Aalborg University

Displaying 1-40 of 87 results

  • White Papers // Apr 2014

    Using Wireless Network Coding to Replace a Wired with Wireless Backhaul

    Cellular networks are evolving towards dense deployment of small cells. This in turn demands flexible and efficient backhauling solutions. A viable solution that reuses the same spectrum is wireless backhaul where the Small Base Station (SBS) acts as a relay. In this paper, the authors consider a reference system that...

    Provided By Aalborg University

  • White Papers // Jan 2014

    Towards Trust Engineering for Opportunistic Cloud Services: A Systematic Review of Trust Engineering in Cloud Computing

    The systematic review methodology has been employed to review trust related studies in cloud computing. It was observed that trusted computing technologies and reputation based approaches are the main approaches to trust engineering in cloud computing. Also, trusted third party approaches and the deployment model play a significant role in...

    Provided By Aalborg University

  • White Papers // Dec 2013

    Schedulability and Energy Efficiency for Multi-core Hierarchical Scheduling Systems

    The authors propose a compositional framework for modeling and analyzing the schedulability and energy efficiency of embedded hierarchical scheduling systems running on a multicore platform. The framework is realized using Parameterized Stopwatch Automata describing the concrete task behavior. The schedulability can be verified in a compositional way using UPPAAL, and...

    Provided By Aalborg University

  • White Papers // Oct 2013

    Novel Threshold Cryptography-Based Group Authentication (TCGA) Scheme for the Internet of Things (IoT)

    Internet of Things (IoT) is an emerging paradigm where the devices around the user (persistent and non-persistent) are connected to each other to provide seamless communication, and contextual services. In the IoT, each device cannot be authenticated in the short time due to unbounded number of devices, and receipt of...

    Provided By Aalborg University

  • White Papers // Aug 2013

    Trust Management System for Opportunistic Cloud Services

    The authors have over the past three years been working on the feasibility of Opportunistic Cloud Services (OCS) for enterprises. OCS is about enterprises strategically contributing and utilizing spare IT resources as cloud services. One of the major challenges that such a platform faces is data security and trust management...

    Provided By Aalborg University

  • White Papers // Jun 2013

    Kodo: An Open and Research Oriented Network Coding Library

    This paper introduces the Kodo network coding library. Kodo is an open source C++ library intended to be used in practical studies of network coding algorithms. The target users for the library are researchers working with or interested in network coding. To provide a research friendly library Kodo provides a...

    Provided By Aalborg University

  • White Papers // Jun 2013

    Business Model Innovation with the NEFFICS Platform and VDML

    The NEFFICS platform combines an open innovation social media platform with a business modeling and operations platform. Business Model Innovation is supported with a basis in a Business Model framework with seven dimensions, where each dimension is supported by a corresponding diagram view from the authors' proposed Value Delivery Modeling...

    Provided By Aalborg University

  • White Papers // May 2013

    Low-Rate Machine-Type Communication via Wireless Device-to-Device (D2D) Links

    Wireless cellular networks feature two emerging technological trends. The first is the direct Device-To-Device (D2D) communications, which enables direct links between the wireless devices that reutilize the cellular spectrum and radio interface. The second is that of Machine-Type Communications (MTC), where the objective is to attach a large number of...

    Provided By Aalborg University

  • White Papers // May 2013

    Reliable Reception of Wireless Metering Data With Protocol Coding

    Stationary collectors reading wireless, battery powered smart meters, often operate in harsh channel conditions to cut network installation cost to a minimum, challenging the individual link to each meter. The desired performance measure is reliable reception of at least some data from as many as possible meters, rather than increasing...

    Provided By Aalborg University

  • White Papers // Feb 2013

    Object Classification Based Context Management for Identity Management in Internet of Things

    As computing technology is becoming more tightly coupled into dynamic and mobile world of the Internet of Things (IoT), security mechanism is more stringent, flexible and less intrusive. Scalability issue in IoT makes Identity Management (IdM) of ubiquitous objects more challenging, and there is a need of context-aware access control...

    Provided By Aalborg University

  • White Papers // Feb 2013

    Fuzzy Similarity Measures Approach in Benchmarking Taxonomies of Threats Against SMEs in Developing Economies

    There are various threats that militate against SMEs in developing economies. However, most SMEs fall on the conservative "TV News Effect" of most-publicized cyber-threats or incidences, with disproportionate mitigation measures. This paper endeavors to establish taxonomy of threat agents to fill in the void. Various fuzzy similarity measures based on...

    Provided By Aalborg University

  • White Papers // Dec 2012

    C-Cube: Elastic Continuous Clustering in the Cloud

    Continuous clustering analysis over a data stream reports clustering results incrementally as updates arrive. Such analysis has a wide spectrum of applications, including traffic monitoring and topic discovery on micro-blogs. A common characteristic of streaming applications is that the amount of workload fluctuates, often in an unpredictable manner. On the...

    Provided By Aalborg University

  • White Papers // Nov 2012

    Macro Transmission Power Reduction for HetNet Co-Channel Deployments

    Enhanced Inter-Cell Interference Coordination (eICIC) techniques are targeted to improve the system and cell-edge throughput of Heterogeneous Networks (HetNets) in LTE-Advanced systems. In order to protect pico UEs from the strong macro interference, the macro eNB can either stop data transmission or simply reduce the transmission power during certain subframes....

    Provided By Aalborg University

  • White Papers // Nov 2012

    Cognitive Access Policies Under a Primary ARQ Process via Forward-Backward Interference Cancellation

    This paper introduces a novel technique for access by a cognitive Secondary User (SU) using best-effort transmission to a spectrum with an incumbent Primary User (PU), which uses Type-I Hybrid ARQ. The technique leverages the primary ARQ protocol to perform Interference Cancellation (IC) at the SU receiver (SUrx). Two IC...

    Provided By Aalborg University

  • White Papers // Oct 2012

    Realistic Energy Saving Potential of Sleep Mode for Existing and Future Mobile Networks

    In this paper, the authors present an extensive overview on an energy saving feature referred to as 'site sleep mode', designed for existing and future mobile broadband networks. In addition to providing a detailed understanding of the main concept, the paper also provides various studies and results to highlight potential...

    Provided By Aalborg University

  • White Papers // Oct 2012

    Development of a Mobile EEG-Based Biometric Authentication System

    In recent years, the need for greater security for storing personal and business data or accessing corporate networks on mobile devices is growing rapidly, and one of the potential solutions is to employ the innovative biometric authentication techniques. This paper presents the development of a mobile biometric authentication system based...

    Provided By Aalborg University

  • White Papers // Aug 2012

    Intrinsic Information Conveying for Network Coding Systems

    This paper investigated the possibility of intrinsic information conveying in network coding systems. The information is embedded into the coding vector by constructing the vector based on a set of predefined rules. This information can subsequently be retrieved by any receiver. The starting point is Random Linear Network Coding (RLNC)...

    Provided By Aalborg University

  • White Papers // Jun 2012

    Design and Analysis of LT Codes with Decreasing Ripple Size

    In this paper, the authors propose a new design of LT codes, which decreases the amount of necessary overhead in comparison to existing designs. The design focuses on a parameter of the LT decoding process called the ripple size. This parameter was also a key element in the design proposed...

    Provided By Aalborg University

  • White Papers // May 2012

    Data Dissemination in the Wild: A Testbed for High-Mobility MANETs

    This paper investigates the problem of efficient data dissemination in Mobile Ad hoc NETworks (MANETs) with high mobility. A testbed is presented; which provides a high degree of mobility in experiments. The testbed consists of 10 autonomous robots with mobile phones mounted on them. The mobile phones form an IEEE...

    Provided By Aalborg University

  • White Papers // May 2012

    Rate Regions for Coordination of Decode-and-Forward Relays and Direct Users

    Recently, the ideas of wireless Network Coding (NC) has significantly enriched the area of wireless cooperation/ relaying. They bring substantial gains in spectral efficiency mainly in scenarios with two - way relaying. Inspired by the ideas of wireless NC, recently the authors have proposed techniques for Coordinated Direct/Relay (CDR) transmissions....

    Provided By Aalborg University

  • White Papers // May 2012

    Efficient Admission Control for Next Generation Cellular Networks

    This paper proposes a novel efficient Admission Control (AC) algorithm, which guarantees Quality of Service (QoS) for new users while maintaining QoS for existing users and also increases the number of users admitted in to the system. To guarantee the QoS, a Markov based modeling of the queue in the...

    Provided By Aalborg University

  • White Papers // May 2012

    Application of Bayesian Hierarchical Prior Modeling to Sparse Channel Estimation

    Existing methods for sparse channel estimation typically provide an estimate computed as the solution maximizing an objective function defined as the sum of the log-likelihood function and a penalization term proportional to the L1-norm of the parameter of interest. However, other penalization terms have proven to have strong sparsity-inducing properties....

    Provided By Aalborg University

  • White Papers // May 2012

    Ripple Design of LT Codes for AWGN Channel

    In this paper, the authors present an analytical framework for designing LT codes in Additive White Gaussian Noise (AWGN) channels. They show that some of analytical results from Binary Erasure Channels (BEC) also hold in AWGN channels with slight modifications. This enables them to apply a ripple-based design approach, which...

    Provided By Aalborg University

  • White Papers // May 2012

    Orientation Sensing Using Multiple Passive RFID Tags

    Knowing the inclination of an object can be valuable information in a supply chain application, e.g. when handling orientation sensitive objects. In this paper, the authors present a method for sensing the inclination using Radio Frequency IDentification (RFID) technology. The method requires standard RFID equipment and assumes that each object...

    Provided By Aalborg University

  • White Papers // May 2012

    A Study of Trade-Off Between Opportunistic Resource Allocation and Interference Alignment in Femtocell Scenarios

    One of the main problems in wireless heterogeneous networks is interference between macro- and femto-cells. Using Orthogonal Frequency-Division Multiple Access (OFDMA) to create multiple frequency orthogonal sub-channels, this interference can be completely avoided if each sub-channel is exclusively used by either macro- or a femto-cell. However, such an orthogonal allocation...

    Provided By Aalborg University

  • White Papers // Apr 2012

    Spectrum Aggregation: Initial Outcomes from SAMURAI Project

    Multi-user MIMO and Spectrum Aggregation (also referred to Carrier Aggregation) are two key enablers of next generation wireless systems. Although those techniques were already quite well investigated at theoretical level, their practical implementation is not immediate and raises numerous challenges. The SAMURAI project aims at investigating such challenges as well...

    Provided By Aalborg University

  • White Papers // Apr 2012

    A Context-Aware User Interface for Wireless Personal-Area Network Assistive Environments

    The daily life of people with severe motor system impairments is challenging and thus often subordinated to extensive external help; increasing their level of self-support is thus highly desirable. Recent advances in wireless communications, in particular in wireless personal-area networks, serve as technological enablers well suited for implementing smart and...

    Provided By Aalborg University

  • White Papers // Apr 2012

    Opportunistic Interference Cancelation and User Selection in Cognitive Multiple Access Network

    This paper investigates the problem of spectrally efficient operation of a multi-user uplink cognitive radio system in the presence of a single primary link. The secondary system applies Opportunistic Interference Cancelation (OIC) and decode the primary signal when such an opportunity is created. The authors derive the achievable rate in...

    Provided By Aalborg University

  • White Papers // Mar 2012

    On the Impact of Information Delay on Location-Based Relaying: A Markov Modeling Approach

    For centralized selection of communication relays, the necessary decision information needs to be collected from the mobile nodes by the access point (centralized decision point). In mobile scenarios, the required information collection and forwarding delays will affect the reliability of the collected information and hence will influence the performance of...

    Provided By Aalborg University

  • White Papers // Mar 2012

    Uplink Multi-Cluster Scheduling With MU-MIMO for LTE-Advanced With Carrier Aggregation

    LTE-Advanced is the evolutionary path from LTE Release 8. It is designed to significantly enhance the performance of LTE Release 8 in terms of higher peak data rates, improved system capacity and coverage, and lower latency. These enhancements allow LTE-Advanced to meet or exceed the IMT-Advanced requirements and are being...

    Provided By Aalborg University

  • White Papers // Feb 2012

    Buffer-Aided Relaying with Adaptive Link Selection

    In this paper, the authors consider a simple network consisting of a source, a half-duplex decode-and-forward relay, and a destination. They propose a new relaying protocol employing adaptive link selection, i.e., in any given time slot, based on the channel state information of the source-relay and the relay-destination link a...

    Provided By Aalborg University

  • White Papers // Feb 2012

    Computing Nash Equilibrium In Wireless Ad Hoc Networks: A Simulation-Based Approach

    This paper studies the problem of computing Nash equilibrium in wireless networks modeled by Weighted Timed Automata. Such formalism comes together with a logic that can be used to describe complex features such as timed energy constraints. The authors' contribution is a method for solving this problem using Statistical Model...

    Provided By Aalborg University

  • White Papers // Feb 2012

    Multi-User MIMO and Carrier Aggregation in 4G Systems: The SAMURAI Approach

    The market success of broadband multimedia-enabled devices such as smart phones, tablets, and laptops is increasing the demand for wireless data capacity in mobile cellular systems. In order to meet such requirements, the introduction of advanced techniques for increasing the efficiency in spectrum usage was required. Multi User -Multiple Input...

    Provided By Aalborg University

  • White Papers // Oct 2011

    Downlink Radio Resource Management for LTE-Advanced System with Combined MU-MIMO and Carrier Aggregation Features

    In this paper, the authors study the performance enhancement of a downlink LTE-Advanced system with a combination of the multi-user MIMO and carrier aggregation transmission techniques. Radio resource management for the systems with the combined features are proposed, and the system performance is evaluated. Extensive simulations with various traffic load...

    Provided By Aalborg University

  • White Papers // Sep 2011

    Cognitive Transmissions Under a Primary ARQ Process Via Backward Interference Cancellation

    In this paper, the authors address the problem of the coexistence of Primary and Secondary Users (PU and SU, respectively) in a wireless network, where the PU employs a retransmission based error control technique (ARQ). This mechanism offers the SU a non trivial opportunity: by decoding the Primary Message (PM),...

    Provided By Aalborg University

  • White Papers // Sep 2011

    Feedback Compression Schemes for Downlink Carrier Aggregation in LTE-Advanced

    With full Channel State Information (CSI) available, it has been shown that Carrier Aggregation (CA) in the downlink can significantly improve the data rate experienced at the User Equipments (UE). However, full CSI feedback in all Component Carriers (CCs) requires a large portion of the uplink bandwidth and the feedback...

    Provided By Aalborg University

  • White Papers // Aug 2011

    LinkMind: Link Optimization in Swarming Mobile Sensor Networks

    A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the...

    Provided By Aalborg University

  • White Papers // Jun 2011

    On the Need of Network Coding for Mobile Clouds

    This paper advocates the need of network coding for mobile clouds. Mobile clouds as well as network coding are describing two novel concepts. The concept of mobile clouds describes the potential of mobile devices to communicate with each other and form a cooperative cluster in which new services and potentials...

    Provided By Aalborg University

  • White Papers // Apr 2011

    Interference Cancelation Schemes for Uplink Transmission in Femtocells

    The authors present techniques that solve the near-far problems in femtocell networks. When a co-channel configuration is used, a transmission in the macrocell may cause interference to a femtocell. They introduce methods to cancel the interference caused by the macrocell to a femtocell by using the high-rate link between the...

    Provided By Aalborg University

  • White Papers // Apr 2011

    Proposed on Device Capability Based Authentication Using AES-GCM for Internet of Things(IoT)

    Economics of scale in Internet of Things (IoT) presents new security challenges for ubiquitous devices in terms of authentication, addressing and embedded security. Currently available cryptographic techniques require further analysis to determine applicability to IoT. The authors introduce an authentication and encryption protocol which serves as a proof of concept...

    Provided By Aalborg University

  • White Papers // Mar 2009

    Towards Linking Virtual Models With Physical Objects in Construction Using RFID - Review of Ontologies

    Virtual models have in recent years proven their worth in practice relating to building design. Today virtual models of the complete project are created before the project is carried out in practice. The immediate advantages of this are great; it introduces fewer errors, gives a better production basis, improved clarity...

    Provided By Aalborg University

  • White Papers // Jan 2010

    Integrated Data Management for Mobile Services in the Real World

    Market research companies predict a huge market for services to be delivered to mobile users. Services include route guidance, point-of-interest search, metering services such as road pricing and parking payment, traffic monitoring, etc. The authors' believe that no single such service will be the killer service, but that suites of...

    Provided By Aalborg University

  • White Papers // Mar 2010

    Intelligent Co-Operative Pim Architecture for Image Analysis and Pattern Recognition

    Computer memory systems are increasingly a bottleneck limiting application performance. Processor-In-Memory (PIM) architectures, which capitalize on merging the processing unit with its memory unit on the same chip, promise to remove this limitation by providing a tremendous increase in available memory bandwidth and significant reduction in memory latency for a...

    Provided By Aalborg University

  • White Papers // Mar 2009

    Beyond Technological Diversification: The Impact Of Employee Diversity On Innovation

    This paper investigates the effect of employee diversity in terms of gender, age, ethnicity and education on the firm's likelihood of introducing an innovation. The analysis draws on data from a recent innovation survey. This data is merged with a linked employer employee dataset that allow us to identify the...

    Provided By Aalborg University

  • White Papers // Jan 2009

    Interprocedural Dataflow Analysis Over Weight Domains With Infinite Descending Chains

    The authors study generalized fixed-point equations over idempotent semirings and provide an efficient algorithm for the detection whether a sequence of Kleene's iterations stabilizes after a finite number of steps. Previously known approaches considered only bounded semirings where there are no infinite descending chains. The main novelty of the work...

    Provided By Aalborg University

  • White Papers // Nov 2010

    Protocol Coding Through Reordering of User Resources: Applications and Capacity Results

    While there are continuous efforts to introduce new communication systems and standards, it is legitimate to ask the question: How can one send additional bits by minimally changing the systems that are already operating? This is of a significant practical interest, since it has a potential to generate additional value...

    Provided By Aalborg University

  • White Papers // Sep 2009

    An Authentication Code Against Pollution Attacks in Network Coding

    Systems exploiting network coding to increase their throughput suffer greatly from pollution attacks which consist of injecting malicious packets in the network. The pollution attacks are amplified by the network coding process, resulting in a greater damage than under traditional routing. In this paper, the authors address this issue by...

    Provided By Aalborg University

  • White Papers // Dec 2009

    A Note on the Injection Distance

    Kotter and Kschischang showed in that the network coding counterpart of Gabidulin codes performs asymptotically optimal with respect to the subspace distance. Recently, Silva and Kschischang introduced in the injection distance to give a detailed picture of what happens in noncoherent network coding. The authors show that the above codes...

    Provided By Aalborg University

  • White Papers // Jun 2009

    Optimal One Bit Time Reversal for UWB Impulse Radio in Multi-User Wireless Communications

    In this paper, with the purpose of further reducing the complexity of the system, while keeping its temporal and spatial focusing performance, the authors investigate the possibility of using optimal one bit Time Reversal (TR) system for impulse radio ultra wideband multi-user wireless communications. The results show that, by optimally...

    Provided By Aalborg University

  • White Papers // Sep 2009

    Formation, Organisation And Management Of The (Global) Value Chain In A Theoretical Perspective

    One of the significant trends in inter-firm studies over the past two decades has been the rapid development of interest in value chain and value chain management. While competition and thus the horizontal dimension of the organisation of economic activity is dominant within Industrial Economics and Organisation, the authors have...

    Provided By Aalborg University

  • White Papers // Nov 2009

    Paradigms In International Business Research - Classifications And Applications

    Business management scholars have frequently lamented over the gap between dominant management theories on the one hand and business practices on the other. Some scholars argue that the observed gap is partly due to the varied and divergent meta-theoretical (paradigmatic) foundations on which published studies have been based (Aram and...

    Provided By Aalborg University

  • White Papers // Sep 2010

    Formal Analysis of Privacy for Vehicular Mix-Zones

    Safety critical applications for recently proposed vehicle to Vehicle Ad-hoc NETworks (VANETs) rely on a beacon signal, which poses a threat to privacy since it could allow a vehicle to be tracked. Mix-zones, where vehicles encrypt their transmissions and then change their identifiers, have been proposed as a solution to...

    Provided By Aalborg University

  • White Papers // Nov 2009

    Distributed Development: Challenges & Management Practices Of Danish Industrial Leaders

    This paper discusses management practices of Danish industrial firms in relation to the main challenges they face during the transition from highly concentrated R&D to dispersed R&D. This is a qualitative study featuring 3 case studies of Danish industrial leaders with globalised operations. This paper builds on the Offshore Capability...

    Provided By Aalborg University

  • White Papers // May 2009

    Energy Saving Potential Using Active Networking on Linux Mobile Phones

    This paper investigates the deployment of active networking on mobile devices. The objective is to determine the possibility of decreasing energy consumption on mobile devices accessing Internet services, by use of active networking. The approach is to move the TCP/IP stack from the mobile device onto an access point. To...

    Provided By Aalborg University

  • White Papers // May 2009

    Implementation and Performance Analysis of Cooperative Medium Access Control Protocol for CSMA/CA Based Technologies

    In this paper, the authors investigate three different MAC protocols based on CSMA/CA in terms of throughput and channel access delay. The investigation is based on analytical models and real implementations on a testbed developed for this purpose. While the first MAC approach is alike IEEE802.11, the other two approaches...

    Provided By Aalborg University

  • White Papers // May 2009

    Energy Evaluation for Bluetooth Link Layer Packet Selection Scheme

    This paper is investigating the energy saving potential of Bluetooth. Using the Asynchronous Connectionless Link (ACL) for data transmission, Bluetooth provides different packet types, namely DM and DH packets. Each packet has a different payload size and in the actual implementation the packet selection is based on the channel conditions....

    Provided By Aalborg University

  • White Papers // May 2009

    Evolutionary Theory for Cluster Head Election in Cooperative Clusters Implementing Network Coding

    In this paper a cluster head election problem is studied for a cooperative wireless network. The nodes in the cluster use random linear network coding to enhance the throughput performance in spreading the data for a file download service. Some of the nodes in the cluster will access through their...

    Provided By Aalborg University

  • White Papers // Apr 2011

    Interference Cancelation Schemes for Uplink Transmission in Femtocells

    The authors present techniques that solve the near-far problems in femtocell networks. When a co-channel configuration is used, a transmission in the macrocell may cause interference to a femtocell. They introduce methods to cancel the interference caused by the macrocell to a femtocell by using the high-rate link between the...

    Provided By Aalborg University

  • White Papers // Sep 2009

    MIMO Performance Evaluation in a Street Microcell Using a Spatial Fading Emulator in Comparison With a Radio Propagation Test

    This paper presents effectiveness of a RF-controlled spatial fading emulator on MIMO performance evaluation in a street microcell environment in comparison with a radio propagation test. The fading emulator can produce a radio propagation environment with uniform and non-uniform Angular Power Spectra (APS) in the horizontal plane. In this paper,...

    Provided By Aalborg University

  • White Papers // Jun 2010

    Emulation of Wireless Multi-Hop Topologies With Online Mobility Simulation

    Communication in wireless networks is affected by uncontrollable disturbances in the channel. Effects of these disturbances are exacerbated in networks with dynamic topologies and multiple hops. Lack of control of the channel complicates testing applications in such networks as test conditions are hard, or impossible, to reproduce. This paper describes...

    Provided By Aalborg University

  • White Papers // Feb 2011

    Software Architecture Design for a Dynamic Spectrum Allocation-Enabled Cognitive Radio Testbed

    The evolution of wireless communications is bringing into reality the dense deployment of femto and local area cells, which represents a challenging scenario for proving the effectiveness of Cognitive Radio (CR) frameworks. In particular the Dynamic Spectrum Allocation (DSA) paradigm aims at solving the resource allocation problem in a fully...

    Provided By Aalborg University

  • White Papers // Sep 2011

    Feedback Compression Schemes for Downlink Carrier Aggregation in LTE-Advanced

    With full Channel State Information (CSI) available, it has been shown that Carrier Aggregation (CA) in the downlink can significantly improve the data rate experienced at the User Equipments (UE). However, full CSI feedback in all Component Carriers (CCs) requires a large portion of the uplink bandwidth and the feedback...

    Provided By Aalborg University

  • White Papers // Feb 2011

    Location Assisted Handover Optimization for Heterogeneous Wireless Networks

    Mobile users typically experience better connectivity if their mobile device performs handover to an available WiFi network rather than using a cellular network. For a moving user the window of opportunity is limited and the timing of the handover is therefore crucial. In this paper, the authors propose two location-based...

    Provided By Aalborg University

  • White Papers // Feb 2012

    Buffer-Aided Relaying with Adaptive Link Selection

    In this paper, the authors consider a simple network consisting of a source, a half-duplex decode-and-forward relay, and a destination. They propose a new relaying protocol employing adaptive link selection, i.e., in any given time slot, based on the channel state information of the source-relay and the relay-destination link a...

    Provided By Aalborg University

  • White Papers // Nov 2012

    Cognitive Access Policies Under a Primary ARQ Process via Forward-Backward Interference Cancellation

    This paper introduces a novel technique for access by a cognitive Secondary User (SU) using best-effort transmission to a spectrum with an incumbent Primary User (PU), which uses Type-I Hybrid ARQ. The technique leverages the primary ARQ protocol to perform Interference Cancellation (IC) at the SU receiver (SUrx). Two IC...

    Provided By Aalborg University

  • White Papers // May 2012

    A Study of Trade-Off Between Opportunistic Resource Allocation and Interference Alignment in Femtocell Scenarios

    One of the main problems in wireless heterogeneous networks is interference between macro- and femto-cells. Using Orthogonal Frequency-Division Multiple Access (OFDMA) to create multiple frequency orthogonal sub-channels, this interference can be completely avoided if each sub-channel is exclusively used by either macro- or a femto-cell. However, such an orthogonal allocation...

    Provided By Aalborg University

  • White Papers // May 2012

    Ripple Design of LT Codes for AWGN Channel

    In this paper, the authors present an analytical framework for designing LT codes in Additive White Gaussian Noise (AWGN) channels. They show that some of analytical results from Binary Erasure Channels (BEC) also hold in AWGN channels with slight modifications. This enables them to apply a ripple-based design approach, which...

    Provided By Aalborg University

  • White Papers // Jun 2012

    Design and Analysis of LT Codes with Decreasing Ripple Size

    In this paper, the authors propose a new design of LT codes, which decreases the amount of necessary overhead in comparison to existing designs. The design focuses on a parameter of the LT decoding process called the ripple size. This parameter was also a key element in the design proposed...

    Provided By Aalborg University

  • White Papers // Mar 2010

    Cognitive Mesh Network Under Interference from Primary User

    In a commonly accepted usage scenario, a cognitive radio appears as a secondary user of certain spectrum which is licensed to another, primary system. A prominent example of cognitive system is a mesh network operating under the interference from primary system. For such a scenario, the authors propose techniques for...

    Provided By Aalborg University

  • White Papers // Dec 2009

    Efficient Spectrum Leasing via Centralized Control of a Random Secondary User Back Off

    In this paper, the authors have designed robust spectrum leasing solutions among N secondary users with a constraint on the total interference at a particular primary receiver (where robustness is with respect to the selfish behavior of the secondary users). They have used a secondary network power control game to...

    Provided By Aalborg University

  • White Papers // Oct 2011

    Downlink Radio Resource Management for LTE-Advanced System with Combined MU-MIMO and Carrier Aggregation Features

    In this paper, the authors study the performance enhancement of a downlink LTE-Advanced system with a combination of the multi-user MIMO and carrier aggregation transmission techniques. Radio resource management for the systems with the combined features are proposed, and the system performance is evaluated. Extensive simulations with various traffic load...

    Provided By Aalborg University

  • White Papers // Apr 2012

    Spectrum Aggregation: Initial Outcomes from SAMURAI Project

    Multi-user MIMO and Spectrum Aggregation (also referred to Carrier Aggregation) are two key enablers of next generation wireless systems. Although those techniques were already quite well investigated at theoretical level, their practical implementation is not immediate and raises numerous challenges. The SAMURAI project aims at investigating such challenges as well...

    Provided By Aalborg University

  • White Papers // Sep 2010

    Wireless Broadband Access: Policy Implications of Heterogeneous Networks

    A wireless heterogeneous network can help increase the access transmission speed and contribute thereby to the broadband deployment policies of administrations and telecommunications operators. Given the technical particularities of wireless heterogeneous networks, the deployment of wireless heterogeneous networks raises a number of challenges that need to be addressed by regulatory...

    Provided By Aalborg University

  • White Papers // Sep 2010

    Copenhagen as a Centre of Excellence for Mobile and Wireless Communication - The Interplay Between Supply and Demand

    The aim of this paper is to analyze the potential of the Copenhagen capital region to maintain a leading position in development and provision of mobile technologies. The paper presents empirical data on the mobile sector in the capital region in order to identify strengths and weaknesses of the Capital...

    Provided By Aalborg University

  • White Papers // Sep 2010

    Competition Between Fixed and Mobile Broadband Access Based on Mobility and Data Volume

    This paper proposes a duopoly model based on a model initially introduced by Shubik and Levitan to analyze the competition based on mobility and data volume between fixed and mobile broadband access. By the description of asymmetrical characteristics of fixed and mobile broadband offers and demand functions, Nash equilibrium can...

    Provided By Aalborg University

  • White Papers // Aug 2011

    LinkMind: Link Optimization in Swarming Mobile Sensor Networks

    A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the...

    Provided By Aalborg University

  • White Papers // May 2009

    On the Impact of 2G and 3G Network Usage for Mobile Phones' Battery Life

    Over the last years mobile phones had a remarkable evolution. From a simple device for voice communication, it became a full blown multimedia device with multiple features and appealing services. In parallel with the introduction of novel services, mobile devices became more and more energy-hungry reducing the operational time for...

    Provided By Aalborg University

  • White Papers // May 2009

    Implementation of Random Linear Network Coding on OpenGL-Enabled Graphics Cards

    This paper describes the implementation of network coding on OpenGL-enabled graphics cards. Network coding is an interesting approach to increase the capacity and robustness in multi-hop networks. The current problem is to implement random linear network coding on mobile devices which are limited in computational power, energy, and memory. Some...

    Provided By Aalborg University

  • White Papers // May 2009

    PictureViewer - A Mobile Application Using Network Coding

    This paper looks into the implementation details of network coding for a mobile application running on commercial mobile phones. The mobile application coined PictureViewer can convey pictures from one source device to many neighboring devices using WiFi. The advantage of network coding in this context is that the source devices...

    Provided By Aalborg University

  • White Papers // Jan 2010

    A Genetic Algorithm for Source Election in Cooperative Clusters Implementing Network Coding

    Reference scenarios of the present research are clusters of cooperating wireless nodes, implementing random linear network coding to enhance the throughput performance of file downloading and information spreading services. In particular, a sub-set of cluster nodes will access, through their cellular link, parts of a file to be exchanged among...

    Provided By Aalborg University