University of Thessaly

Displaying 1-22 of 22 results

  • White Papers // Apr 2013

    Non-Asymptotic and Second-Order Achievability Bounds for Coding with Side-Information

    The authors present novel non-asymptotic or finite blocklength achievability bounds for three side-information problems in network information theory. These include the Wyner-Ahlswede-Korner (WAK) problem of almost-lossless source coding with rate-limited side-information, the Wyner-Ziv (WZ) problem of lossy source coding with side-information at the decoder and the Gel'fand-Pinsker (GP) problem of...

    Provided By University of Thessaly

  • White Papers // May 2012

    Low Complexity Algorithm for Inter-Layer Prediction of H.264/SVC

    Inter-layer prediction of H.264/SVC can help to improve the coding efficiency with increased computation complexity. This paper presents a low complexity algorithm for inter-layer prediction. The proposed algorithm focuses on the reduction of the candidate modes by making use of the correlations of the encoding cost between the base layer...

    Provided By University of Thessaly

  • White Papers // Mar 2012

    An Experimental Framework for Channel Sensing Through USRP/GNU Radios

    In the last decade testbeds have been setup to evaluate network protocols and algorithms under realistic settings. In order to draw solid conclusions about the corresponding experimental results, it is important for the experimenter to have a detailed view of the existing channel conditions. Moreover, especially in the context of...

    Provided By University of Thessaly

  • White Papers // Mar 2012

    Wireless Video Transmission With Over-the-Air Packet Mixing

    In this paper, the authors propose a system for wireless video transmission with a wireless PHYsical layer (PHY) that supports cooperative forwarding of interfered/superimposed packets. Their system model considers multiple and independent unicast transmissions between network nodes while a number of them serve as relays of the interfered/superimposed signals. For...

    Provided By University of Thessaly

  • White Papers // Dec 2011

    Competition and Regulation in Wireless Services Markets

    Consider a city where 3 commercial operators (companies) and one municipal operator offer WiFi Internet access to the citizens (users). The companies charge for their services and offer better rates than the municipal WiFi service which however is given gratis. Users with high needs will select one of the companies....

    Provided By University of Thessaly

  • White Papers // Jul 2011

    A Software Framework for Alleviating the Effects of MAC-Aware Jamming Attacks in Wireless Access Networks

    The IEEE 802.11 protocol inherently provides the same long-term through-put to all the clients associated with a given Access Point (AP). In this paper, the authors first identify a clever, low-power jamming attack that can take advantage of this behavioral trait: the placement of a low-power jammer in a way...

    Provided By University of Thessaly

  • White Papers // May 2011

    Optimal Control of Sleep Periods for Wireless Terminals

    The authors consider a mobile connected to a base station, saving energy by shutting off its transceiver, and they try to answer the fundamental question: what is the optimal sleep policy? Firstly, they study the model from optimal control perspective. They consider off-times (periods of inactivity) of unknown duration. They...

    Provided By University of Thessaly

  • White Papers // Apr 2011

    Ncrawl: Network Coding for Rate Adaptive Wireless Links

    Intersession Network Coding (NC) can provide significant performance benefits via mixing packets at wireless routers; these benefits are especially pronounced when NC is applied in conjunction with intelligent link scheduling. NC however imposes certain processing operations, such as encoding, decoding, copying and storage. When not utilized carefully, all these operations...

    Provided By University of Thessaly

  • White Papers // Apr 2011

    Improving the Performance of Styx Based Services Over High Latency Links

    Today, latency is the main limiting factor for distributed systems over the Internet. WANs and wireless networks have achieved high throughput, but limitations on the speed of light put a strict boundary on latency. New protocols have to be deployed in order to reduce the effects of latency. At the...

    Provided By University of Thessaly

  • White Papers // Mar 2011

    A Framework and Experimental Study for Discrimination of Collision and Channel Errors in Wireless LANs

    A fundamental unresolved problem in wireless networks is that of distinguishing packet errors that are caused by deteriorated link conditions and noise, from errors that occur due to packet collisions. In this paper, the authors develop advanced algorithms based on Cyclic Redundancy Check (CRC) that solve this problem. Specifically, their...

    Provided By University of Thessaly

  • White Papers // Jan 2011

    Interconnection of Geographically Distributed Wireless Mesh Testbeds: Resource Sharing on a Large Scale

    Creating large scale testbeds for evaluating wireless mesh technologies and protocols, and for testing their ability to support real world applications in realistic environments, is a crucial step towards the ultimate success of the WMN paradigm. In this paper, the authors suggest the hierarchical federation of a planetary scale infrastructure,...

    Provided By University of Thessaly

  • White Papers // Oct 2010

    Experimenting With P2P Traffic Optimization for Wireless Mesh Networks in a Federated OMF-PlanetLab Environment

    The ultimate success of the Wireless Mesh Network paradigm (WMN) in large scale deployments depends on the ability to test it in real world scenarios. A typical application scenario which is worth to be investigated in such a context is peer-to-peer traffic management. The creation of large scale testbeds for...

    Provided By University of Thessaly

  • White Papers // Jul 2010

    Measurement Aggregation and Routing Techniques for Energy-Efficient Estimation in Wireless Sensor Networks

    Wireless sensor networks are fundamentally different from other wireless networks due to energy constraints and spatial correlation among sensor measurements. Mechanisms that efficiently compress and transport sensor data in the network are needed. The authors consider the problem of maximizing lifetime of wireless sensor networks that are entitled with the...

    Provided By University of Thessaly

  • White Papers // Jun 2010

    New Channel Allocation Techniques for Power Efficient WiFi Networks

    Energy efficiency becomes evergreen than ever before. Over the last few years a significant research in wireless communications, aiming to enhance communications efficiency subject to constraint of power consumption, has given rise to optimization techniques of power control and management in wireless networks. Although the initial target was the utilization...

    Provided By University of Thessaly

  • White Papers // Mar 2010

    A Demonstration of a Management Tool for Assessing Channel Quality Information in Wireless Testbeds

    The gradually growing need for testbed use so as networking algorithms to be validated in real environment, has given rise to optimal utilization of testbed resources. Towards this direction, the authors present a new management tool that is used for assessing channel quality information in wireless testbed deployments. NITOS Connectivity...

    Provided By University of Thessaly

  • White Papers // Feb 2010

    Reputation-Based Internet Sharing in Wireless Neighborhood Community Networks

    This paper proposes easily applicable distributed reputation-based policies to motivate users of a wireless community to share their Internet connection in a p2p fashion. The goal is the provision of free and good quality Internet access anytime and anywhere inside the community. The authors study general systems of users with...

    Provided By University of Thessaly

  • White Papers // Jan 2010

    Cities Competition, Place Marketing And Economic Development In South Europe: The Barcelona Case As FDI Destination

    The aim of the paper is to focus on the especially interesting area of South Europe and to present and points out the strategic development process, in one of the most representative examples of its successful implementation, which is the city of Barcelona. Barcelona, which in the last 20 years,...

    Provided By University of Thessaly

  • White Papers // Dec 2009

    Quantifying the Overhead Due to Routing Probes in Multi-Rate WMNs

    The selection of high-throughput routes is a key element towards improving the performance of wireless multihop networks. While several routing metrics have been proposed in the literature, it has been shown that link-quality aware metrics can provide significantly higher end-to-end throughput. To date, the online computation of such metrics requires...

    Provided By University of Thessaly

  • White Papers // Oct 2009

    M-Learning and M-Commerce in Pervasive Environments

    During the past decade, Mobile Learning (m-learning) and Pervasive Learning (p-learning) are attracting increasing worldwide, due to a number of technical and societal reasons. The emergence of the knowledge society poses new requirements for education and training: the knowledge-based economy requires a flexible, well-trained workforce; and the citizens of the...

    Provided By University of Thessaly

  • White Papers // Mar 2009

    Routing-Aware Channel Selection in Multi-Radio Mesh Networks

    Efficient channel selection is essential in 802.11 mesh deployments, for minimizing contention and interference among co-channel devices and thereby supporting a plurality of QoS-sensitive applications. In this paper, the authors propose ARACHNE, a routing-aware channel selection protocol for wireless mesh networks. ARACHNE is distributed in nature, and motivated by the...

    Provided By University of Thessaly

  • White Papers // Nov 2008

    Design and Deployment Considerations for High Performance MIMO Testbeds

    MIMO (Multiple Input Multiple Output) enabled systems are characterized by higher reliability and transmission rates, as compared to conventional SISO (Single Input Single Output) systems. However, unless administered properly, the MIMO technology may not facilitate very high throughputs on point-to-point wireless links. Therefore, it becomes imperative for the network architect...

    Provided By University of Thessaly

  • White Papers // Sep 2008

    LAC: Load-Aware Channel Selection in 802.11 WLANs

    Dense deployments of hybrid WLANs result in high levels of interference and low end-user throughput. Many frequency allocation mechanisms for WLANs have been proposed by a large body of previous studies. However, none of these mechanisms considers the load that is carried by APs in terms of channel conditions, number...

    Provided By University of Thessaly

  • White Papers // May 2012

    Low Complexity Algorithm for Inter-Layer Prediction of H.264/SVC

    Inter-layer prediction of H.264/SVC can help to improve the coding efficiency with increased computation complexity. This paper presents a low complexity algorithm for inter-layer prediction. The proposed algorithm focuses on the reduction of the candidate modes by making use of the correlations of the encoding cost between the base layer...

    Provided By University of Thessaly

  • White Papers // Apr 2013

    Non-Asymptotic and Second-Order Achievability Bounds for Coding with Side-Information

    The authors present novel non-asymptotic or finite blocklength achievability bounds for three side-information problems in network information theory. These include the Wyner-Ahlswede-Korner (WAK) problem of almost-lossless source coding with rate-limited side-information, the Wyner-Ziv (WZ) problem of lossy source coding with side-information at the decoder and the Gel'fand-Pinsker (GP) problem of...

    Provided By University of Thessaly

  • White Papers // Oct 2009

    M-Learning and M-Commerce in Pervasive Environments

    During the past decade, Mobile Learning (m-learning) and Pervasive Learning (p-learning) are attracting increasing worldwide, due to a number of technical and societal reasons. The emergence of the knowledge society poses new requirements for education and training: the knowledge-based economy requires a flexible, well-trained workforce; and the citizens of the...

    Provided By University of Thessaly

  • White Papers // Nov 2008

    Design and Deployment Considerations for High Performance MIMO Testbeds

    MIMO (Multiple Input Multiple Output) enabled systems are characterized by higher reliability and transmission rates, as compared to conventional SISO (Single Input Single Output) systems. However, unless administered properly, the MIMO technology may not facilitate very high throughputs on point-to-point wireless links. Therefore, it becomes imperative for the network architect...

    Provided By University of Thessaly

  • White Papers // Jan 2010

    Cities Competition, Place Marketing And Economic Development In South Europe: The Barcelona Case As FDI Destination

    The aim of the paper is to focus on the especially interesting area of South Europe and to present and points out the strategic development process, in one of the most representative examples of its successful implementation, which is the city of Barcelona. Barcelona, which in the last 20 years,...

    Provided By University of Thessaly

  • White Papers // Jul 2011

    A Software Framework for Alleviating the Effects of MAC-Aware Jamming Attacks in Wireless Access Networks

    The IEEE 802.11 protocol inherently provides the same long-term through-put to all the clients associated with a given Access Point (AP). In this paper, the authors first identify a clever, low-power jamming attack that can take advantage of this behavioral trait: the placement of a low-power jammer in a way...

    Provided By University of Thessaly

  • White Papers // Dec 2009

    Quantifying the Overhead Due to Routing Probes in Multi-Rate WMNs

    The selection of high-throughput routes is a key element towards improving the performance of wireless multihop networks. While several routing metrics have been proposed in the literature, it has been shown that link-quality aware metrics can provide significantly higher end-to-end throughput. To date, the online computation of such metrics requires...

    Provided By University of Thessaly

  • White Papers // Mar 2009

    Routing-Aware Channel Selection in Multi-Radio Mesh Networks

    Efficient channel selection is essential in 802.11 mesh deployments, for minimizing contention and interference among co-channel devices and thereby supporting a plurality of QoS-sensitive applications. In this paper, the authors propose ARACHNE, a routing-aware channel selection protocol for wireless mesh networks. ARACHNE is distributed in nature, and motivated by the...

    Provided By University of Thessaly

  • White Papers // Sep 2008

    LAC: Load-Aware Channel Selection in 802.11 WLANs

    Dense deployments of hybrid WLANs result in high levels of interference and low end-user throughput. Many frequency allocation mechanisms for WLANs have been proposed by a large body of previous studies. However, none of these mechanisms considers the load that is carried by APs in terms of channel conditions, number...

    Provided By University of Thessaly

  • White Papers // May 2011

    Optimal Control of Sleep Periods for Wireless Terminals

    The authors consider a mobile connected to a base station, saving energy by shutting off its transceiver, and they try to answer the fundamental question: what is the optimal sleep policy? Firstly, they study the model from optimal control perspective. They consider off-times (periods of inactivity) of unknown duration. They...

    Provided By University of Thessaly

  • White Papers // Jul 2010

    Measurement Aggregation and Routing Techniques for Energy-Efficient Estimation in Wireless Sensor Networks

    Wireless sensor networks are fundamentally different from other wireless networks due to energy constraints and spatial correlation among sensor measurements. Mechanisms that efficiently compress and transport sensor data in the network are needed. The authors consider the problem of maximizing lifetime of wireless sensor networks that are entitled with the...

    Provided By University of Thessaly

  • White Papers // Jun 2010

    New Channel Allocation Techniques for Power Efficient WiFi Networks

    Energy efficiency becomes evergreen than ever before. Over the last few years a significant research in wireless communications, aiming to enhance communications efficiency subject to constraint of power consumption, has given rise to optimization techniques of power control and management in wireless networks. Although the initial target was the utilization...

    Provided By University of Thessaly

  • White Papers // Oct 2010

    Experimenting With P2P Traffic Optimization for Wireless Mesh Networks in a Federated OMF-PlanetLab Environment

    The ultimate success of the Wireless Mesh Network paradigm (WMN) in large scale deployments depends on the ability to test it in real world scenarios. A typical application scenario which is worth to be investigated in such a context is peer-to-peer traffic management. The creation of large scale testbeds for...

    Provided By University of Thessaly

  • White Papers // Jan 2011

    Interconnection of Geographically Distributed Wireless Mesh Testbeds: Resource Sharing on a Large Scale

    Creating large scale testbeds for evaluating wireless mesh technologies and protocols, and for testing their ability to support real world applications in realistic environments, is a crucial step towards the ultimate success of the WMN paradigm. In this paper, the authors suggest the hierarchical federation of a planetary scale infrastructure,...

    Provided By University of Thessaly

  • White Papers // Mar 2010

    A Demonstration of a Management Tool for Assessing Channel Quality Information in Wireless Testbeds

    The gradually growing need for testbed use so as networking algorithms to be validated in real environment, has given rise to optimal utilization of testbed resources. Towards this direction, the authors present a new management tool that is used for assessing channel quality information in wireless testbed deployments. NITOS Connectivity...

    Provided By University of Thessaly

  • White Papers // Mar 2011

    A Framework and Experimental Study for Discrimination of Collision and Channel Errors in Wireless LANs

    A fundamental unresolved problem in wireless networks is that of distinguishing packet errors that are caused by deteriorated link conditions and noise, from errors that occur due to packet collisions. In this paper, the authors develop advanced algorithms based on Cyclic Redundancy Check (CRC) that solve this problem. Specifically, their...

    Provided By University of Thessaly

  • White Papers // Apr 2011

    Improving the Performance of Styx Based Services Over High Latency Links

    Today, latency is the main limiting factor for distributed systems over the Internet. WANs and wireless networks have achieved high throughput, but limitations on the speed of light put a strict boundary on latency. New protocols have to be deployed in order to reduce the effects of latency. At the...

    Provided By University of Thessaly

  • White Papers // Mar 2012

    Wireless Video Transmission With Over-the-Air Packet Mixing

    In this paper, the authors propose a system for wireless video transmission with a wireless PHYsical layer (PHY) that supports cooperative forwarding of interfered/superimposed packets. Their system model considers multiple and independent unicast transmissions between network nodes while a number of them serve as relays of the interfered/superimposed signals. For...

    Provided By University of Thessaly

  • White Papers // Dec 2011

    Competition and Regulation in Wireless Services Markets

    Consider a city where 3 commercial operators (companies) and one municipal operator offer WiFi Internet access to the citizens (users). The companies charge for their services and offer better rates than the municipal WiFi service which however is given gratis. Users with high needs will select one of the companies....

    Provided By University of Thessaly

  • White Papers // Apr 2011

    Ncrawl: Network Coding for Rate Adaptive Wireless Links

    Intersession Network Coding (NC) can provide significant performance benefits via mixing packets at wireless routers; these benefits are especially pronounced when NC is applied in conjunction with intelligent link scheduling. NC however imposes certain processing operations, such as encoding, decoding, copying and storage. When not utilized carefully, all these operations...

    Provided By University of Thessaly

  • White Papers // Mar 2012

    An Experimental Framework for Channel Sensing Through USRP/GNU Radios

    In the last decade testbeds have been setup to evaluate network protocols and algorithms under realistic settings. In order to draw solid conclusions about the corresponding experimental results, it is important for the experimenter to have a detailed view of the existing channel conditions. Moreover, especially in the context of...

    Provided By University of Thessaly

  • White Papers // Feb 2010

    Reputation-Based Internet Sharing in Wireless Neighborhood Community Networks

    This paper proposes easily applicable distributed reputation-based policies to motivate users of a wireless community to share their Internet connection in a p2p fashion. The goal is the provision of free and good quality Internet access anytime and anywhere inside the community. The authors study general systems of users with...

    Provided By University of Thessaly