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  • 1.
    Alay, Özgü
    et al.
    Simula Research Laboratory, Norway.
    Lutu, Andra
    Simula Research Laboratory, Norway.
    García, Rafael
    IMDEA Networks Institute, Spain.
    Peón Quirós, Miguel
    IMDEA Networks Institute, Spain.
    Mancuso, Vincenzo
    IMDEA Networks Institute, Spain.
    Hirsch, Thomas
    Celerway AS, Norway.
    Dely, Tobias
    Celerway AS, Norway.
    Werme, Jonas
    Celerway AS, Norway.
    Evensen, Kristian
    Celerway AS, Norway.
    Hansen, Audun
    Celerway AS, Norway.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Karlsson, Jonas
    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).
    Safari Khatouni, Ali
    Politecnico di Torino.
    Mellia, Marco
    Politecnico di Torino.
    Ajmone Marsan, Marco
    Politecnico di Torino.
    Monno, Roberto
    Nextworks, Italy.
    Lønsethagen, Håkon
    Telenor R&D, Norway.
    MONROE, a distributed platform to measure and assess mobile broadband networks: demo2016Inngår i: Proceedings of the Tenth ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation, and Characterization, New York, NY, USA: Association for Computing Machinery (ACM), 2016, s. 85-86Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This demo presents the MONROE distributed platform and how it can be used to implement measurement and assessment experiments with operational mobile broadband networks (MBBs). MONROE provides registered experimenters with open access to hundreds of nodes, distributed over several European countries and equipped with multiple MBB connections, and a backend system that collects the measurement results. Experiments are scheduled through a user-friendly web client, with no need to directly access the nodes. The platform further embeds tools for real-time traffic flow analysis and a powerful visualization tool.

  • 2.
    Alay, Özgü
    et al.
    Simula Research Laboratory, Norway.
    Lutu, Andra
    Simula Research Laboratory, Norway.
    Peón-Quirós, Miguel
    IMDEA Networks Institute, Spain.
    Mancuso, Vincenzo
    IMDEA Networks Institute, Spain.
    Hirsch, Thomas
    Celerway Communications, Norway.
    Evensen, Kristian
    Celerway Communications, Norway.
    Hansen, Audun
    Celerway Communications, Norway.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Karlsson, Jonas
    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).
    Safari Khatouni, Ali
    Politecnico di Torino, Italy.
    Mellia, Marco
    Politecnico di Torino, Italy.
    Ajmone Marsan, Marco
    IMDEA Networks Institute, Spain and Politecnico di Torino, Italy.
    Experience: An open platform for experimentation with commercial mobile broadband networks2017Inngår i: MobiCom '17 Proceedings of the 23rd Annual International Conference on Mobile Computing and Networking, New York: Association for Computing Machinery (ACM), 2017, s. 70-78Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Open experimentation with operational Mobile Broadband (MBB) networks in the wild is currently a fundamental requirement of the research community in its endeavor to address the need of innovative solutions for mobile communications. Even more, there is a strong need for objective data about stability and performance of MBB (e.g., 3G/4G) networks, and for tools that rigorously and scientifically assess their status. In this paper, we introduce the MONROE measurement platform: an open access and flexible hardware-based platform for measurements and custom experimentation on operational MBB networks. The MONROE platform enables accurate, realistic and meaningful assessment of the performance and reliability of 11 MBB networks in Europe. We report on our experience designing, implementing and testing the solution we propose for the platform. We detail the challenges we overcame while building and testing the MONROE testbed and argue our design and implementation choices accordingly. We describe and exemplify the capabilities of the platform and the wide variety of experiments that external users already perform using the system

  • 3.
    Alay, Özgü
    et al.
    Simula Research Laboratory, Norway.
    Lutu, Andra
    Simula Research Laboratory, Norway.
    Rafael, García
    IMDEA Networks Institute, Spain.
    Peón Quirós, Miguel
    IMDEA Networks Institute, Spain.
    Mancuso, Vincenzo
    IMDEA Networks Institute, Spain.
    Hirsch, Thomas
    Celerway AS, Norway.
    Tobias, Dély
    Celerway AS, Norway.
    Werme, Jonas
    Celerway AS, Norway.
    Evensen, Kristian
    Celerway AS, Norway.
    Fosselie Hansen, Audun
    Celerway AS, Norway.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Karlsson, Jonas
    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).
    Safari Khatouni, Ali
    Politecnico di Torino, Italy.
    Mellia, Marco
    Politecnico di Torino, Italy.
    Ajmone Marsan, Marco
    Politecnico di Torino & IMDEA Networks, Italy.
    Monno, Roberto
    Nextworks, Italy.
    Lønsethagen, Håkon
    Telenor R&D, Norway.
    Measuring and Assessing Mobile Broadband Networks with MONROE2016Inngår i: 2016 IEEE International Symposium on a World of Wireless, Mobile, and Multimedia Networks (WoWMoM), Red Hook: IEEE, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mobile broadband (MBB) networks underpin numerous vital operations of the society and are arguably becoming the most important piece of the communications infrastructure. In this demo paper, our goal is to showcase the potential of a novel multi-homed MBB platform for measuring, monitoring and assessing the performance of MBB services in an objective manner. Our platform, MONROE, is composed of hundreds of nodes scattered over four European countries and a backend system that collects the measurement results. Through a user-friendly web client, the experimenters can schedule and deploy their experiments. The platform further embeds traffic analysis tools for real-time traffic flow analysis and a powerful visualization tool.

  • 4.
    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 (Fagfellevurdert)
  • 5.
    Cavalcanti de Castro, Marcel
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. 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.
    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.
    Capacity Increase for Voice over IP Traffic through Packet Aggregation in Wireless Multihop Mesh Networks2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recently, Voice over IP (VoIP) has become an important service for the future internet. However, for ubiquitous wireless VoIP services, greater coverage will be necessary as promised by the advent of e.g. 802.11 WLAN based wireless meshed networks. Unfortunately, the transmission of small (voice) packets imposes high overhead which leads to low capacity for VoIP over 802.11 based multihop meshed networks. In this work, we present a novel packet aggregation mechanism that significantly enhances capacity of VoIP in wireless meshed networks while still maintaining satisfactory voice quality. Extensive experiments using network simulation ns-2 confirm that our packet aggregation algorithm can lead to a significantly increase in the number of supported concurrent VoIP flows over a variety of different hop numbers while reducing the MAC layer contention

  • 6.
    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 Networks2014Inngår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 68, s. 26-37Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 7.
    Karlsson, Jonas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Improving TCP Performance in Wireless Multi-hop Networks: Design of Efficient Forwarding and Packet Processing Techniques2011Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Due to the high availability of cheap hardware, wireless multi-hop networks and in particular Wireless Mesh Networks (WMNs) are becoming popular in more and more contexts. For instance, IEEE 802.11 based WMNs have already started to be deployed as means to provide Internet access to rural areas in the developing world. To lower the cost and increase the coverage in such deployments, the wired network is extended with a wireless backbone of fixed mesh routers. With advances in technology and reduction in price comes also the possibility for more powerful wireless nodes, having multiple radios that allow transmitting on different channels in parallel.

    To be a successful platform for providing general Internet access, wireless multi-hop networks must provide support for common Internet applications. As most of the applications in the Internet today use the Transmission Control Protocol (TCP), TCP performance is crucial. Unfortunately, the design of TCP’s congestion control that made it successful in today’s Internet makes it perform less than optimal in wireless multi-hop networks. This is due to, among others, TCP’s inability to distinguish wireless losses from congestion losses. The current trend for operating system designers is also to focus TCP development on high-speed fixed networks, rather than on wireless multi-hop networks. To enable wireless multi hop networks as a successful platform there is therefore a need to provide good performance using TCP variants commonly deployed in the Internet.

    In this thesis, we develop novel proposals for the network layer in wireless multi-hop networks to support TCP traffic more efficiently. As an initial study, we experimentally evaluate different TCP variants, with and without mobile nodes, in a MANET context.

    Our results show that TCP Vegas, which does not provoke packet loss to determine available bandwidth, reduces the stress on the network while still providing the same or slightly increased performance, compared to TCP Newreno. We further propose and evaluate packet aggregation combined with aggregation aware multi-path forwarding to better utilize the available bandwidth.

    IP layer packet aggregation, where small packets are combined to larger ones before sent to the link layer, has been shown to improve the performance in wireless multi-hop networks for UDP and small packet transfers. Only few studies have been made on the impact of packet aggregation on TCP traffic, despite the fact that TCP traffic constitutes the majority of the Internet traffic. We propose a novel aggregation algorithm that is specifically addressing TCP relevant issues like packet reordering, fairness and TCP timeouts. In a typical WMN scenario, the aggregation algorithm increases TCP performance by up to 70 % and decreases round trip time (RTT) by up to 40 %.

    A detailed evaluation of packet aggregation in a multi radio setting has shown that a naive combination of multi path routing and packet aggregation can cause valuable aggregation opportunities to be lost. Therefore, we propose a novel combined packet aggregation and aggregation aware forwarding strategy that can reduce delay, packet loss and increase TCP performance by around 30 %.

  • 8.
    Karlsson, Jonas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Transport-Layer Performance in Wireless Multi-Hop Networks2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Wireless communication has seen a tremendous growth in the last decades. Continuing on this trend, wireless multi-hop networks  are nowadays used or planned for use in a multitude of contexts, spanning from Internet access at home to emergency situations.

    The Transmission Control Protocol (TCP) provides reliable and ordered delivery of a data and is used by major Internet applications such as web browsers, email clients and file transfer programs. TCP traffic is also the dominating traffic type on the Internet. However, TCP performs less than optimal in wireless multi-hop networks due to packet reordering, low link capacity, packet loss and variable delay.

    In this thesis, we develop novel proposals for enhancing the network and transport layer to improve TCP performance in wireless multi-hop networks. As initial studies, we experimentally evaluate the performance of different TCP variants, with and without mobile nodes. We further evaluate the impact of multi-path routing on TCP performance and propose packet aggregation combined with aggregation aware multi-path forwarding as a means to better utilize the available bandwidth. The last contribution is a novel extension to multi-path TCP to  enable single-homed hosts to fully utilize the network capacity.

  • 9.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Batlle Linares, Alba
    TCP Performance: in hybrid Mobile Ad Hoc Networks2008Bok (Fagfellevurdert)
    Abstract [en]

    Nowadays a lot of research efforts focus on Mobile Ad-hoc NETworks (MANETS). A MANET is a collection of mobile autonomous nodes, which can move arbitrary, leading to a constantly changing network topology. However, today most of the information is still stored on wired servers. Due to the different topological natures of wired and MANET networks, interconnectivity is not trivial. To further complicate the situation the Transmission Control Protocol (TCP) is designed for wired networks, in a MANET with different link and route characteristics, as multihop and frequent packet losses, the performance of current TCP proposals drop considerably.

    The purpose of this book is to give an overview of the current MANET Internet connectivity situation and to evaulate TCP performance in a hybrid MANET where mobile nodes connect to a wired network through a gateway

  • 10.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Batlle Linares, Alba
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Sung Lee, Bu
    TCP Performance in Mobile Ad Hoc Networks Connected to the Internet2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A Mobile Ad Hoc Network (MANET) is a collection of mobile nodes (MN) that communicate using wireless links without support from any pre-existing infrastructure network. Packets are delivered from a source to a destination using packet forwarding capabilities of intermediate nodes. Therefore, MNs act as both end systems and routers. Mobile Ad Hoc networking has been considered as one of the most important and essential technologies that support future Pervasive Computing Scenarios. Recently, the usage of MANETs in the scope of 4G scenarios has attracted much research efforts and MANETs are seen as one way to extend coverage of hotspots in order to provide Internet connectivity to mobile users. However, TCP performance is crucial for user satisfaction but TCP is well known to suffer from low performance in wireless environments. In this paper, we evaluate several alternative TCP protocols on their suitability for Internet connected MANETs. We conclude that TCP- Vegas is a viable option as its performance is not significantly worse than those TCP variants highly specialized for MANETs but it is compatible with standard Internet protocols

  • 11.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Di Stasi, Giovanni
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Avallone, Stefano
    An Aggregation Aware Multi-path Forwarding Paradigm for Wireless Mesh Networks2011Inngår i: Proceedings of 10th International IFIP-TC6 conference on Networking, Springer Berlin/Heidelberg, 2011Konferansepaper (Fagfellevurdert)
  • 12.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Di Stasi, Giovanni
    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.
    Avallone, Stefano
    Computer Science Department, University “Federico II” of Naples, Via Claudio 21, 80125 Naples, Italy.
    An Aggregation Aware Multi-path Forwarding Paradigm for Wireless Mesh Networks2011Inngår i: IEEE MASS 2011. Proceedings of the 8th IEEE International Conference on Mobile Ad-hoc and Sensor Systems, IEEE Computer Society, 2011, s. 765-770Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In multi-radio wireless mesh networks, a networkdevice simultaneously transmits packets over different channelsby using multiple radios. Such frequency diversity not only increasesthroughput but makes multi-path routing approaches extremelyinteresting. This is because the channel diversity reducesthe risk for intra- and inter-flow interference. A fundamentalproblem to solve is the forwarding strategy which determineswhich packets to be sent over what multi-path segments atany given time. Ideally, the forwarding strategy should scheduleflows according to the capacity constraints imposed by thechannel assignment. However, the possibility to improve MAClayer efficiency by aggregating small packets into larger onesis reduced when packets are forwarded to different next-hops.In this paper, we develop a novel packet forwarding strategyfor multi-radio mesh networks that combines the benefits ofmulti-path routing with packet aggregation. In our cross-layerapproach, we effectively trade-off aggregation opportunities withchannel diversity. Simulation results show that our approach canimprove network throughput and delay by up to 15 percentand 25 percent, respectively, compared with aggregation unawareforwarding strategies.

  • 13.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Di Stasi, Giovanni
    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.
    Avallone, Stefano
    Computer Science Department, University “Federico II” of Naples, Via Claudio 21, 80125 Naples, Italy.
    An Aggregation Aware Multi-path Forwarding Paradigm for Wireless Mesh Networks : AA-L2R Aggregation Aware Multi-path Routing2011Konferansepaper (Fagfellevurdert)
  • 14.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Dimitrov, Velizar G.
    Department of Communication Networks, Technical University of Sofia, boulevard Kliment Ohridski 8, Sofia, Bulgaria.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Nilsson, Jan
    Swedish Defence Research Agency (FOI), Box 1165, SE - 581 11 Linköping, Sweden.
    Hansson, Anders
    Swedish Defence Research Agency (FOI), Box 1165, SE - 581 11 Linköping, Sweden.
    Performance Evaluation for TCP in Tactical Mobile Ad hoc Networks2012Inngår i: Proceedings of International Conference on Wireless Information Networks and Systems, SciTePress, 2012, s. 277-282Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Tactical networks are used in military and rescue operations to provide timely and accurate information to operating teams.  Tactical networks have traditionally used long distance narrow band radio links. However, although these links provide robust real-time communication the limited bandwidth makes them less suited for high data-rate applications.  To support high-data rate TCP applications such as providing digital images and maps, emerging tactical networks use shorter range but higher data-rate wide band radio links and multi-hop.  Due to the requirement of cheap up-front cost, most MANET research has focused on Carrier Sense Multiple Access (CSMA) networks. However, in tactical networks, where bounded delays are important, Time Division Multiple Access (TDMA) can give better possibility to support the Quality of Service needed for real-time communication.  The purpose of this paper is to assess and compare the throughput of three state-of-the-art TCP versions and two routing protocols over TDMA based MANETs.

  • 15.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Hurtig, Per
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    MPTCP PathFinder - finding your ways to aggregated bandwidth2012Rapport (Annet vitenskapelig)
    Abstract [en]

    Many  networks are multi-path; mobile devices have multiple interfaces, data centers have redundant paths and ISPs forward traffic over disjoint paths to perform load-balancing. Multi-path TCP (MPTCP) is a new mechanism that transparently divides a TCP connection into subflows and distributes them over a host's network interfaces. While this enables multi-homed systems like e.g. smartphones to use several interfaces and thus different, and mostly disjoint, network paths for a single transmission, most end-systems are still single-homed. With one interface, standard MPTCP creates only a single subflow, making single-homed systems unable to benefit from MPTCP's functionality. In this paper we propose PathFinder, an MPTCP extension that tries to estimate the number of subflows required to fully utilize  the network capacity, enabling single-homed hosts to reap the benefits of MPTCP. We evaluate MPTCP with PathFinder and compare its performance to standard MPTCP. The evaluation shows that PathFinder is able to open a limited but sufficient amount of subflows to significantly increase the throughput when compared to using standard MPTCP.

  • 16.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Hurtig, Per
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    di Stasi, Giovanni
    University of Naples "Federico II", Italy.
    Impact of Multi-path Routing on TCP Performance2012Inngår i: 2012 IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM 2012), Washington, DC: IEEE Press, 2012, s. 1-3Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Routing packets over multiple disjoint paths towards a destination can increase network utilization by load-balancing the traffic over the network. The drawback of load-balancing is that different paths might have different delay properties, causing packets to be reordered. This can reduce TCP performance significantly, as reordering is interpreted as a sign of congestion. Packet reordering can be avoided by letting the network layer route strictly on flow-level. This will, however, also limit the ability to achieve optimal network throughput. There are also several proposals that try to mitigate the effects of reordering at the transport layer. In this paper, we perform an initial evaluation of such TCP reordering mitigations in multi-radio multi-channel wireless mesh networks when using multi-path routing. We evaluate two TCP reordering mitigation techniques implemented in the Linux kernel. The transport layer mitigations are compared using different multi-path routing strategies. Our findings show that, in general, flow-level routing gives the best TCP performance and that transport layer reordering mitigations only marginally can improve performance.

  • 17.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Hurtig, Per
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    di Stasi, Giovanni
    (University of Naples "Federico II", Italy.
    Impact of Multi-path Routing on TCP Performance in Wireless Mesh Networks2012Inngår i: Proceedings of the 8th Swedish National Computer Networking Workshop (SNCNW 2012), 2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Routing packets over multiple disjoint paths to- wards a destination can increase network utilization by load- balancing the traffic over the network. The drawback of load-balancing is that different paths might have different delay properties, causing packets to be reordered. This can reduce TCP performance significantly, as reordering is interpreted as a sign of congestion. Packet reordering can be avoided by letting the network layer route strictly on flow-level. This will, however, also limit the ability to achieve optimal network throughput. There are also several proposals that try to mitigate the effects of reordering at the transport layer. In this paper, we perform an initial evaluation of such TCP reordering mitigations in multi-radio multi-channel wireless mesh networks when using multi-path routing. We evaluate two TCP reordering mitigation techniques implemented in the Linux kernel. The transport layer mitigations are compared using different multi-path routing strategies. Our findings show that, in general, flow-level routing gives the best TCP performance and that transport layer reordering mitigations only marginally can improve performance. 

  • 18.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Hurtig, Per
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    di Stasi, Giovanni
    Department of Computer Science, University of Naples "Federico II", Italy.
    The Interaction Between TCP Reordering Mechanisms and Multi-path Forwarding in Wireless Mesh Networks2012Inngår i: 2012 IEEE 8th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), IEEE Press, 2012, s. 276-283Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Routing packets over multiple disjoint paths towards a destination can increase network utilization by load-balancing the traffic over the network. In wireless mesh networks, multi-radio multi-channel nodes are often used to create a larger set of interference-free paths thus increasing the chance of load-balancing. The drawback of load-balancing is that different paths might have different delay properties, causing packets to be reordered. This can reduce TCP performance significantly, as reordering is interpreted as a sign of congestion. Packet reordering can be avoided by letting the network layer forward traffic strictly on flow-level. This would avoid the negative drawbacks of packet reordering, but will also limit the ability to achieve optimal network throughput. On the other hand, there are several proposals that try to mitigate the effects of reordering at the transport layer. In this paper, we perform an in-depth evaluation of such TCP reordering mitigations in multi-radio multi-channel wireless mesh networks when using multi-path forwarding. We evaluate two TCP reordering mitigation techniques implemented in the Linux kernel. The transport layer mitigations are compared using different multi-path forwarding strategies. Our findings show that, in general, flow-level forwarding gives the best TCP performance and that transport layer reordering mitigations only marginally can improve performance

  • 19.
    Karlsson, Jonas
    et al.
    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.
    TCP Performance and Packet Aggregation in Wireless Mesh Networks under low link quality2008Inngår i: Second ERCIM Workshop on eMobility / [ed] Torsten Braun, Geert Heenk, Dimitri Konstantas, Markus Wulff, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recently, Wireless Mesh Networks (WMNs) have attracted attention as means to provide alternative internet connectivity to rural areas or communities. In WMNs, wireless access points communicate with each other wirelessly forming a true wireless, mesh based access network of mesh relay nodes (MRN). Mesh gateways (MG) provide internet connectivity and standard mobile clients attach to MRNs, which forward packets via other MRNs to other meshed clients or through MGs to the internet. Therefore, the wireless backbone comprised of MRNs and MGs is similar to static, internet connected Ad Hoc networks. A major problem is however scalability of WMNs as well as MAC and PHY layer overhead for packet transmission. Capacity of WMNs can be increased significantly by aggregating (combining) several smaller packets into larger ones [1][2]. This is in particular beneficial to VoIP flows where packet sizes are small. The overall number of packets is reduced, average packet size increased and contention will take place only once for the larger packets. A relay node will then process fewer large packets instead of many small ones. While such aggregation mechanisms have been proposed for single-hop infrastructure WLAN, designing an aggregation strategy for multi-hop WMNs is a hard problem because in this multi-hop environment, signal quality and congestion for each link is different. When mesh relay nodes aggregate small packets, there is an inherent trade-off regarding packet size. Aggregating more packets leads to larger packets, which reduces the overall number of packets in the mesh and thus reduces multi-hop contention and packet loss due to collisions. However, such larger (aggregated) packets can lead to higher packet loss for a link that operates at low signal quality [3]. To find the optimum frame size for packet aggregation is therefore not trivial and depends on traffic and link quality which can vary over time and might be different for each link in a multi hop path. In this paper, we will evaluate if packet aggregation is beneficial when applied to standard TCP in a WMN environment with low quality links. For integration of Mesh Networks into 4G environment, the transport layer needs to be compatible and interoperable with already deployed transport protocols. We will therefore compare end-to-end performance of standard TCP (with Selective and Delayed ACKs) using different MSS sizes in a mesh environment, both with and without deploying packet aggregation. Delayed ACKs and Selective ACKs has shown to be beneficial in multihop environments as the number of packets is reduced leading to less contention [4]

  • 20.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Evaluation of Packet Aggregation with TCP Traffic in Wireless Mesh Networks2010Manuskript (preprint) (Annet (populærvitenskap, debatt, mm))
  • 21.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Impact of Packet Aggregation on TCP performance in Wireless Mesh Networks2009Inngår i: Proceedings of the First IEEE WoWMoM Workshop on Hot Topics in Mesh Networking (HotMESH'09), IEEE , 2009, s. 1-7Konferansepaper (Fagfellevurdert)
  • 22.
    Karlsson, Jonas
    et al.
    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.
    Brunstrom, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    TCP Performance Evaluation in Wireless Mesh Networks using Packet Aggregation2012Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Wireless Mesh Networks (WMNs) have attracted attention as a way to provide alternative wireless Internet connectivity. In a WMN, access points communicate with each other wirelessly, forming a wireless mesh backbone network. One major problem in WMNs is low performance due to MAC and PHY layer overhead for transmission of small packets. Around 44 percent of the packets in the Internet are smaller than 100 bytes and a majority of these packets are TCP packets. The capacity of WMNs can therefore be increased significantly by packet aggregation (concatenation) of TCP packets. In this paper, we evaluate the impact of packet aggregation on TCP performance in WMNs. Using both synthetic and trace based traffic distributions we demonstrate that packet aggregation can not only increase capacity for TCP in such networks but also reduce round trip times.

  • 23.
    Karlsson, Jonas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    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. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Effect of Packet Aggregation in Wireless Mesh Networks: Analyzing TCP performance2009Inngår i: Proceedings of the 9th Scandinavian Workshop on Wireless Adhoc Networks: Adhoc'09, Uppsala: Uppsala universitet , 2009Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Recently, Wireless Mesh Networks (WMNs) have attracted attention as a way to provide alternative Internet connectivity to rural areas or communities. In WMNs, wireless access points communicate with each other wirelessly, forming a true wireless mesh based access network of mesh relay nodes (MRNs). A major problem is, however, scalability of WMNs as well as MAC and PHY layer overhead for packet transmission. Capacity of WMNs can be increased significantly by aggregating (combining) several smaller packets into larger ones. This is in particular beneficial to flows where many packets are of small sizes such as voice flows. TCP could also benefit, as by aggregating several packets together there is a reduced collision risk between TCP DATA and TCP ACKs in addition to the reduced MAC layer contention. In this paper, we investigate the impact of packet aggregation on TCP in Wireless Mesh Networks. Using several different scenarios we demonstrate that packet aggregation can not only increase capacity for TCP in such networks but also improve fairness and reduce end-to-end delay

  • 24.
    Kassler, Andreas
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Karlsson, Jonas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Performance Comparison of Different TCP Flavours2009Inngår i: Traffic and QoS Management in Wireless Multimedia Networks, Springer , 2009Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 25.
    Khatouni, Ali Safari
    et al.
    Politecn Torino, Turin, Italy.
    Mellia, Marco
    Politecn Torino, Turin, Italy.
    Ajmone Marsan, Marco
    Politecn Torino, Turin, Italy ; IMDEA Networks Inst, Leganes, Spain.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Karlsson, Jonas
    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).
    Alay, Ozgu
    Simula Res Lab, Fornebu, Norway.
    Lutu, Andra
    Simula Res Lab, Fornebu, Norway.
    Midoglu, Cise
    Simula Res Lab, Fornebu, Norway.
    Mancuso, Vincenzo
    IMDEA Networks Inst, Leganes, Spain.
    Speedtest-like Measurements in 3G/4G Networks: the MONROE Experience2017Inngår i: 2017 PROCEEDINGS OF THE 29TH INTERNATIONAL TELETRAFFIC CONGRESS (ITC 29), VOL 1, IEEE, 2017, s. 169-177Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mobile Broadband (MBB) Networks are evolving at a fast pace, with technology enhancements that promise drastic improvements in capacity, connectivity, coverage, i.e., better performance in general. But how to measure the actual performance of a MBB solution? In this paper, we present our experience in running the simplest of the performance test: "speedtest-like" measurements to estimate the download speed offered by actual 3G/4G networks. Despite their simplicity, download speed measurements in MBB networks are much more complex than in wired networks, because of additional factors (e.g., mobility of users, physical impairments, diversity in technology, operator settings, mobile terminals diversity, etc.). We exploit the MONROE open platform, with hundreds of multihomed nodes scattered in 4 different countries, and explicitly designed with the goal of providing hardware and software solutions to run large scale experiments in MBB networks. We analyze datasets collected in 4 countries, over 11 operators, from about 50 nodes, for more than 2 months. After designing the experiment and instrumenting both the clients and the servers with active and passive monitoring tools, we dig into collected data, and provide insight to highlight the complexity of running even a simple speedtest. Results show interesting facts, like the occasional presence of NAT, and of Performance Enhancing Proxies (PEP), and pinpoint the impact of different network configurations that further complicate the picture. Our results will hopefully contribute to the debate about performance assessment in MBB networks, and to the definition of much needed benchmarks for performance comparisons of 3G, 4G and soon of 5G networks.

  • 26.
    Peón-Quirós, Miguel
    et al.
    IMDEA Networks, Madrid, Spain .
    Mancuso, Vincenzo
    IMDEA Networks, Madrid, Spain .
    Comite, Vincenzo
    La Sapienza University, Italy.
    Lutu, Andra
    Simula Research Lab, Norway.
    Alay, Özgü
    Simula Research Lab, Norway.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Karlsson, Jonas
    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, Oslo, Norway .
    Results from Running an Experiment as a Service Platform for Mobile Networks2017Inngår i: WiNTECH '17 Proceedings of the 11th Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization, New York, USA: Association for Computing Machinery (ACM), 2017, s. 9-16Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we present a selection from a vast range of experiments run with MONROE, our experiment as a service platform open to external researchers. 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. We also 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 by external research groups and developers that have been granted access to the platform

1 - 26 of 26
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