 16th century to the Industrial Revolution. One of many myths about the usury doctrine - the prohibition against demanding anything above the principal in a loan (mutuum) - is that it ceased to be observed in...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Low-Cost Hardware Profiling of Run-Time and Energy in FPGA Embedded Processors

    Field-Programmable Gate Arrays (FPGAs) are a widely used technology in the design of embedded systems due to their improving speed, density and power, steadily decreasing cost, and their programmability which reduces a product's time-to-market. The advent of FPGA soft processors permits the creation of hybrid systems within a single FPGA...

    Provided By University of Toronto

  • White Papers // Jun 2002

    Profitability, Growth and Efficiency in the US Life Insurance Industry

    This study explores the relationship between operational efficiency and profitability and growth in the life Insurance industry, and provides a framework for linking operating performance and financial success. Earnings and growth have particular importance to life insurance companies; earnings and capital determine the viability of the insurer, while growth is...

    Provided By University of Toronto

  • White Papers // Jan 2005

    Teams Vs. Individual Accountability: Solving Multi-Task Problems Through Job Design

    Many organizations are structured so that workers are jointly accountable for performance; even though alternative organizational structures are available that would align incentive compensation more closely with each worker's tasks. One develops a multi-task agency model that demonstrates that such organizations may be optimal when multi-task problems are severe and/or...

    Provided By University of Toronto

  • White Papers // Jun 2010

    Repatriation Taxes And Foreign Direct Investment: Evidence From Tax Treaties

    This paper examines the effects on foreign direct investment of worldwide versus territorial tax systems. Canada operates a hybrid system of international taxation, under which dividends repatriated from affiliates located in tax treaty partner countries are exempt from domestic taxation, while repatriations from non-treaty countries are subject to a foreign...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Learning Mixture Models With the Latent Maximum Entropy Principle

    The paper presents a new approach to estimating mixture models based on a new inference principle the author has proposed: the Latent Maximum Entropy principle (LME). LME is different both from Jaynes' maximum entropy principle and from standard maximum likelihood estimation. The paper demonstrates the LME principle by deriving new...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Haste: Practical Online Network Coding in a Multicast Switch

    The use of network coding has been shown to improve throughput in input-queued multicast switches, but not without costs of computational complexity and delays. This paper investigates the design of efficient online network coding algorithms in a switch with multicast traffic. The paper presents Haste, an online opportunistic coding algorithm...

    Provided By University of Toronto

  • White Papers // Sep 2010

    SnowFlock: Rapid Virtual Machine Cloning for Cloud Computing

    Virtual Machine (VM) fork is a new cloud computing abstraction that instantaneously clones a VM into multiple replicas running on different hosts. This paper focuses on the primitive of VM fork and the Xen-based implementation SnowFlock. Virtualization provides many benefits such as security, performance isolation, ease of management, and flexibility...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Constructing Complex Semantic Mappings Between XML Data and Ontologies

    Much data is published on the Web in XML format satisfying schemas, and to make the Semantic Web a reality, such data needs to be interpreted with respect to ontologies. Interpretation is achieved through a semantic mapping between the XML schema and the ontology. The authors present work on the...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Distributed Cross-Layer Optimization of Wireless Sensor Networks: A Game Theoretic Approach

    This paper proposes a distributed optimization framework for wireless multihop sensor networks base on a game theoretic approach. The authors show that the cross-layer optimization problem can be decomposed into two subproblems corresponding to two separate layers (the physical and the application layers) of the overall system. By modelling each...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Content-Based Routing in Mobile Ad Hoc Networks

    The publish/subscribe model of communication provides sender/receiver decoupling and selective information dissemination that is appropriate for mobile environments characterized by scarce resources and a lack of ?xed infrastructure. The authors propose and evaluate three content-based routing protocols: CBR is an adaptation of existing distributed publish/subscribe protocols for wired networks, FT-CBR...

    Provided By University of Toronto

  • White Papers // Jan 2010

    QoS-Aware Adaptive Services in Mobile Ad-Hoc Networks

    Ad-hoc wireless networks consist of mobile nodes interconnected by multi-hop wireless paths. Unlike conventional wireless networks, ad-hoc networks have no fixed network infrastructure or administrative support. Because of the dynamic nature of the network topology and limited bandwidth of wireless channels, Quality-of-Service (QoS) provisioning is an inherently complex and difficult...

    Provided By University of Toronto

  • White Papers // Jul 2010

    BPM in Cloud Architectures: Business Process Management With SLAs and Events

    Applications are becoming increasingly distributed and loosely coupled in terms of their development processes, software architectures, deployment platforms, and other aspects. For example, in Web mashups, utility or cloud computing environments, and Service-Oriented Architectures (SOA) applications are developed by orchestrating reusable services using high level workflows or business processes. Application...

    Provided By University of Toronto

  • White Papers // Sep 2010

    The Sarbanes-Oxley Act And Exit Strategies Of Private Firms

    The costs and benefits of the Sarbanes-Oxley Act of 2002 (SOX) have been oft-debated since the inception of the Act. Much of the extant literature has assessed the costs and benefits of SOX to publicly-traded companies. The authors focus on the costs of SOX compliance for private firms wanting to...

    Provided By University of Toronto

  • White Papers // Nov 2010

    Monitoring and Recovery of Web Service Applications

    For a system of distributed processes, correctness can be ensured by (Statically) checking whether their composition satisfies properties of interest. However, web services are distributed processes that dynamically discover properties of other web services. Since the overall system may not be available statically and since each business process is supposed...

    Provided By University of Toronto

  • White Papers // Aug 2010

    Optimizing Computation of Recovery Plans for BPEL Applications

    A BPEL application is an orchestration of (Possibly third-party) web services. These services, which can be written in a variety of languages, communicate through published interfaces. Third-party services can be dynamically discovered, and may be modified without notice. BPEL includes mechanisms for dealing with termination and for specifying compensation actions...

    Provided By University of Toronto

  • White Papers // May 2010

    Dude, Where's That IP? Circumventing Measurement-Based IP Geolocation

    Many applications of IP geolocation can benefit from geolocation that is robust to adversarial clients. These include applications that limit access to online content to a specific geographic region and cloud computing, where some organizations must ensure their virtual machines stay in an appropriate geographic region. This paper studies the...

    Provided By University of Toronto

  • White Papers // Sep 2009

    Herding, Contrarianism And Delay In Financial Market Trading

    Herding and contrarian behavior are often cited features of real-world financial markets. Theoretical models of continuous trading that study herding and contrarianism, however, usually do not allow traders to choose when to trade or to trade more than once. The authors present a large-scale experiment to explore these features within...

    Provided By University of Toronto

  • White Papers // Feb 2010

    Work in Progress: End-to-End Throughput With Cooperative Communication in Multi-Channel Wireless Networks

    Although cooperative communication has been proposed at the physical layer to address multi-path fading effects, how physical layer gains with cooperative communication can translate to tangible performance benefits in end-to-end flows remains to be an open problem. This paper represents one step forward towards a deeper understanding of the interplay...

    Provided By University of Toronto

  • White Papers // May 2010

    Network Coding in Relay-Based Networks

    Since its inception in information theory, network coding has attracted a significant amount of research attention in recent years. Shortly after theoretical explorations in wired networks, the use of network coding in wireless networks towards improving throughput has been widely recognized. In this chapter, the authors present a survey of...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Efficient Resource Allocation With Flexible Channel Cooperation in OFDMA Cognitive Radio Networks

    Recently, a cooperative paradigm for single-channel cognitive radio networks has been advocated, where primary users can leverage secondary users to relay their traffic. However, it is not clear how such cooperation can be exploited in multi-channel networks effectively. Conventional cooperation entails that data on one channel has to be relayed...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Publishing Bibliographic Data on the Semantic Web Using BibBase

    The authors present BibBase, a system for publishing and managing bibliographic data available in BibTeX files on the Semantic Web. BibBase uses a powerful yet light-weight approach to transform BibTeX files into rich Linked Data as well as custom HTML and RSS code that can readily be integrated within a...

    Provided By University of Toronto

  • White Papers // Feb 2010

    Leveraging Personal Devices for Stronger Password Authentication From Untrusted Computers

    Internet authentication for popular end-user transactions, such as online banking and e-commerce, continues to be dominated by passwords entered through end-user Personal Computers (PCs). Most users continue to prefer (typically untrusted) PCs over smaller personal devices for actual transactions, due to usability features related to keyboard and screen size. However...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Distributed Minimum Energy Data Gathering and Aggregation in Sensor Networks

    Recent technological advances have enabled the production of low-cost sensor nodes. These sensor nodes are small in size, and are equipped with limited sensing, processing, and transmission capabilities. They can be deployed in large numbers to form sensor networks with the ability of distributed wireless sensing. In practice, sensor nodes...

    Provided By University of Toronto

  • White Papers // Dec 2009

    SlideOR: Online Opportunistic Network Coding in Wireless Mesh Networks

    Opportunistic routing significantly increases unicast throughput in wireless mesh networks by effectively utilizing the wireless broadcast medium. With network coding, opportunistic routing can be implemented in a simple and practical way without resorting to a complicated scheduling protocol. Traditionally, due to the constraints of computational complexity, a protocol utilizing network...

    Provided By University of Toronto

  • White Papers // Nov 2009

    Structured Admission Control Policy in Heterogeneous Wireless Networks With Mesh Underlay

    This paper investigates into optimal admission control policies for Heterogeneous Wireless Networks (HWN), considering an integration of wireless mesh networks with an overlaying cellular infrastructure. In order to characterize the overflow traffic from the underlaying mesh to the overlay, a Partially-Observable Markov-Modulated Poisson Process (POMMPP) traffic model is developed. This...

    Provided By University of Toronto

  • White Papers // Jan 2011

    A Lagrangian Approach for the Optimal Placement of Wireless Relay Nodes in Wireless Local Area Networks

    The throughput capacity of WLANs can be improved the authors propose an optimization formulation based on Lagrangian relaxation and a subgradient algorithm to compute the best placement of a fixed number of Relay Nodes (RNs) in a WLAN. The authors apply this optimization framework to a multi-rate WLAN based on...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Topological Properties Affect the Power of Network Coding in Decentralized Broadcast

    There exists a certain level of ambiguity regarding whether network coding can further improve download performance in P2P content distribution systems, as compared to commonly applied heuristics such as rarest first protocols. In this paper, the authors revisit the problem of broadcasting multiple data blocks from a single source in...

    Provided By University of Toronto

  • White Papers // Feb 2010

    Null Keys: Limiting Malicious Attacks Via Null Space Properties of Network Coding

    The performance of randomized network coding can suffer significantly when malicious nodes corrupt the content of the exchanged blocks. Previous work have introduced error correcting codes by generalizing some well known bounds in coding theory. Such codes are based on introducing redundancy in space domain. Other approaches require the use...

    Provided By University of Toronto

  • White Papers // Oct 2009

    Asymptotic Rate Limits for Randomized Broadcasting With Network Coding

    Motivated by peer-to-peer content distribution and media streaming applications, the authors study the broadcasting problem in a time-discretized model, with integer valued upload and download capacity constraints at nodes. The authors analyze both deterministic centralized and randomized decentralized protocols that can achieve optimal packet receiving rates at the nodes. In...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Incorporating Random Linear Network Coding for Peer-to-Peer Network Diagnosis

    Recent studies show that network coding improves multicast session throughput. In this paper, the authors demonstrate how random linear network coding can be incorporated to provide network diagnosis for peer-to-peer systems. The authors present a new trace collection protocol that allows operators to diagnose peer-to-peer networks. It is essential to...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Novasky: Cinematic-Quality VoD in a P2P Storage Cloud

    In this paper, the authors present Novasky, a real-world Video-on-Demand (VoD) system capable of delivering cinematic-quality video streams to end users. The foundation of the Novasky design is a Peer-to-Peer (P2P) storage cloud, storing and refreshing media streams in a decentralized fashion using local storage spaces of end users. They...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Wireless Communication Systems

    Wireless communications networks to provide telephone service to mobile users have been rapidly developed in the past 15 years. Beginning with the first generation analog systems which provide voice service the authors are now on the verge of the standardization of 3rd generation systems which will have the capability to...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Completion Delay Reduction in Lossy Feedback Scenarios for Instantly Decodable Network Coding

    In this paper, the authors study the effect of packet feedback loss events on the broadcast completion delay performance of instantly decodable network coding. These feedback loss events result in a continuous lack of knowledge about the reception status at different subsets of receivers. This lack of knowledge creates a...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Distributed Optimal TXOP Control for Throughput Requirements in IEEE 802.11e Wireless LAN

    This paper designs a distributed Transmission OPportunity (TXOP) adaptation algorithm for IEEE802.11e Enhanced Distributed Channel Access (EDCA). Each node measures its throughput in a window and compares it with a target value. If the measured throughput is higher than the target value, the node reduces its TXOP, otherwise if the...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Reliable Network Coded MAC in Vehicular Ad-Hoc Networks

    The authors consider the problem of designing cooperative driver assistance and collision warning systems in vehicular networks. In this problem each car has a small size state information message that should be received by its neighbourhood within a short lifetime of L timeslots. Because of the safety nature of the...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Distributional Measures of Semantic Distance: A Survey

    The ability to mimic human notions of semantic distance has widespread applications. Some measures rely only on raw text (distributional measures) and some rely on knowledge sources such as WordNet. Although extensive studies have been performed to compare WordNet-based measures with human judgment, the use of distributional measures as proxies...

    Provided By University of Toronto

  • White Papers // Jun 2012

    Cost Efficient Datacenter Selection for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, in a cost efficient manner. Previous work focused mostly on the electricity cost of datacenters. The approaches favor datacenters...

    Provided By University of Toronto

  • White Papers // May 2012

    A General and Practical Datacenter Selection Framework for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, depending on factors including performance, cost, etc. Previous work focused on efficiency and invariably considered the simple objective of...

    Provided By University of Toronto

  • White Papers // May 2012

    Oruta: Privacy-Preserving Public Auditing for Shared Data in the Cloud

    With cloud storage services, it is commonplace for data to be not only stored in the cloud, but also shared across multiple users. However, public auditing for such shared data - while preserving identity privacy - remains to be an open challenge. In this paper, the authors propose the first...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Simplified Simulation Models for Indoor MANET Evaluation Are Not Robust

    The authors evaluate the robustness of simplified mobility and radio propagation models for indoor MANET simulations. A robust simplification allows researchers to extrapolate simulation results and reach reliable conclusions about the expected performance of protocols in real life. They show that common simplified mobility and radio propagation models are not...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Throughput Analysis of Multiple Access Relay Channel Under Collision Model

    Despite much research on the throughput of relaying networks under idealized interference models, many practical wireless networks rely on physical-layer protocols that preclude the concurrent reception of multiple transmissions. In this paper, the authors develop analytical frameworks for the uplink of a multi-source single-channel relay-aided wireless system where transmissions are...

    Provided By University of Toronto