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  • 351.
    Boano, Carlo Alberto
    et al.
    University of Lübeck.
    Wennerström, Hjalmar
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Zúñiga, Marco Antonio
    TU Delft.
    Brown, James
    Lancaster University.
    Keppitiyagama, Chamath
    Swedish Institute of Computer Science.
    Oppermann, Felix Jonathan
    University of Lübeck.
    Roedig, Utz
    Lancaster University.
    Nordén, Lars-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Voigt, Thiemo
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Römer, Kay
    University of Lübeck.
    Hot Packets: A systematic evaluation of the effect of temperature on low power wireless transceivers2013In: Proc. 5th Extreme Conference on Communication, New York: ACM Press, 2013, p. 7-12Conference paper (Refereed)
    Abstract [en]

    Temperature is known to have a significant effect on the performance of radio transceivers: the higher the temperature, the lower the quality of links. Analysing this effect is particularly important in sensor networks because several applications are exposed to harsh environmental conditions. Daily or hourly changes in temperature can dramatically reduce the throughput, increase the delay, or even lead to network partitions. A few studies have quantified the impact of temperature on low-power wireless links, but only for a limited temperature range and on a single radio transceiver. Building on top of these preliminary observations, we design a low-cost experimental infrastructure to vary the onboard temperature of sensor nodes in a repeatable fashion, and we study systematically the impact of temperature on various sensornet platforms. We show that temperature affects transmitting and receiving nodes differently, and that all platforms follow a similar trend that can be captured in a simple first-order model. This work represents an initial stepping stone aimed at predicting the performance of a network considering the particular temperature profile of a given environment.

  • 352. Boccardi, Federico
    et al.
    Andrews, Jeffrey
    Elshaer, Hisham
    Dohler, Mischa
    Parkvall, Stefan
    KTH, School of Electrical Engineering (EES), Communication Theory. Univ Calif San Diego, San Diego.
    Popovski, Petar
    Singh, Sarabjot
    Why to Decouple the Uplink and Downlink in Cellular Networks and How To Do It2016In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 54, no 3, p. 110-117Article in journal (Refereed)
    Abstract [en]

    Ever since the inception of mobile telephony, the downlink and uplink of cellular networks have been coupled, that is, mobile terminals have been constrained to associate with the same base station in both the downlink and uplink directions. New trends in network densification and mobile data usage increase the drawbacks of this constraint, and suggest that it should be revisited. In this article we identify and explain five key arguments in favor of downlink/uplink decoupling based on a blend of theoretical, experimental, and architectural insights. We then overview the changes needed in current LTE-A mobile systems to enable this decoupling, and then look ahead to fifth generation cellular standards. We demonstrate that decoupling can lead to significant gains in network throughput, outage, and power consumption at a much lower cost compared to other solutions that provide comparable or lower gains.

  • 353.
    Bodinger, Ronnie
    KTH, Superseded Departments, Teleinformatics.
    An MPLS Connection Manager for an Edge Router1998Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Internet has been growing rapidly over the last couple of years. The increasing demand for network bandwidth is becoming a huge problem. To solve this problem, new methods must be developed. Ericsson’s solution is the use of MultiProtocol Label Switching (MPLS). MPLS has the potential to have a major impact on IP networking. It has the simplicity and dynamic nature of an IP network, but retains the performance of an ATM network. Furthermore, from an administrator’s point of view, MPLS will drastically simplify network management.

    The key principle behind MPLS is to be able to forward by switching packets through a network instead of routing packets. In order to do this, paths are established at the data link layer throughout the MPLS network. A fixed length identifier known as “label” identifies each path. Then the packets are simply forwarded on the path using layer two switching, instead of performing layer three routing.

    By using MPLS, performance is increased and it provides a good basis for traffic engineering, Quality of Service (QoS) guarantees, and Virtual Private Networks (VPN).

    I have implemented an MPLS ATM driver for an Ericsson AXI 510 Edge Router. The driver is responsible for converting generic MPLS labels into standard ATM labels (VPI/VCI). The driver also modifies the forwarding process in the router so that ATM paths are used to forward the packets, instead of the conventional forwarding methods. This implementation has been partly tested and it complies with MPLS current Internet drafts so far.

  • 354.
    Boeira, Felipe
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS). Federal University of Rio Grande do Sul, Porto Alegre, Brazil & Linköping University, Linköping, Sweden.
    Barcellos, Marinho P.
    Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Pignaton de Freitas, Edison
    Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Asplund, Mikael
    Linköping University, Linköping, Sweden.
    Effects of Colluding Sybil Nodes in Message Falsification Attacks for Vehicular Platooning2017In: 2017 IEEE Vehicular Networking Conference (VNC) / [ed] Onur Altintas, Claudio Casetti, Nicholas Kirsch, Renato Lo Cigno & Rui Meireles, 2017Conference paper (Refereed)
    Abstract [en]

    This paper studies the impact of vulnerabilities associated with the Sybil attack (through falsification of multiple identities) and message falsification in vehicular platooning. Platooning employs Inter-Vehicular Communication (IVC) to control a group of vehicles. It uses broadcast information such as acceleration, position, and velocity to operate a longitudinal control law. Cooperation among vehicles allows platoons to reduce fuel consumption and risks associated with driver mistakes. In spite of these benefits, the use of network communication to control vehicles exposes a relevant attack surface that can be exploited by malicious actors. To carry out this study, we evaluate five scenarios to quantify the potential impact of such attacks, identifying how platoons behave under varying Sybil attack conditions and what are the associated safety risks. This research also presents the use of location hijacking attack. In this attack, innocent vehicles that are not part of a platoon are used as a way to create trust bond between the false identities and the physical vehicles. We demonstrate that the ability to create false identities increases the effectiveness of message falsification attacks by making them easier to deploy and harder to detect in time.

  • 355.
    Boeira, Felipe
    et al.
    Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Barcellos, Marinho
    Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Pignaton de Freitas, Edison
    Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Asplund, Mikael
    Linköping University, Linköping, Sweden.
    On the impact of sybil attacks in cooperative driving scenarios2017In: 2017 IFIP Networking Conference (IFIP Networking) and Workshops, IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    Platooning employs a set of technologies to manage how a group of vehicles operates, including radar, GPS and Inter-Vehicular Communication (IVC). It uses broadcasted information such as acceleration, position and velocity to operate vehicle members of the platoon. Cooperation among vehicles allows platoons to reduce fuel consumption and risks associated with driver mistakes. In spite of these benefits, the use of IVC to control vehicles exposes a relevant attack surface that can be exploited by malicious actors. In this paper we study the impact of vulnerabilities associated with the Sybil attack (through falsification of multiple identities) and message falsification in vehicular platooning. Simulation results show that this attack may impact the longitudinal control and compromise the entire platoon control. © Copyright 2018 IEEE

  • 356.
    Bogdanov, Kirill
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Latency Dataset for the paper "The Nearest Replica Can Be Farther Than You Think"2015Data set
  • 357.
    Bogdanov, Kirill
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Reducing Long Tail Latencies in Geo-Distributed Systems2016Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Computing services are highly integrated into modern society. Millions of people rely on these services daily for communication, coordination, trading, and accessing to information. To meet high demands, many popular services are implemented and deployed as geo-distributed applications on top of third party virtualized cloud providers. However, the nature of such deployment provides variable performance characteristics. To deliver high quality of service, such systems strive to adapt to ever-changing conditions by monitoring changes in state and making run-time decisions, such as choosing server peering, replica placement, and quorum selection.

    In this thesis, we seek to improve the quality of run-time decisions made by geo-distributed systems. We attempt to achieve this through: (1) a better understanding of the underlying deployment conditions, (2) systematic and thorough testing of the decision logic implemented in these systems, and (3) by providing a clear view into the network and system states which allows these services to perform better-informed decisions.

    We performed a long-term cross datacenter latency measurement of the Amazon EC2 cloud provider. We used this data to quantify the variability of network conditions and demonstrated its impact on the performance of the systems deployed on top of this cloud provider.

    Next, we validate an application’s decision logic used in popular storage systems by examining replica selection algorithms. We introduce GeoPerf, a tool that uses symbolic execution and lightweight modeling to perform systematic testing of replica selection algorithms. We applied GeoPerf to test two popular storage systems and we found one bug in each.

    Then, using traceroute and one-way delay measurements across EC2, we demonstrated persistent correlation between network paths and network latency. We introduce EdgeVar, a tool that decouples routing and congestion based changes in network latency. By providing this additional information, we improved the quality of latency estimation, as well as increased the stability of network path selection.

    Finally, we introduce Tectonic, a tool that tracks an application’s requests and responses both at the user and kernel levels. In combination with EdgeVar, it provides a complete view of the delays associated with each processing stage of a request and response. Using Tectonic, we analyzed the impact of sharing CPUs in a virtualized environment and can infer the hypervisor’s scheduling policies. We argue for the importance of knowing these policies and propose to use them in applications’ decision making process.

  • 358.
    Bogdanov, Kirill
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Peón-Quirós, Miguel
    Complutense University of Madrid.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Kostic, Dejan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    The Nearest Replica Can Be Farther Than You Think2015In: Proceedings of the ACM Symposium on Cloud Computing 2015, Association for Computing Machinery (ACM), 2015, p. 16-29Conference paper (Refereed)
    Abstract [en]

    Modern distributed systems are geo-distributed for reasons of increased performance, reliability, and survivability. At the heart of many such systems, e.g., the widely used Cassandra and MongoDB data stores, is an algorithm for choosing a closest set of replicas to service a client request. Suboptimal replica choices due to dynamically changing network conditions result in reduced performance as a result of increased response latency. We present GeoPerf, a tool that tries to automate the process of systematically testing the performance of replica selection algorithms for geodistributed storage systems. Our key idea is to combine symbolic execution and lightweight modeling to generate a set of inputs that can expose weaknesses in replica selection. As part of our evaluation, we analyzed network round trip times between geographically distributed Amazon EC2 regions, and showed a significant number of daily changes in nearestK replica orders. We tested Cassandra and MongoDB using our tool, and found bugs in each of these systems. Finally, we use our collected Amazon EC2 latency traces to quantify the time lost due to these bugs. For example due to the bug in Cassandra, the median wasted time for 10% of all requests is above 50 ms.

  • 359.
    Bogdanov, Kirill
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Peón-Quirós, Miguel
    Complutense University of Madrid.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Kostić, Dejan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Toward Automated Testing of Geo-Distributed Replica Selection Algorithms2015In: Proceedings of the 2015 ACM Conference on Special Interest Group on Data Communication, Association for Computing Machinery (ACM), 2015, p. 89-90Conference paper (Refereed)
    Abstract [en]

    Many geo-distributed systems rely on a replica selection algorithms to communicate with the closest set of replicas.  Unfortunately, the bursty nature of the Internet traffic and ever changing network conditions present a problem in identifying the best choices of replicas. Suboptimal replica choices result in increased response latency and reduced system performance. In this work we present GeoPerf, a tool that tries to automate testing of geo-distributed replica selection algorithms. We used GeoPerf to test Cassandra and MongoDB, two popular data stores, and found bugs in each of these systems.

  • 360.
    Bogdanov, Kirill
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Reda, Waleed
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab). Université catholique de Louvain.
    Kostic, Dejan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Canini, Marco
    KAUST.
    Kurma: Fast and Efficient Load Balancing for Geo-Distributed Storage Systems: Evaluation of Convergence and Scalability2018Report (Other academic)
    Abstract [en]

    This report provides an extended evaluation of Kurma, a practical implementation of a geo-distributed load balancer for backend storage systems. In this report we demonstrate the ability of distributed Kurma instances to accurately converge to the same solutions within 1% of the total datacenter’s capacity and the ability of Kurma to scale up to 8 datacenters using a single CPU core at each datacenter.

  • 361. Bohge, Mathias
    et al.
    Gross, James
    Wolisz, Mathias
    Optimal Power Masking in Soft Frequency Reuse based OFDMA Networks2009Conference paper (Refereed)
    Abstract [en]

    Soft frequency reuse is a strong tool for co-channel interference mitigation in cellular OFDMAILTE networks. The performance of such networks significantly depends on the configuration of the power masks that implement the soft frequency reuse patterns. In this paper, we investigate the performance of different power mask configurations against the optimal case, in which a central entity optimally distributes power and resource blocks among the users of the network. It is shown that large differences exist between the performance of different mask types and the optimal case in both, the overall cell throughput, as well as the cell-edge user performance.

  • 362.
    Bohge, Mathias
    et al.
    TU Berlin.
    Naghibi, Farshad
    TU Berlin.
    Wolisz, Adam
    TU Berlin.
    The use of guard bands to mitigate multiple access interference in the OFDMA uplink2008In: Proceedings of the 13th International OFDM-Workshop (InOWo),, 2008, p. 75-79Conference paper (Refereed)
    Abstract [en]

    The usual approach to mitigate multiple access interference (MAI) in the uplink of cellular OFDMA based systems is to use relatively large cyclic prefixes as time domain guard periods. In this paper, we suggest to use a combination of short time domain guard periods and frequency domain guard bands to protect against MAI instead. Guard bands can be added and removed as necessary and, thus, increase the MAI protection flexibility. We show that, if optimally applied, the use of guard bands can significantly increase the system’s uplink capacity or minimum capacity per user.

  • 363.
    Boin, Arjen
    et al.
    Crisisplan & Leiden University.
    Bynander, Fredrik
    Swedish National Defence College, Department of Security, Strategy and Leadership (ISSL), CRISMART (National Center for Crisis Management Research and Training).
    Pintore, Giovanni
    CRS4 Visual Computing Group Pula(CA), Italy.
    Ganovelli, Fabio
    ISTI-CNR Pisa, Italy.
    Leventakis, George
    Center for Security Studies - KEMEA Athens, Greece.
    Ahmad, Alexandre
    DIGINEXT Toulouse, France.
    Balet, Olivier
    DIGINEXT Toulouse, France.
    Building an IT Platform for Strategic Crisis Management Preparation2014In: 10th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), IEEE conference proceedings, 2014, p. 20-27Conference paper (Refereed)
    Abstract [en]

    This paper presents the result of the work achieved in the frame of three successive European Projects, which aimed to build an innovative system to assist security managers in the crisis preparation, training and management phases. The iterative approach of the consortium is presented, as well as the results. A novel interactive and shared Common Operational Picture is proposed which has been validated by three large scale demonstrations. On-going and future work focusing on the security concepts and measures of building interiors is moreover presented.

  • 364. Bonanni, L
    et al.
    Ebner, Hannes
    Hockenberry, M
    Sayan, B
    Brandt, Nils
    Csikszentmihàlyi, N
    Ishii, H
    Turpeinen, Marko
    Young, S
    Zapico, Jorge Luis
    KTH Royal Institute of Technology.
    Sourcemap. org: First Application of Linked and Open LCA Data to Support Sustainability2011Conference paper (Refereed)
  • 365.
    Bonanni, Leonardo
    et al.
    MIT Media Lab, USA.
    Ebner, Hannes
    KTH Royal Institute of Technology.
    Hockenberry, Matthew
    MIT Media Lab , USA.
    Sayan, Bianca
    University of Waterloo , Canada.
    Zapico Lamela, Jorge Luis
    KTH Royal Institute of Technology.
    Brandt, Nils
    MIT Media Lab, USA.
    Csikszentmihàlyi, Chris
    MIT Media Lab , USA.
    Ishii, Hiroshi
    MIT Media Lab, USA.
    Turpeinen, Marko
    MIT Media Lab, USA.
    Young, Steven
    University of Waterloo, Canada.
    The Open Sustainability Project: A Linked Data Approach to LCA2010In: LCA X, Bridging Science, Policy, and the Public 2-4 November 2010, Portland, Oregon, 2010Conference paper (Other academic)
    Abstract [en]

    The proprietary nature of LCA tools and information limits widespread adoption of sustainability measures. We introduce the Open Sustainability Project(OSP), a Linked Data resource for broadening access to LCA in an effort to increase the transparency and accuracy of environmental impact assessments(2, 9).The OSP applies Free and Open Source Software(FOSS) principles and Linked Data structures to LCA standards and reporting so that communities including students, SME’s and the general public can participate in the assessment and verification of sustainability practices(1,6). The highly flexible data format allows disparate data sources and assessments to be compared along an open standard compliant with ISO 14048 reporting(5, 8, 12).In addition, the OSP makes available a free database of Life Cycle Assessment data using an approach based on Linked Data and RESTful interfaces which supports the development of rich third-party applications for specific user groups and industries(7). This novel combination of linked data and web-based tools is inherently transparent so that LCA practices can be standardized, compared and verified by a broad community.The OSP is an international collaboration between academics, government and industry groups leveraging expertise in LCA, Open Data and web-based tools for sustainability(10). Our first Open Source and Open Data web sustainability tools have confirmed the potential to engage a wider audience, with over two thousand registered users, three thousand environmental assessments performed and over 330,000 page views from more than 75 countries since September 2009(3, 4, 11). The OSP aims to expand reach of LCA through a free and open Application Programming Interface(API) to support distributed development of third-party applications for sustainability assessment through the emerging metrics for social and environmental sustainability(a free LCA "App Store"). These applications are intended to disseminate LCA standards, encourage transparency in environmental reporting and leverage Collective Intelligence in the collection, publication and verification of LCA.The OSP aims to transform LCA into a collaborative process where data collection, analysis, assessment and reporting benefit from the feedback and ideas of a growing worldwide LCA community.

  • 366.
    Bondarevs, Andrejs
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Huss, Patrik
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Ye, Qin-Zhong
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Universal Internet of Things Solution: Protocol Independent2017In: 2017 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL TECHNOLOGY (ICIT), IEEE , 2017, p. 1313-1318Conference paper (Refereed)
    Abstract [en]

    The diversity of wireless networks and protocols used by Internet of Things makes solutions non-interoperable. Moreover, some Things are not always able to communicate due to resource constrains or environmental factors. In this paper, those issues are addressed by introducing the concept of virtual Things. It means that each real Thing is virtualized in a local server or in the cloud, enabling communication with the user through a common protocol, i.e., the Internet Protocol. The virtual Thing has its own Internet Protocol address and authentication measure to control the access.

  • 367.
    Boonphoka, Terut
    et al.
    Huazhong Univ Sci and Technol, Peoples R China.
    Pappas, Nikolaos
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Zhong, Yi
    Huazhong Univ Sci and Technol, Peoples R China.
    Ge, Xiaohu
    Huazhong Univ Sci and Technol, Peoples R China.
    Uthansakul, Peerapong
    Suranaree Univ Technol, Thailand.
    Quek, Tony Q. S.
    Singapore Univ Technol and Design, Singapore.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Performance Analysis of Full-Duplex Relay Channel with Random Access2017In: 2017 IEEE GLOBECOM WORKSHOPS (GC WKSHPS), IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    Relay is useful in wireless networks to assist the sources to deliver packets to the destinations. In this paper, the effect of full-duplex relay with random access is evaluated. Based on the model of two sources, two destinations, and one full-duplex relay with two queues, we obtain the analytical expressions for significant parameters, such as the arrival rate and the service rate for queues at the relay. Then, we evaluate the per-user throughput and the per-user average delay as functions of the signal-to-interference-plus-noise ratio (SINR) threshold and the self-interference cancelation coefficient through both analysis and simulation. We also consider the case where the two queues at the relay have different priorities and evaluate the effect of different transmit probabilities on the system performance. Our results reveal that the transmit probabilities and the transmit powers have an enormous impact on the self-interference, the average size and the empty probability of the queues. Specially, the queues tend to be stable when increasing the transmit probabilities and the transmit powers.

  • 368.
    Booth, Todd
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Andersson, Karl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Critical Infrastructure Network DDoS Defense, via Cognitive Learning2017In: / [ed] Pietro Manzoni, Universitat Politècnica de València, Spain, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017Conference paper (Refereed)
    Abstract [en]

    Some public and private services are called part of the Critical Infrastructure (CI), which are considered as the most important services to protect the functioning of a society and the economy.  Many CIs provide services via the Internet and thus cyber-attacks can be performed remotely.  It is now very simple and free to find and download software, which automates performing cyber-attacks.  A recent example is that two teenagers, with close to no security knowledge, created an on-line business. They would run cyber-attacks (online booter service called vDOS, as reported by Brian Krebs) for a small fee. They reportedly earned over 600,000 USD in a short period of time by conducting a large number of automated DDoS cyber-attacks. Then Krebs was retaliated against, and the highest DDoS attack bandwidth ever recorded, 620 Gbps, was launched against Krebs. In this paper we show how cognitive learning can be used to significantly mitigate any effects of DDoS network attacks, against the critical infrastructure.

  • 369.
    Borges Vieira, Alex
    et al.
    Universidade Federal de Juiz de Fora, DCC-UFJF.
    Couto da Silva, Ana Paula
    Universidade Federal de Juiz de Fora, DCC-UFJF.
    Henrique, Francisco
    Universidade Federal de Juiz de Fora, DCC-UFJF.
    Goncalves, Glauber
    Universidade Federal de Minas Gerais, DCC-UFMG.
    de Carvalho Gomes, Pedro
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    SopCast P2P live streaming: live session traces and analysis2013In: Proceedings of the 4th ACM Multimedia Systems Conference: MMSys 2013, Association for Computing Machinery (ACM), 2013, p. 125-130Conference paper (Refereed)
    Abstract [en]

    P2P-TV applications have attracted a lot of attention fromthe research community in the last years. Such systemsgenerate a large amount of data which impacts the networkperformance. As a natural consequence, characterizingthese systems has become a very important task to developbetter multimedia systems. However, crawling data fromP2P live streaming systems is particularly challenging bythe fact that most of these applications have privateprotocols. In this work, we present a set of logs from a verypopular P2P live streaming application, the SopCast. Wedescribe our crawling methodology, and present a briefSopCast characterization. We believe that our logs and thecharacterization can be used as a starting point to thedevelopment of new live streaming systems.

  • 370.
    Borgh, Joakim
    et al.
    Ericsson Res, Stockholm, Sweden.
    Ngai, Edith
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Ohlman, Börje
    Ericsson Res, Stockholm, Sweden.
    Malik, Adeel Mohammad
    Ericsson Res, Stockholm, Sweden.
    Employing attribute-based encryption in systems with resource constrained devices in an information-centric networking context2017In: 2017 Global Internet of Things Summit (GIoTS), IEEE, 2017, p. 397-402Conference paper (Other academic)
    Abstract [en]

    Attribute-Based Encryption (ABE) is considered to be one of the most promising ways to be enforce access control in Information-Centric Networking (ICN). As the Internet of Things (IoT) is being considered as one of the primary use cases for ICN it raises the question of the compatibility between IoT and ABE. An important part of the IoT is the resource constrained devices, for them there is a challenge to perform the computationally expensive operations required for ABE. In this paper we consider ABE in sensor networks and discuss the strengths and weaknesses of a system solution where the ABE operations are performed on the sensors. To properly discuss these concerns we have implemented two ABE schemes, a Single-authority ABE (SA-CP-ABE) scheme and a Multi-authority ABE (MA-CP-ABE) scheme. Results regarding the execution time, RAM usage, data overhead and battery consumption of these implementations on a sensor are presented. We conclude that it is possible, already today, to perform ABE on sensors for smaller policies. The main limitation in deploying ABE in sensors is the RAM size of the sensors.

  • 371.
    Borgström, Kristofer
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Multimedia Messaging Service Components for Web 2.02008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this master’s thesis is to simplify the exchange (in both directions) of multimedia content between mobile phones and network attached web servers. The solution proposed in this report specifically concerns displaying Multimedia Messaging Service (MMS) messages via a web browser connected to a network-attached web server and graphically authoring MMS messages via a web interface.

    This thesis project is important because it brings multimedia content, in the form of MMS messages, from isolation in the telecommunication world closer to wide availability via the Internet. This transition is very important as the Internet is where media is shared with the world today. This approach brings added value to end users who want to share content generated using their phone on a web site. It also provides added value to operators who want to increase the amount of MMS traffic in their networks.

    The solution is non-trivial because there are a number of complexities at both ends. This is because the MMS messages that are authored at mobile phones differ between both handset models and manufacturers. Moreover, the format used for MMS (MMS SMIL) is not widely used on the Internet, thus a transformation to an Internet browser supported format must be performed. The thesis examines to what extent this transformation can be completely automatic and how MMS messages can be authored through a web interface.

    The results show that MMS messages can be successfully transformed to HTML and embedded directly in web pages, thus providing a seamless experience for viewing MMS messages. Depending on the content of the MMS message in question, the current browser and which media player plug-ins are available, the generated HTML will be displayed differently. The results also show that MMS messages can be composed in real time* through a web interface with good results.

  • 372.
    Borgviken, Jonathan
    et al.
    Halmstad University, School of Information Technology.
    Johansson, Carl
    Halmstad University, School of Information Technology.
    Industrial Wireless IPv6 Sensor device2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 373.
    Borison, Torbjorn
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Object Synchronization and Security for Mobile Communications Devices2001Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main objective of this master’s thesis project was to investigate and find solutions to the problem of how to combine the SyncML synchronisation specification with object security and thus protection of personal information, such as contacts and calendar entries in mobile devices.

    SyncML is a new synchronisation specification agreed upon by major device developers (Ericsson, Palm, Motorola, etc.) and the major synchronisation server developers (Starfish, Puma, fusionOne, etc.). It is independent of transport (HTTP, WSP, or OBEX) platform, operating system, and application and simplifies synchronisation of personal information between dissimilar SyncML supportive devices.

    SyncML compliant devices are fully capable of synchronising information with a third party operated Internet based server and a desktop computer. This allows us to access, up-date and maintain information independent of Intranets or geographical position. However, synchronising and storing confidential personal information on an third party operated Internet based server entails weaknesses in our personal information security. Even if transport and storage security are used, how secure is the server where this information is stored since this server has the highest probability of being attacked. Can we really trust that an employee or other person with valid appropriated administrators access to the storage facility with the appropriate knowledge, working together with the third party server operator, won’t try to access our stored information? To prevent this, the personal information’s confidentiality must be guaranteed before the information leaves the device.

    When synchronising and exchanging personal information, the information is often marked according to a specific format. The three de-facto standard PIM formats are: (1) vCard (contact information), (2) vCalendar, and (3) iCalendar (calendar and scheduling information). These formats divide the personal information into properties. Each property is assigned to contain a small piece of the personal information entry (e.g. a telephone number, an e-mail address, the time when the calendar event begins, etc.).

    Furthermore to preserve the interoperability between different devices given by SyncML, authorised recipients must automatically be able to reverse the encryption process and decrypt the encrypted property value. Therefore general cryptographic formats are used (e.g. CMS, PGP and the newly developed XML Encryption). They add information needed by the recipients (e.g. algorithm used, padding method used on the plain text, etc.), encrypt the plaintext into cipher text, and decrypt the cipher text into plain text given the correct key.

  • 374.
    Boström, Tomas
    et al.
    KTH, Superseded Departments, Teleinformatics.
    Lindroos, Olle
    KTH, Superseded Departments, Teleinformatics.
    Hellström, Lennart
    KTH, Superseded Departments, Teleinformatics.
    Simple Mobile IP1999Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis describes an implementation and evaluation of an IP mobility management protocol, Simple Mobile IP. The protocol enables dynamic address allocation and configuration of mobile terminals through utilisation of DHCP.

    Simple Mobile IP provides IP mobility within one administrative domain, in contrast to the global mobility in conventional Mobile IP. Both protocols use IP tunnelling but in Simple Mobile IP the tunnel runs along the optimised route, thus avoiding triangular routing.

    The protocol was implemented on the Linux platform and evaluated in a wireless LAN environment. The solution detects subnet transitions at the link layer, resulting in loss of IP connectivity for approximately 100 ms when mobile terminals move between subnets. The overhead, introduced by IP tunnelling, reduces the throughput by 3.8% in a wireless LAN environment.

  • 375.
    Bozakov, Zdravko
    et al.
    Dell EMC, Ireland.
    Mangiante, Simone
    Dell EMC, Ireland.
    Hernandez Benet, Cristian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT.
    Santos, Ricardo
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Buckley, Donagh
    Dell EMC, Ireland.
    A NEAT framework for enhanced end-host integration in SDN environments2017In: 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN), IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    SDN aims to facilitate the management of increasingly complex, dynamic network environments and optimize the use of the resources available therein with minimal operator intervention. To this end, SDN controllers maintain a global view of the network topology and its state. However, the extraction of information about network flows and other network metrics remains a non-trivial challenge. Network applications exhibit a wide range of properties, posing diverse, often conflicting, demands towards the network. As these requirements are typically not known, controllers must rely on error-prone heuristics to extract them. In this work, we develop a framework which allows applications deployed in an SDN environment to explicitly express their requirements to the network. Conversely, it allows network controllers to deploy policies on end-hosts and to supply applications with information about network paths, salient servers and other relevant metrics. The proposed approach opens the door for fine grained, application-aware resource optimization strategies in SDNs

  • 376.
    Bratel, Daniel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    Bernestrå, Christopher
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    Internet of Things i Hyresfastigheter: Förutsättningar för implementering av ny teknik2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this report is to review the current conditions exsisting for the implementation of Internet of Things in apartment buildings and how insight can be accomplished for these conditions in real estate companies. Internet of Things is a technology which has increased in popularity in later years and builds on objects connecting to each other or the internet. In conjunction with the reduction of implementation costs for the technology and the increase of possible applications, an interest has grown in many different business sectors. This study concerns the real estate company FinaHem, where the conditions for measurement of different values using connected sensors is analyzed. To answer the formulated questions regarding technological efficiency, financial factors and how a potential solution using Internet of Things would be recieved by tenants, this paper is designed as a case study. The case study evaluates the operations of FinaHem and utilizes both qualitative and quantitative methods, as well as a business case method. The result and the analysis from the study indicates important factors for the company’s conditions to implement Internet of Things. Technological solutions regarding energy savings, detections of water damage, and visualisation has exhibited business value. Furthermore, the importance of evaluating opinions from residents, and creating a positive experience for them, is established.

  • 377.
    Bratu, Vlad-Ioan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Antenna Tilt Load Balancing in Self-Organizing Networks2013In: International Journal of Research in Wireless Systems, ISSN 2320-3617, Vol. 2, no 1, p. 21-26Article in journal (Other academic)
    Abstract [en]

    Base station antenna tilt is a powerful tuning parameter in traditional cellular network optimization. With theintroduction of Self-Organizing Networks (SON), this parameter may now be used also in the context of self-optimization.One envisioned scenario is load balancing (LB), where the coverage shaping properties of the antenna radiation pattern canbe used to control the cell borders. In this paper, a generalized framework for antenna tilt LB is presented and discussed. Inorder to assess the performance of antenna tilt as a tool for load balancing, simulations are performed to determine theeffect of tilt angle, vertical beamwidth and handover offset. The results show that there is a direct relation between theseparameters and the number of users that can be shifted towards neighboring cells. In conclusion, it is found that usingantennas with narrow vertical beamwidths together with small hand over offsets is an efficient way of performing loadbalancing but results also in high SIR variations.

  • 378.
    Bratu, Vlad-Ioan
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Base station antenna tilt for load balancing2013In: 2013 7th European Conference on Antennas and Propagation (EUCAP), New York: IEEE , 2013, p. 2039-2043Conference paper (Refereed)
    Abstract [en]

    The coverage shaping and interference reduction ability of base station antenna tilt are important tools in cellular network optimization. Through tilt changes, the coverage area of a serving cell may also be either reduced or expanded. Therefore, antenna tilt has the potential to be used for load balancing purposes. This paper gives an overview of base station antennas performance and antenna tilt. Simulations are performed in order to determine the impact of tilt changes when used for load balancing. The results show that while antenna tilt load balancing can improve the Grade of Service (GoS) in a congested cell, it will also influence the user bit rates and total cell throughput for both the congested cell and the neighbors.

  • 379.
    Bratu, Vlad-Ioan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Base Station Antenna Tilt for Load Balancing and Potential use in Self-Optimizating Networks2013Conference paper (Other academic)
    Abstract [en]

    The coverage shaping and interference reduction ability of base station antenna tilt are important tools in cellular network optimization. Through tilt changes, the coverage area of a serving cell may also be either reduced or expanded. Therefore, antenna tilt has the potential to be used for load balancing purposes. With the introduction of Self-Organizing Networks (SON) in the mobile communications, this parameter may now be used also in the context of self-optimization, to address the common situation where traffic has an uneven spatial distribution between serving cells. This work gives an overview of base station antennas and antenna tilt. Simulations are performed in order to determine the impact of tilt changes when used for load balancing. The effect of tilt angle, vertical beam width and handover offset are analyzed also. The results show that there is a direct relation between these parameters and the number of users that can be shifted towards neighboring cells. In conclusion, it is found that using antennas with narrow vertical beam widths together with small hand over offsets is an efficient way of performing load balancing but results also in high SIR. Although antenna tilt load balancing can improve the Grade of Service (GoS) in a congested cell, it will also influence the user bit rates and total cell throughput for both the congested cell and the neighbors.

  • 380.
    Brejcha, Mikael
    KTH, Superseded Departments, Teleinformatics. KTH, School of Information and Communication Technology (ICT).
    Talaria: A Distributed Architecture for Supporting Monitoring and Collaborative Information Retrieval1999Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

     As the amount of information available via the Internet continues to explode, new means of finding and keeping oneself updated on sources of information must be found. This report presents a system that monitors sources of information on behalf of a user and also introduces new sources of information that potentially could be of interest to the user. As monitored information updates it can be directed to a variety of different displaying devices, ranging from simple pagers to advanced desktop computers. Ideas behind the design of the architecture are explained. The report explains why the system will scale as the number of users increases. The report describes measures taken to ensure user privacy.

  • 381.
    Bremstedt Pedersen, Ivan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Andersson, Alfred
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    More than downloading: Visualization of data produced by sensors in a home environment2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A home automation system usually contains a set of tools that users use to control devices in their homes, often remotely. These devices often include but are not limited to light switches, thermostats, thermometers, window blinds, and climate controls. The potential for these kinds of systems is huge because of the sheer number of devices that could be controlled and managed with minimal and inexpensive extra hardware. Many of the appliances in a normal home could benefit from being connected to a system that allows the owner to manage and control the devices in their home. Thus the number of potential devices is orders of magnitude larger than the number of homes connected to the system. There are several systems on the market that provide systems to monitor and control a home environment, however these systems only support specific in system devices. This uncovers a problem where a homeowner only has the opportunity to use specific products that fit into these systems. By introducing an open platform for the public that are not bound to any system we can allow more devices to be integrated in the home and contribute to further development of smarter homes.

    The goal with this project was to provide a scalable open platform with the possibility of asynchronous updating. This has been done by implementing multiple logical parts to both provide a web interface for the user and to allow us to handle communication and storage of data. All these parts are linked together to form a system of servers that handles all background operations. This thesis discusses and presents implementations of all of these servers, how they are implemented, communicate with each other, provide secure connections and how they can scale with increasing usage. In this process we also discuss and present techniques that were used, how to use them and their benefits, to help us reach our goal.

  • 382.
    Brenning, Magnus
    et al.
    KTH, School of Technology and Health (STH).
    Olander, Björn
    KTH, School of Technology and Health (STH).
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Medical Engineering.
    Vennberg, Johan
    KTH, School of Technology and Health (STH).
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering. 2Laboratory for communication networks, School of Electrical Engineering, KTH.
    NeTraWeb - A Web-Based Traffic Flow Performance Meter2006In: 4th Swedish National Computer Networking Workshop SNCNW 2006, 2006Conference paper (Refereed)
    Abstract [en]

    This paper presents a web-based traffic flow performance meter. The NeTraWeb tool configures and automates the measurement activities, including storage and presentation of the main performance parameters.

  • 383.
    Brewka, Lukasz
    et al.
    DTU.
    Sköldström, Pontus
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Telecommunication Systems Laboratory, TSLab (closed 2012-01-01).
    Gavler, Anders
    Acreo AB.
    Nordell, Viktor
    Acreo AB.
    Wessing, Henrik
    DTU.
    Dittmann, Lars
    DTU.
    ALPHA Proposal of mapping QoS parameters between UPnP home network and GMPLS access2011In: ACCESS NETWORKS, 2011, p. 226-239Conference paper (Refereed)
    Abstract [en]

     This paper is treating the interdomain QoS signaling between the home and access domains with a focus on applying it for providing QoS between a UPnP-QoS based home network and GMPLS based access network. The work presented here is defining a possible approach for an interface between UPnP-QoS and GMPLS in order to move towards end-to-end QoS establishment as well as investigating the complexity of such a solution. We present the QoS parameters and mechanisms in both UPnP-QoS and GMPLS and how they can be matched to create a coherent QoS architecture.

  • 384.
    Brewka, Lukasz
    et al.
    DTU.
    Sköldström, Pontus
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Telecommunication Systems Laboratory, TSLab (closed 2012-01-01).
    Gavler, Anders
    Acreo AB.
    Nordell, Viktor
    Acreo AB.
    Wessing, Henrik
    DTU.
    Dittmann, Lars
    DTU.
    QoS enabled resource allocation over an UPnP-QoS/€”GMPLS controlled edge2011In: 2011 IEEE Consumer Communications and Networking Conference, CCNC'2011, 2011, p. 218-222Conference paper (Refereed)
    Abstract [en]

    This paper focuses on the problem of coherent resource allocation within home and access networks. The interdomain QoS signaling discussed here enables the initiation of the QoS provisioning in the home and access from the end device in users home. The home network considered in this paper is UPnP-QoS enabled while the access network is GMPLS based. We propose and implement an interface between aforementioned network segments allowing for end-to-end QoS establishment. We present the QoS parameters and mechanisms in both UPnP-QoS and GMPLS and how they can be matched to create a coherent QoS architecture. Additionally we investigate the complexity of such a solution and present implementation results.

  • 385.
    Briat, Corentin
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Jönsson, Ulf
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Karlsson, Gunnar
    KTH, School of Electrical Engineering (EES), Communication Networks. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Sandberg, Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nonlinear state-dependent delay modeling and stability analysis of internet congestion control2010In: 49TH IEEE CONFERENCE ON DECISION AND CONTROL (CDC), 2010, p. 1484-1491Conference paper (Refereed)
    Abstract [en]

    It is shown that the queuing delay involved in the congestion control algorithm is state-dependent and does not depend on the current time. Then, using an accurate formulation for buffers, networks with arbitrary topologies can be built. At equilibrium, our model reduces to the widely used setup by Paganini et al. Using this model, the delay-derivative is analyzed and it is proved that the delay time-derivative does not exceed one for the considered topologies. It is then shown that the considered congestion control algorithm globally stabilizes a delay-free single buffer network. Finally, using a specific linearization result for systems with state-dependent delays from Cooke and Huang, we show the local stability of the single bottleneck network.

  • 386.
    Briat, Corentin
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Jönsson, Ulf T.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Karlsson, Gunnar
    KTH, School of Electrical Engineering (EES), Communication Networks. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Sandberg, Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Yavuz, Emre Altug
    KTH, School of Electrical Engineering (EES), Communication Networks.
    An axiomatic fluid-flow model for congestion control analysis2011In: 2011 50th IEEE Conference on Decision and Control andEuropean Control Conference (CDC-ECC), 2011, p. 3122-3129Conference paper (Refereed)
    Abstract [en]

    An axiomatic model for congestion control isderived. The proposed four axioms serve as a basis for theconstruction of models for the network elements. It is shownthat, under some assumptions, some models of the literature canbe recovered. A single-buffer/multiple-users topology is finallyderived and studied for illustration.

  • 387.
    Briat, Corentin
    et al.
    KTH, School of Electrical Engineering (EES), Communication Networks. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Yavuz, Emre A.
    KTH, School of Electrical Engineering (EES), Communication Networks. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Karlsson, Gunnar
    KTH, School of Electrical Engineering (EES), Communication Networks. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    A conservation-law-based modular fluid-flow model for network congestion modeling2012In: 2012 Proceedings - IEEE INFOCOM, IEEE Computer Society, 2012, p. 2050-2058Conference paper (Refereed)
    Abstract [en]

    A modular fluid-flow model for network congestion analysis and control is proposed. The model is derived from an information conservation law stating that the information is either in transit, lost or received. Mathematical models of network elements such as queues, users, and transmission channels, and network description variables, including sending/ acknowledgement rates and delays, are inferred from this law and obtained by applying this principle locally. The modularity of the devised model makes it sufficiently generic to describe any network topology, and appealing for building simulators. Previous models in the literature are often not capable of capturing the transient behavior of the network precisely, making the resulting analysis inaccurate in practice. Those models can be recovered from exact reduction or approximation of this new model. An important aspect of this particular modeling approach is the introduction of new tight building blocks that implement mechanisms ignored by the existing ones, notably at the queue and user levels. Comparisons with packet-level simulations corroborate the proposed model.

  • 388.
    Broman, Fredrik
    et al.
    KTH, Superseded Departments, Teleinformatics.
    Tarberg, Fredrik
    KTH, Superseded Departments, Teleinformatics.
    Implementation andAnalyses of theMobile-IP Protocol1996Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report is the result of a masters degree project conducted at the Department of Teleinformatics at the Royal Institute of Technology during the autumn 1995. The area investigated is the Mobile Internet Protocol, especially its implementation and efficiency.

    The thesis work is divided into three areas. The first area includes the development and implementation of a Management Information Base for the Mobile-IP protocol. The second area deals with the porting of a Mobile-IP implementation for SunOS to MachOS and Solaris. The last area covers the tests done to measure the throughput and latency of the protocol.

  • 389.
    Broms, Daniel
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Access restrictions in surrogates using Portable Channel Representation2002Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This Master thesis investigates how content with access restrictions can be handled in a Content Distribution Network (CDN). The thesis focuses on CDNs where the distribution is made using Portable Channel Representation (PCR), a description of content that enables installation on any platform. There has been a demand from customers for access restriction support when distributing web sites. Ranging from personal homepages wanting to restrict access using some simple password authentication protocol to corporate websites wanting HTTPS support.

    This thesis starts with a survey of available authentication mechanisms as well as available publication protocols with support for protection. This provided the basis for the design of the new protection element for PCR spanning most protection requirements. The PCR model is realized using XML in the Lokomo Software Suite. The new design has been implemented in the context of the Lokomo Software Suite. The protection has been shown to correctly install basic authentication on both Apache’s HTTP Server and Microsoft’s Internet Information Server.

  • 390. Brotherton, M.D
    et al.
    Huynh-Thu, Q
    Hands, D
    Brunnström, Kjell
    Subjective Multimedia Quality Assessment.2006In: IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, ISSN 0916-8508, E-ISSN 1745-1337, Vol. E89-A, no 11, p. 2920-2932Article in journal (Refereed)
  • 391. Brown, J.
    et al.
    Roedig, U.
    O'Donovan, T.
    Sreenan, C. J.
    He, Z.
    Voigt, Thiemo
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Pottner, B.
    Wolf, L.
    Klein, A.
    Silva, J. Sa
    Vassiliou, V.
    doO, J.
    GINSENG: Performance Control in Wireless Sensor Networks2011In: 8th European Conference on Wireless Sensor Networks (EWSN’11), 2011Conference paper (Refereed)
  • 392. Brown, James
    et al.
    McCarthy, Ben
    Roedig, Utz
    Voigt, Thiemo
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Sreenan, Cormac J.
    BurstProbe: Debugging Time-Critical Data Delivery in Wireless Sensor Networks2011In: 8th European Conference on Wireless Sensor Networks (EWSN’11), 2011Conference paper (Refereed)
  • 393.
    Brundin, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    LESpy - PCM Link Analyzer2002Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report will discuss the design of a test tool, a PCM link analyzer, LESpy. The development of LESpy is based upon reuse of C++ source code from previous test equipment from INEO, LESim. The purpose of LESpy is a tool for analyzing two telephony interfaces in Ericsson’s ”Radio in the Local Loop” system RAS 1000. Monitoring the Channel Associated Signaling (CAS) interface was the primary goal. As second goal was to find a solution to analyze the ISDN interface.

    The report presents some background information about telephony, computer telephony, the RAS 1000 system, and the development and target environment (IBM’s operating system OS/2). It also describes building blocks and functionality, i.e. the nodes, components, classes, and use cases of LESpy through UML diagrams.

    The result of the project is a test tool where most of the requirements were fulfilled through inheritance of new classes and new functionality by polymorphism. As required supervision and address signaling could be monitored and saved to a file.

  • 394.
    Brunnström, K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    3D user experience and display performance2013In: Proceedings, 2013Conference paper (Refereed)
  • 395.
    Brunnström, K
    ACREO AB.
    Percieved QoS and Test suites: keynote2008In: ETSI Workshop on Effects of transmission Performance on Multimedia QoS, Prague, 2008Conference paper (Refereed)
  • 396.
    Brunnström, K
    et al.
    Acreo AB, Sweden.
    Hands, D
    BT Innovate, UK.
    Speranza, F
    Communications Research Centre, Canada.
    Webster, A
    NTIA/ITS, United States.
    VQEG Validation and ITU Standardisation of Objective Perceptual Video Quality Metrics2009In: IEEE signal processing magazine (Print), ISSN 1053-5888, E-ISSN 1558-0792, Vol. 26, no 3, p. 96-101Article in journal (Refereed)
    Abstract [en]

    For industry, the need to access accurate and reliable objective video metrics has become more pressing with the advent of new video applications and services such as mobile broadcasting, Internet video, and Internet Protocol television (IPTV). Industry-class objective quality- measurement models have a wide range of uses, including equipment testing (e.g., codec evaluation), transmission- planning and network-dimensioning tasks, head-end quality assurance, in- service network monitoring, and client-based quality measurement. The Video Quality Experts Group (VQEG) is the primary forum for validation testing of objective perceptual quality models. The work of VQEG has resulted in International Telecommunication Union (ITU) standardization of objective quality models designed for standard- definition television and for multimedia applications. This article reviews VQEG's work, paying particular attention to the group's approach to validation testing.

  • 397.
    Brunnström, K
    et al.
    Acreo, Stockholm, Sweden.
    Nordström, L
    Andrén, B
    Visual experience of quality degradation when viewing computer and notebooks displays from an oblique angle2011In: Journal of the Society for Information Display, ISSN 1071-0922, E-ISSN 1938-3657, Vol. 19, no 5, p. 387-397Article in journal (Refereed)
    Abstract [en]

    This study focused on evaluating the user experience of the viewing-angle-dependent quality of computer and notebook displays. The tests were performed in a test lab using a notebook with a prismatic display and a computer monitor with a conventional LCD. The notebook display was tilted and turned during an image-quality test and tilted during an acuity test. On the computer monitor, the turn and tilt was simulated in the image-quality test, for checking the TCO requirements. The results from the image-quality test show that the parameter used in the TCO requirement, luminance ratio, would be a reasonable predictor of image quality. However, the experiment with the notebook display shows that, in general, this is not the case, especially for larger viewing angles where the physical characteristics do not show a gradual variation in luminance. Therefore, the luminance ratio in TCO requirements shall be used with caution. In addition, the results for the notebook display show that the visual acu ity decreased faster with increasing viewing angle than predicted from the luminance decrease alone. This means that it will be harder to resolve small details and will, therefore, have a negative influence on the visual ergonomics.

  • 398.
    Brunnström, K
    et al.
    Acreo AB, Stockholm, Sweden.
    Schenkman, B
    Jacobsen, B
    Object Detection in Cluttered Infrared Images.2003In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 42, no 2, p. 388-399Article in journal (Refereed)
    Abstract [en]

    Implementation of the Johnson criteria for infrared images is the probabilities of a discrimination technique. The inputs to the model are the size of the target, the range to it, and the temperature difference against the background. The temperature difference is calculated without taking the background structure into consideration, but it may have a strong influence on the visibility of the target. We investigated whether a perceptually based temperature difference should be used as input. Four different models are discussed: 1. a probability of discrimination model largely based on the Johnson criteria for infrared images, 2. a peak signal-to-noise ratio model, 3. a signal-to-clutter ratio model, and 4. two versions of an image discrimination model based on how human vision analyzes spatial information. The models differ as to how much they try to simulate human perception. To test the models, a psychophysical experiment was carried out with ten test persons, measuring contrast threshold detection in five different infrared backgrounds using a method based on a two-alternative forced-choice methodology. Predictions of thresholds in contrast energy were calculated for the different models and compared to the empirical values. Thresholds depend on the background, and these can be predicted well by the image discrimination models, and better than the other models. Future extensions are discussed.

  • 399.
    Brunnström, K
    et al.
    Acreo AB, Stockholm, Sweden.
    Schenkman, B.N
    Acreo AB, Stockholm, Sweden.
    Comparison of the predictions of a spatio-temporal model with the detection of distortion in small moving images2002In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 41, no 3, p. 711-722Article in journal (Refereed)
  • 400.
    Brunnström, K
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems. Acreo Swedish ICT AB.
    Wang, K
    Acreo Swedish ICT AB.
    Andrén, B
    Acreo Swedish ICT AB.
    Simulator sickness analysis of 3D video viewing on passive 3DTV2013In: Stereoscopic Displays and Applications XXIV / [ed] Woods, A. J., Holliman, N. S., and Favalora, G. E., Bellingham, WA, USA: SPIE - International Society for Optical Engineering, 2013, p. 864802-Conference paper (Refereed)
567891011 351 - 400 of 3433
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