Chinese University of Hong Kong

Displaying 81-119 of 119 results

  • White Papers // Feb 2011

    Capacity Bounds for Full-Duplex Two-Way Relay Channel With Feedback

    The authors consider a Two-way Relay Channel (TRC) in which two terminals exchange their messages with the help of a relay between them. The two terminals transmit messages to the relay through the Multiple Access Channel (MAC) and the relay transmits messages to the two terminals through the Broadcast Channel...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    Cross-Layer Optimization for Wireless Networks With Deterministic Channel Models

    Cross-layer optimization is a key step in wireless network design that coordinates the resources allocated to different layers in order to achieve globally optimal network performance. Existing works on cross-layer optimization for wireless networks often adopt simplistic physical-layer models for wireless channels, such as treating interference as noise or interference...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    Regulating Wireless Access Pricing

    Today's wireless networks are interconnected. A network provider can charge other network providers access prices for serving communication sessions originated from other networks. Meanwhile, a network provider also charges its users directly for using the network services. This paper looks at the proper choices of user pricing and access pricing...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    The Capacity Region of the Three Receiver Less Noisy Broadcast Channel

    The authors determine the capacity region of a 3-receiver less noisy broadcast channel. The difficulty in extending the two-receiver result to three-receivers involves extending the Csiszarsum lemma to three or more sequences, a standard difficulty in this area. In this paper, they bypass the difficulty by using a new information...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    On the Degree of Freedom for Multi-Source Multi-Destination Wireless Network With Multi-Layer Relays

    Degree of Freedom (DoF) region provides an approximation of capacity region in high Signal-to-Noise Ratio (SNR) regime, while sum DoF gives the scaling factor. In this correspondence, the authors analyze the DoF region and sum DoF for unicast layered multi-hop relay wireless networks with arbitrary number of source/destination/relay nodes, arbitrary...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    Minimality Attack in Privacy Preserving Data Publishing Technical Report TR 2006-28

    Data publishing generates much concern over the protection of individual privacy. In the well-known k-anonymity model and the related models such as l-diversity and (? k)-anonymity, the adversary is assumed to possess knowledge about an external table with information of the quasi-identifiers of individuals. In this paper, the authors show...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    Distributing Layered Encoded Video Through Caches

    The efficient distribution of stored information has become a major concern in the Internet which has increasingly become a vehicle for the transport of stored video. Because of the highly heterogeneous access to the Internet, researchers and engineers have argued for layered encoded video. In this paper the authors investigate...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2011

    On the Access Pricing Issues of Wireless Mesh Networks

    This paper studies the use of pricing as an incentive mechanism to encourage private, self-interested nodes to participate in a public wireless mesh network and cooperate in the packet forwarding service. The authors' focus is on the "Economic behavior" of the network nodes - the pricing and purchasing strategies of...

    Provided By Chinese University of Hong Kong

  • White Papers // Dec 2010

    Does Banking Competition Alleviate Or Worsen Credit Constraints Faced By Small And Medium Enterprises? Evidence From China

    Banking competition may enhance or hinder the financing of Small and Medium Enterprises (SMEs). Using a survey on the financing of China's SMEs combined with detailed bank branch information; the authors investigate how concentration in the local banking market affects the availability of credit. It is found that lower market...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2010

    Adaptive Channel Recommendation for Dynamic Spectrum Access

    The authors propose a dynamic spectrum access scheme where secondary users recommend "Good" channels to each other and access accordingly. They formulate the problem as an average reward based Markov decision process. They show the existence of the optimal stationary spectrum access policy, and explore its structure properties in two...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2010

    Revenue Maximization for Communication Networks With Usage-Based Pricing

    The authors study the optimal usage-based pricing problem in a resource-constrained network with one profit-maximizing Service Provider (SP) and multiple groups of surplus-maximizing users. With the assumption that the SP knows the utility function of each user (thus complete information), they find that the complete price differentiation scheme can achieve...

    Provided By Chinese University of Hong Kong

  • White Papers // Sep 2010

    Optimal Distributed P2P Streaming Under Node Degree Bounds

    The authors study the problem of maximizing the broadcast rate in Peer-To-Peer (P2P) systems under node degree bounds, i.e., the number of neighbors a node can simultaneously connect to is upper-bounded. The problem is critical for supporting high-quality video streaming in P2P systems, and is challenging due to its combinatorial...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2010

    Distributed Algorithm Design for Network Optimization Problems With Coupled Objectives

    This paper establishes a framework for designing fast, robust, and distributed algorithms for solving network utility maximization problems with coupled objective functions. The authors use two case studies in wireless communications to illustrate the key ideas: reverse-engineering the algorithm based on the KKT conditions of the optimization problem, and proving...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2010

    Characterizing the Lifetime Reliability of Manycore Processors with Core-Level Redundancy

    With aggressive technology scaling, integrated circuits suffer from ever increasing wearout effects and their lifetime reliability has become a serious concern for the industry. For manycore processors that integrate a large number of processor cores on a single silicon die, introducing core-level redundancy is an effective way to alleviate this...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2010

    Universal and Robust Distributed Network Codes

    Random linear network codes can be designed and implemented in a distributed manner, with low computational complexity. However, these codes are classically implemented over finite fields whose size depends on some global network parameters (size of the network, the number of sinks) that may not be known prior to code...

    Provided By Chinese University of Hong Kong

  • White Papers // Jul 2010

    On Resource Management for Cloud Users: A Generalized Kelly Mechanism Approach

    Cloud computing provides network software companies with a platform to develop Software as a Service (SaaS) applications. The pay-as-you-go pricing model unties these SaaS providers from large capital outlays in hardware deployment and maintenance. Depending on the level of virtualization and service abstraction, cloud vendors provide different functionalities to the...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2010

    FADE: Secure Overlay Cloud Storage With File Assured Deletion

    While one can now outsource data backup to third-party cloud storage services so as to reduce data management costs, security concerns arise in terms of ensuring the privacy and integrity of outsourced data. The authors design FADE, a practical, implementable, and readily deployable cloud storage system that focuses on protecting...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2010

    pCloud: A Distributed System for Practical PIR

    computational Private Information Retrieval (cPIR) protocols allow a client to retrieve one bit from a database, without the server inferring any information about the queried bit. These protocols are too costly in practice because they invoke complex arithmetic operations for every bit of the database. In this paper the authors...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2010

    A Simple Model for a Generic Class of P2P Streaming Algorithms

    P2P streaming tries to achieve scalability (like P2P file distribution) and at the same time meet real-time playback requirements. It is a challenging problem still not well understood. In this paper, the authors describe a simple stochastic model that can be used to compare different downloading strategies with random peer...

    Provided By Chinese University of Hong Kong

  • White Papers // Feb 2010

    Applying Physical-Layer Network Coding in Wireless Networks

    A main distinguishing feature of a wireless network compared with a wired network is its broadcast nature, in which the signal transmitted by a node may reach several other nodes, and a node may receive signals from several other nodes, simultaneously. Rather than a blessing, this feature is treated more...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2010

    A Lock-Free, Cache-Efficient Multi-Core Synchronization Mechanism for Line-Rate Network Traffic Monitoring

    Line-rate data traffic monitoring in high-speed networks is essential for network management. To satisfy the line-rate requirement, one can leverage multi-core architectures to parallelize traffic monitoring so as to improve information processing capabilities over traditional uni-processor architectures. Nevertheless, realizing the full potential of multi-core architectures still needs substantial work, especially...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2010

    Concatenated Polar Codes

    Polar codes have attracted much recent attention as the first codes with low computational complexity that provably achieve optimal rate-regions for a large class of information-theoretic problems. One significant drawback, however, is that for current constructions the probability of error decays sub-exponentially in the block-length (more detailed designs improve the...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2010

    On Broadcast Channels With Binary Inputs and Symmetric Outputs

    The authors study the capacity regions of broadcast channels with binary inputs and symmetric outputs. They study the partial order induced by the more capable ordering of broadcast channels for channels belonging to this class. This study leads to some surprising connections regarding various notions of dominance of receivers. The...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2010

    An Information Inequality and Evaluation of Marton's Inner Bound for Binary Input Broadcast Channels

    The authors establish an information inequality that is intimately connected to the evaluation of the sum rate given by Marton's inner bound for two-receiver broadcast channels with a binary input alphabet. This generalizes a recent result where the inequality was established for a particular channel, the binary skew-symmetric broadcast channel....

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2010

    Holistic Twig Joins on Indexed XML Documents

    Finding all the occurrences of a twig pat-tern specified by a selection predicate on multiple elements in an XML document is a core operation for efficient evaluation of XML queries. Holistic twig join algorithms were proposed recently as an optimal solution when the twig pattern only involves ancestor-descendant relationships. This...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2010

    Peer Clustering and Firework Query Model

    The importance of distributed information sharing systems has been confirmed by the appearance and popularity of P2P applications such as Gnutella and Napster. One problem that the users face with such applications is that due to lack of a centralized server to keep track of what data are being stored...

    Provided By Chinese University of Hong Kong

  • White Papers // Dec 2009

    On the Performance Bounds of Practical Wireless Network Coding

    Network coding is an attracting technology that has been shown to be able to improve the throughput of wireless networks. However, there still lacks fundamental understanding on how network coding works under realistic scenarios. In this paper, the authors examine the performance of a recently proposed network coding system under...

    Provided By Chinese University of Hong Kong

  • White Papers // Dec 2009

    Effective Carrier Sensing in CSMA Networks Under Cumulative Interference

    This paper proposes and investigates the concept of a safe carrier-sensing range that can guarantee interference-safe (also termed hidden-node-free) transmissions in CSMA networks under the cumulative interference model. Compared with the safe carrier-sensing range under the commonly assumed but less realistic pairwise interference model, the authors show that the safe...

    Provided By Chinese University of Hong Kong

  • White Papers // Dec 2009

    An Information Inequality for the BSSC Channel

    The authors establish an information theoretic inequality concerning the binary skew-symmetric broadcast channel that was conjectured by one of the authors. This inequality helps to quantify the gap between the sum rate obtained by the inner bound and outer bound for the binary skew-symmetric broadcast channel. The broadcast channel is...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2009

    Towards Improving an Algebraic Marking Scheme for Tracing DDoS Attacks

    Distributed Denial of Service (DDoS) attacks could be considered as one of the most serious security problems to the Internet today. To locate the sources of the attack packets, the authors usually need to find the paths through which the attack packets traversed from the sources to the victim. In...

    Provided By Chinese University of Hong Kong

  • White Papers // Oct 2009

    An Achievable Rate Region for the 2-Receiver Broadcast Channel Obtained by Viewing It as an Interference Channel

    The authors derive an achievable region for the 2-receiver broadcast channel with private messages only by incorporating ideas of message splitting as in the Han-Kobayashi scheme for the interference channel. The achievable region they obtain is equivalent to the best-known achievable region under this scenario, obtained by Marton. The scheme...

    Provided By Chinese University of Hong Kong

  • White Papers // Oct 2009

    Probabilistic Analysis of the Semidefinite Relaxation Detector in Digital Communications

    A fundamental problem in modern digital communication is that of the joint detection of several information carrying symbols that are being transmitted over a Multiple-Input Multiple-Output (MIMO) communication channel. Such a problem arises in many contexts. For instance, consider a wireless communication setting, where there are multiple antennae at both...

    Provided By Chinese University of Hong Kong

  • White Papers // Sep 2009

    Optimization Techniques in Wireless Communications

    This paper collects several research results on the use of optimization techniques in wireless communications. Recent advances in linear and nonlinear optimization facilitate progress in many areas of communications. In wireless and mobile communications this progress provides opportunities for introducing new standards and improving existing services. Supporting multimedia traffic with...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2009

    Soft Network Coding in Wireless Two-Way Relay Channels

    Application of network coding in wireless Two-Way Relay Channels (TWRC) has received much attention recently because of its ability to improve throughput significantly. In traditional designs, network coding operates at upper layers above (including) the link layer and it requires the input packets to be correctly decoded. However, this requirement...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2009

    Interference With Symbol-Misalignment

    This paper studies the impact of interference asynchrony among different links in a wireless network. Without deliberate coordination and cooperation among the active links, there is a naturally occurring misalignment between the symbols of the targeted signal of a receiver and the symbols of the interfering signals. Interestingly, the authors...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2009

    Exploring the Optimal Chunk Selection Policy for Data-Driven P2P Streaming Systems

    Data-driven P2P streaming systems can potentially provide good playback rate to a large number of viewers. One important design problem in such P2P systems is to determine the optimal chunk selection policy that provides high continuity playback under the server's upload capacity constraint. The authors present a general and unified...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2009

    On Oligopoly Spectrum Allocation Game in Cognitive Radio Networks With Capacity Constraints

    Dynamic spectrum sharing is a promising technology to improve spectrum utilization in the future wireless networks. The flexible spectrum management provides new opportunities for licensed primary user and unlicensed secondary users to reallocate the spectrum resource efficiently. In this paper, the authors present an oligopoly pricing framework for dynamic spectrum...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2009

    Test Architecture Design and Optimization for Three-Dimensional SoCs

    Core-based System-on-Chips (SoCs) fabricated on Three-Dimensional (3D) technology are emerging for better integration capabilities. Effective test architecture design and optimization techniques are essential to minimize the manufacturing cost for such giga-scale integrated circuits. In this paper, the authors propose novel test solutions for 3D SoCs manufactured with die-to-wafer and die-to-die...

    Provided By Chinese University of Hong Kong

  • White Papers // Oct 2008

    Price Discrimination Between Retailers With And Without Market Power

    Some retail markets are more competitive than others. A manufacturer with market power in the wholesale market who sells his product to competing retailers in cities and monopolistic ones in each of various towns must set the wholesale price difference between towns and cities to be smaller than the transportation...

    Provided By Chinese University of Hong Kong

  • White Papers // Feb 2011

    P2P Streaming Capacity

    Peer-To-Peer (P2P) systems provide a scalable way to stream content to multiple receivers over the Internet. The maximum rate achievable by all receivers is the capacity of a P2P streaming session. The authors provide a taxonomy of sixteen problem formulations, depending on whether there is a single P2P session or...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2011

    Amplify-and-Forward in Wireless Relay Networks

    A general class of wireless relay networks with a single source-destination pair is considered. Intermediate nodes in the network employ an amplify-and-forward scheme to relay their input signals. In this case the overall input-output channel from the source via the relays to the destination effectively behaves as an inter-symbol interference...

    Provided By Chinese University of Hong Kong

  • White Papers // May 2011

    Distributed Optimization for Combinatorial Coding Subgraph Selection Problems

    Many network design cases with network coding can be formulated as combinatorial optimization problems, which are NP-hard and hard to approximate even in a centralized manner. In this paper, guided by Markov approximation framework, the authors provide a unified distributed solution for one important subcategory of combinatorial network coding problems:...

    Provided By Chinese University of Hong Kong

  • White Papers // Jul 2011

    On the Role of Network Coding in Uncoordinated Multihop Content Distribution Over Ad Hoc Networks

    The authors consider the problem of multi-hop communication in ad hoc networks. This work was originally motivated by vehicular networks, and has application in numerous fields. The key constraint in such systems is the infeasibility of coordination. Because no single node has global knowledge of the network topology, centralized scheduling...

    Provided By Chinese University of Hong Kong

  • White Papers // Jul 2011

    Celerity: A Low-Delay Multi-Party Conferencing Solution

    In this paper, the authors attempt to revisit the problem of multi-party conferencing from a practical perspective, and to rethink the design space involved in this problem. They believe that an emphasis on low end-to-end delays between any two parties in the conference is a must, and the source sending...

    Provided By Chinese University of Hong Kong

  • White Papers // Apr 2012

    A Game Theoretic Analysis on Incentive Mechanisms for Wireless Ad Hoc VoD Systems

    Wireless ad hoc networks enable the wireless devices to directly communicate with each other. An emerging application in such systems is video-on-demand service that can greatly reduce the content server's workload by utilizing the nodes' resources. Such an application relies on the cooperation of all participating nodes. However, the nodes...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2013

    Moving Big Data to the Cloud

    Cloud computing, rapidly emerging as a new computation paradigm, provides agile and scalable resource access in a utility-like fashion, especially for the processing of big data. An important open issue here is how to efficiently move the data, from different geographical locations over time, into a cloud for effective processing....

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2012

    A Scalable Algorithm for Maximizing Range Sum in Spatial Databases

    This paper investigates the MaxRS problem in spatial databases. Given a set O of weighted points and a rectangular region r of a given size, the goal of the MaxRS problem is to find a location of r such that the sum of the weights of all the points covered...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2012

    Spectrum Broker by Geo-Location Database

    Geo-location database driven white space network is a very promising approach for improving secondary spectrum utilization. In this paper, the authors consider the business modeling for geo-location database driven white space network. In their proposed model, the database acts as a spectrum broker buying (reserving) bandwidth from spectrum licensees in...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2012

    Blind Known Interference Cancellation With Parallel Real Valued Belief Propagation Algorithm

    This paper investigates interference-cancellation schemes at the receiver, in which the original data of the interference is known a priori. Such a priori knowledge is common in wireless relay networks. Directly removing the known interference requires accurate estimate of the interference channel, which may be difficult in many situations. The...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2012

    Analysis and Construction of Functional Regenerating Codes With Uncoded Repair for Distributed Storage Systems

    Modern distributed storage systems apply redundancy coding techniques to stored data. One form of redundancy is based on regenerating codes, which can minimize the repair bandwidth, i.e., the amount of data transferred when repairing a failed storage node. Existing regenerating codes mainly require surviving storage nodes encode data during repair....

    Provided By Chinese University of Hong Kong

  • White Papers // Oct 2009

    Probabilistic Analysis of the Semidefinite Relaxation Detector in Digital Communications

    A fundamental problem in modern digital communication is that of the joint detection of several information carrying symbols that are being transmitted over a Multiple-Input Multiple-Output (MIMO) communication channel. Such a problem arises in many contexts. For instance, consider a wireless communication setting, where there are multiple antennae at both...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2012

    Simple and E Ective Dynamic Provisioning for Power-Proportional Data Centers

    Energy consumption represents a significant cost in data center operation. A large fraction of the energy, however, is used to power idle servers when the workload is low. Dynamic provisioning techniques aim at saving this portion of the energy, by turning o unnecessary servers. In this paper, the authors explore...

    Provided By Chinese University of Hong Kong

  • White Papers // Jul 2012

    Analog Network Coding in General SNR Regime: Performance of Network Simplification

    A communication scenario where a source communicates with a destination over a directed layered relay network is considered. Each relay performs analog network coding where it scales and forwards the signals received at its input. In this scenario, the authors address the question: What portion of the maximum end-to-end achievable...

    Provided By Chinese University of Hong Kong

  • White Papers // May 2013

    Physical-Layer Multicasting by Stochastic Transmit Beamforming and Alamouti Space-Time Coding

    Consider transceiver designs in a multiuser Multi-Input Single-Output (MISO) downlink channel, where the users are to receive the same data stream simultaneously. This problem, known as physical-layer multicasting, has drawn much interest. Presently, a popularized approach is transmit beamforming, in which the beamforming optimization is handled by a rank-one approximation...

    Provided By Chinese University of Hong Kong

  • White Papers // Mar 2013

    Multi-Group Multicast Beamforming in Cognitive Radio Networks Via Rank-Two Transmit Beamformed Alamouti Space-Time Coding

    In this paper, the authors consider transmit design in Multiple-Input Single-Output (MISO) Multi-group Multicast (MM) Cognitive Radio (CR) systems. Previously, Semi-Definite Relaxation (SDR)-based transmit beamforming has been very successful in transmit design. However, recent research shows that further performance gain is possible by suitably modifying the transmit structure. Here, they...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2012

    Rank-Two Transmit Beamformed Alamouti Space-Time Coding for Physical-Layer Multicasting

    In physical-layer multicasting over a multiuser MISO downlink channel, transmit beamforming using Semi-Definite Relaxation (SDR) has been a popular approach. In this paper, the authors propose a rank-2 transmit beamformed Alamouti space-time code scheme, which may be seen as a generalization of the previous SDR-based beamforming framework. The beamforming problem...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2011

    Safe Convex Approximation to Outage-Based MISO Secrecy Rate Optimization Under Imperfect CSI and With Artificial Noise

    Consider a scenario in which an MISO channel is overheard by multiple single-antenna eavesdroppers. The transmitter has perfect Channel State Information (CSI) with the legitimate channel, but has imperfect CSI with the eavesdroppers' channels. The CSI uncertainties are assumed stochastic. The authors formulate an Artificial-Noise (AN)- aided secrecy-rate maximization problem...

    Provided By Chinese University of Hong Kong

  • White Papers // Feb 2011

    Cheap Semidefinite Relaxation MIMO Detection Using Row-by-Rowblock Coordinate Descent

    This paper considers the problem of low complexity implementation of high-performance Semi-Definite Relaxation (SDR) MIMO detection methods. Currently, most SDR MIMO detectors are implemented using interior-point methods. Although, such implementations have worst-case polynomial complexity (approximately cubic in the problem size), they can be quite computationally costly in practice. Here, the...

    Provided By Chinese University of Hong Kong

  • White Papers // Apr 2013

    Transmission Sequence Design and Allocation for Wide Area Ad Hoc Networks

    In this paper, the authors examine the question of designing and allocating transmission sequences to users in a mobile ad hoc network that has no spatial boundary. A basic tenet of the transmission sequence approach for addressing the media access control problem is that under normal operation conditions, there is...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2012

    A Unification of Network Coding and Routing

    For a linear network code, the encoding profile is specified by, for every output channel of a node, the set of input channels whose symbols upon which the symbol on the output channel depends. For a given single-source network coding problem, it is of fundamental interest to characterize all feasible...

    Provided By Chinese University of Hong Kong

  • White Papers // Feb 2011

    Capacity Bounds for Full-Duplex Two-Way Relay Channel With Feedback

    The authors consider a Two-way Relay Channel (TRC) in which two terminals exchange their messages with the help of a relay between them. The two terminals transmit messages to the relay through the Multiple Access Channel (MAC) and the relay transmits messages to the two terminals through the Broadcast Channel...

    Provided By Chinese University of Hong Kong

  • White Papers // Feb 2011

    Delay Invariant Convolutional Network Codes

    In this paper, the authors define delay invariant convolutional network codes which guarantee multicast communication at asymptotically optimal rates in networks with arbitrary delay patterns. They show the existence of such a code over every symbol field. Moreover, the code can be constructed with high probability when coding coefficients are...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2013

    Coding for Linear Operator Channels Over Finite Fields

    Linear Operator Channels (LOCs) are motivated by the communications through networks employing Random Linear Network Coding (RLNC). Following the recent information theoretic results about LOCs, the authors propose two coding schemes for LOCs and evaluate their performance. These schemes can be used in networks employing RLNC without constraints on the...

    Provided By Chinese University of Hong Kong

  • White Papers // May 2011

    On the Security and Efficiency of Content Distribution via Network Coding

    Content distribution via network coding has received a lot of attention lately. However, direct application of network coding may be insecure. In particular, attackers can inject "Bogus" data to corrupt the content distribution process so as to hinder the information dispersal or even deplete the network resource. Therefore, content verification...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2013

    A Cooperative Game Based Allocation for Sharing Data Center Networks

    In current IaaS datacenters, tenants are suffering unfairness since the network bandwidth is shared in a best-effort manner. To achieve predictable network performance for rented Virtual Machines (VMs), cloud providers should guarantee minimum bandwidth for VMs or allocate the network bandwidth in a fairness fashion at VM-level. At the same...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2011

    On Detecting Malicious Behaviors in Interactive Networks: Algorithms and Analysis

    Interactive networks are vulnerable to various attacks due to the existence of malicious nodes which do not comply with the network protocol so as to achieve their own purposes. For example, in a Peer-To-Peer (P2P) streaming system, since each peer needs to participate in uploading data to other peers, malicious...

    Provided By Chinese University of Hong Kong

  • White Papers // Dec 2012

    Upper Bounds on the Capacity of Binary Channels With Causal Adversaries

    Alice wishes to transmit a message u to Bob over a binary-input binary-output channel. To do so, she encodes u into a length-n binary vector x and transmits it over the channel. However, the channel is controlled by a malicious adversary Calvin who may observe the transmissions, and attempts to...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2013

    Construction of Linear Network Codes That Achieve a Rened Singleton Bound

    The network error correction problem study is to extend classical error correction coding theory to a general network setting. In Cai and Yeung, network generalizations of the Hamming bound, the Singleton bound, and the Gilbert-Varshamov bound in classical algebraic coding theory were obtained. In particular, the tightness of the Singleton...

    Provided By Chinese University of Hong Kong

  • White Papers // May 2011

    Practical Network Coding on Three-Node Point-to-Point Relay Networks

    The authors study the three-node point-to-point relay network which consists of two terminal nodes and one relay node between them and investigate practical network coding schemes for the network. The rate region achievable by the practical network coding schemes is obtained, and a procedure for constructing the linear network codes...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2013

    Enabling Data Integrity Protection in Regenerating-Coding-Based Cloud Storage: Theory and Implementation

    To protect outsourced data in cloud storage against corruptions, adding fault tolerance to cloud storage, along with efficient data integrity checking and recovery procedures, becomes critical. Regenerating codes provide fault tolerance by striping data across multiple servers, while using less repair traffic than traditional erasure codes during failure recovery. Therefore,...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2013

    RevDedup: A Reverse Deduplication Storage System Optimized for Reads to Latest Backups

    De-duplication is known to effectively eliminate duplicates, yet it introduces fragmentation that degrades read performance. The authors propose RevDedup, a de-duplication system that optimizes reads to the latest backups of Virtual Machine (VM) images using reverse de-duplication. In contrast with conventional de-duplication that removes duplicates from new data, RevDedup removes...

    Provided By Chinese University of Hong Kong

  • White Papers // Sep 2013

    On the Speedup of Recovery in Large-Scale Erasure-Coded Storage Systems

    Modern storage systems stripe redundant data across multiple nodes to provide availability guarantees against node failures. One form of data redundancy is based on XOR-based erasure codes, which use only XOR operations for encoding and decoding. In addition to tolerating failures, a storage system must also provide fast failure recovery...

    Provided By Chinese University of Hong Kong

  • White Papers // Aug 2013

    NCCloud: A Network-Coding-Based Storage System in a Cloud-of-Clouds

    To provide fault tolerance for cloud storage, recent studies propose to stripe data across multiple cloud vendors. However, if a cloud suffers from a permanent failure and loses all its data, the authors need to repair the lost data with the help of the other surviving clouds to preserve data...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2012

    Single Disk Failure Recovery for X-code-based Parallel Storage Systems

    In modern parallel storage systems (e.g., cloud storage and data centers), it is important to provide data availability guarantees against disk (or storage node) failures via redundancy coding schemes. One coding scheme is X-code, which is double-fault tolerant while achieving the optimal update complexity. When a disk/node fails, recovery must...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2011

    An Extensible Design of a Load-Aware Virtual Router Monitor in User Space

    Router virtualization enables multiple virtual routers to be hosted on a physical shared substrate, and hence facilitates network management and experimentation. One critical issue of router virtualization is resource allocation of virtual routers. The authors explore this issue in the user-space design in order to allow extensibility. They develop a...

    Provided By Chinese University of Hong Kong

  • White Papers // Jan 2013

    An Experimental Study of Cascading Performance Interference in a Virtualized Environment

    In a consolidated virtualized environment, multiple Virtual Machines (VMs) are hosted atop a shared physical substrate. They share the underlying hardware resources as well as the software virtualization components. Thus, one VM can generate performance interference to another co-resident VM. This paper explores the adverse impact of performance interference from...

    Provided By Chinese University of Hong Kong

  • White Papers // Jun 2013

    Limits of Provable Security for Homomorphic Encryption

    In this paper the authors revisit the question of basing cryptography on NP-hardness. If P equals NP then computationally secure encryption is impossible. Is the converse true? Despite considerable e orts, there is no candidate encryption scheme whose security can be plausibly reduced to the worst-case hardness of some NP-complete...

    Provided By Chinese University of Hong Kong

  • White Papers // Nov 2009

    Towards Improving an Algebraic Marking Scheme for Tracing DDoS Attacks

    Distributed Denial of Service (DDoS) attacks could be considered as one of the most serious security problems to the Internet today. To locate the sources of the attack packets, the authors usually need to find the paths through which the attack packets traversed from the sources to the victim. In...

    Provided By Chinese University of Hong Kong