RWSoftware

Displaying 1-40 of 160 results

  • White Papers // Oct 2013

    Slimfit - A HIP DEX Compression Layer for the IP-Based Internet of Things

    The HIP Diet EXchange (DEX) is an end-to-end security protocol designed for constrained network environments in the IP-based Internet of Things (IoT). It is a variant of the IETF-standardized Host Identity Protocol (HIP) with a refined protocol design that targets performance improvements of the original HIP protocol. To stay compatible...

    Provided By RWSoftware

  • White Papers // Oct 2013

    Towards Data Handling Requirements-Aware Cloud Computing

    The adoption of the cloud computing paradigm is hindered by severe security and privacy concerns which arise when outsourcing sensitive data to the cloud. One important group is those concerns regarding the handling of data. On the one hand, users and companies have requirements how their data should be treated....

    Provided By RWSoftware

  • White Papers // Oct 2013

    On Semi-Static Interference Coordination Under Proportional Fair Scheduling in LTE Systems

    In this paper, the authors consider the design of semi-static inter-cell interference coordination schemes for LTE networks. In this approach, base stations coordinate the power settings per resource block over long time spans such as seconds. In order to optimize the power settings, one needs to employ models which predict...

    Provided By RWSoftware

  • White Papers // Oct 2013

    A Cloud Design for User-Controlled Storage and Processing of Sensor Data

    Ubiquitous sensing environments such as sensor networks collect large amounts of data. This data volume is destined to grow even further with the vision of the Internet of Things. Cloud computing promises to elastically store and process such sensor data. As an additional benefit, storage and processing in the Cloud...

    Provided By RWSoftware

  • White Papers // Oct 2013

    A Receiver-Based 802.11 Rate Adaptation Scheme With On-Demand Feedback

    Classical 802.11 rate adaptation algorithms rely on feedback from the receiver to correctly choose a sending rate, typically in the form of ACKnowledgments (ACKs). In the absence of such frames, novel techniques are required for rate selection. The authors present a novel On-Demand Feedback Rate Adaptation Algorithm (OFRA) that works...

    Provided By RWSoftware

  • White Papers // Oct 2013

    Security Challenges in the IP-Based Internet of Things

    A direct interpretation of the term Internet of Things refers to the use of standard Internet protocols for the human-to-thing or thing-to-thing communication in embedded networks. Although the security needs are well-recognized in this domain, it is still not fully understood how existing IP security protocols and architectures can be...

    Provided By RWSoftware

  • White Papers // Oct 2013

    SliceTime: A Platform for Scalable and Accurate Network Emulation

    Network emulation brings together the strengths of network simulation (scalability, modeling and flexibility) and real-world software prototypes (realistic analysis). Unfortunately network emulation fails if the simulation is not real-time capable, e.g., due to large scenarios or complex models. So far, this problem has generally been addressed by providing massive computing...

    Provided By RWSoftware

  • White Papers // Oct 2013

    Detecting Correlation Violations and Data Races by Inferring Non-Deterministic Reads

    With the introduction of multicore systems and parallel programs concurrency bugs have become more common. A notorious class of these bugs is data races that violate correlations between variables. This happens, for example, when the programmer does not update correlated variables atomically, which is needed to maintain their semantic relationship....

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  • White Papers // Oct 2013

    Predicting Parallelization of Sequential Programs Using Supervised Learning

    The authors investigate an automatic method for classifying which regions of sequential programs could be parallelized, using dynamic features of the code collected at runtime. They train a supervised learning algorithm on versions of the NAS Parallel Benchmark (NPB) code hand-annotated with OpenMP parallelization directives in order to approximate the...

    Provided By RWSoftware

  • White Papers // Oct 2013

    SensorCloud: Towards the Interdisciplinary Development of a Trustworthy Platform for Globally Interconnected Sensors and Actuators

    Although Cloud Computing promises to lower IT costs and increase users' productivity in everyday life, the unattractive aspect of this new technology is that the user no longer owns all the devices which process personal data. To lower scepticism, the project SensorCloud investigates techniques to understand and compensate these adoption...

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  • White Papers // Oct 2013

    Efficient Offloading of Parallel Kernels Using MPI Comm Spawn

    The integration of accelerators into cluster systems is currently one of the architectural trends in high performance computing. Usually, those accelerators are manycore compute devices which are directly connected to individual cluster nodes via PCI Express. Recent advances of accelerators, however, do not require a host CPU anymore and now...

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  • White Papers // Sep 2013

    A Multi-Agent Approach to Unstructured Data Analysis Based on Domain-Specific Onthology

    At present most organizations deal with large quantity of documents, licenses, manuals, emails, business letters, financial and technical reports etc. It is already impossible to process all these documents by hand, without automatic assistance. Ontological knowledge bases are a good solution for storing information from these documents, and automatically completing...

    Provided By RWSoftware

  • White Papers // Sep 2013

    Efficient Rough Set Theory Merging

    Theory exploration is a term describing the development of a formal (i.e. with the help of an automated proof-assistant) approach to selected topic, usually within mathematics or computer science. This activity however usually doesn't reflect the view of science considered as a whole, not as separated islands of knowledge. Merging...

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  • White Papers // Sep 2013

    Discovery of Cancellation Regions within Process Mining Techniques

    Process mining is a relatively new field of computer science which deals with process discovery and analysis based on event logs. In this paper, the authors consider the problem of discovering work flow nets with cancellation regions from event logs. Cancellations occur in the majority of real-life event logs. In...

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  • White Papers // Sep 2013

    Analysis of Multilayer Neural Networks with Direct and Cross-Forward Connection

    Artificial neural networks are of much interest for many practical reasons. As of today, they are widely implemented. Of many possible ANNs, the most widely used ANN is the back-propagation model with direct connection. In this model the input layer is fed with input data and each subsequent layers are...

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  • White Papers // Aug 2013

    A Dynamic Resource Management System for Network-Attached Accelerator Clusters

    Over the years, cluster systems have become increasingly heterogeneous by equipping cluster nodes with one or more accelerators such as Graphic Processing Units (GPU). These devices are typically attached to a compute node via PCI Express. As a consequence, batch systems such as TORQUE/Maui and SLURM have been extended to...

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  • White Papers // Jul 2013

    Discovery of Potential Parallelism in Sequential Programs

    Although multicore CPUs are dominating the market of desktops and servers, writing programs that utilize the available hardware parallelism on these architectures still remains a challenge. In this paper, the authors present a dynamic approach for automatically identifying potential parallelism in sequential programs. Their method is based on the notion...

    Provided By RWSoftware

  • White Papers // Apr 2013

    The Cloud Needs Cross-Layer Data Handling Annotations

    Now-a-days, an ever-increasing number of service providers take advantage of the cloud computing paradigm in order to efficiently offer services to private users, businesses, and governments. However, while cloud computing allows to transparently scale back-end functionality such as computing and storage, the implied distributed sharing of resources has severe implications...

    Provided By RWSoftware

  • White Papers // Mar 2013

    Automatic Generation of Parallel Unit Tests

    Multithreaded software is subject to data races. Currently available data race detectors report such errors to the developer, but consume large amounts of time and memory; many approaches are not applicable for large software projects. Unit tests containing fractions of the program lead to better results. The authors propose AutoRT,...

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  • White Papers // Feb 2013

    A Heuristic Header Error Recovery Scheme for RTP

    Streaming applications often tolerate bit errors in their received data well. This is contrasted by the enforcement of correctness of the packet headers and payload by network protocols. The authors investigate a solution for the Real-time Transport Protocol (RTP) that is tolerant to errors by accepting erroneous data. It recovers...

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  • White Papers // Jan 2013

    On the Outage Probability and Effective Capacity of Multiple Decode-and-Forward Relay System

    This paper investigates the quality-of-service performance of multiple decode-and-forward relay system. In particular, the authors study the outage probability and effective capacity performance of the system based on average channel gain. First, a closed-form expression of outage probability is derived which is more concise than the previous work. Second, they...

    Provided By RWSoftware

  • White Papers // Jan 2013

    MR-DSJ: Distance-Based Self-Join for Large-Scale Vector Data Analysis with MapReduce

    Data analytics gets faced with huge and tremendously increasing amounts of data for which MapReduce provides a very convenient and effective distributed programming model. Various algorithms already support massive data analysis on computer clusters but, in particular, distance-based similarity self-joins lack efficient solutions for large vector data sets though they...

    Provided By RWSoftware

  • White Papers // Dec 2012

    SMC-MuSe: A Framework for Secure Multi-Party Computation on MultiSets

    Secure Multi-Party Computation (SMC) offers a theoretically well-founded way to enable applications that preserve their users' privacy. However, the practical use of SMC has often been questioned in the past. This is partly due to the fact that the system assumptions made in theory are hard to meet in practice...

    Provided By RWSoftware

  • White Papers // Oct 2012

    A Dynamic Accelerator-Cluster Architecture

    Accelerators such as Graphics Processing Units (GPUs) provide an inexpensive way of improving the performance of cluster systems. In such an arrangement, the individual nodes of the cluster are directly connected to one or more accelerator devices via PCI Express. This results in a static mapping of accelerators onto compute...

    Provided By RWSoftware

  • White Papers // Oct 2012

    First Survey Results of Quantified User Behavior in User-in-the-Loop Scenarios for Sustainable Wireless Networks

    Traffic in mobile radio networks is expected to continue to increase by 100% per year. This imposes a big challenge for future generations (4G and 5G) of access technologies which were previously dimensioned for over-provisioning especially in the busy hours. Recent forecasts hint that this assumption and approach will not...

    Provided By RWSoftware

  • White Papers // Oct 2012

    Quantified User Behavior in User-in-the-Loop Spatially and Demand Controlled Cellular Systems

    User-centric services are a growing concern. While the digital society definitely needs better Quality-of-Experience (QoE) for the user, the applications on smart mobile devices will continue to raise traffic in mobile radio networks by almost 100% per annum. Future generations of access technologies are challenged by this and the conventional...

    Provided By RWSoftware

  • White Papers // Oct 2012

    The Outage Performance of Realtime Transmission in Multiple Asynchronous Relays Enhanced OFDM System

    This paper considers the outage performance of multiple relays transmission in Orthogonal Frequency Division Multiplexing (OFDM) systems. Relaying has been suggested in general to improve the reliability of wireless systems significantly and is therefore a candidate for wireless industrial communication systems that need to meet tough latency and outage requirements....

    Provided By RWSoftware

  • White Papers // Oct 2012

    Performance Analysis Techniques for Task-Based OpenMP Applications

    To harness the available performance of today's multi-core systems, applications need to make efficient use of the available parallelism. Cores sitting idle, for example in communication calls waiting for data to arrive or in synchronization operations due to load imbalance, waste resources and reduce the overall performance of the application....

    Provided By RWSoftware

  • White Papers // Oct 2012

    Rate Selection Analysis Under Semi-Persistent Scheduling in LTE Networks

    Upcoming LTE networks have basically two different modes for scheduling data in the down-link by the base station. Dynamic scheduling brings the advantage of exploiting instantaneous channel state information while it puts on the other hand a significant burden on the system in terms of overhead and computation requirements. Especially...

    Provided By RWSoftware

  • White Papers // Sep 2012

    Energy Efficiency of Network-Based Acoustic Echo Control in Mobile Radio

    In this paper, the authors investigate the energy efficiency of network-based Acoustic Echo Control (AEC). Usually, AEC is implemented in the mobile terminal. Due to the limited resources of the mobile terminal in terms of the battery, computational capacity and memory, the complexity of the AEC algorithm has to be...

    Provided By RWSoftware

  • White Papers // Sep 2012

    Pattern-Independent Detection of Manual Collectives in MPI Programs

    In parallel applications, a significant amount of communication occurs in a collective fashion to perform, for example, broadcasts, reductions, or complete exchanges. Although the MPI standard defines many convenience functions for this purpose, which not only improve code readability and maintenance but are usually also highly efficient, many application programmers...

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  • White Papers // Aug 2012

    Distributed TV Spectrum Allocation for Cognitive Cellular Network Under Game Theoretical Framework

    This paper proposes efficient schemes for wireless cellular base stations to utilize TV white spectrum (such base stations referred to as white base stations - WBS), so that WBSes can provide good services to their end terminals without violating the incumbent TV services. In particular, the authors consider two complementary...

    Provided By RWSoftware

  • White Papers // Jul 2012

    Impact of Measurement Configurations on the Accuracy of Propagation Model Estimation With Applications to Dynamic Spectrum Access

    In this paper, the authors investigate the possibility of using measurement-based propagation models in the framework of Dynamic Spectrum Access (DSA), where secondary users can opportunistically access the licensed spectrum of a primary system. In principle this will provide a precise representation of the radio environment since it takes into...

    Provided By RWSoftware

  • White Papers // Jul 2012

    Reachability of the Capacity in Parallel Quantised Channels

    Based upon profound knowledge about wireless communication systems that was gathered during the past decades, modelling biological systems analogously has become more and more popular. Although the assumptions about the latter are sometimes less reliable than those about technical systems, some models have proven useful in explaining the behaviour of...

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  • White Papers // Jun 2012

    Interference Management in Heterogeneous Wireless Networks Based on Context Information

    Femtocells and WiFi have been considered as viable concepts in cellular networks to increase overall system capacity. Critical functionalities for the successful integration of such technologies in macro-cellular topologies are related to radio resource allocation and interference management techniques that must ensure seamless intra-cell and inter-cell interoperation among macro- and...

    Provided By RWSoftware

  • White Papers // Jun 2012

    Performance Evaluation of Channel Access Protocols in Overlapping ECMA-368 Wireless Personal Area Networks

    Medium Access Control (MAC) protocols for Wireless Local Area Networks (WLANs) as well as Wireless Personal Area Networks (WPANs) like Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) are known to provide stable distributed channel access for multiple users. The wide acceptance of wireless systems operating in licensed-exempt frequencies demands...

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  • White Papers // Jun 2012

    Cell Spectral Efficiency Optimization in Relay Enhanced Cells

    The broad acceptance of Smartphones results in increasing capacity demands for mobile radio networks. Decode-and-Forward (DF)-Relay Stations (RSs) are promising to improve Cell Spectral Efficiency (CSE) and to better meet the capacity demands. In this paper, the authors investigate the potential of DF-RSs combined with a pico Base Station (BS)...

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  • White Papers // Jun 2012

    Detecting Irregularities in Blog Comment Language Affecting POS Tagging Accuracy

    Studying technology acceptance requires the survey and analysis of user opinions to identify acceptance-relevant factors. In addition to surveys, Web 2.0 poses a huge collection of user comments regarding different technologies. Extracting acceptance-relevant factors and user opinions from such comments requires the application of Natural Language Processing (NLP) methods, particularly...

    Provided By RWSoftware

  • White Papers // Jun 2012

    How a Layered REM Architecture Brings Cognition to Today's Mobile Networks

    In this paper, the authors present a layered Radio Environment Map (REM) architecture along with its applications to the Self-Organizing Network (SON) functionalities of heterogeneous LTE radio-access networks comprising macrocells and femtocells. In this architecture, the functional blocks re-appear with different spatial and temporal granularity at different architectural layers. Although,...

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  • White Papers // May 2012

    Distributed Compressed Sensing for the MIMO MAC With Correlated Sources

    In this paper, the authors consider the transmission of jointly sparse signals over a MIMO MAC composed of two transmitters and one receiver. Distributed compression is performed at the transmitters using a liner transformation and joint reconstruction at the receiver is enabled using the theory of distributed compressed sensing. The...

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  • White Papers // Apr 2008

    Parallel Operation of Half-and Full-Duplex FDD in Future Multi-Hop Mobile Radio Networks

    There are two basic duplexing schemes for present and future mobile radio networks, Frequency-Division Duplex (FDD) and Time-Division Duplex (TDD). In general each of these methods has its benefits and drawbacks. However, both schemes have their scenarios where they perform best. In future mobile radio systems typical wireless data communication...

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  • White Papers // May 2008

    Wireless Local Danger Warning Using Inter-Vehicle Communications in Highway Scenarios

    Emergency Electronic Brake Light (EEBL) is one of the most promising applications using Vehicular Ad-hoc NETwork (VANET) technologies to enhance the driving safety of automotive users. This paper is based on the previous work that authors develop a novel self-organized message dissemination scheme, namely Cluster-based Broadcast (CB), for the EEBL...

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  • White Papers // May 2008

    IEEE 802.11s - Mesh Deterministic Access

    In 2003, interests in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 Working Group (WG) led to formation of Task Group (TG) "S". 802.11s develops an amendment for Wireless Local Area Network (WLAN) mesh. Unlike existing WLAN mesh products, 802.11s forms a transparent 802 broadcast domain that supports any...

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  • White Papers // Jun 2009

    Theoretical Analysis of Saturation Throughput in MU-DCF

    In this paper, the calculation of saturation throughput for previously proposed Multi-User - Distributed Coordination Function (MU-DCF) is presented. MU-DCF is an IEEE 802.11 based protocol that supports Multi-User (MU)-Multiple Input-Multiple Output (MIMO) transmissions. The analysis is for two extreme case scenarios: Access Point (AP) downlink in a hotspot scenario,...

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  • White Papers // Jun 2009

    An FDD Multihop Cellular Network for 3GPP-LTE

    The future cellular radio networks like 3G-LTE are based on an OFDMA physical layer. The duplex scheme is preferably Frequency Division (FDD) because of its advantages in long range. Huge area coverage in a cost-efficient way is important problem for the early deployment. Time after time the demand in densely...

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  • White Papers // May 2008

    Capacity and Coverage Analysis of a 3GPP-LTE Multihop Deployment Scenario

    Broadband wireless access will be deployed in a cellular way with 3GPP-LTE. For the first rollout the main demand is huge area coverage. With only few available base station sites that are connected to an access fiber, multihop (relaying) techniques can be used well to fill the coverage gaps. Later...

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  • White Papers // Mar 2009

    The Influence of Subchannel Diversity on the Performance of OFDMA Systems Based on IEEE 802.16

    The performance of a mobile radio system based on OFDMA is determined by the type of mapping of logical sub-channels, which are allocated for data transmissions, onto the frequency channel. The mapping scheme affects the diversity both within and between the OFDMA sub-channels. This paper provides a performance comparison of...

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  • White Papers // Jun 2009

    Opportunistic Wireless Internet Access in Vehicular Environments Using Enhanced WAVE Devices

    The emerging Car-To-Car communication (C2C) technology, known as Wireless Access in Vehicular Environments (WAVE), enables vehicles on the roadway to communicate with each other and with the roadside infrastructure. In addition to safety-relevant services, drivers may also need internet access through C2C communications for infotainment services and car maintenance services,...

    Provided By RWSoftware

  • White Papers // Jun 2012

    How a Layered REM Architecture Brings Cognition to Today's Mobile Networks

    In this paper, the authors present a layered Radio Environment Map (REM) architecture along with its applications to the Self-Organizing Network (SON) functionalities of heterogeneous LTE radio-access networks comprising macrocells and femtocells. In this architecture, the functional blocks re-appear with different spatial and temporal granularity at different architectural layers. Although,...

    Provided By RWSoftware

  • White Papers // Jun 2012

    Interference Management in Heterogeneous Wireless Networks Based on Context Information

    Femtocells and WiFi have been considered as viable concepts in cellular networks to increase overall system capacity. Critical functionalities for the successful integration of such technologies in macro-cellular topologies are related to radio resource allocation and interference management techniques that must ensure seamless intra-cell and inter-cell interoperation among macro- and...

    Provided By RWSoftware

  • White Papers // Jul 2012

    Impact of Measurement Configurations on the Accuracy of Propagation Model Estimation With Applications to Dynamic Spectrum Access

    In this paper, the authors investigate the possibility of using measurement-based propagation models in the framework of Dynamic Spectrum Access (DSA), where secondary users can opportunistically access the licensed spectrum of a primary system. In principle this will provide a precise representation of the radio environment since it takes into...

    Provided By RWSoftware

  • White Papers // Oct 2012

    Rate Selection Analysis Under Semi-Persistent Scheduling in LTE Networks

    Upcoming LTE networks have basically two different modes for scheduling data in the down-link by the base station. Dynamic scheduling brings the advantage of exploiting instantaneous channel state information while it puts on the other hand a significant burden on the system in terms of overhead and computation requirements. Especially...

    Provided By RWSoftware

  • White Papers // Oct 2012

    The Outage Performance of Realtime Transmission in Multiple Asynchronous Relays Enhanced OFDM System

    This paper considers the outage performance of multiple relays transmission in Orthogonal Frequency Division Multiplexing (OFDM) systems. Relaying has been suggested in general to improve the reliability of wireless systems significantly and is therefore a candidate for wireless industrial communication systems that need to meet tough latency and outage requirements....

    Provided By RWSoftware

  • White Papers // Jan 2013

    On the Outage Probability and Effective Capacity of Multiple Decode-and-Forward Relay System

    This paper investigates the quality-of-service performance of multiple decode-and-forward relay system. In particular, the authors study the outage probability and effective capacity performance of the system based on average channel gain. First, a closed-form expression of outage probability is derived which is more concise than the previous work. Second, they...

    Provided By RWSoftware

  • White Papers // Aug 2012

    Distributed TV Spectrum Allocation for Cognitive Cellular Network Under Game Theoretical Framework

    This paper proposes efficient schemes for wireless cellular base stations to utilize TV white spectrum (such base stations referred to as white base stations - WBS), so that WBSes can provide good services to their end terminals without violating the incumbent TV services. In particular, the authors consider two complementary...

    Provided By RWSoftware

  • White Papers // Apr 2012

    Multi-Level Parallelism for Time-And Cost-Efficient Parallel Discrete Event Simulation on GPUs

    Developing complex technical systems requires a systematic exploration of the given design space in order to identify optimal system configurations. However, studying the effects and interactions of even a small number of system parameters often requires an extensive number of simulation runs. This in turn results in excessive runtime demands...

    Provided By RWSoftware

  • White Papers // Mar 2012

    Know Thy Simulation Model: Analyzing Event Interactions for Probabilistic Synchronization in Parallel Simulations

    Efficiently scheduling and synchronizing parallel event execution constitutes the fundamental challenge in parallel discrete event simulation. Existing synchronization algorithms typically do not analyze event interactions within the simulation model - mainly to minimize runtime overhead and complexity. However, the authors argue that disregarding event interactions results in a lack of...

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  • White Papers // May 2011

    Predicting Runtime Performance Bounds of Expanded Parallel Discrete Event Simulations

    Predicting and analyzing runtime performance characteristics is a vital step in the development process of parallel discrete event simulations. For instance, model developers need to identify and eliminate performance bottlenecks within a simulation model in order to derive a model structure that aids parallel execution. Similarly, developers of parallel simulation...

    Provided By RWSoftware

  • White Papers // May 2010

    A Game-Theoretic Approach to Routing Under Adversarial Conditions

    The authors present a game-theoretic framework for modeling and solving routing problems in dynamically changing networks. The model covers the aspects of reactivity and non-termination, and it is motivated by quality-of-service provisioning in cognitive radio networks where data transmissions are interfered by primary systems. More precisely, they propose an infinite...

    Provided By RWSoftware

  • White Papers // Apr 2010

    A Two-Stage Approach to WLAN Planning: Detailed Performance Evaluation Along the Pareto Frontier

    This paper proposes an efficient solution to the open problem of network planning for large-scale WLAN deployments. WLAN performance is governed by the CSMA-CA protocol, whose dynamic effects are difficult to capture. Accurate performance evaluation depends on simulations and takes time. A detailed analysis of dozens candidate designs with varying...

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  • White Papers // Apr 2010

    How Bad Is Interference in IEEE 802.16e Systems?

    This paper presents a performance model for dynamic resource allocation in cellular deployments of IEEE 802.16e-like systems. More specifically, the authors derive a framework which allows to quantify the number of VoIP calls that can be supported in downlink of such systems purely based on the average SINR per terminal....

    Provided By RWSoftware

  • White Papers // Dec 2009

    The K - Constrained Bipartite Matching Problem: Approximation Algorithms and Applications to Wireless Networks

    In communication networks, resource assignment problems appear in several different settings. These problems are often modeled by a maximum weight matching problem in bipartite graphs and efficient matching algorithms are well known. In several applications, the corresponding matching problem has to be solved many times in a row as the...

    Provided By RWSoftware

  • White Papers // Apr 2010

    Considering Microelectronic Trends in Advanced Wireless System Design

    Wireless communication system design has been a booming topic since the shift into the digital era in the 1990s. In the same period of time, microelectronic technologies have reached new paradigm points as they were going deeper into the sub-micron area. This paper gives an overview of these emerging constraints...

    Provided By RWSoftware

  • White Papers // Sep 2012

    Energy Efficiency of Network-Based Acoustic Echo Control in Mobile Radio

    In this paper, the authors investigate the energy efficiency of network-based Acoustic Echo Control (AEC). Usually, AEC is implemented in the mobile terminal. Due to the limited resources of the mobile terminal in terms of the battery, computational capacity and memory, the complexity of the AEC algorithm has to be...

    Provided By RWSoftware

  • White Papers // Jan 2013

    MR-DSJ: Distance-Based Self-Join for Large-Scale Vector Data Analysis with MapReduce

    Data analytics gets faced with huge and tremendously increasing amounts of data for which MapReduce provides a very convenient and effective distributed programming model. Various algorithms already support massive data analysis on computer clusters but, in particular, distance-based similarity self-joins lack efficient solutions for large vector data sets though they...

    Provided By RWSoftware

  • White Papers // Apr 2012

    Intelligibility Assessment of a System for Artifical Bandwidth Extension of Telephone Speech

    For the present study, the extension from the 0.3 - 3.4 kHz range towards higher audio frequencies was considered. The employed ABWE algorithm follows the source-filter model of speech production. Techniques for Artificial BandWidth Extension (ABWE) aim to extend the limited audio bandwidth of current narrowband telephone systems (0.3 -...

    Provided By RWSoftware

  • White Papers // Apr 2013

    The Cloud Needs Cross-Layer Data Handling Annotations

    Now-a-days, an ever-increasing number of service providers take advantage of the cloud computing paradigm in order to efficiently offer services to private users, businesses, and governments. However, while cloud computing allows to transparently scale back-end functionality such as computing and storage, the implied distributed sharing of resources has severe implications...

    Provided By RWSoftware

  • White Papers // Oct 2009

    Multicell Multicast Beamforming with Delayed SNR Feedback

    The authors evaluate the performance of beam-forming in the downlink of a Single Frequency Network (SFN), in which common data is transmitted to all participating users simultaneously. The beam-forming is jointly optimized for all cells in the network and for all users. The algorithm is based on spatio-temporal correlation knowledge...

    Provided By RWSoftware

  • White Papers // Aug 2011

    Rate-Compatible LDPC Codes using Optimized Dummy Bit Insertion

    Much attention has been paid to Low-Density Parity-Check (LDPC) codes since their rediscovery by MacKay. They belong to the most powerful channel coding techniques known today and have a broad range of applications. In wireless communication systems it is desirable to be able to adjust the code rate of the...

    Provided By RWSoftware

  • White Papers // Dec 2012

    SMC-MuSe: A Framework for Secure Multi-Party Computation on MultiSets

    Secure Multi-Party Computation (SMC) offers a theoretically well-founded way to enable applications that preserve their users' privacy. However, the practical use of SMC has often been questioned in the past. This is partly due to the fact that the system assumptions made in theory are hard to meet in practice...

    Provided By RWSoftware

  • White Papers // Apr 2012

    FSASD: A Framework for Establishing Security Associations for Sequentially Deployed WMN

    Wireless Mesh Networks (WMN) mainly consists of an infrastructure of Mesh Routers (MRs) that are wirelessly interconnected. In many application scenarios these MRs are placed in publicly accessible places and may therefore be compromised by an attacker. Any security framework for WMNs should thus be able to cope with compromised...

    Provided By RWSoftware

  • White Papers // Apr 2012

    Enabling Fair and Privacy-Preserving Applications Using Reconciliation Protocols on Ordered Sets

    Fair and privacy-preserving reconciliation protocols on ordered sets have been introduced recently. Despite the fact that these protocols promise to have a great impact in a variety of applications, so far their practical use has been explored to a limited extent only. This paper addresses this gap. As main contributions,...

    Provided By RWSoftware

  • White Papers // Apr 2012

    Wireless Mesh Network Security: State of Affairs

    Wireless Mesh Networks (WMNs) surely are one of the most prominent trends for Next Generation Networks. Their future success, however, depends on their security features. In this paper, the authors step back to classify and characterize Wireless Mesh Networks as a whole. This high-level vantage point helps one to define...

    Provided By RWSoftware

  • White Papers // Feb 2010

    Performance Analysis of Reuse Partitioning Techniques in OFDMA Based Cellular Radio Networks

    Reuse partitioning is a useful method for mitigating Co-Channel Interference (CCI) in Orthogonal Frequency Division Multiple Access (OFDMA) based cellular environments. In this paper, theoretical analysis of a series of reuse partitioning approaches is carried out, which contains the well-known Soft Frequency Reuse (SFR) scheme, the novel Enhanced Fractional Frequency...

    Provided By RWSoftware

  • White Papers // Feb 2010

    A Closed Loop Control Model Separating Resource and Packet Scheduling in Multihop Cellular Networks

    4G cellular systems and the IMT Advanced candidates will provide broadband wireless access with QoS. Especially in multihop configurations of these systems the base station controls resources centrally while relays can take over a part of the responsibility on the second hop. To make this work on layer two, scheduling...

    Provided By RWSoftware

  • White Papers // Oct 2009

    Frequency Reuse Techniques for Attaining Both Coverage and High Spectral Efficiency in OFDMA Cellular Systems

    Inter-Cell Interference (ICI) is always a big obstacle to attain wide area coverage and high spectral efficiency in cellular systems. In this paper, the authors make a study of two well-known frequency reuse approaches, namely the Soft Frequency Reuse (SFR) scheme and the Incremental Frequency Reuse (IFR) scheme. Both of...

    Provided By RWSoftware

  • White Papers // Dec 2010

    Prototypical Implementation of a Service Oriented Wireless Sensor Networks Application

    The Wireless Sensor Networks (WSN) environments are increasingly becoming intelligent with the rapid boost in the capabilities of sensor nodes. The Sun Small Programmable Object Technology (SPOT) platform offers a high-end sensing device in terms of processing, memory and battery configurations compared to the other existing in the community. Within...

    Provided By RWSoftware

  • White Papers // Jun 2010

    Spectrum Load Smoothing in IEEE 802.16 Systems

    Today's framework for radio spectrum regulation and spectrum usage is undergoing fundamental changes. In the face of scarce radio resources, regulators, industry, and the research community are initiating promising approaches towards a more flexible spectrum usage, as for example cognitive radios for dynamic spectrum assignment. In this paper an intelligent...

    Provided By RWSoftware

  • White Papers // Nov 2009

    Mobile Web Services in Health Care and Sensor Networks

    The Wireless Sensor Networks (WSN) environments are increasingly becoming intelligent with the rapid boost in the capabilities of sensor nodes. The sun Small Programmable Object Technology (SPOT) platform offers a high-end sensing device in terms of processing, memory and battery configurations compared to other existing in the community. Within the...

    Provided By RWSoftware

  • White Papers // Oct 2009

    Enhanced Fractional Frequency Reuse to Increase Capacity of OFDMA Systems

    Inter-Cell Interference (ICI) mitigation is always a big challenge issue in cellular systems. In this paper, the authors propose an Enhanced Fractional Frequency Reuse (EFFR) scheme combined with power allocation and an interference-aware reuse mechanism to achieve not only ICI limitation at cell edge but also enhancement of overall cell...

    Provided By RWSoftware