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  • 51.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Reliable and Secure Communication in SCTP2010Konferensbidrag (Refereegranskat)
  • 52.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Garcia, Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    NEWCOM DR6.2: First report on frameworks/models matching Department 6 needs2005Rapport (Refereegranskat)
    Abstract [en]

    During the first phase of NEWCOM the focus areas of Department 6 were identified and refined. A number of relevant knowledge gaps were identified for the areas transport protocols, architectures and cross-layer aspects, and modelling. In this deliverable we describe a first set of frameworks/models to support research integration within the Department. The integration approach and the defined models/frameworks are described for each one of the selected knowledge gaps. The deliverable also includes a report on tools, software libraries and traces that can be shared between the partners

  • 53.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Asplund, Katarina
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Garcia, Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Enhancing TCP Performance by Allowing Controlled Loss2000Konferensbidrag (Refereegranskat)
  • 54.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Cavalcanti de Castro, Marcel
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Karlsson, Jonas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Palazzo, S
    DR11.2: Intermediate report on resource management issues and routing/forwarding schemes for opportunistic networks2009Rapport (Refereegranskat)
  • 55.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Cavalcanti de Castro, Marcel
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lavén, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Dely, Peter
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Galluccio, L
    NEWCOM++ DR11.3: Final report on the activities and results of WPR112010Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This document is the last deliverable of WPR.11 and presents an overview of the final activities carried out within the NEWCOM++ Workpackage WPR.11 during the last 18 months. We provide a description of the most consolidated Joint Research Activities (JRAs) and the main results so far obtained. We also address some considerations on the future activities which are expected to continue at the end of NEWCOM++

  • 56.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    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.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Martucci, Leonardo
    NEWCOM DR7.1: Report on the knowledge gaps to be filled and the action plan2004Rapport (Refereegranskat)
    Abstract [en]

    This deliverable is the starting point of the activities in the NEWCOM Department 7 QoS Provision in Wireless Networks: Mobility, Security and Radio Resource Management. It provides the view of the department in terms of the objectives of the European research on Wireless Network aspects and, after developing the framework for QoS provision in wireless networks, it identifies the knowledge gaps existing in the fields of radio resource allocation, mobility management and security issues. As a result of that, the action plan for the future activities in the department is established

  • 57.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Garcia, Johan
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    NEWCOM DR6.1: Report on the knowledge gaps to be filled and the action plan2004Rapport (Refereegranskat)
    Abstract [en]

    The EU FP6 network of excellence in wireless communication, Newcom, is a large network that covers most areas of wireless communication. The research work within Newcom is organized into a number of departments and projects where Department 6 addresses Protocols and Architectures, and Traffic Modelling for (Reconfigurable/ Adaptive) Wireless Networks. The scope of Department 6 is quite broad making it important to further identify and refine the focus areas of the department. This document summarizes research areas that fall within the competence of and are of interest for the members of Department 6 and also describes the background of the partners within these areas. A set of knowledge gaps that will be addressed within the department are identified. A number of integrating activities that can be used to coordinate the efforts of the partners are described and an action plan for the continued work within the department is provided

  • 58.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Garcia, Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    NEWCOM DR6.4: Proceedings of the Newcom Department 6 Second Technical Workshop2005Rapport (Refereegranskat)
    Abstract [en]

    The Second Newcom Department 6 Technical Workshop was organized in Barcelona on September 16-17, 2005. The workshop program contained 6 presentations and provided a good overview of ongoing research integration activities within the department. All of the three areas of the department, transport protocols, architectures and cross-layer aspects, and modelling were represented with presentations. This deliverable contains the presentation material from the workshop. The included presentations are:



    - Westwood-SCTP: A Transport Protocol for Traffic Balancing on Multihomed Hosts

    - Transport Layer Handover using SCTP

    - The Optimization of Transport Protocol over Ad-Hoc Networks

    - Wireless Networks Emulation

    - An Analytical Model of Rate-Controlled MPEG Video Sources in a UMTS Network

    - An Analytical Model of a Rate-controlled MPEG-4 Video Source Capturing both Intra-frame and Inter-frame Correlation



    As an option, a supporting paper for the presentation could also be supplied by the authors. The

    deliverable contains supporting articles for two of the presentations

  • 59.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Kearns, P
    Global Predicate Detection Based on Transport Layer Vector Time1997Konferensbidrag (Refereegranskat)
  • 60.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Kearns, Phil
    Transport Layer versus Application Layer Vector Time1997Rapport (Refereegranskat)
    Abstract [en]

    Vector time has emerged as a useful technique for solving problems in distributed systems. Although vector time is likely to be maintained by supporting code positioned in kernel space or in message-passing middleware, vector time is traditionally viewed as if it were defined at the application layer.

    In this paper we consider vector time as perceived at the transport layer. We establish existing relationships between transport layer and application layer vector time. Transport layer vector time provides a more up-to-date view of the current system state. Furthermore, transport layer vector time preserves any interprocess causal relationships captured by application layer vector time. We illustrate how the more up-to-date view of the transport layer can improve both the accuracy and the efficiency for algorithms on which concurrency has an adverse effect. Some general guidelines for when transport layer vector time may be appropriate are provided. The possibility of updating vector time for acknowledgment messages is also considered. A new

    distributed termination detection algorithm based on this feature is presented

  • 61.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Proceedings of the 2nd International Workshop on Security and Communication Networks (IWSCN 2010)2010Bok (Refereegranskat)
    Abstract [en]

    This publication contains the Proceedings of the 2nd International Workshop on Security and Communication Networks (IWSCN 2010) that will be held on May 2628, 2010 in Karlstad, Sweden. IWSCN 2010 brings together researchers, developers, practitioners, and users interested in the area of security and communication networks. The workshop focuses on how to design, build, and evaluate future networks that are secure, reliable, and provide high and predictable performance. The aim of the workshop is to serve as a forum for presenting current and future work, as well as to exchange research ideas in these fields.Papers containing research contributions focusing on aspects of security and communication networks were solicited for submission to IWSCN 2010. A total of 40 papers were received, representing authors from 20 different countries and 5 different continents. Each paper was reviewed by at least three members of the technical program committee. After a thorough review process, 13 papers were selected for presentation at the workshop, giving an acceptance rate of 32.5%. In addition to the technical papers, two keynote presentations on The Changing Performance Goals in Internet Video Streaming and Dependable Protocols for Wireless Sensor Networks will be provided by Carsten Griwodz from the Simula Research Laboratory AS in Norway and Levente Buttyán from Budapest University of Technology and Economics in Hungary, respectively. Furthermore, a tutorial on Penetration Testing from an Attacker Perspective will be given by Vesa Virta from the National Defence Radio Establishment in Sweden.IWSCN 2010 is organized by the Department of Computer Science at Karlstad University and is supported by the Euro-NF and Newcom++ EU Networks of Excellence, and IEEE Sweden Section. The workshop is sponsored by Compare Karlstad Foundation, Coromatic, and TeliaSonera, and we thank them for their support. We also gratefully thank all authors, members of the program committee, and the local organizing committee for contributing to the scientific quality of the workshop

  • 62.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Garcia, Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    NEWCOM DR6.6: Second report on common frameworks/models matching Department 62006Rapport (Refereegranskat)
    Abstract [en]

    Work within Department 6 of NEWCOM is organized into the areas transport protocols, architectures and cross-layer aspects, and modelling. In this deliverable we provide a second report on the frameworks/models used to support research integration within the Department. The integration approach and the defined models/frameworks are described for each one of the three areas of the department. The deliverable also includes an updated report on tools, software libraries and traces that can be shared between the partners

  • 63.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Garcia, Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    NEWCOM DR6.7: Proceedings of the Newcom Department 6 Second Technical Workshop2006Rapport (Refereegranskat)
    Abstract [en]

    The Third Newcom Department 6 Technical Workshop was organized in Catania, Italy, on February 2, 2006. The workshop program contained 4 presentations and contained reports on ongoing integrated research activities as well as presentation intended to initiate additional joint research within the department. All of the three areas of the department, transport protocols, architectures and cross-layer

    aspects, and modelling were represented with presentations. This deliverable contains the presentation material from the workshop. The included presentations are:



    - P2P-based Video transmission in wireless networks

    - Transport Layer Handover using SCTP

    - WIPEMU 4G System Emulation and Sample Results

    - Wireless Networks Emulation



    Where available the presentation notes are also included with the presentations

  • 64.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Garcia, Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    NEWCOM DR6.9: Proceedings of the Newcom Department 6 Fourth Technical Workshop2006Rapport (Refereegranskat)
    Abstract [en]

    The Fourth Newcom Department 6 Technical Workshop was organized in Toulouse, France, on September 13-14, 2006. The workshop program contained 6 presentations and contained reports on ongoing integrated research activities as well as presentation intended to initiate additional joint research activities between the partners. All of the three areas of the department, transport protocols, architectures and cross-layer aspects, and modelling were represented with presentations. This deliverable contains the presentation material from the workshop. The included presentations are:



    - P2P Video Transmission over Heterogeneous Wired/Wireless Networks: A Starting Point for Integrated Research

    - DCCP Overview and First Experiments

    - Estimation of the SCTP Failover Time

    - Improving End to End Goodput of Ad Hoc Networks with SCTP Multihoming

    - A Taxonomy and Survey of SCTP Research

    - Integrating KAUnet and SWINE



    Where available the presentation notes are also included with the presentations

  • 65.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Ottosson, T.
    The Introduction of Soft Information in IP-Based Wireless Networks2001Konferensbidrag (Refereegranskat)
    Abstract [en]

    The underlying physical link is transparent in most IP-based networks. Contrary to this commonly accepted

    design rule, we propose that the applications should be made aware of the channel conditions. This is especially

    fruitful for wireless links where the performance is many orders of magnitudes lower than in fixed networks.

    Instead of wasting resources to make the wireless link behave as a fixed link, the application could take care of

    the adaptation to the channel condition. The presented solution assumes that soft information consisting of a

    reliability measure of the received bits is produced in the physical layer. This soft information is then propagated

    to the application. The application may use this information to distinguish between errors caused by fading and network congestion. Another possible use for soft information is to make the applications adapt the source and channel codes to the current channel condition and thus maximize performance.

  • 66.
    Brunström, Anna
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Simha, R
    Dynamic versus Static Load Balancing in a Pipeline Computation1997Ingår i: International Journal of Modeling and Simulation. Vol. 17, No 4, 1997, pp317-327Artikel i tidskrift (Refereegranskat)
  • 67.
    Budzisz, Lukasz
    et al.
    Signal Theory and Communication Dept., Universitat Politechnìca de Catalunya.
    Ferrus, Ramon
    Signal Theory and Communication Dept., Universitat Politechnìca de Catalunya.
    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.
    An Analytical Estimation of the Failover Time in SCTP Multihoming Scenarios2007Ingår i: IEEE Wireless Communications and Networking Conference, IEEE , 2007, s. 3929-3934Konferensbidrag (Refereegranskat)
    Abstract [en]

    The motivation behind this paper is a need to have a more accurate estimation of the failover time in SCTP. The traditional one, commonly used in the literature, is based on the sum of the consecutive retransmission timeouts. This is not always appropriate, especially when using the SCTP multihoming feature as a basis for achieving transport layer mobility in wireless networking scenarios, where the transition time between available paths becomes a key aspect for the optimisation. Two new factors are introduced into the proposed estimation formula to reflect the influence of the network parameters and the behaviour of the most common protocol implementations. For the proposed model, we perform a best-worst case analysis, and then illustrate it with an example of a detailed estimation. Finally, we perform simulations comparing our proposal with the traditional estimation in a typical transport layer mobility scenario including long thin networks.

  • 68.
    Budzisz, Lukasz
    et al.
    Department of Signal Theory and Communications (TSC), Universitat Politecnica de Catalunya.
    Ferrús, Ramon
    Brunstrom, Anna
    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.
    Fracchia, Roberta
    Motorola Labs – Paris, France.
    Galante, Giulio
    Istituto Superiore Mario Boella.
    Casadewall, Ferran
    Department of Signal Theory and Communications (TSC), Universitat Politecnica de Catalunya.
    Towards transport-layer mobility: Evolution of SCTP multihoming2008Ingår i: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 31, nr 5, s. 980-998Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recently, growing availability of emerging wireless technologies has pushed the demand to integrate different wireless-network technologies such as: wireless local-area networks, cellular networks, and personal and short-range networks. The inter-working of heterogeneous radio access networks poses many technical challenges, with mobility management being one of the most important. In this paper we survey the existing proposals and show that transport-layer mobility is a viable candidate for implementing seamless handover in heterogeneous wireless access networks. Since the mobile Stream Control Transmission Protocol (mSCTP) is at the core of most relevant transport-layer mobility schemes being currently studied, we identify the key scenarios where the protocol can effectively leverage the multihoming feature to enhance handover support. Moreover, to provide the reader with a complete overview of the mSCTP's application area, we also survey the situations where the use of mSCTP-based schemes is not possible or has some limitations. Then, in one of the identified key scenarios, we investigate several challenging open issues related to path management and path-transition optimization by considering bandwidth-estimation schemes and link-layer support. Finally, we consider introducing concurrent multipath transfer (CMT) into mSCTP-based mobility schemes, as a future research direction.

  • 69.
    Budzisz, Łukasz
    et al.
    Technische Universität Berlin, Berlin, Germany.
    Garcia, 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).
    Ferrús, Ramon
    Universitat Politècnica de Catalunya, Barcelona, Spain.
    A taxonomy and survey of SCTP research2012Ingår i: ACM Computing Surveys, ISSN 0360-0300, E-ISSN 1557-7341, Vol. 44, nr 4, s. -36, artikel-id 18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Stream Control Transmission Protocol (SCTP) is a relatively recent general-purpose transport layer protocol for IP networks that has been introduced as a complement to the well-established TCP and UDP transport protocols. Although initially conceived for the transport of PSTN signaling messages over IP networks, the introduction of key features in SCTP, such as multihoming and multistreaming, has spurred considerable research interest surrounding SCTP and its applicability to different networking scenarios. This article aims to provide a detailed survey of one of these new features—multihoming—which, as it is shown, is the subject of evaluation in more than half of all published SCTP-related articles. To this end, the article first summarizes and organizes SCTP-related research conducted so far by developing a four-dimensional taxonomy reflecting the (1) protocol feature examined, (2) application area, (3) network environment, and (4) study approach. Over 430 SCTP-related publications have been analyzed and classified according to the proposed taxonomy. As a result, a clear perspective on this research area in the decade since the first protocol standardization in 2000 is given, covering both current and future research trends. On continuation, a detailed survey of the SCTP multihoming feature is provided, examining possible applications of multihoming, such as robustness, handover support, and loadsharing.

  • 70. Burnett, Robert
    et al.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Nilsson, Anders G.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för informatik och projektledning.
    Perspectives on Multimedia: Communication, Media and Information Technology2003Bok (Refereegranskat)
    Abstract [en]

    The uses of multimedia are rapidly increasing. Its power to present information in ways not previously possible and its integration of resources, allow for the creation of rich learning environments. The book "Perspectives on Multimedia: Communication, Media and Information Technology" provides a critical examination of the latest multimedia developments and approaches, such as Interface Technology and QoS architectures.



    Topics covered include:

    - The key concepts intrinsic to digital forms of multimedia: integration, interactivity, hypermedia, immersion, narrativity, and hybridity.

    - The development of Informatiuon Technology (IT) usage in society and in the business community.

    - How modern IT enables private companies and public organisations to support business operations, create new business opportunities, and to promote more proactive service management.

    - Multimedia from a computer science perspective and how computer science provides the technical foundation for the computer software and hardware that drives the information usage.



    Gives a broad range of perspectives on key issues for interactive multimedia in organsiations and industry today. This book will be of interest to practioners involved in multimedia development in an organisation, management consultants gviving professional advice on digital solutions and inforamtion technology matters to their customer organisations and academics focusing on business and technical aspects of multimedia frameworks

  • 71.
    di stasi, Giovanni
    et al.
    Computer Science Department, University “Federico II” of Naples, Via Claudio 21, 80125 Naples, Italy.
    Karlsson, Jonas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Avallone, Stefano
    Computer Science Department, University “Federico II” of Naples, Via Claudio 21, 80125 Naples, Italy.
    Canonico, Roberto
    Computer Science Department, University “Federico II” of Naples, Via Claudio 21, 80125 Naples, Italy.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Combining Multi-Path Forwarding and Packet Aggregation for Improved Network Performance in Wireless Mesh Networks2014Ingår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 68, s. 26-37Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wireless mesh networks (WMNs) based on the IEEE 802.11 standard are becoming increasingly popular as a viable alternative to wired networks. WMNs can cover large or difficult to reach areas with low deployment and management costs. Several multi-path routing algorithms have been proposed for such kind of networks with the objective of load balancing the traffic across the network and providing robustness against node or link failures. Packet aggregation has also been proposed to reduce the overhead associated with the transmission of frames, which is not negligible in IEEE 802.11 networks. Unfortunately, multi-path routing and packet aggregation do not work well together, as they pursue different objectives. Indeed, while multi-path routing tends to spread packets among several next-hops, packet aggregation works more efficiently when several packets (destined to the same next-hop) are aggregated and sent together in a single MAC frame. In this paper, we propose a technique, called aggregation aware forwarding, that can be applied to existing multi-path routing algorithms to allow them to effectively exploit packet aggregation so as to increase their network performance. In particular, the proposed technique does not modify the path computation phase,but it just influences the forwarding decisions by taking the state of the sending queues into account.We demonstrated our proposed technique by applying it to Layer-2.5, a multi-path routing and forwarding paradigm for WMNs that has been previously proposed.We conducted a thorough performance evaluation by means of the ns-3 network simulator, which showed that our technique allows to increase the performance both in terms of network throughput and end-to-end delay.

  • 72.
    Eklund, Johan
    et al.
    Karlstads universitet, Institutionen för informationsteknologi.
    Brunstrom, Anna
    Karlstads universitet, Institutionen för informationsteknologi.
    Performance of Network Redundancy Mechanisms in SCTP2005Rapport (Övrigt vetenskapligt)
    Abstract [en]

    One of the ambitions when designing the Stream Control Transmission Protocol was to offer a robust transfer of traffic between hosts. For this reason SCTP was designed to support multihoming, which presumes the possibility to set up several paths between the same hosts in the same session. If the primary path between a source machine and a destination machine breaks down, the traffic may still be sent to the destination, by utilizing one of the alternate paths. The failover that occurs when changing path is to be transparent to the application.

    This paper describes the results from experiments concerning SCTP failover performance, which means the time between occurrence of a break on the primary path until the traffic is run smoothly on the alternate path. The experiments are performed mainly to verify the Linux Kernel implementation of SCTP (LK-SCTP) and is run on the Emulab platform. The results will serve as a basis for further experiments.

    The experiments are performed in a network without concurrent traffic and in conclusion the results from the experiments correspond well to the values found in other studies and they are close to the theoretical best values. As expected the parameter Path.Max.Retrans has a great impact on the failover time. One observation is that the failover time and the max transfer time for a message are dependent upon the status in the network when the break of the primary path occurs.

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  • 73.
    Eklund, Johan
    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.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Improving mSCTP-based Vertical Handovers by Increasing the Initial Congestion Window2011Ingår i: / [ed] Johan Eklund,Karl-Johan Grinnemo, Anna Brunstrom, 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wireless networks play an increasingly important role in our daily lives. However, the wireless landscape comprises serveralnetwork technologies, and which technology to use is often context dependent and varies over time: In urban areas, WiFi viaa WiFi hotspot might be the preferred access technology, while in rural areas 3G, HSPA or some other 3GPP technologymight be the only viable alternative. To this end, a large number of vertical handover solutions, ranging from link-level toapplication-level solutions, has been proposed in the past several years.We believe that the Stream Control Transmission Protocol and its extension for Dynamic Address Reconfiguration (mSCTP)make up an attractive vertical handover solution, especially in cases where there are little or no economic incentives to modify orupgrade the existing network infrastructure. Currently, we are implementing an mSCTP-based mobility management frameworkfor Android smartphones and tablets, and as part of that work we are considering ways of mitigating the effects of a handoveron ongoing transport sessions.A mobile terminal with several network interfaces may traverse different types of networks (WLAN, UMTS, HSPA).A seamless handover between these networks may be achieved by the transport protocol, Stream Control TransmissionProtocol(SCTP), with its multihoming facility (mSCTP), in conjunction with a mobility manager monitoring the availablenetwork interfaces. SCTP, a reliable transport protocol, closely related to TCP, encompasses slow-start in the beginning of asession. This slow-start phase is also activated to probe for network capacity on the target path after a handover, which couldresult in unncessarily reduced throughput in case of spare capacity in the network. The throughput degradation in could becrucial for an ongoing real time session, like video conferencing. In this study we have conducted experiments on the benefitof increasing the initial congestion window to reduce the negative impact of the slow start phase. We have by experimentsquantified the performance gain from an increasd initial window, and have seen that there a reduction in maximum transfertime for a message of about 50 % in scenarios with real-time video, compared to the default initial congestion window. Theimprovement is most prominent in sessions with high transfer delays. One easy, and thus very attractive, way to improveon the handover performance is to increase the initial congestion window on the handover target path. Although a seeminglycontroversal proposition, one should bear in mind that researchers at Google and other cloud computing companies are currentlystrongly promoting a drastic increase of TCP’s initial congestion window within IETF.

  • 74.
    Eklund, Johan
    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.
    Impact of SACK delay and link delay on Failover performance in SCTP2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Stream Control Transmission Protocol (SCTP) was developed

    to support the transfer of telephony signaling over

    IP networks. One of the ambitions when designing SCTP

    was to offer a robust transfer of traffic between hosts. For

    this reason SCTP was designed to support multihoming,

    which gives the possibility to set up several paths between

    the same hosts in the same session. If the primary path between

    a source machine and a destination machine breaks

    down, the traffic may still be sent to the destination by utilizing

    one of the alternate paths. The failover that occurs

    when changing path is to be transparent to the application.

    Consequently, the time between occurrence of a break on

    the primary path until the traffic is run smoothly on one of

    the alternate paths is important. This paper presents experimental

    results concerning SCTP failover performance. The

    focus in this paper is to evaluate the impact of the SACK

    delay and link delay on the failover time as well as on the

    maximum transfer time for a single message, which complements

    earlier studies in this area. The results show a

    significant performance impact of the SACK delay as well

    as of the link delay. This suggests that the SACK delay

    is an important parameter to tune to enhance application

    transparency in failure situations

  • 75.
    Eklund, Johan
    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.
    Performance of Network Redundancy Mechanisms in SCTP2005Rapport (Refereegranskat)
    Abstract [en]

    One of the ambitions when designing the Stream Control Transmission Protocol was to offer a robust transfer of traffic between hosts. For this reason SCTP was designed to support multihoming, which presumes the possibility to set up several paths between the same hosts in the same session. If the primary path between a source machine and a destination machine breaks down, the traffic may still be sent to the destination, by utilizing one of the alternate paths. The failover that occurs when changing path is to be transparent to the application.



    This paper describes the results from an experiment concerning SCTP failover performance, which means the time between occurrence of a break on the primary path until the traffic is run smoothly on the alternate path. The experiment is performed mainly to verify the Linux Kernel implementation of SCTP (LK-SCTP) and is run on the Emulab platform. The results will serve as a basis for further experiments.



    The experiment is performed in a network without concurrent traffic and in conclusion the results from the experiment correspond well to the values found in other studies and they are close to the theoretical best values. As expected the parameter Path.Max.Retrans has a great impact on the failover time. One observation is that the failover time and the max transfer time for a message are dependent upon the status in the network when the break of the primary path occurs.

  • 76.
    Eklund, Johan
    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.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Cheimonidis, Georgios
    Ismailov, Yuri
    Delay Penalty during SCTP Handover2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The rapidly growing interest in untethered Internet connections such as WLAN and 3G/4G mobile connections,calls for intelligent session management, not least in terms of handovers. As part of an effort to develop a SCTP-based session management framework, we are studying ways of improving the SCTP handover delay forreal-time traffic by optimizing the startup delay on the handover-target path. We have developed a theoretical model that predicts the transfer times of SCTP messages during the startup on a new path. This paper validates our model. It shows that the model can be used to predict message transfer times in variable bitrate flows. The paper further employs our model to study the startup delay penalty during handover for the spectrum of network conditions considered relevant for real-time traffic over mobile connections.

  • 77.
    Eklund, Johan
    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.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Cheimonidis, Georgios
    Ismailov, Yuri
    Impact of Slow Start on SCTP Handover Performance2011Ingår i: Proceedings of 20th International Conference on Computer Communications and Networks: ICCCN2011, IEEE conference proceedings, 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The rapidly growing interest in untethered Internet connections, especially in terms of WLAN and 3G/4G mobile connections, calls for intelligent session management: a mobile device should be able to provide a reasonable end-user experience despite location changes, disconnection periods and, not least, handovers. As part of an effort to develop a SCTP-based session management framework that meets these criteria, we are studying ways of improving the SCTP handover delay for real-time traffic; especially the startup delay on the connection between a mobile device and the target access point. To obtain an appreciation of the theoretically feasible gains of optimizing the startup delay on the handover-target path, we have developed a model that predicts the transfer times of SCTP messages during slow start. This paper experimentally validates our model and demonstrates that it could be used to predict the message transfer times in a variable bitrate flow by approximating the variable flow with a constant dito. It also employs our model to obtain an appreciation of the startup delay penalties incured by slow start during handovers in typical mobile, real-time traffic scenarios.

  • 78.
    Eklund, Johan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Grinnemo, Karl-Johan
    School of Information and Communication Technology, KTH Royal Institute of Technology.
    Baucke, Stephan
    Ericsson Research, Germany.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Tuning SCTP Failover for Carrier Grade Telephony Signaling2010Ingår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 54, nr 1, s. 133-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Stream Control Transmission Protocol (SCTP) has not only been selected as the signaling transport protocol of choice in IETF SIGTRAN, the architecture that bridges circuit-switched and IP-based mobile core networks, but also plays a pivotal role in SAE/LTE, the next-generation UMTS/HSPA networks. To meet the redundancy requirements of telecom signaling traffic, SCTP includes a failover mechanism that enables rerouting of traffic from an unreachable network path to a backup path. However, the recommendations provided by IETF on how to configure the SCTP failover mechanism to meet telecom signaling requirements are kept quite general and leave much of the tuning to the telecom equipment vendor and/or operator. Several works by us and others have been carried out to study the effect of different SCTP parameters on the failover performance. The main contribution of this paper is that it gives a coherent treatment of how to configure the SCTP failover mechanism for carrier-grade telephony signaling, and provides practically usable configuration recommendations. The paper also discusses an alternate or complementary way of optimizing the SCTP failover mechanism by relaxing the exponential backoff that foregoes a retransmission timeout in SCTP. Some results showing significantly reduced failover times by use of this mechanism, with only marginal deteriorating effects on a signaling network, are discussed and analyzed in the paper.

  • 79.
    Eklund, Johan
    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).
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Efficient Scheduling to Reduce Latency for Signaling Traffic using CMT-SCTP2016Ingår i: 27th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), September 4-7, Valencia, Spain, IEEE, 2016, s. 2127-2132Konferensbidrag (Refereegranskat)
    Abstract [en]

    To mitigate delay spikes during transmission of bursty signaling traffic, concurrent multipath transmission (CMT) over several paths in parallel could be an option. Still, unordered delivery is a well known problem when concurrently transmitting data over asymmetric network paths, leading to extra delay due to Head-of-Line Blocking (HoLB). The Stream Control Transmission Protocol (SCTP), designed as a carrier for signaling traffic over IP, is currently being extended with support for CMT (CMT-SCTP). To reduce the impact of HoLB, SCTP has support for transmission of separate data flows, called SCTP streams. In this paper, we address sender scheduling to optimize latency for signaling traffic using CMT-SCTP. We present dynamic stream-aware (DS) scheduling, which utilizes the SCTP stream concept, and continuously considers the current network status as well as the data load to make scheduling decisions. We implement a DS scheduler and compare it against some existing schedulers. Our investigation suggests that DS scheduling could significantly reduce latency compared to dynamic path scheduling that does not consider streams. Moreover, we show that naive round-robin scheduling may provide low latency over symmetric network paths, but may transmit data on non-beneficial asymmetric network paths leading to increased latency. Finally, our results show that a static stream based approach, found beneficial for bulk traffic, is not appropriate for bursty signaling traffic. 

  • 80.
    Eklund, Johan
    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.
    Implications of using a Large Initial Congestion Window to Improve mSCTP Handover Delay2012Ingår i: MOBILITY 2012 : The Second International Conference on Mobile Services, Resources, and Users / [ed] Josef Noll, University of Oslo & Movation, Norway, Alessandro Bazzi, CNR - IEIIT, Italy, IARIA , 2012, , s. 6s. 116-121Konferensbidrag (Refereegranskat)
    Abstract [en]

    The currently rather heterogeneous wireless landscape makes handover between different network technologies, so-called vertical handover, a key to a continued success for wireless Internet access. Recently, an extension to the Stream Control Transmission Protocol (SCTP) – the Dynamic Address Reconfiguration (DAR) extension – was standardized by IETF. This extension enables the use of SCTP for vertical handover. Still, the way vertical handover works in SCTP with DAR makes it less suitable for real-time traffic. Particularly, it takes a significant amount of time for the traffic to ramp up to full speed on the handover target path. In this paper, we study the implications of an increased initial congestion window for real-time traffic on the handover target path when competing traffic is present. The results clearly show that an increased initial congestion window could significantly reduce the transfer delay for real-time traffic, provided the fair share of the available capacity on the handover target path is sufficiently higher than the send rate required by the real-time flow. Additionally, we notice that this performance gain comes without penalizing the competing traffic.

  • 81.
    Eklund, Johan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Grinnemo, Karl-Johan
    Tieto Enator AB, Karlstad, Sweden.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    On the Relation Between SACK Delay and SCTP Failover Performance for Different Traffic Distributions2008Ingår i: Proceedings on the Fifth International Conference on Broadband Communications, Networks and Systems, IEEE , 2008, s. 577-584Konferensbidrag (Refereegranskat)
    Abstract [en]

    The stream control transmission protocol (SCTP) is an important component in the ongoing evolution towards IP in the fixed and mobile telephone networks. It is the transport protocol being used in the ongoing deployment of IETFpsilas signaling transport (SIGTRAN) architecture for tunneling of traditional telephony signaling traffic over IP. Further SCTP represents an alternative for future SIP signaling traffic. Key to the success of SCTP is its ability to recover from network failures, in particular failed network paths. SCTP includes multihoming and a failover mechanism which should swiftly shift from a failed or unavailable network path to a backup path. However, several studies have shown that SCTPpsilas failover performance is dependent on factors both related to protocol parameters and network conditions. This paper complements these studies by providing a comprehensive evaluation of the impact of SACK delay under various traffic distributions. The results show a clear relation between the traffic distribution and the impact of the SACK delay on SCTP failover performance. Severe negative effects are observed for low intensity traffic composed of individual signaling messages. On the other hand, our results show limited impact of SACK delay for high intensity and bursty traffic. Furthermore, the results show a limited increase in network traffic by reducing the SACK delay at low traffic intensities and even less impact on network traffic at high traffic intensities. Based on these results we recommend a decrease of the SCTP SACK timer to a small value in signaling scenarios

  • 82.
    Eklund, Johan
    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.
    On the Use of an Increased Initial Congestion Window to Improve mSCTP Handover Performance2012Ingår i: WAINA 2012: 26th International Conference on Advanced Information Networking and Applications Workshops / [ed] Leonard Barolli, Tomoya Enokido, Fatos Xhafa, Makoto Takizawa, IEEE Press, 2012, s. 1101-1106Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the wireless landscape being ratherheterogeneous, handover between different networktechnologies, so-called vertical handover, becomes keyto a continued success for wireless Internet access.Recently, an extension to the Stream Control Trans-mission Protocol (SCTP) – the Dynamic Address Re-configuration (DAR) extension – was standardized bythe IETF. This extension enables the use of SCTPfor vertical handover. Still, the way vertical handoverworks in SCTP with DAR makes it less suitable for real-time traffic. Particularly, it takes a significant amountof time for the traffic to ramp up to full speed on thehandover target path. In this paper, we study the ex-tent to which an increased initial congestion window onthe handover target path decreases the transfer delayspikes in real-time video traffic experienced during avertical handover. The impact on both standard andhigh-definition video traffic is considered. The resultsof our study suggest that an increased initial congestionwindow does indeed significantly decrease the spikes inthe video traffic. However, the results also indicate thatit does not resolve the problem altogether.

  • 83.
    Eklund, Johan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Grinnemo, Karl-Johan
    School of Information and Communication Technology, KTH Royal Institute of Technology.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Theoretical Analysis of an Ideal Startup Scheme in Multihomed SCTP2010Ingår i: Networked Services and Applications - Engineering, Control and Management: 16th EUNICE/IFIP WG 6.6 Workshop, EUNICE 2010, Trondheim, Norway, June 28-30, 2010 / [ed] Finn Arve Aagesen, Svein Johan Knapskog, Springer , 2010, s. 155-166Konferensbidrag (Refereegranskat)
    Abstract [en]

    SCTP congestion control includes the slow-start mechanism to probe the network for available bandwidth. In case of a path switch in a multihomed association, this mechanism may cause a sudden drop in throughput and increased message delays. By estimating the available bandwidth on the alternate path it is possible to utilize a more efficient startup scheme. In this paper, we analytically compare and quantify the degrading impact of slow start in relation to an ideal startup scheme. We consider three different scenarios where a path switch could occur. Further, we identify relevant traffic for these scenarios. Our results point out that the most prominent performance gain is seen for applications generating high traffic loads, like video conferencing. For this traffic, we have seen reductions in transfer time of more than 75% by an ideal startup scheme. Moreover, the results show an increasing impact of an improved startup mechanism with increasing RTTs

  • 84.
    Eklund, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    On the Impact of Data Scheduling to Reduce Latency for Telephony Signaling Traffic using CMT-SCTP2015Ingår i: The 11th Swedish National Computer Networking Workshop (SNCNW), Karlstad, Sweden, May 28-29, 2015., 2015Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    SCTP is a transport protocol targeted for telephony signaling traffic. Although SCTP from its inception supported multihoming, it has until now not supported concurrent mul- tipath transfer. However, this is about to change: Currently a standard for concurrent multipath transfer is underway. Since it is unclear whether concurrent multipath transfer could reduce transmission latency, this paper evaluates two algorithms for scheduling signaling traffic for transmission. We find that the mechanisms may provide good performance and to some extent enables for service differentiation. Still, the results indicate that unpredictable traffic require dynamic scheduling.

  • 85.
    Eklund, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Stream-aware Scheduling to Improve Latency for Signaling Traffic using CMT-SCTP2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    To mitigate delay spikes during transmission ofbursty signaling traffic, concurrent multipath transmission(CMT) over several paths in parallel could be an option. Still,unordered delivery is a well known problem when transmittingover asymmetric network paths, leading to extra delay due toHead-of-Line Blocking (HoLB). The Stream Control TransmissionProtocol (SCTP) is designed as a carrier for signaling trafficover IP to reduce the impact of HoLB. SCTP has support fortransmission of separate flows, called SCTP streams. SCTP iscurrently being extended with support for CMT (CMT-SCTP). Inthis paper, we address sender scheduling to optimize latency forsignaling traffic over CMT-SCTP. We present dynamic streamaware(DS) scheduling, which utilizes the SCTP stream concept,and continuously considers the current network status as well asthe data load to make scheduling decisions. We implement a DSScheduler and compare it against a dynamic path (DP) schedulerthat does not consider streams. Our investigation shows that DSscheduling could significantly reduce latency compared to a DPscheduler.

  • 86.
    Eklund, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    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).
    Using multiple paths in SCTP to reduce latency for signaling traffic2018Ingår i: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 129, s. 184-196Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increase in traffic volumes as well as the heterogeneity in network infrastructure in the upcoming 5G cellular networks will lead to a dramatic increase in volumes of control traffic, i.e., signaling traffic, in the networks. Moreover, the increasing number of low-power devices with an on-off behavior to save energy will generate extra control traffic. These increased traffic volumes for signaling traffic, often generated as bursts of messages, will challenge the signaling application timing requirements on transmission. One of the major transport protocols deployed for signaling traffic in cellular networks is the Stream Control Transmission Protocol (SCTP), with support for multiple paths as well as for independent data flows. This paper evaluates transmission over several paths in SCTP to keep the latency low despite increasing traffic volumes. We explore different transmission strategies and find that concurrent multipath transfer over several paths will significantly reduce latency for transmission over network paths with the same or similar delay. Still, over heterogeneous paths, careful, continuous sender scheduling is crucial to keep latency low. To this end, we design and evaluate a sender scheduler that considers path characteristics as well as queuing status and data flows of different priority to make scheduling decisions. Our results indicate that by careful dynamic sender scheduling, concurrent multipath transfer could lead to reduced latency for signaling traffic irrespective of path or traffic characteristics.

  • 87. Faigl, Zoltán
    et al.
    Fazekas, Péter
    Lindskog, Stefan
    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.
    Analytical Analysis of the Performance Overheads of IPsec in Mobile IPv6 Scenarios2008Ingår i: Advances in Mobile and Wireless Communications: Views of the 16th IST Mobile and Wireless Communication Summit / [ed] István Frigyes, Janos Bito, and Péter Bakki, Berlin/Heidelberg, Germany: Springer-Verlag , 2008Kapitel i bok, del av antologi (Refereegranskat)
  • 88. Faigl, Zoltán
    et al.
    Fazekas, Péter
    Lindskog, Stefan
    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.
    Performance Analysis of IPsec in MIPv6 Scenarios2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes an analysis of the performance overheads caused by the processing and space requirements of IPsec when protecting Mobile IPv6 (MIPv6) signaling. Signaling between the Mobile Nodes and the Home Agent (HA) in a large-scale reference scenario is considered. The analysis is based on queuing theory and focuses on the overall utilization of the HA by the MIPv6 signaling processes as well as the total mean response time for a mobility process in the network. The results can assist network designers in finding the most appropriate security configuration for their specific network and mobility scenario

  • 89. Faigl, Zoltán
    et al.
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT.
    Tóth, Katalin
    Providing Tunable Security in IEEE 802.11i Enabled Networks2006Rapport (Övrigt vetenskapligt)
    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 report, 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 configuratio (s). The performance metric used is latency. The concept is illustrated using the IEEE 802.11i wireless local area networking standard.

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  • 90. Faigl, Zoltán
    et al.
    Lindskog, Stefan
    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.
    Experimental Evaluation of the Performance Costs of Different IKEv2 Authentication Methods2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents an experimental evaluation of the costs of different IKEv2 authentication methods. The studied methods are pre-shared keys (PSK), extensible authentication protocol (EAP) using MD5 and TLS, which are typically referred to as EAP-MD5 and EAP-TLS, respectively. For the EAP-based methods RADIUS is used as AAA server. Different lengths of certification chains are studied in the EAP-TLS case. The paper first presents a brief overview of the considered authentication methods. Then, an experimental comparison of the costs for computations and messages transfers associated with the authentication methods are provided. The measurement results illustrate the practical costs involved for IKEv2 authentication, and show the performance implications of using different authentication methods. EAP-TLS is several times more demanding than both PSK and EAP-MD5. When EAP-TLS is used, the length of certificate chains also has a notable impact on performance

  • 91. Faigl, Zoltán
    et al.
    Lindskog, Stefan
    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.
    IKEv2 Performance when Protecting Mobile IPv6 Signaling2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes an analysis of the performance overheads caused by the processing and space requirements of the IKEv2 protocol using Diameter and EAP-TLS authentication when protecting Mobile IPv6 signaling. IKEv2 negotiation between mobile nodes, the home agent, and the AAA server in a large-scale reference scenario is considered. The analysis is based on queuing theory and focuses on the overall utilization of the home agent and the AAA server by the IKEv2 reauthentication processes as well as the total mean response time for such a process in the network

  • 92. Faigl, Zoltán
    et al.
    Lindskog, Stefan
    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.
    Tóth, Katalin
    Providing Tunable Security in IEEE 802.11i Enabled Networks2006Rapport (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 report, 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.

  • 93.
    Fairhurst, Gorry
    et al.
    University of Aberdeen, UK..
    Jones, Tom
    University of Aberdeen, UK..
    Bozakov, Zdravko
    Dell EMC, Ireland.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Damjanovic, Dragana
    Mozilla.
    Eckert, Toerless
    CISCO.
    Evensen, Kristian Riktor
    Celerway.
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Fosselie Hansen, Audun
    Celerway.
    Khademi, Naeem
    University of Oslo, Norway.
    Mangiante, Simon
    Dell EMC.
    McManus, Patrick
    Mozilla.
    Papastergiou, Giorgos
    Simula.
    Ros, David
    Simula.
    Tüxen, Michael
    FH Münster, Germany.
    Vyncke, Eric
    CISCO.
    Welzl, Michael
    University of Oslo, Norway.
    Deliverable D1.1 - NEAT Architecture2016Rapport (Refereegranskat)
    Abstract [en]

    Ossification of the Internet transport-layer architecture is a significant barrier to innovation of the Internet. Such innovation is desirable for many reasons. Current applications often need to implement their own mechanisms to receive the transport service they need, but many do not have the breadth of adapting to all possible network characteristics. An updated transport architecture can do much to make the Internet more flexible and extensible. New ground-breaking services often require different or updated transport protocols, could benefit from better signalling between application and network, or desire a more flexible choice of which network path is used for which traffic. This document therefore proposes a new transport architecture. Such architecture lowers the barrier to service innovation by proposing a “transport system”, the NEAT System, that can leverage the rich set of available transport protocols. It paves the way for an architectural change of the Internet where new transport-layer services can seamlessly be integrated and quickly made available, minimising deployment difficulties, and allowing Internet innovators to take advantage of them wherever possible. The document provides a survey of the state-of-the-art to identify the architectural obstacles to, and opportunities for, evolution of the transport layer. It also details a set of general requirements for a new transport architecture. This new architecture is motivated by a set of use-cases, followed by a description of the NEAT architecture for a transport system, designed to permit applications to select appropriate transports based on their needs and the available transport services.

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  • 94. Fida, Mah-Rukh
    et al.
    Kousias, Konstantinos
    Lutu, Andra
    Rajiullah, Mohammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Alay, Ozgu
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Argyriou, Antonios
    FLEX-MONROE: A unified platform for experiments under controlled and operational LTE settings2017Ingår i: WiNTECH 2017 Proceedings of the 11th Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization, Association for Computing Machinery (ACM), 2017, s. 1-8Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents FLEX-MONROE, a unique platform that facilitates achieving a thorough understanding of LTE networks, one that captures the status of current operational MBB networks and that also enables LTE performance improvements by allowing experimentation in an environment with controllable LTE parameters. Using this platform, we propose to investigate how variations in the LTE network parameters influence the network characteristics, which, in turn, translate to application performance metrics that represent the end-user experience. We argue that the FLEX-MONROE platform is crucial to understand, validate and ultimately improve how current operational MBB networks perform, towards providing guidelines for designing future 5G architectures. Furthermore, understanding the effects of low-level tweaks in network parameters in the LTE infrastructure on the application performance is critical to provide guidelines on how to improve the application performance in the current but also future MBB networks

  • 95.
    Fida, Mah-Rukh
    et al.
    University of Edinburgh, UK.
    Kousias, Konstantinos
    Simula Research Laboratory, Norway.
    Lutu, Andra
    Simula Research Laboratory, Norway.
    Rajiullah, Mohammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Alay, Özgü
    Simula Research Laboratory, Norway.
    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).
    Argyriou, Antonios
    University of Thessaly, Greece.
    Demo: experimentation in controlled and operational LTE settings with FLEX-MONROE2017Ingår i: Proceedings of the 11th Workshop on Wireless Network Testbeds, Experimental evaluation & Characterization WiNTECH '17, Association for Computing Machinery (ACM), 2017, s. 93-94Konferensbidrag (Refereegranskat)
    Abstract [en]

    This demo paper presents FLEX-MONROE, a platform that facilitates better understanding of current LTE Mobile Broadband(MBB) networks and enables performance improvementsby allowing experimentation with controllable LTE parameters. The platform enables investigating impact oflow-level network parameter tweaks in LTE infrastructure onthe application performance. We argue that FLEX-MONROEis crucial to provide guidelines on improving application performance both in the current and future MBB networks

  • 96. Garcia, J
    et al.
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Efficent Image Transfer for Wireless Networks2000Konferensbidrag (Refereegranskat)
  • 97.
    Garcia, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Alfredsson, Stefan
    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).
    Delay metrics and delay characteristics: A study of four Swedish HSDPA+ and LTE networks2015Ingår i: 2015 European Conference on Networks and Communications (EuCNC), IEEE, 2015, s. 234-238Konferensbidrag (Refereegranskat)
    Abstract [en]

    Network delays and user perceived latencies are of major importance in many applications in cellular networks. Delays can be measured with multiple approaches and at different protocol layers. This work involves a detailed examination of several delay metrics from a network, transport, and application perspective. The study explores base delay as well as latency under load, capturing also the effect of buffering. The examination is based on a comprehensive active measurement campaign performed in the networks of four Swedish operators. The results show that the delay captured by different metrics can vary significantly, with delay captured from the TCP three-way-handshake and adaptive ping measurements giving the most consistent results for base network delay in our measurements. As expected, when background traffic is introduced measured delay increases by an order of magnitude due to buffering in the network, highlighting the importance of also capturing latency under load when describing network performance. Finally, using an analytic model of flow completion time, we show that well-selected network measurements can provide a good prediction of higher layer delay performance.

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  • 98.
    Garcia, Johan
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Alfredsson, 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.
    The Impact of Loss Generation on Emulation-Based Protocol Evaluation2006Ingår i: PDCN'06 Proceedings of the 24th IASTED international conference on Parallel and distributed computing and networks / [ed] Fahringer, T., Anaheim, USA: ACTA Press, 2006, 1, s. 231-237Konferensbidrag (Refereegranskat)
    Abstract [en]

    Network emulation has for a long time been an important tool for evaluating the performance of communication protocols. By emulating network characteristics, such as restricted bandwidth, delay and losses, knowledge about the behavior and performance of actual protocol implementations can be obtained. This paper focuses on the generation of losses in network emulators and shows the beneficial effects of being able to control the generation of losses in a precise way. Both the possibility to get additional knowledge about a protocol implementations behavior, as well as statistical benefits such as paired experiments are discussed. By extending the loss generation to also include bit-error generation, in addition to packet losses, a finer level of abstraction is provided. Deterministic bit-error generation allows detailed and repeatable studies of bit-error sensitive protocol behavior. TCP and a loss differentiating variant of TCP is used to illustrate the utility of improved loss generation.

  • 99.
    Garcia, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Alfredsson, Stefan
    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.
    A Measurement Based Study of TCP Protocol Efficiency in Cellular Networks2014Ingår i: Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), 2014 12th International Symposium on, IEEE, 2014, s. 131-136Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper examines the efficiency of resource utilization with respect to short-lived TCP flows in various cellular networks. The examination is done from the vantage point of an end-user who would like to use as much as possible of the cellular transmission resources that are available at any given time, thus minimizing the delays associated with communication. Based on a comprehensive measurement campaign we first derive network characteristics with regards to base RTT, RTT under load, and average throughput. A protocol efficiency metric is introduced to capture how efficiently short TCP flows are in fact able to use the instantaneously available transmission resources in a cellular network. The measurements show that short TCP connections have low efficiency in 3. SG (HSPA+) and 4G (LTE) mobile broadband networks, and that the improved latency and throughput characteristics of 4G in relation to 3. SG nevertheless results in lower short-flow efficiency for 4G.

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  • 100.
    Garcia, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Alfredsson, Stefan
    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).
    Estimating data transfer capacity for intermittent connectivity: A transport aware model2016Ingår i: 2016 IEEE 27th Annual International Symposium On Personal, Indoor, And Mobile Radio Communications (PIMRC), New York: IEEE, 2016, s. 1-6Konferensbidrag (Refereegranskat)
    Abstract [en]

    Communication performed with mobile devices will experience varying levels of connectivity as the communication device moves in and out of coverage. A subset of mobile communication devices operate under conditions where the connectivity is characterized by relatively short contact periods occurring intermittently. In this paper we propose a model to predict the amount of data that can be transferred during such short contact periods. The model includes aspects of the transport layer slow-start behavior and is validated using data from a long-running measurement campaign in the networks of four Swedish cellular networks. Further validation of the modeling assumptions is performed by employing a numerical optimization technique based on non-linear least squares regression using the iterative Levenberg-Marquardt approach. The model is then used to explore the relevant parameter space.

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