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  • 201.
    Lavén, Andreas
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Latency Aware Anypath Routing and Channel Scheduling for Multi-Radio Wireless Mesh Networks2014Ingår i: IEEE WCNC'14 Track 3 (Mobile and Wireless Networks), IEEE, 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wireless mesh network (WMN), radio nodes that form a mesh topology, is an interesting architectural candidate for the future wireless Internet. A dense access network can rapidly be deployed at a reasonable cost because there is no need to wire the mesh access points. However, WMNs typically do not perform well with latency-sensitive data traffic, such as Voice over IP (VoIP), due to restricted bandwidth. In this paper, we present the design, implementation and evaluation of LA-APOLSR for hybrid WMNs, where mesh nodes have two radios; a fixed radio for receiving and a switchable radio which rapidly changes channels to send to neighbor nodes. The key novelty of our approach is to use anypath routing for latency-sensitive traffic while normal traffic is treated using single path routing. Also, we develop a novel queuing strategy which prioritizes latency-sensitive traffic. A detailed evaluation using KAUMesh, an in-house multi-radio wireless mesh testbed, shows a reduction in latency and packet loss for VoIP traffic without negatively impacting competing TCP background traffic.

  • 202.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Lundin, Reine
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Faigl, Zoltán
    A Conceptual Model of Tunable Security Services2006Ingår i: Wireless Communication Systems, 2006.: ISWCS '06. 3rd International Symposium on, Piscataway, NJ: IEEE , 2006, s. 531-535Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we propose a conceptual model for tunable security services. The aim of the model is to provide a tool that can be used to describe and analyze such services in a structured and consistent way. The proposed model can thus serve as a basis to examine the possibilities available for constructing tunable security services based on current and future networking standards and to identify missing requirements. It can also be used to describe and compare previous research results. In the paper, four different use cases are presented that illustrates the powerfulness of the proposed model.

  • 203.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    A Comparison of End-to-End Security Solutions for SCTP2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    A comparison of three different end-to-end security solutions for the stream control transmission protocol (SCTP) is presented in this paper. The compared solutions are SCTP over IPsec, TLS over SCTP, and secure socket SCTP (SS-SCTP). The two former are standardized solutions, whereas the latter is a newly proposed solution that was designed to offer as much security differentiation support as possible using standardized solutions and mechanisms. The comparison focuses on three main issues: packet protection, security differentiation, and message complexity. SS-SCTP compares favorably in terms of offered security differentiation and message overhead. Confidentiality protection of SCTP control information is, however, only offered by SCTP over IPsec

  • 204.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    An End-to-End Security Solution for SCTP2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    The stream control transmission protocol (SCTP) is a fairly new transport protocol that was initially designed for carrying signaling traffic in IP networks. SCTP offers a reliable end-to-end (E2E) transport. Compared to TCP, SCTP provides a much richer set of transport features such as message oriented transfer, multistreaming to handle head-of-line blocking, and multihoming for enhanced failover. These are all very attractive features, but at the same time proven hard and complex to secure for E2E transports. All existing security solutions have limitations. In this paper, a survey of existing solutions is first given. Then, an alternative solution is proposed. The proposed solution uses the new authenticated chunks for SCTP for integrity protection, TLS for key exchange and authentication, and symmetric encryption implemented at the socket layer for confidentiality protection. A qualitative comparison of the described E2E security solutions is also given

  • 205.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Design and Implementation of a Tunable Encryption Service for Networked Applications2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    To achieve the best possible QoS tradeoff between security and performance for networked applications, a tunable and differential treatment of security is required. In this paper, we present the design and implementation of a tunable encryption service. The proposed service is based on a selective encryption paradigm in which the applications can request a desired encryption level. Encryption levels are selected by the applications at the inception of sessions, but can be changed at any time during their lifetime. A prototype implementation is described along with an initial performance evaluation. The experimental results demonstrate that the proposed service offers a high degree of security adaptiveness at a low cost

  • 206.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Secure Socket SCTP: A Multi-layer End-to-End Security Solution2008Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 207.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    The Design and Implementation of Secure Socket SCTP2009Ingår i: Transactions on Computational Science, Vol. 5730, s. 180-199Artikel i tidskrift (Refereegranskat)
  • 208.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    The Design and Message Complexity of Secure Socket SCTP2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes the design of secure socket SCTP (SS-SCTP). SS-SCTP is a new end-to-end security solution that uses the AUTH extension for integrity protection of messages and TLS for mutual authentication and key negotiation. Data confidentiality is in SS-SCTP provided through encryption at the socket layer. SS-SCTP aims to offer a high degree of security differentiation based on features in the base SCTP protocol as well as in standardized extensions. The flexible message concept provided in the base protocol plays a central role in the design of SS-SCTP. In the paper, a comparison of the message complexity produced by SS-SCTP, SCTP over IPsec, and TLS over SCTP is also presented. The main conclusion that can be drawn from the comparison is that, depending on the traffic pattern, SS-SCTP produces either less or similar message overhead compared to the standardized solutions when transferring user data

  • 209.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Tunable Security Support for Wireless Applications2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    A tunable and differential treatment of security is needed to achieve the best possible balance between security and performance for wireless applications. In this paper, we present a tunable encryption service that is based on a selective encryption paradigm in which applications can request a desired encryption level. Encryption levels are selected at the inception of a session, but can be changed at any time during its lifetime. In the paper, a prototype implemented on top of the Stream Control Transmission Protocol (SCTP) is described and an initial performance evaluation is presented. The results demonstrate that the proposed service offers a high degree of security adaptiveness at a low cost

  • 210.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    A Measurement Study on IKEv2 Authentication Performance in Wireless Networks2009Konferensbidrag (Refereegranskat)
    Abstract

    This paper presents an experimental evaluation of the performance costs of a wide variety of authentication methods over IKEv2 in wireless networks. The studied methods are preshared keys (PSK), extensible authentication protocol (EAP) using MD5, SIM, TTLS-MD5, TLS, and PEAP-MSCHAPv2. For the EAP-based methods RADIUS is used as authentication, authorization, and accounting (AAA) server. Two network scenarios, WiFi and UMTS, are considered. The measurement results illustrate the practical costs involved for IKEv2 authentication, and show significant performance differences between the methods

  • 211.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    Analyzing Tunable Security Services2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper analyzes three existing tunable security services based on a conceptual model. The aim of the study is to examine the tunable features provided by the different services in a structured and consistent way. This implies that for each service user preferences as well as environment and application characteristics that influence the choice of a certain security configuration are identified and discussed

  • 212.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    Performance Evaluation of IKEv2 Authentication Methods in Next Generation Wireless Networks2010Ingår i: Journal of Security and Communication Networks, ISSN 1939-0122, Vol. 3, nr 1, s. 83-98Artikel i tidskrift (Refereegranskat)
    Abstract

    Secure communications have a key role in future networks and applications. Information security provisions such as authorization, authentication, and encryption must be added to current communications protocols. To accomplish this, each protocol must be reexamined to determine the impact on performance of adding such security services. This paper presents an experimental evaluation of the performance costs of a wide variety of authentication methods over IKEv2 in real and partly emulated scenarios of next generation wireless networks. The studied methods are pre-shared keys (PSKs), extensible authentication protocol (EAP) using MD5, SIM, TTLS-MD5, TLS, and PEAP-MSCHAPv2. For the EAP-based methods, RADIUS is used as the authentication, authorization, and accounting (AAA) server. Different lengths of certificate chains are studied in case of the TLS-based methods, i.e., TTLS-MD5, TLS, and PEAP-MSCHAPv2. The paper first presents a brief overview of the considered authentication methods. Then, a comparison of the costs for message transfers and computations associated with the authentication methods is provided. The measurement results are verified through a simple analysis, and interpreted by discussing the main contributing factors of the costs. The measurement results illustrate the practical costs involved for IKEv2 authentication, and the implications of the use of different methods are discussed

  • 213.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    Tunable Security Services for Wireless Networks2008Ingår i: Adaptation and Cross Layer Design in Wireless Networks / [ed] Mohamed Ibnkahla, Boca Raton, FL, USA: CRC , 2008Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    This chapter introduces the concept of tunable security services for wireless networks. The aim of the chapter is to describe how security can be traded against performance. A survey and analysis of existing tunable services, which have been explicitly designed to offer various security levels during system operation, is provided. In total eight different services are analyzed in detail. The selection of services is made to cover a broad spectrum of services and to illustrate services at different communication layers. Two services from each of the following four layers are described and analyzed: application layer, transport layer, network layer, and, data link layer. Additional tunable security services are also briefly introduced. The analysis illustrates that tunability can be used in many different contexts and achieved through various mechanisms. From the analysis it is also evident that more suitable security and performance metrics are needed

  • 214.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    Tóth, Katalin
    Providing Tunable Security Services2006Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 215.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    Tóth, Katalin
    Providing Tunable Security Services: An IEEE 802.11i Example2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The basic idea of QoS is to provide mechanisms that can offer different service levels, which are expressed through well-defined parameters that are specified at run-time on the basis of need. Bit rate, throughput, delay, jitter, and packet loss rate are all examples of common QoS parameters suggested for packet networks. These parameters are all aimed to express (and guarantee) a certain service level with respect to reliability and/or performance. In this paper, we investigate how security can be treated as yet another QoS parameter through the use of tunable security services. The main idea with this work is to let users specify a trade-off between security and performance through the choice of available security configuration(s). The performance metric used is latency. The concept is illustrated using the IEEE 802.11i wireless local area networking standard

  • 216.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Jonsson, Erland
    Dynamic Data Protection Services for Network Transfers: Concepts and Taxonomy2004Konferensbidrag (Refereegranskat)
    Abstract [en]

    Security should be thought of as a tunable system attribute that allows users to request a specific protection level as a service from the system. This approach will be suitable in future networking environments with heterogeneous devices that have varying computing resources. The approach is also appropriate for multimedia applications that require tuning of the protection level to maintain performance at levels that are acceptable to users. In this paper, we investigate data protection services for network transfers that are designed to offer variable protection levels and propose a taxonomy for such services. The taxonomy provides a unified terminology for dynamic data protection services and a framework in which they can systematically be inspected, evaluated, and compared. The taxonomy is also intended to provide a basis for the development and identification of current and future user and/or application needs. It comprises four dimensions: type of protection service, protection level, protection level specification, and adaptiveness. On the basis of the taxonomy, a survey and categorization of existing dynamic data protection services for network transfers are made

  • 217.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Jonsson, Erland
    Survey and Classification of Dynamic Data Protection Services for Network Applications2005Ingår i: Proceedings of the Fifth Conference for the Promotion of Research in IT at New Universities and University Colleges in Sweden (Promote IT 2005) / [ed] Janis Bubenko jr, Owen Eriksson, Hans Fernlund, and Mikael Lind, Lund, Sweden: Studentlitteratur , 2005Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Security should be thought of as a tunable system attribute that allows users to request a specific protection level as a service from the system. This approach will be suitable in future networking environments with heterogeneous devices that have varying computing resources. The approach is also appropriate for multimedia applications that require tuning the protection level to maintain performance at levels that are acceptable to users. In this paper, we survey a number of existing data protection services for network transfers that are designed to offer variable protection levels. The services are classified according to a taxonomy proposed in the paper

  • 218.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Faigl, Zoltán
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    A Conceptual Model for Analysis and Design of Tunable Security Services2008Ingår i: Journal of NetworksArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Security is an increasingly important issue for networked services. However, since networked

    environments may exhibit varying networking behavior and contain heterogeneous devices with

    varying resources tunable security services are needed. A tunable security service is a service that

    provides different security configurations that are selected, and possibly altered, at run-time. In this

    paper, we propose a conceptual model for analysis and design of tunable security services. The

    proposed model can be used to describe and compare existing tunable security services and to

    identify missing requirements. Five previously proposed services are analyzed in detail in the paper.

    The analysis illustrates the powerfulness of the model, and highlights some key aspects in the

    design of tunable security services. Based on the conceptual model, we also present a high-level

    design methodology that can be used to identify the most appropriate security configurations for a

    particular scenario

  • 219.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Data Protection based on Physical Separation: Concepts and Application Scenarios2005Ingår i: Computational Science and Its Applications: ICCSA 2005. Part IV / [ed] Gervasi, O.; Gavrilova, M.L.; Kumar, V.; Laganà, A.; Lee, H.P.; Mun, Y.; Taniar, D.; Tan, C.J.K., Berlin: Springer , 2005, s. 1331-1340Konferensbidrag (Refereegranskat)
    Abstract [en]

    Data protection is an increasingly important issue in today's communication networks. Traditional solutions for protecting data when transferred over a network are almost exclusively based on cryptography. As a complement, we propose the use of multiple physically separate paths to accomplish data protection. A general concept for providing physical separation of data streams together with a threat model is presented. The main target is delay-sensitive applications such as telephony signaling, live TV, and radio broadcasts that require only lightweight security. The threat considered is malicious interception of network transfers through so-called eavesdropping attacks. Application scenarios and techniques to provide physically separate paths are discussed

  • 220.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Physical Separation for Data Protection based on SCTP Multihoming2004Ingår i: Proceedings of the Second Swedish National Computer Networking Workshop: SNCNW2004, Karlstad, 2004Konferensbidrag (Refereegranskat)
    Abstract [en]

    Network security is an increasingly important issue. Traditional solutions for protecting data when transferred over the network are almost exclusively based on cryptography. As a complement, we propose the use of SCTP and its support for physically separate paths to accomplish protection against eavesdropping attacks near the end points.

  • 221.
    Lindskog, Stefan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Lundin, Reine
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Middleware Support for Tunable Encryption2006Ingår i: Wireless Information Systems: Proceedings of the 5th International Workshop on Wireless Information Systems / [ed] Qusay H. Mahmoud, Hans Weghorn, Setubal , Portugal: INSTICC Press , 2006, s. 36-46Konferensbidrag (Refereegranskat)
    Abstract [en]

    To achieve an appropriate tradeoff between security and performance for wireless applications, a tunable and differential treatment of security is required.

    In this paper, we present a tunable encryption service designed as a middleware that is based on a selective encryption paradigm. The core component of the middleware provides block-based selective encryption. Although the selection of which data to encrypt is made by the sending application and is typically content-dependent, the representation used by the core component is application and content-independent. This frees the selective decryption module at the receiver from the need for application or content-specific knowledge. The sending application specifies the data to encrypt either directly or through a set of highlevel application interfaces. A prototype implementation of the middleware isdescribed along with an initial performance evaluation. The experimental results demonstrate that the generic middleware service offers a high degree of security adaptiveness at a low cost.

     

  • 222.
    Lundin, Reine
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    A Model-based Analysis of Tunability in Privacy Services2008Ingår i: The Future of Identity in the Information Society: Proceedings of the Third IFIP WG 9.2, 9.6/ 11.6, 11.7/FIDIS International Summer School on The Future of Identity in the Information Society, Karlstad University, Sweden, August 4-10, 2007, Springer-Verlag New York, 2008, s. 343-356Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    In this paper, we investigate the tunable privacy features provided by Internet Explorer version 6 (IE6), Mix Net and Crowds, by using a conceptual model for tunable security services. A tunable security service is defined as a service that has been explicitly designed to offer various security configurations that can be selected at run-time. Normally, Mix Net and Crowds are considered to be static anonymity services, since they were not explicitly designed to provide tunability. However, as discussed in this paper, they both contain dynamic elements that can be used to utilize the trade-off between anonymity and performance. IE6, on the other hand, was indeed designed to allow end users to tune the level of privacy when browsing the Internet

  • 223.
    Lundin, Reine
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Analysis of Anonymity Services from a Tunable Perspective2007Ingår i: The Future of Identity in the Information Society: Proceedings of the Third IFIP WG 9.2, 9.6/ 11.6, 11.7/FIDIS International Summer School on The Future of Identity in the Information Society, Karlstad University, Sweden / [ed] Simone Fischer-Huebner, Penny Duquenoy, Albin Zuccato, Leonardo Martucci, Boston: IFIP , 2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we investigate the tunable features provided by Mix-Nets and Crowds using a conceptual model for tunable secu- rity services. A tunable security service is deflned as a service that has been explicitly designed to ofier various security levels that can be se- lected at run-time. Normally, Mix-Nets and Crowds are considered to be static anonymity services, since they were not explicitly designed to provide tunability. However, as discussed in this paper, they both con- tain dynamic elements that can be used to achieve a tradeofi between anonymity and performance

  • 224.
    Lundin, Reine
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Fischer-Hubner, Simone
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Using Guesswork as a Measure for Confidentiality of Selectively Encrypted Messages2006Ingår i: Quality of Protection: Security Measurements and Metrics / [ed] Dieter Gollmann, Fabio Massacci and Artsiom Yautsiukhin, Boston: Springer, 2006, s. 173-184Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    n this paper, we start to investigate the security implications of selective encryption. We do this by using the measure guesswork, which gives us the expected number of guesses that an attacker must perform in an optimal brute force attack to reveal an encrypted message. The characteristics of the proposed measure are investigated for zero-order languages. We also introduce the concept of reduction chains to describe how the message (or rather search) space changes for an attacker with different levels of encryption.

  • 225.
    Lundin, Reine
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Fischer-Hübner, Simone
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Measuring Confidentiality of Selectively Encrypted Messages Using Guesswork2005Ingår i: Proceeding of the Third Swedish National Computer Networking Workshop (SNCNW 2005), Halmstad: Högskolan i Halmstad , 2005, s. 99-102Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we start to investigate the security implications of selective encryption. We do this by using the measure guesswork, which gives us the expected number of guesses that an attacker performs in an optimal brute force attack to reveal an encrypted message. The characteristics of the proposed measure are only investigated for zero-order languages, and we give some basic initial results. The work is in progress and later papers will examine higher order of languages.

  • 226.
    Mancuso, Vincenzo
    et al.
    IMDEA Networks Institute, Spain.
    Peón Quirós, Miguel
    IMDEA Networks Institute, Spain; Ecole Polytech Fed Lausanne, Switzerland.
    Midoglu, Cise
    Simula Res Lab, Norway.
    Moulay, Mohamed
    IMDEA Networks Inst, Spain; University Carlos III of Madrid, Spain.
    Comite, Vincenzo
    IMDEA Networks Inst, Spain; University La Sapienza, Italy.
    Lutu, Andra
    Simula Res Lab, Norway.
    Alay, Ozgu
    Simula Res Lab, Norway.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Rajiullah, Mohammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Mellia, Marco
    Politecnico di Torino, Italy.
    Khatouni, Ali Safari
    Politecnico di Torino, Italy.
    Hirsch, Thomas
    Celerway, Norway.
    Results from running an experiment as a service platform for mobile broadband networks in Europe2019Ingår i: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 33, s. 89-101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article we present a selection from a vast range of experiments run with MONROE, our open experiment as a service (EaaS) platform for measurements and experimentation in Mobile Broadband Networks. We show that the platform can be used to benchmark network performance in a repeatable and controlled manner thanks to the collection of a rich set of geotagged metadata and the execution of discretionary user experiments. Indeed, with the sheer amount of data collected from 12 commercial mobile operators across Europe, MONROE offers an unprecedented opportunity to monitor, analyze and ultimately improve the status of current and future mobile broadband networks. Besides, we show how flexibly the platform allows combining metadata and experimental data series during the experiments or by means of post-processing, and show results produced by our own experiments as well as comment on results obtained by external research groups and developers that have been granted access to our platform.

  • 227.
    Mandalari, Anna Maria
    et al.
    University Carlos III of Madrid, Spain.
    Lutu, Andra
    Telefonica Research, Spain.
    Custura, Ana
    University of Aberdeen, Scotland.
    Khatouni, Ali Safari
    Politecnico di Torino, Italy.
    Alay, Özgü
    Simula Metropolitan, Norway.
    Bajpai,, Vaibhav
    Technische Universität München, Germany.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Ott, Jörg
    Technische Universität München, Germany.
    Mellia, Marco
    Politecnico di Torino, Italy.
    Fairhust, Gorry
    University of Aberdeen, Scotland.
    Experience: Implications of Roaming in Europe2018Ingår i: MobiCom '18. Proceedings of the 24th Annual International Conference on Mobile Computing and Networking / [ed] Rajeev Shorey, Rohan Murty, New York, USA: ACM Publications, 2018, s. 179-189Konferensbidrag (Refereegranskat)
    Abstract [en]

    "Roam like Home" is the initiative of the European Commission (EC) to end the levy of extra charges when roaming within the European region. As a result, people are able to use data services more freely across Europe. However, the implications roaming solutions have on performance have not been carefully examined. This paper provides an in-depth characterization of the implications of international data roaming within Europe. We build a unique roaming measurement platform using 16 different mobile networks deployed in six countries across Europe. Using this platform, we measure different aspects of international roaming in 3G and 4G networks, including mobile network configuration, performance characteristics, and content discrimination. We find that operators adopt common approaches to implementing roaming, resulting in additional latency penalties of ∼60 ms or more, depending on geographical distance. Considering content accessibility, roaming poses additional constraints that leads to only minimal deviations when accessing content in the original country. However, geographical restrictions in the visited country make the picture more complicated and less intuitive.

  • 228.
    Mohideen, Althaff C.
    et al.
    University of Aberdeen, UK.
    Rajiullah, Mohammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Secchi, Raffaello
    University of Aberdeen, UK.
    Fairhurst, Gorry
    University of Aberdeen, UK.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Weinrank, Felix
    Münster University of Applied Sciences, Germany.
    Evaluating the impact of transport mechanisms on web performance for effective web access2019Ingår i: Journal of Network and Computer Applications, ISSN 1084-8045, E-ISSN 1095-8592, Vol. 137, s. 25-34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper explores the design trade-offs required for an Internet transport protocol to effectively support web access. It identifies a set of distinct transport mechanisms and explores their use with a focus on multistreaming. The mechanisms are studied using a practical methodology that utilise the range of transport features provided by TCP and SCTP. The results demonstrate the relative benefit of key transport mechanisms and analyse how these impact web access performance. Our conclusions help identify the root causes of performance impairments and suggest appropriate choices guiding the design of a web transport protocol. Performing this analysis at the level of component transport mechanisms enables the results to be utilised in the design of new transport protocols, such as IETF QUIC.

  • 229.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    5G Mobile Networks – Requirements, Enabling Technologies, and Research Activities2017Ingår i: Comprehensive Guide to 5G Security / [ed] Madhusanka Liyanage, Andrei Gurtov, Mika Yliantilla, Ijaz Ahmed & Ahmed Bux Abro, John Wiley & Sons, 2017Kapitel i bok, del av antologi (Refereegranskat)
  • 230.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    SDN helps velocity in Big Data2018Ingår i: Big Data and Software Defined Networks / [ed] Javid Taheri, London: IET Digital Library, 2018, 1, s. 207-228Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Currently, improving the performance of Big Data in general and velocity in particular is challenging due to the inefficiency of current network management, and the lack of coordination between the application layer and the network layer to achieve better scheduling decisions, which can improve the Big Data velocity performance. In this chapter, we discuss the role of recently emerged software defined networking (SDN) technology in helping the velocity dimension of Big Data. We start the chapter by providing a brief introduction of Big Data velocity and its characteristics and different modes of Big Data processing, followed by a brief explanation of how SDN can overcome the challenges of Big Data velocity. In the second part of the chapter, we describe in detail some proposed solutions which have applied SDN to improve Big Data performance in term of shortened processing time in different Big Data processing frameworks ranging from batch-oriented, MapReduce-based frameworks to real-time and stream-processing frameworks such as Spark and Storm. Finally, we conclude the chapter with a discussion of some open issues.

  • 231.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). The University of Sydney, Australia.
    SDN/NFV-Based Mobile Packet Core Network Architectures: A Survey2017Ingår i: IEEE Communications Surveys and Tutorials, ISSN 1553-877X, E-ISSN 1553-877X, Vol. 19, nr 3, s. 1567-1602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The emergence of two new technologies, namely Software Defined Networking (SDN) and Network Function Virtualization (NFV) have radically changed the development of network functions and the evolution of network architectures. These two technologies bring to mobile operators the promises of reducing costs, enhancing network flexibility and scalability, and shortening the time-to-market of new applications and services. With the advent of SDN and NFV and their offered benefits, the mobile operators are gradually changing the way how they architect their mobile networks to cope with ever-increasing growth of data traffic, massive number of new devices and network accesses, and to pave the way towards the upcoming fifth generation (5G) networking. This paper aims at providing a comprehensive survey of state-of-the-art research work, which leverages SDN and NFV into the most recent mobile packet core network architecture, Evolved Packet Core (EPC). The research work is categorized into smaller groups according to a proposed four-dimensional taxonomy reflecting the (1) architectural ap- proach, (2) technology adoption, (3) functional implementation, and (4) deployment strategy. Thereafter, the research work is exhaustively compared based on the proposed taxonomy and some added attributes and criteria. Finally, the paper identifies and discusses some major challenges and open issues such as scalability and reliability, optimal resource scheduling and allocation, management and orchestration, network sharing and slicing that raise from the taxonomy and comparison tables that need to be further investigated and explored. 

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  • 232.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Carlsson, Adrian
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Cheng, Jun
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    On the Use of 5G for Inter-substation GOOSE Transmission in Smart Grid2019Ingår i: Proceedings of the Fifteenth Swedish National Computer Workshop (SNCNW), Luleå, Sweden. June 2019, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Protection and automation in a smart grid environmentoften have stringent real-time communication requirementsbetween devices within a substation as well as between distantlylocated substations. The Generic Object Oriented SubstationEvent (GOOSE) messaging service has been proposed to achievethis goal as it allows to transfer time-critical information within afew milliseconds. However, the transmission of GOOSE messagesare often limited to a small Local Area Network (LAN).In this paper, we propose the use of the fifth generation ofmobile networks (5G) as a means to transport GOOSE messagesin a large scale smart grid environment. The end-to-end delay ismeasured between GOOSE devices over an 5G network with thefocus on the core network using the Open5GCore platform in alab environment. Although there is a lack of a real radio accessnetwork, the experimental results confirm that the delay withinthe rest of the 5G network is small enough for it to be feasiblefor inter-substation GOOSE transmissions.

  • 233.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Cheng, Jun
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Brunstrom, Anna
    On the Use of a Virtualized 5G Core for Time Critical Communication in Smart Grid2020Ingår i: 2020 8th IEEE International Conference on Mobile Cloud Computing, Services, and Engineering (MobileCloud), Oxford, UK, August 3-6, 2020Konferensbidrag (Refereegranskat)
    Abstract [en]

    Protection and automation in a smart grid environment often have stringent real-time communication requirements between devices within a substation, as well as between distantly located substations. The Generic Object Oriented Substation Event (GOOSE) protocol has been proposed to achieve this goal as it allows to transfer time-critical information within a few milliseconds. However, the transmission of GOOSE messages is often limited to a small Local Area Network (LAN). An earlier work has proposed to use the fifth generation of mobile networks (5G) as a means to transport IP-based GOOSE messages in a large-scale smart grid environment. On the basis of this work, this paper designs and implements an alternative solution for Ethernet-based GOOSE communication over a virtualized 5G core network that does not require any modification of the existing network protocol stack and thus is much easier to deploy. Our experimental results show that the delay introduced by the core network is in the order of sub milliseconds, while the oneway delay without a real radio access network, and without background traffic, is less than 1 ms. Moreover, these delays can be significantly reduced with a container-based deployment rather than a virtual machine-based one. Assuming a 1-ms delay budget for a 5G radio access network, our evaluation confirms that it is indeed feasible to use 5G for GOOSE transmission in IEC 61850 substation automation systems.

  • 234.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A Deployable Containerized 5G Core Solution forTime Critical Communication in Smart Grid2020Konferensbidrag (Refereegranskat)
  • 235. Nguyen, Van-Giang
    et al.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Load balancing for a Virtual and Distributed MME using Weighted Round Robin2018Ingår i: The Fourteenth Swedish National Computer Networking Workshop (SNCNW)., SNCNW , 2018, s. 1-4Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In this paper, we aim at tackling the scalability ofthe Mobility Management Entity (MME) which is one of the key control plane entities of the 4G Evolved Packet Core (EPC). One of the solutions to this problem is to virtualize the MME by adopting the Network Function Virtualization (NFV) technology and deploy it as a pool of virtualized instances (vMMEs) with a frontend load balancer. Although several designs have been proposed, a large part of them does not consider the load balancing aspect. To this end, we propose using a Weighted Round Robin (WRR) algorithm for balancing signaling load in a MME architecture. We implement and compare its performance to two currently used algorithms: random and round robin. Experimental results show that the WRR algorithm can significantly reduce the control plane latency as compared to the other two schemes.

    Publikationen är tillgänglig i fulltext från 2020-12-31 09:36
  • 236.
    Nguyen, Van-Giang
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    On Load Balancing for a Virtual and Distributed MME in the 5G Core2018Ingår i: 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), IEEE, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we aim at tackling the scalability problem of the Mobility Management Entity (MME), which plays a crucial role of handling control plane traffic in the current 4G Evolved Packet Core as well as the next generation mobile core, 5G. One of the solutions to this problem is to virtualize the MME by applying Network Function Virtualization principles and then deploy it as a cluster of multiple virtual MME instances (vMMEs) with a front-end load balancer. Although several designs have been proposed, most of them assume the use of simple algorithms such as random and round-robin to balance the incoming traffic without any performance assessment. To this end, we implemented a weighted round robin algorithm which takes into account the heterogeneity of resources such as the capacity of vMMEs. We compare this algorithm with a random and a round-robin algorithm under two different system settings. Experimental results suggest that carefully selected load balancing algorithms can significantly reduce the control plane latency as compared to simple random or round-robin schemes.

  • 237.
    Nordby, Eivind J
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Blom, Martin
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    A Case Study of an Industry Project1999Rapport (Övrigt vetenskapligt)
  • 238.
    Nordby, Eivind J
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Blom, Martin
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Error Management with Design Contracts2001Konferensbidrag (Refereegranskat)
  • 239.
    Nordby, Eivind J
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Blom, Martin
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    On the Relation between Design Contracts and Errors; A Software Development Strategy2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    When designing a software module or system, a systems engineer must consider and differentiate between how the system responds to external and internal errors. External errors cannot be eliminated and must be tolerated by the system, while the number of internal errors should be minimized and the faults they result in should be detected and removed. This paper presents a development strategy based on design contracts and a case study of an industrial project in which the strategy was successfully applied. The goal of the strategy is to minimize the number of internal errors during the development of a software system while accommodating external errors. A distinction is made between weak and strong contracts. These two types of contracts are applicable to external and internal errors respectively. According to the strategy, strong contracts should be applied initially to promote the correctness of the system. Before release, the contracts governing external interfaces should be weakened and error management of external errors enabled. This transformation of a strong contract to a weak one is harmless to client modules

  • 240.
    Nordby, Eivind J
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Blom, Martin
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Underhåll av programvara2000Ingår i: Del av kapitel 5 i "Industriell Programvaruteknik. Forskningsresultat i kortform”, NUTEK Förlag Nr: B 2000:01 (www.nutek.se) , 2000Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 241. Norlund, K.
    et al.
    Ottosson, T.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Fairness Measures for Best Effort Traffic in Wireless Networks2004Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes that fairness in wireless

    networks should be measured using one of the following

    new measures: the deterministic unfairness bound called the wireless absolute fairness bound (WAFB) or the statistical unfairness bound called the 99-percentile wireless absolute fairness bound (WAFB99). Compared with previous fairness de_nitions, the new fairness measures are better suited for measuring fairness of scheduling disciplines that exploit multiuser diversity.

    A new scheduling discipline called opportunistic proportional fair scheduling is de_ned. Numerical results show that the new scheduling discipline has slightly higher throughput and slightly better fairness than proportional fair scheduling.

  • 242. Norlund, K.
    et al.
    Ottosson, T.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    TCP fairness measures for scheduling algorithms in wireless networks2005Konferensbidrag (Refereegranskat)
  • 243.
    Oljira, Dejene Boru
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Analysis of Network Latency in Virtualized Environments2016Ingår i: Global Communications Conference (GLOBECOM), 2016 IEEE, IEEE, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    Virtualization is central to cloud computing systems. It abstracts computing resources to be shared among multiple virtual machines (VMs) that can be easily managed to run multiple applications and services. To benefit from the advantages of cloud computing, and to cope with increasing traffic demands, telecom operators have adopted cloud computing. Telecom services and applications are, however, characterized by real-time responsiveness, strict end-to-end latency, and high reliability. Due to the inherent overhead of virtualization, the network performance of applications and services can be degraded. To improve the performance of emerging applications and services that demand stringent end-to-end latency, and to understand the network performance bottleneck of virtualization, a comprehensive performance measurement and analysis is required. To this end, we conducted controlled and detailed experiments to understand the impact of virtualization on end-to-end latency and the performance of transport protocols in a virtualized environment. We also provide a packet delay breakdown in the virtualization layer which helps in the optimization of hypervisor components. Our experimental results indicate that the end-to-end latency and packet delay in the virtualization layer are increased with co-located VMs.

  • 244.
    Oljira, Dejene Boru
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Measurement and Analysis of Network Performance in Virtualized Environments2016Ingår i: Proceedings of the 12th Swedish National Computer Networking Workshop (SNCNW), June 2016, Sundsvall, Sweden, 2016Konferensbidrag (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 245.
    Oljira, Dejene Boru
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Validating the Sharing Behavior and Latency Characteristics of the L4S Architecture2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Internet services such as virtual reality, interactive cloud applications, and online gaming, have a strict quality of service requirements (e.g., low-latency). However, the current Internet is not able to satisfy the low-latency requirements of these applications. This as the standard TCP induces high queuing delays when used by capacity-seeking traffic, which in turn results in unpredictable latency. The Low Latency Low Loss Scalable throughput (L4S) architecture aims to address this problem by combining scalable congestion controls (e.g., DCTCP) with early congestion signaling from the network. For incremental deployment, the L4S architecture defines a Dual Queue Coupled AQM that enables the safe coexistence of scalable and classic (e.g., Reno, Cubic, etc.) flows on the global Internet. The DualPI2 AQM is a Linux kernel implementation of a Dual Queue Coupled AQM. In this paper, we benchmark the DualPI2 AQM to validate experimental result(s) reported in previous works that demonstrate the coexistence of scalable and classic congestion controls, and its low-latency service. Our results validate the coexistence of scalable and classic flows using DualPI2 single queue AQM while the result with dual queue shows neither rate nor window fairness between the flows.

  • 246.
    Oljira, Dejene Boru
    et al.
    Karlstads universitet.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Validating the Sharing Behavior and Latency Characteristics of the L4S Architecture2020Övrigt (Refereegranskat)
    Abstract [en]

    The strict low-latency requirements of applications such as virtual reality, online gaming, etc., can not be satisfied by the current internet. This is due to the characteristics of classic TCP such as Reno and TCP Cubic which induce high queuing delays when used for capacity-seeking traffic, which in turn results in unpredictable latency. The Low Latency, Low Loss, Scalable throughput (L4S) architecture addresses this problem by combining scalable congestion controls such as DCTCP and TCP Prague with early congestion signaling from the network. It defines a Dual Queue Coupled (DQC) AQM that isolates low-latency traffic from the queuing delay of classic traffic while ensuring the safe co-existence of scalable and classic flows on the global Internet. In this paper, we benchmarktheDualPI2 scheduler, a reference implementation of DQC AQM, to validate some of the experimental result(s) reported in the previous works that demonstrate the co-existence of scalable and classic congestion controls and its low-latency service. Our results validate the co-existence of scalable and classic flows using DualPI2 Singlequeue (SingleQ) AQM, and queue latency isolation of scalable flows using DualPI2 Dual queue (DualQ) AQM. However, the rate or win-dow fairness between DCTCP without fair-queuing (FQ) pacing and TCP Cubic using DualPI2 DualQ AQM deviates from the original results. We attribute the difference in our results and the original results to the sensitivity of the L4S architecture to traffic bursts and the burst sending pattern of the Linux kernel.

  • 247.
    Oljira, Dejene Boru
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A Model for QoS-Aware VNF Placement and Provisioning2017Ingår i: Network Function Virtualization and Software Defined Networks (NFV-SDN), 2017 IEEE Conference on / [ed] IEEE, IEEE, 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    Network Function Virtualization (NFV) is a promising solution for telecom operators and service providers to improve business agility, by enabling a fast deployment of new services, and by making it possible for them to cope with the increasing traffic volume and service demand. NFV enables virtualization of network functions that can be deployed as virtual machines on general purpose server hardware in cloud environments, effectively reducing deployment and operational costs. To benefit from the advantages of NFV, virtual network functions (VNFs) need to be provisioned with sufficient resources and perform without impacting network quality of service (QoS). To this end, this paper proposes a model for VNFs placement and provisioning optimization while guaranteeing the latency requirements of the service chains. Our goal is to optimize resource utilization in order to reduce cost satisfying the QoS such as end- to-end latency. We extend a related VNFs placement optimization with a fine-grained latency model including virtualization overhead. The model is evaluated with a simulated network and it provides placement solutions ensuring the required QoS guarantees. 

  • 248.
    Oljira, Dejene Boru
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Taheri, Javid
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    MDTCP: Towards a Practical Multipath Transport Protocol for Telco Cloud Datacenters2018Ingår i: 9th International Conference on the Network of the Future (NOF), IEEE, 2018, s. 9-16Konferensbidrag (Refereegranskat)
  • 249. Ottosson, T.
    et al.
    Ahlén, A.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Sternad, M.
    Svensson, A.
    Toward 4G IP-based Wireless Systems: A Proposal for the Uplink2002Konferensbidrag (Refereegranskat)
  • 250. Ottosson, T.
    et al.
    Ahlén, A.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Sternad, M.
    Svensson, A.
    Towards 4G IP-based Wireless Systems2001Konferensbidrag (Refereegranskat)
    Abstract [en]

    A packet switched wireless cellular system with wide area coverage and high throughput is proposed. It is designed to be cost effective and to provide high spectral efficiency.

    The high performance is achieved by the use of long term channel predictions, in both time and frequency, scheduling among users, and smart antennas combined with adaptive modulation and power control. Calculations of the spectral efficiency of the downlink, based on reasonable simplifying assumptions, indicate that a tremendous capacity can be attained for moderate numbers of users and terminal antennas.

    We also briefly discuss other means for performance improvements such as alternatives to standard TCP, interlayer interaction/communication, and the use of positioning information.

234567 201 - 250 av 301
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