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  • 3101.
    Viggiani, Fabio
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Design and implementation of a non-aggressive automated penetration testing tool: An approach to automated penetration testing focusing on stability and integrity for usage in production environments2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The focus of this Master’s thesis project is automated penetration testing. A penetration test is a practice used by security professionals to assess the security of a system. This process consists of attacking the system in order to reveal flaws.  Automating the process of penetration testing brings some advantages, the main advantage being reduced costs in terms of time and human resources needed to perform the test. Although there exist a number of automated tools to perform the required procedures, many security professionals prefer manual testing. The main reason for this choice is that standard automated tools make use of techniques that might compromise the stability and integrity of the system under test. This is usually not acceptable since the majority of penetration tests are performed in an operating environment with high availability requirements.

    The goal of this thesis is to introduce a different approach to penetration testing automation that aims to achieve useful test results without the use of techniques that could damage the system under test. By investigating the procedures, challenges, and considerations that are part of the daily work of a professional penetration tester, a tool was designed and implemented to automate this new process of non-aggressive testing.

    The outcome of this thesis project reveals that this tool is able to provide the same results as standard automated penetration testing procedures. However, in order for the tool to completely avoid using unsafe techniques, (limited) initial access to the system under test is needed.

  • 3102. Vijayakumar, P.
    et al.
    Anand, Kannan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Bose, S.
    Maheswari, V.
    Kowsalya, R.
    Kannan, A.
    Hierarchical key management scheme for securing mobile agents with optimal computation time2012Inngår i: International Conference on Modelling Optimization and Computing, Elsevier, 2012, Vol. 38, s. 1432-1443Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Mobile agents are well suited for accessing contents of distributed web based applications including internet business. Such kinds of access must be secure enough enabling only authorized mobile agents to retrieve the contents from the distributed servers. This kind of security is provided by several algorithms including RSA based digital signature and elliptic curve digital signature cryptography. The main differences among the algorithms of the past literatures lie in the computational time of encryption and decryption of the keys used for encrypting and decrypting the content. In this paper we propose a modified hierarchical date constrained key management scheme which potentially reduces the overall computation time needed for key derivation and key signature check operations. Different algorithms are compared with our proposed mechanism and the experimental results show that the proposed method reduces the overall key derivation and key signature check computational time.

  • 3103.
    Vikrant, Nikam
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Design and Performance Evaluation of Resource Allocation Mechanisms in Optical Data Center Networks2016Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A datacenter hosts hundreds of thousands of servers and a huge amount of bandwidth is required to accommodate communication between thousands of servers. Several packet switched based datacenter architectures are proposed to cater the high bandwidth requirement using multilayer network topologies, however at the cost of increased network complexity and high power consumption. In recent years, the focus has shifted from packet switching to optical circuit switching to build the data center networks as it can support on demand connectivity and high bit rates with low power consumption.

    On the other hand, with the advent of Software Defined Networking (SDN) and Network Function Virtualization (NFV), the role of datacenters has become more crucial. It has increased the need of dynamicity and flexibility within a datacenter adding more complexity to datacenter networking. With NFV, service chaining can be achieved in a datacenter where virtualized network functions (VNFs) running on commodity servers in a datacenter are instantiated/terminated dynamically. A datacenter also needs to cater large capacity requirement as service chaining involves steering of large aggregated flows. Use of optical circuit switching in data center networks is quite promising to meet such dynamic and high capacity traffic requirements.

    In this thesis work, a novel and modular optical data center network (DCN) architecture that uses multi-directional wavelength switches (MD-WSS) is introduced. VNF service chaining use case is considered for evaluation of this DCN and the end-to-end service chaining problem is formulated as three inter-connected sub-problems: multiplexing of VNF service chains, VNFs placement in the datacenter and routing and wavelength assignment. This thesis presents integer linear programming (ILP) formulation and heuristics for solving these problems, and numerically evaluate them.

  • 3104.
    Villa, Tania
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Merz, R.
    Vidales, P.
    Performance evaluation of OFDMA femtocells link-layers in uncontrolled deployments2010Inngår i: 2010 European Wireless Conference, EW 2010, 2010, s. 825-832Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The rapidly increasing use of smart phones with Internet access or data connectivity solutions for laptops is putting the infrastructure of cellular operators under stress. Both the number of devices and the bandwidth requirement are increasing. Indoor usage is also becoming prominent. One envisioned solution is the use of so-called femtocells. Femtocells are portable and low-cost base-stations for in-home usage. They are deployed by end-users and are connected to the operator network by a digital subscriber line (DSL), cable modem or optical fiber connection. The femtocells are operated along with the macrocell in a typical two-tier network structure. The regular base stations operate in one tier and the femtocells operate in the other tier. In a shared spectrum configuration, the uncontrolled deployment and loose control of the femtocells generate challenging interference management scenarios. With extensive simulations, we perform an evaluation of several femtocell to femtocell interference scenarios and one macrocell to femtocell scenario. We focus on typical 4G cases, with an orthogonal frequency-division multiple access (OFDMA) physical layer and full frequency reuse. Our results show that without any interference management, system performance is significantly degraded and that complete outages occur in specific cases.

  • 3105.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology, Finland.
    3GPP LTE Versus IEEE 802.11p/WAVE: Which Technology is Able to Support Cooperative Vehicular Safety Applications?2012Inngår i: IEEE Wireless Communications Letters, ISSN 2162-2337, Vol. 1, nr 2, s. 125-128Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The concept of vehicular ad-hoc networks enables the design of emergent automotive safety applications, which are based on the awareness among vehicles. Recently, a suite of 802.11p/WAVE protocols aimed at supporting car-to-car communications was approved by IEEE. Existing cellular infrastructure and, above all 3GPP LTE, is being considered as another communication technology appropriate for vehicular applications. This letter provides a theoretical framework which compares the basic patterns of both the technologies in the context of safety-of-life vehicular scenarios. We present mathematical models for the evaluation of the considered protocols in terms of successful beacon delivery probability.

  • 3106.
    Vinel, Alexey
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint-Petersburg, Russia.
    Performance Aspects of Vehicular Ad-hoc Networks: Current Research and Possible Trends2009Inngår i: Leistungs-, Zuverlässigkeits- und Verlässlichkeitsbewertung von Kommunikationsnetzen und verteilten Systemen: 5. GI/ITG-Workshop MMBnet 2009, 10./11. September 2009 / [ed] Bernd E. Wolfinger & Klaus-D. Heidtmann, Hamburg: Universität Hamburg , 2009, s. 14-23Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Performance analysis of vehicular ad-hoc networks (VANETs) currently attracts a lot of attention among governments, automobile and automatics manufactures, academia research community, etc. This paper provides a brief overview of VANET-related studies with a strong emphasis to the active-safety provisioning by means of vehicle-to-vehicle communications. In contrast to the already existing large number of simulation studies, only few analytical results for the performance analysis of vehicle-to-vehicle information exchange protocols are published up to now. Some of our recent research results filling this gap are presented.

  • 3107.
    Vinel, Alexey
    et al.
    Department of Communication Engineering, Tampere University of Technology, Tampere, Finland.
    Bellalta, Boris
    Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain.
    Chilamkurti, Naveen
    Department of Computer Science and Engineering, La Trobe University, Melbourne, Australia.
    Koucheryavy, Yevgeni
    Department of Communication Engineering, Tampere University of Technology, Tampere, Finland.
    Scalability analysis of infrastructure networks for vehicular safety applications2012Inngår i: Proceedings - 2012 International Conference on Connected Vehicles and Expo, ICCVE 2012 / [ed] Juan E. Guerrero, New York: IEEE Communications Society, 2012, s. 124-127Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Vehicular adhoc networks are able to provide the awareness among cars, which is exploited by the emergent automotive safety applications, such as lane change warning and electronic brakes. Beaconing, i.e. periodic broadcasting of status messages by each vehicle, is a core communication pattern which all the critical vehicular safety applications rely on. A set of IEEE 802.11p/WAVE (Wireless Access in Vehicular Environments) protocols is specially designed to support vehicleto-vehicle communication. Notwithstanding, many studies raise the scalability problem of 802.11p carrier sense multiple access, which makes it impossible for the protocol to guarantee the required performance in dense road traffic scenarios. Thus, existing cellular broadband wireless access (BWA) infrastructure, e.g. 3GPP Long Term Evolution (LTE), IEEE 802.16e (Mobile WiMAX), can be considered as an additional opportunity to support vehicular cooperative safety applications. In this paper we introduce a simple stochastic model for the evaluation of the BWA network used for the beaconing. This model can serve as an easy tool to understand the theoretical limits of different BWA technologies in intelligent transportation systems use cases. © 2012 IEEE.

  • 3108.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation of the Russian Academy of Sciences (SPIIRAS), St. Petersburg, Russia.
    Bellalta, BorisUniversitat Pompeu Fabra, Barcelona, Spain.Sacchi, ClaudioUniversity of Trento, Povo (Trento), Italy.Lyakhov, AndreyInstitute for Information Transmission Problems, Moscow, Russia.Telek, MiklósBudapest University of Technology and Economics, Budapest, Hungary.Oliver, MiquelUniversitat Pompeu Fabra, Barcelona, Spain.
    Multiple Access Communications: Third International Workshop, MACOM 2010, Barcelona, Spain, September 13-14, 2010. Proceedings2010Konferanseproceedings (Fagfellevurdert)
    Abstract [en]

    The proceedings contain 27 papers. The topics discussed include: physical model based interference classification and analysis; a test-based scheduling protocol (TBSP) for periodic data gathering in wireless sensor networks; adaptive minimum conditional bit-error-rate linear multiuser detection for STBC-MC-CDMA systems transmitting over mobile radio channels; on the performance of single LDGM codes for iterative data fusion over the multiple access channel; preliminary results on the adoption of de Bruijn binary sequences in DC-DMA systems; analysis of different channel sharing strategies in cognitive radio networks; queueing system with alternating service rates for free space optics-radio hybrid channel; an efficient method for proportional differentiated admission control implementation; cross-layer channel-aware approaches for modern wireless networks; and using agent-oriented simulation system AGNES for evaluation of sensor networks. © Springer-Verlag Berlin Heidelberg 2010

  • 3109.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Belyaev, Evgeny
    Tampere University of Technology, Finland.
    Bellalta, Boris
    Universitat Pompeu Fabra, Spain.
    Hu, Honglin
    Shanghai Research Center for Wireless Communications, China.
    Live Video Streaming in Vehicular Networks2014Inngår i: Communication Technologies for Vehicles, Nets4Cars/Nets4Trains/Nets4Aircraft 2014 / [ed] A. Sikora, M. Berbineau, A. Vinel, M. Jonsson, A. Pirovano, M. Aguado, Heidelberg, Germany: Springer Berlin/Heidelberg, 2014, s. 156-162Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The coming years will see the adoption of IEEE 802.11p equipment, which enables broadband vehicle-to-vehicle and vehicle-to-roadside connectivity. The design and validation of prospective safety and infotainment applications in VANETs (Vehicular Ad-hoc NETworks) are currently areas of dynamic research. In this paper we introduce novel vehicular applications that are based on video transmission and targeted at improving road safety, efficiency and public security. We argue the case for the practical feasibility of the proposed applications in terms of the number of vehicles that can be supported with acceptable visual quality in VANETs environment. © 2014 Springer International Publishing.

  • 3110.
    Vinel, Alexey
    et al.
    Tampere University of Technology, Department of Communications Engineering.
    Belyaev, Evgeny
    Tampere University of Technology, Department of Signal Processing.
    Egiazarian, Karen
    Tampere University of Technology, Department of Signal Processing.
    Koucheryavy, Yevgeni
    Tampere University of Technology, Department of Communications Engineering.
    An Overtaking Assistance System Based on Joint Beaconing and Real-Time Video Transmission2012Inngår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 61, nr 5, s. 2319-2329Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Overtaking on rural roads often becomes dangerous when oncoming traffic is detected by the driver too late or its speed is underestimated. Recently proposed cooperative overtaking assistance systems, which are based on Vehicular Ad hoc NETworks (VANETs), rely on either real-time video transmission or the exchange of status messages (beacons). In the first case, a video stream captured by a camera installed at the windshield of a vehicle is compressed and broadcast to any vehicles driving behind it, where it is displayed to the driver. In the second case, beacons that include position, speed, and direction are frequently broadcast by all the vehicles to ensure detection of oncoming traffic as early as possible and to issue a warning to the driver whenever needed. In this paper, we demonstrate that the performance of a video-based overtaking assistant can be significantly improved if codec channel adaptation is undertaken by exploiting information from the beacons about any forthcoming increase in the load of the multiple access channel used. The theoretical framework presented describes the basic patterns of such a coupled overtaking assistant and can serve as a useful guideline for the future practical implementation of the system. The benefits of our approach are demonstrated in relation to the practical scenario of H.264/AVC video coding and IEEE 802.11p/Wireless Access in Vehicular Environments (WAVE) intervehicle communication standards. © 2012 IEEE.

  • 3111.
    Vinel, Alexey
    et al.
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Belyaev, Evgeny
    Tampere University of Technology, Tampere, Finland.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Using of beaconing for robust video transmission in overtaking assistance applications2012Inngår i: 2012 IEEE Vehicular Technology Conference (VTC Fall): Proceedings, Piscataway, N.J.: IEEE Press, 2012, s. 1-4Konferansepaper (Fagfellevurdert)
  • 3112.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES). Tampere University of Technology, Tampere, Finland.
    Belyaev, Evgeny
    Tampere University of Technology, Tampere, Finland.
    Lamotte, Olivier
    Hochschule für Technik Rapperswil, Rapperswil, Switzerland.
    Gabbouj, Moncef
    Tampere University of Technology, Tampere, Finland.
    Koucheryavy, Yevgeni
    Tampere University of Technology, Tampere, Finland.
    Egiazarian, Karen
    Tampere University of Technology, Tampere, Finland.
    Video transmission over IEEE 802.11p: Real-world measurements2013Inngår i: 2013 IEEE International Conference on Communications Workshops (ICC), Piscataway, NJ: IEEE Press, 2013, s. 505-509, artikkel-id 6649286Konferansepaper (Fagfellevurdert)
    Abstract [en]

    IEEE 802.11p/ITG-G5 vehicle-to-vehicle communication technology, which enables the new class of safety and infotainment applications, is currently an emerging research topic in both industry and academia. The proposed spectrum allocation of 10 Mhz channels for DSRC (Dedicated Short Range Communication) in 5.9 GHz band for the USA and Europe allows considering the transmission of video information between vehicles as one of the grounding blocks for future automotive applications. Although several published works addressed the problems of video content delivery in VANETs (Vehicular Ad-hoc NETworks), no work has been reported on real-world measurements of visual quality for video being transmitted over the IEEE 802.11p vehicle-to-vehicle communication channel. This paper presents a real-time scalable video codec as well as the first results of visual quality measurements for the video information transmitted using the off-the-shelf Componentality FlexRoad DSRC equipment. © 2013 IEEE.

  • 3113.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences.
    Berbineau, MarionIFSTTAR.Manohara Pai, M.M.Manipal University.Koucheryavy, YevgeniDepartment of Communications Engineering, Tampere University of Technology.Gusikhin, OlegFord Research & Adv. Engineering .Prokhorov, DanilToyota Research Institute North America.Rodrigues, JoelUniversity of Beira Interior.Zhang, YanSimula Research Laboratory.
    2011 11th International Conference on ITSTelecommunications2011Konferanseproceedings (Fagfellevurdert)
  • 3114.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Breu, Jakob
    Mercedes-Benz Research & Development, Sindelfingen, Germany.
    Luan, Tom
    Xidian University, Xi'an, China.
    Hu, Honglin
    Shanghai Institute of Microsystem and Information Technology, Shanghai, China.
    Emerging Technology for 5G-Enabled Vehicular Networks2017Inngår i: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 24, nr 6, s. 12-12Artikkel i tidsskrift (Fagfellevurdert)
  • 3115.
    Vinel, Alexey
    et al.
    Department of Communications Engineering, Tampere University of Technology.
    Campolo, Claudia
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria.
    Petit, Jonathan
    Research Center IRIT, Paul Sabatier University.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology.
    Trustworthy Broadcasting in IEEE 802.11p/WAVE Vehicular Networks: Delay Analysis2011Inngår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 15, nr 9, s. 199-201Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Safety and non-safety applications envisioned for Vehicular Ad hoc NETworks (VANETs) heavily rely on broadcasting for the exchange of data and status messages. New threats to road safety and efficiency raise if security requirements for broadcasting are not properly met. The decision whether or not a driver can trust information about a reported hazard should take into account the tradeoff between the decision delay, false warning probability and likelihood of missing the hazard. Although broadcasting in VANETs has been analytically studied at least for the simplified assumptions, related works do not jointly consider the reliability of the medium access control (MAC) protocol and the trust issues. In this letter, a new analytical model is designed for evaluating the latency required to guarantee trustworthiness in VANETs. This model explicitly accounts the operation of 802.11p/WAVE MAC protocol and computes mean decision delay as a function of number of vehicles, ratio of intruders as well as contention window sizes. © IEEE

  • 3116.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Chen, Wen-Shyen Eric
    ProphetStor Data Services, Milpitas, CA, USA.
    Xiong, Neal N.
    Department of Business and Computer Science, Southwestern Oklahoma State University, Weatherford, Oklahoma, USA.
    Rho, Seungmin
    Department of Media Software at Sungkyul University, Anyang, South Korea.
    Chilamkurti, Naveen
    Department of Computer Science and Telecommunications, La Trobe University, Melbourne, Australia.
    Vasilakos, Athanasios V.
    Luleå University of Technology, Luleå, Sweden.
    Enabling wireless communication and networking technologies for the internet of things2016Inngår i: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 23, nr 5, s. 8-9, artikkel-id 7721735Artikkel i tidsskrift (Fagfellevurdert)
  • 3117.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint-Petersburg, Russia.
    Dudin, Alexander
    Belarusian State University, Minsk, Belaruse.
    Andreev, Sergey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Xia, Feng
    Dalian University of Technology, Dalian, China.
    Performance modeling methodology of emergency dissemination algorithms for vehicular ad-hoc networks2010Inngår i: 2010 7th International Symposium on Communication Systems Networks and Digital Signal Processing (CSNDSP), Piscataway, N.J.: IEEE Press, 2010, s. 397-400Konferansepaper (Fagfellevurdert)
  • 3118.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Russian Federation.
    Fedorov, Konstantin
    Saint-Petersburg State Electrotechnical University (Microelectronics), Russian Federation.
    Random multiple access with successive interference cancellation for centralized networks2009Inngår i: IEEE Eurocon 2009 International Conference Devoted to the 150th Anniversary of Alexander Popov: Proceedings, New York: IEEE Press, 2009, s. 1930--1934Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The development of random multiple access (RMA) algorithms, which are based on the successive interference cancellation (SIC) has attracted attention of scientists in the last years. In this paper a new RMA algorithm for centralized networks, which we refer to as Multi-FS-TREE/SIC is introduced and analyzed. The algorithm is a combination of Multi-FS-ALOHA and SICTA and provides transmission rate more than 0.6.

  • 3119.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint-Petersburg, Russia.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    A novel model for study of broadcasting in wireless networks2009Inngår i: Distributed Computer and Communication Networks. Theory and Applications (DCCN-2009), Moscow: R&D Company , 2009, s. 26-34Konferansepaper (Fagfellevurdert)
  • 3120.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation Russian Academy of Sciences Saint-Petersburg, Russia.
    Koucheryavy, Yevgeni
    Tampere University of Technology Department of Communication Engineering Tampere, Finland.
    On the delay lower bound for the emergency message dissemination in vehicular ad-hoc networks2009Inngår i: Local Computer Networks, 2009. LCN 2009. IEEE 34th Conference on, Washington, DC: IEEE Computer Society, 2009, s. 652-654Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Active safety in vehicular environment can be achieved by means of installation of the wireless equipment on the boards of cars. Design of highly efficient protocols for car-to-car communications is a challenging task. If an emergency situation happens on the road, the information about it should be disseminated to the stakeholders with low delay and high reliability. In this paper, we derive a theoretical lower bound for the mean message transmission delay in multi-hop vehicular ad-hoc networks.

  • 3121.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint-Petersburg, Russia.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Andreev, Sergey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Staehle, Dirk
    University of Wurzburg, Wurzburg, Germany.
    Estimation of a successful beacon reception probability in vehicular ad-hoc networks2009Inngår i: Proceedings of the 2009 International Conference on Wireless Communications and Mobile Computing: connecting the world wirelessly : 2009, Leipzig, Germany, June 21-24, 2009, New York, NY: ACM Press, 2009, s. 416-420Konferansepaper (Fagfellevurdert)
  • 3122.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Lan, Lin
    Hitachi Europe SAS, Sophia-Antipolis, France.
    Lyamin, Nikita
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Vehicle-to-vehicle communication in C-ACC/platooning scenarios2015Inngår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 53, nr 8, s. 192-197, artikkel-id 7180527Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cooperative adaptive cruise control (C-ACC) and platooning are two emerging automotive intelligent transportation systems (ITS) applications. In this tutorial article we explain their principles, describe related ongoing standardization activities, and conduct performance evaluation of the underlying communication technology. © Copyright 2015 IEEE

  • 3123.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Lyamin, Nikita
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Isachenkov, Pavel
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Modeling of V2V Communications for C-ITS Safety Applications: A CPS Perspective2018Inngår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, nr 8, s. 1600-1603Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tight coupling between the performance of vehicleto-vehicle (V2V) communications and the performance of Cooperative Intelligent Transportation Systems (C-ITS) safety applications is addressed. A Cyber-Physical System (CPS) analytical framework is developed that links the characteristics of V2V communications (such as packet loss probability and packet transmission delay) with the physical mobility characteristics of the vehicular system (such as safe inter-vehicular distance). The study is applied to the Day 1 C-ITS application, Emergency Electronic Brake Lights (EEBL), enabled by ETSI ITS-G5 and IEEE 802.11p standards. © 2018 IEEE

  • 3124.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Ma, Xiaomin
    Oral Roberts University, Tulsa, OK, USA.
    Huang, Dijiang
    Arizona State University, Tempe, AZ, USA.
    Guest Editors’ Introduction: Special Issue on Reliable and Secure VANETs2016Inngår i: IEEE Transactions on Dependable and Secure Computing, ISSN 1545-5971, E-ISSN 1941-0018, Vol. 13, nr 1, s. 2-4Artikkel i tidsskrift (Fagfellevurdert)
  • 3125.
    Vinel, Alexey
    et al.
    Tampere University of Technology, Tampere, Finland.
    Mehmood, RashidSchool of Engineering, Swansea, United Kingdom.Berbineau, MarionIFSTTAR, LEOST, Villeneuve d’Ascq, France.Rico Garcia, CristinaGerman Aerospace Center (DLR), Oberpfaffenhofen-Wessling, Germany.Huang, Chung-MingNational Cheng Kung University, Tainan, Taiwan.Chilamkurti, NaveenLa Trobe University, Bundoora, Melbourne, Australia.
    Communications Technologies for Vehicles: 4th International Workshop, Nets4Cars/Nets4Trains 2012, Vilnius, Lithuania, April 25-27, 2012, Proceedings2012Konferanseproceedings (Fagfellevurdert)
    Abstract [en]

    The proceedings contain 15 papers. The topics discussed include: Cellular Networking Technologies in ITS Solutions: Opportunities and Challenges; effective and efficient security policy engines for automotive on-board networks; ICDMS: an intelligent cloud based disaster management system for vehicular networks; wireless driver and vehicle surveillance system based on IEEE 802.11 networks; architecture of car measurement system for driver monitoring; toward revocation data handling efficiency in VANETs; cluster based data aggregation in vehicular adhoc network; simulations of VANET scenarios with OPNET and sumo; human participatory sensing in fixed route bus information system; scheduling ofvehicles in transportation networks; design and prototype of a train-to-wayside communication architecture; and conceptual architectural design of Indian railway intelligent transportation systems. © Springer-Verlag Berlin Heidelberg 2012

  • 3126.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences.
    Ni, Qiang
    Brunel University, UK.
    Staehle, Dirk
    University of Wurzburg, Germany.
    Turlikov, Andrey
    Saint-Petersburg State University of Aerospace Instrumentation, Russia.
    Capacity analysis of reservation-based random access for broadband wireless access networks2009Inngår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 27, nr 2, s. 171-181Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper we propose a novel model for the capacity analysis on the reservation-based random multiple access system, which can be applied to the medium access control protocol of the emerging WiMAX technology. In such a wireless broadband access system, in order to support QoS, the channel time is divided into consecutive frames, where each frame consists of some consequent mini-slots for the transmission of requests, used for the bandwidth reservation, and consequent slots for the actual data packet transmission. Three main outcomes are obtained: first, the upper and lower bounds of the capacity are derived for the considered system. Second, we found through the mathematical analysis that the transmission rate of reservationbased multiple access protocol is maximized, when the ratio between the number of mini-slots and that of the slots per frame is equal to the reciprocal of the random multiple access algorithm's transmission rate. Third, in the case of WiMAX networks with a large number of subscribers, our analysis takes into account both the capacity and the mean packet delay criteria and suggests to keep such a ratio constant and independent of application-level data traffic arrival rate. © 2006 IEEE.

  • 3127.
    Vinel, Alexey
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Pettersson, Henrik
    Scania, Södertälje, Sweden.
    Lin, Lan
    Hitachi, Sophia Antipolis, France.
    Altintas, Onur
    Toyota, Tokyo, Japan.
    Gusikhin, Oleg
    Ford Research & Adv. Engineering, Dearborn, MI, United States.
    Vehicular networking for autonomous driving: [Guest Editorial]2015Inngår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 53, nr 12, s. 62-63Artikkel i tidsskrift (Fagfellevurdert)
  • 3128.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Russia.
    Rodrigues, Joel
    University of Beira Interior, Covilhã, Portugal.
    Berbineau, Marion
    Institut français des sciences et technologies des transports, de l'aménagement et des réseaux (IFSTTAR), Marne-la-Vallée, France.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Finland.
    Gusikhin, Oleg
    Ford Research & Adv. Engineering, United States.
    Zhang, Yan
    Simula Research Laboratory, Lysaker, Norway.
    ITST 2011 Conference in Saint-Petersburg, Russia2011Inngår i: IEEE Global Communications Newsletter, ISSN 0163-6804, nr Dec., s. 3-4Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 3129.
    Vinel, Alexey
    et al.
    University of Wurzburg, Wurzburg, Germany.
    Staehle, Dirk
    University of Wurzburg, Wurzburg, Germany.
    Pries, Rastin
    University of Wurzburg, Wurzburg, Germany.
    Random Multiple Access in WiMAX: Problems and Solutions2007Inngår i: / [ed] Paulo Simões & Eugen Borcocci, 2007, s. 59-69Konferansepaper (Fagfellevurdert)
  • 3130.
    Vinel, Alexey
    et al.
    Saint-Petersburg State University of Aerospace Instrumentation, Saint-Petersburg, Russia.
    Staehle, Dirk
    University of Wurzburg, Wurzburg, Germany.
    Pries, Rastin
    University of Wurzburg, Wurzburg, Germany.
    Ni, Qiang
    Brunel University, Uxbridge, United Kingdom.
    Performance Analysis of the Polling Scheme in IEEE 802.162007Inngår i: Distributed Computer and Communication Networks. Theory and Applications.: Proceedings of the International Workshop. Vol.1. Moscow, Russia, September 10-12, 2007, Moscow: Institute for Information Transmission Problems (Kharkevich Institute) , 2007, s. 54-67Konferansepaper (Fagfellevurdert)
  • 3131.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint-Petersburg, Russian Federation.
    Staehle, Dirk
    Department of Distributed Systems, University of Wuerzburg, Wuerzburg, Germany.
    Turlikov, Andrey
    Saint-Petersburg State University of Aerospace Instrumentation, Saint-Petersburg, Russian Federation.
    Study of Beaconing for Car-to-Car Communication in Vehicular Ad-Hoc Networks2009Inngår i: Communications Workshops, 2009. ICC Workshops 2009. IEEE International Conference on: Proceedings, Piscataway: IEEE Press, 2009, s. 1-5Konferansepaper (Fagfellevurdert)
    Abstract [en]

    IEEE 802.11p is currently being developed international standard, which specifies physical (PHY) and medium access control (MAC) protocols for car-to-car and carto-infrastructure communication and should become a basis for safety-related and infotainment applications in future vehicular ad-hoc networks (VANETs). In VANETs beaconing is one of the most important communication modes, which is used to advertise the presence of a car to its neighbor cars. For different applications timely and successful delivery of beacons containing speed, direction and position of a car is extremely important. In this paper, we present analytical methods for car-to-car communication analysis and investigate the influence of beacon generation rate on the mean beacon transmission delay and probability of a successful beacon reception in the IEEE 802.11pbased network in both saturated and unsaturated cases.

  • 3132.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Russia.
    Vishnevsky, Vladimir
    Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
    Analysis of Contention-Based Reservation in IEEE 802.16 for the Error-Prone Channel2008Inngår i: Selected Lectures on Multiple Access and Queueing Systems: Revised Selected Papers from International Workshop on Multiple Access Communications - MACOM-2008 (16-17 June 2008, Saint-Petersburg) / [ed] Vishnevsky, V., Vinel, A., Koucheryavy, E. & Staehle, D., Saint-Petersburg: Saint-Petersburg State University of Aerospace Instrumentation , 2008, s. 86-90Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Operation of centralized data network, where infinite population of subscribers perform reservations to get the allowance for packets transmission, is considered under error-prone channel conditions. Medium access control protocol, which combines subscribers’ random access algorithm and central station’s queuing service discipline, is investigated. Bounds for the capacity of the IEEE 802.16-like network with contention-based reservation are presented.

  • 3133.
    Vinel, Alexey
    et al.
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint-Petersburg, Russia.
    Vishnevsky, Vladimir
    Institute for Information Transmission Problems, Russian Academy of Sciences, Saint-Petersburg, Russia.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    A Simple Analytical Model for the Periodic Broadcasting in Vehicular Ad-Hoc Networks2008Inngår i: 2008 IEEE Globecom Workshops, GLOBECOM 2008, Piscataway, N.J.: IEEE Press, 2008, s. 1-5Konferansepaper (Fagfellevurdert)
  • 3134.
    Vinel, Alexey
    et al.
    Saint-Petersburg State University of Aerospace Instrumentation.
    Zhang, Yin
    Siemens AG, Communications, Munich, Germany.
    Lott, Matthias
    Siemens AG, Communications, Munich, Germany.
    Turlikov, Andrey
    Saint-Petersburg State University of Aerospace Instrumentation.
    Performance Analysis of the Random Access in IEEE 802.162005Inngår i: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, New York, USA: IEEE Press, 2005, s. 1596-1600Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recently, the IEEE has standardized the 802.16 protocol for metropolitan broadband wireless access systems. According to the standard, therandom access scheme based on the slotted binary exponential backoff algorithm is used in this system for initial ranging and bandwidth requests transmission. This paper provides both the simulation and analytical models for the investigation of the random access in IEEE 802.16. Based on the assumption of finite number of subscriber stations and ideal channel conditions the delay is evaluated for varying number of transmission opportunities and different backoff window sizes. © 2005 IEEE.

  • 3135.
    Vinel, Alexey
    et al.
    Information Systems Department State University of Aerospace Instrumentation Saint-Petersburg, Russia.
    Zhang, Ying
    Future Radio Concepts Siemens AG Munich, Germany.
    Ni, Qiang
    Electronic & Computer Engineering School of Engineering and Design, Brunel University London, United Kingdom.
    Lyakhov, Andrey
    Laboratory of Information Transmission Networks Institute for Information Transmission Problems, RAS Moscow, Russia.
    Efficient Request Mechanism Usage in IEEE 802.162006Inngår i: Global Telecommunications Conference, GLOBECOM 2006, Piscataway, NJ: IEEE Press, 2006, s. 1-5Konferansepaper (Fagfellevurdert)
    Abstract [en]

    IEEE 802.16 protocols for metropolitanbroadband wireless access systems have been standardizedrecently. According to the standard, a subscriber station candeliver bandwidth request messages to a base station bynumerous methods. This paper provides both the simulation andanalytical models for the investigation of specified random accessmethod, which is compared with centralized polling and stationgroupingmechanisms. Based on the assumptions of Bernoullirequest arrival process and ideal channel conditions, the meandelay of a request transmission is evaluated for varying numberof transmission opportunities and different arrival rates.

  • 3136.
    Vinogradova, Julia
    et al.
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    Björnson, Emil
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    Larsson, Erik
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    On the separability of signal and interference-plus-noise subspaces in blind pilot decontamination2016Inngår i: 41st IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 3421-3425Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Consider a multicell multiuser MIMO (multiple-input multiple-output) system with a very large number of antennas at each base station (BS). The number of users in each cell is assumed to be fixed as the number of BS antennas grows large. Under certain conditions on the powers of the transmitting users, the signal eigenvalue spectrum is asymptotically separated from the interference-plus-noise spectrum as the number of BS antennas grows large. As it was observed in [1], this phenomenon allows to mitigate the pilot contamination problem. We provide the power limits for each user in the cell of interest above which such a separation occurs asymptotically. Unlike the approximative methods used in [1], we obtain these power limits by making use of the exact asymptotic characterizations of the interference-plus-noise spectrum. The results are based on the theory of small rank perturbations of large dimensional random matrices.

  • 3137.
    Vinogradova, Julia
    et al.
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    Björnson, Emil
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    Larsson, Erik G
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    DETECTION AND MITIGATION OF JAMMING ATTACKS IN MASSIVE MIMO SYSTEMS USING RANDOM MATRIX THEORY2016Inngår i: 2016 IEEE 17TH INTERNATIONAL WORKSHOP ON SIGNAL PROCESSING ADVANCES IN WIRELESS COMMUNICATIONS (SPAWC), IEEE , 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Consider the uplink of a single-cell multiuser MIMO system with a very large number of antennas, M, at the base station (BS) and K single-antenna users. A jamming device equipped with K-J antennas transmitting signals attempts to degrade the transmission between the users and the BS. In this paper, we propose a detection algorithm of the jamming attack as well as a method for its rejection. The proposed results are based on the application of results from random matrix theory. We assume that K and K-J are fixed as M converges to infinity while the coherence interval tau is assumed to be of the same order of magnitude as M

  • 3138.
    Vishnevsky, Vladimir
    et al.
    Institute for Information Transmission Problems, Russian Academy of Sciences, Russia.
    Samouylov, Konstantin
    Peoples’ Friendship University of Russia, Moscow, Russia.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Finland.
    Vinel, Alexey
    Saint-Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Russia.
    Tkachenko, Dmitry
    IEEE Russia Northwest BT/CE/COM Chapter, Russia.
    ICUMT 2010 Congress in Moscow, Russia2011Inngår i: IEEE Global Communications Newsletter, ISSN 0163-6804, nr March, s. 4-4Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 3139.
    Vishnevsky, Vladimir
    et al.
    Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
    Vinel, AlexeySaint-Petersburg State University of Aerospace Instrumentation, Saint Petersburg, Russia.Koucheryavy, YevgeniDepartment of Communications Engineering, Tampere University of Technology, Tampere, Finland.Staehle, DirkUniversity of Wurzburg, Würzburg, Germany.
    Selected Lectures on Multiple Access and Queueing Systems: Revised Selected Papers from International Workshop on Multiple Access Communications - MACOM-2008 (16-17 June 2008, Saint-Peterburg)2008Konferanseproceedings (Fagfellevurdert)
    Abstract [en]

    Claude Shannon established the foundation for the discipline now known as "multi-user information theory" in his pioneering paper "Two-way Communication Channels" in 1961 and later  Norman Abramson published his paper “The Aloha System – Another Alternative for Computer Communications” in 1970 which introduced the concept of multiple access using a shared commonchannel. After more than 40 years of study, numerous elegant theories and algorithms have beendeveloped for multiple access techniques.

    In recent years, broadband wireless data networks (for instance, IEEE 802.11 Wi-Fi, IEEE802.16 WiMAX) are driving the development of the telecommunication industry and Beyond 3G(B3G) wireless systems are expected to provide a variety of multimedia services in a wide range of wireless and mobile environments. To use the scarce bandwidth resource of the wireless channel, it isnecessary to design channel access control techniques for a large population of users (potentiallyhundreds of mobile stations).

    The aim of these collected articles is to give an overview of the state-of-the-art results inmulti-user communications theory, multiple access techniques, queuing theory and standardizationactivities in areas mostly related to PHY and MAC layer protocols for contemporary wirelessnetworks and their interactions.

  • 3140.
    Visockas, Vilius
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Comparing Expected and Real–Time Spotify Service Topology2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Spotify is a music streaming service that allows users to listen to their favourite music. Due to the rapid growth in the number of users, the amount of processing that must be provided by the company’s data centers is also growing. This growth in the data centers is necessary, despite the fact that much of the music content is actually sourced by other users based on a peer-to-peer model.

    Spotify’s backend (the infrastructure that Spotify operates to provide their music streaming service) consists of a number of different services, such as track search, storage, and others. As this infrastructure grows, some service may behave not as expected. Therefore it is important not only for Spotify’s operations (footnote: Also known as the Service Reliability Engineers Team (SRE)) team, but also for developers, to understand exactly how the various services are actually communicating. The problem is challenging because of the scale of the backend network and its rate of growth. In addition, the company aims to grow and expects to expand both the number of users and the amount of content that is available. A steadily increasing feature-set and support of additional platforms adds to the complexity. Another major challenge is to create tools which are useful to the operations team by providing information in a readily comprehensible way and hopefully integrating these tools into their daily routine. The ultimate goal is to design, develop, implement, and evaluate a tool which would help the operations team (and developers) to understand the behavior of the services that are deployed on Spotify’s backend network.

    The most critical information is to alert the operations staff when services are not operating as expected. Because different services are deployed on different servers the communication between these services is reflected in the network communication between these servers. In order to understand how the services are behaving when there are potentially many thousands of servers we will look for the patterns in the topology of this communication, rather than looking at the individual servers. This thesis describes the tools that successfully extract these patterns in the topology and compares them to the expected behavior.

  • 3141.
    Vlasenko, Michail
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Supervision of video and audio content in digital TV broadcasts2007Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    An automatic system for supervision of the video and audio content in digital TV broadcasts was investigated in this master’s thesis project. The main goal is to find the best and most cost effective solution for Teracom to verify that the broadcast TV content as received by remote receivers is the same as that incoming to Teracom from content providers. Different solutions to this problem will be presented.

    The report begins with some background information about the Swedish terrestrial digital TV network and the MPEG-2 compression standard used to transport audio and video; including a description of the DVB Systems and Transport Stream protocol. It describes two current techniques for the supervision of the audio and video content, including an evaluation of these techniques.

    The first solution is to monitor the video and audio content either by detecting common errors such as frozen picture, visible artifacts, or by comparing the content from two different sources, i.e. a comparison of the output and the input content. The later could be done using video fingerprinting. The second solution monitors the video and audio content indirectly by analyzing the Transport Stream. This could be done either by comparing two Transport Streams to verify that the broadcast signal is identical to the received signal or by detecting common errors in the streams.

    Further two new potential solutions will be presented based on the research utilizing background knowledge of the MPEG-2 compression standard. The thesis ends with a summary with conclusions and evaluations of all four solutions and future work.

  • 3142.
    Vodopivec, Dario
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    On-demand Television combined with non-real-time Peer-to-Peer Content Delivery for Television Content Providers2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    With the expansion of the Internet and an increasing fraction of consumers having broadband connections, more and more content is finding its way on-line. Video content is becoming one of the most popular types of media content on the Internet. Traditional media content providers, such as television networks, are placing their content on the Internet in order to gain a broader audience. On-demand websites such as kanal5play.se allow viewers to view the multimedia content they want at the time of their choice. While this gives viewers flexibility in their viewing, it creates resource problems for content providers.

    Statistics from Kanal5 AB show that, even with individual viewers requesting content when they want, there are still patterns in which multiple viewers watch the same content at the same time. This means there are correlations in the demand for content. With unicast distribution this leads to spikes in requirements for bandwidth to the viewers. These peaks lead to high costs for network and server resources to deliver the requested content, but these resources have low average utilization. This thesis project investigates how a content provider can make use of each viewer’s own resources to deliver content to other users using peer-to-peer techniques. The thesis evaluates what methods can be used in order to reduce the content provider’s resource requirements during peak hours by exploiting copies of contents that have already been delivered to viewers who requested this same content earlier.

    A prototype was made to evaluate the suggested design using Java Remote Method Invocation (RMI), which is built on top of the Transfer Control Protocol (TCP). Experiments show that an initial delay of several seconds is reached on a network with a simulated delay of 100ms, while a minimal initial delay was observed on a network with low delay, i.e. ideal conditions. The throughput results of the prototype show that the suggested solution is adequate for delivering on-demand content supplied by Kanal5 AB. However, the relatively poor startup performance of this solution argues for tuning the application to better work with the TCP protocol or to utilize another transport protocol - especially if the round-trip delay is large as TCP’s 3-way handshake and flow control algorithm limit the performance of the prototype system.

  • 3143.
    Voicu, Andra M.
    et al.
    Rhein Westfal TH Aachen, Inst Networked Syst, Aachen, Germany..
    Lava, Laurent
    Rhein Westfal TH Aachen, Inst Networked Syst, Aachen, Germany..
    Simic, Ljiljana
    Rhein Westfal TH Aachen, Inst Networked Syst, Aachen, Germany..
    Petrova, Marina
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    The Importance of Adjacent Channel Interference: Experimental Validation of ns-3 for Dense Wi-Fi Networks2017Inngår i: Proceedings Of The 20th ACM International Conference On Modelling, Analysis and Simulation of Wireless And Mobile Systems (MSWIM'17), Association for Computing Machinery (ACM), 2017, s. 43-52Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In its evolution to provide ever higher data rates, the Wi-Fi standard has incorporated sophisticated PHY-layer techniques, which has in turn increased the complexity of network-wide interference relationships. Proper modelling of the resulting inter-device interactions is crucial for accurately estimating Wi-Fi network performance, especially in the contemporary context of traffic and network densification. Event-driven simulators like the open-source ns-3 are in principle able to capture these interactions, however it is imperative to validate, against experimental results, whether their underlying models reflect the network behaviour in practice. In this paper we first perform experiments in a large-scale indoor testbed to validate the IEEE 802.11ac Wi-Fi model in ns-3, for various channel width and allocation configurations. Our results show that ns-3 captures Wi-Fi co-channel interactions with reasonable precision, but fails to model adjacent channel interference (ACI), which our experiments show to be critical in dense networks. We therefore propose and implement an ACI model in ns-3. Importantly, our model successfully captures the qualitative behaviour of the CSMA/CA mechanism when transmissions on adjacent channels occur. Further, our ACI implementation significantly improves the accuracy of both the network and per-device throughput estimates for the considered dense IEEE 802.11ac network compared to the basic ns-3 Wi-Fi model without ACI. For example, without ACI modelling, ns-3 overestimates the aggregate network throughput by up to 230%, whereas with our ACI implementation the aggregate throughput estimate is no more than 65% higher than the experimental results.

  • 3144.
    von Heideken, Oskar
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Wennerfeldt, Max
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Serial Video Links in Automotive Applications2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis investigates the available and upcoming serializer and deserializer solutions for MIPI-CSI 2 camera interface, in order to reduce cable cost and lower installation complexity for mounting satellite cameras in automotive applications. A market survey was conducted resulting in several available and coming solutions. One solution found in the survey was selected together with Autoliv Sverige AB for further investigation and implementation in the form of a demonstration platform. The assembled serializer and deserializer units were tested together with a selection of automotive graded cables in order to test the system and establish the best suited cable with regards to cost, weight and performance. The results show that five serializer and deserializer solutions were found and the choice of cables is a trade-off between performance and external factors such as noise and required cable length.

  • 3145.
    Voronov, Alexey
    et al.
    Viktoria Swedish ICT, Gothenburg, Sweden.
    Englund, Cristofer
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab). Viktoria Swedish ICT, Gothenburg, Sweden.
    Bengtsson, Hoai
    Viktoria Swedish ICT, Gothenburg, Sweden.
    Chen, Lei
    Viktoria Swedish ICT, Gothenburg, Sweden.
    Ploeg, Jeroen
    TNO, Helmond, The Netherlands.
    de Jongh, Jan
    TNO, Helmond, The Netherlands.
    van de Sluis, Jacco
    TNO, Helmond, The Netherlands.
    Interactive test tool for interoperable C-ITS development2015Inngår i: 2015 IEEE 18th International Conference on Intelligent Transportation Systems / [ed] Lisa O’Conner, Los Alamitos: IEEE, 2015, s. 1713-1718, artikkel-id 7313370Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the architecture of an Interactive Test Tool (ITT) for interoperability testing of Cooperative Intelligent Transport Systems (C-ITS). Cooperative systems are developed by different manufacturers at different locations, which makes interoperability testing a tedious task. Up until now, interoperability testing is performed during physical meetings where the C-ITS devices are placed within range of wireless communication, and messages are exchanged. The ITT allows distributed (e.g. over the Internet) interoperability testing starting from the network Transport Layer and all the way up to the Application Layer, e.g. to platooning. ITT clients can be implemented as Hardware-in-the-Loop, thus allowing to combine physical and virtual vehicles. Since the ITT considers each client as a black box, manufacturers can test together without revealing internal implementations to each other. The architecture of the ITT allows users to easily switch between physical wireless networking and virtual ITT networking. Therefore, only one implementation of the ITS communication stack is required for both development and testing. This reduces the work overhead and ensures that the stack that is used during the testing is the one deployed in the real world. © 2015 IEEE.

  • 3146. Voronov, Alexey
    et al.
    Englund, Cristofer
    RISE., Swedish ICT, Viktoria.
    Hoang Bengtsson, Hoai
    Chen, Lei
    Ploeg, Jeroen
    de Jongh, Jan
    van de Sluis, Jacco
    Interactive test tool for interoperable C-ITS development2015Inngår i: Intelligent Transportation Systems (ITSC), 2015 IEEE 18th International Conference on, 2015, s. 1713-1718Konferansepaper (Fagfellevurdert)
  • 3147.
    Vu Hoang, Tung
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Secure data and voice over wireless networks in disaster and emergency response2005Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Communication is often limited in a disaster area and other emergency situations where no infrastructure exists or existing infrastructure has been destroyed. This makes its difficult for relief workers in the field to communicate with one another and with their home head office. Ericsson Response has developed a Wireless LAN in Disaster and Emergency Response (WIDER) solution. WIDER is based on broadband Wireless LAN internetworking to satellite and GSMnetworks. The WIDER solution has identified ways for organizations to share their communication infrastructure, and information in a secure and cost effective manner during an emergency response operation. Data over WIDER needs to be secured to prevent from unauthorized access to sensitive information of relief organizations. VoIP calls should be protected against eavesdropping. The thesis investigated how to enhance security solution in WIDER and implement a secure VoIP client. Measurements of the performance of WIDER and the total delay of VoIP over satellite were used to estimate the capability of WIDER before deployment in the field.

  • 3148.
    Vu Hong, Linh
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    DNS Traffic Analysis for Network-based Malware Detection2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Botnets are generally recognized as one of the most challenging threats on the Internet today. Botnets have been involved in many attacks targeting multinational organizations and even nationwide internet services. As more effective detection and mitigation approaches are proposed by security researchers, botnet developers are employing new techniques for evasion. It is not surprising that the Domain Name System (DNS) is abused by botnets for the purposes of evasion, because of the important role of DNS in the operation of the Internet. DNS provides a flexible mapping between domain names and IP addresses, thus botnets can exploit this dynamic mapping to mask the location of botnet controllers. Domain-flux and fast-flux (also known as IP-flux) are two emerging techniques which aim at exhausting the tracking and blacklisting effort of botnet defenders by rapidly changing the domain names or their associated IP addresses that are used by the botnet. In this thesis, we employ passive DNS analysis to develop an anomaly-based technique for detecting the presence of a domain-flux or fast- flux botnet in a network. To do this, we construct a lookup graph and a failure graph from captured DNS traffic and decompose these graphs into clusters which have a strong correlation between their domains, hosts, and IP addresses. DNS related features are extracted for each cluster and used as input to a classication module to identify the presence of a domain-flux or fast-flux botnet in the network. The experimental evaluation on captured traffic traces veried that the proposed technique successfully detected domain-flux botnets in the traces. The proposed technique complements other techniques for detecting botnets through traffic analysis.

  • 3149.
    Vu, Minh thanh
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Lossy distributed storage with limited failure loss2015Inngår i: Proceedings of the International Symposium on Wireless Communication Systems, VDE Verlag GmbH, 2015, s. 191-195Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper a successive refinement problem is considered where decoders can access only distributed storage nodes, subject to an additional constraint on the loss of information if failures happen. We characterize the optimal tradeoff for a given a distortion tuple and an equivocation constraint between storage nodes. A binary example is provided to illustrate the trade-off between the loss of information constraint and the corresponding achievable rate region.

  • 3150.
    Vukadinovic, Vladimir
    et al.
    Disney Research Zürich.
    Helgason, Ólafur
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Karlsson, Gunnar
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    An analytical model for pedestrian content distribution in a grid of streets2013Inngår i: Mathematical and computer modelling, ISSN 0895-7177, E-ISSN 1872-9479, Vol. 57, nr 11-12, s. 2933-2944Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mobile communication devices may be used for spreading multimedia data without support of an infrastructure. Such a scheme, where the data is carried by people walking around and relayed from device to device by means of short range radio, could potentially form a public content distribution system that spans vast urban areas. The transport mechanism is the flow of people and it can be studied but not engineered. We study the efficiency of pedestrian content distribution by modeling the mobility of people moving around in a city, constrained by a given topology. The model is supplemented by simulation of similar or related scenarios for validation and extension. The results show that contents spread well with pedestrian speeds already at low arrival rates into a studied region. Our contributions are both the queuing analytic model that captures the flow of people and the results on the feasibility of pedestrian content distribution.

60616263646566 3101 - 3150 of 3542
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