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  • 101.
    Ala-Häivälä, Anders
    Karlstad University, Faculty of Social and Life Sciences.
    Batch-digitalisering och GIS-anpassning av analoga enkätdata2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    This report describes the work with utilizing and adapting data from a visitor poll for use in a GIS. The poll was performed by the Municipality of Karlstad and the Swedish Forest Agency to survey peoples visit patterns in the I2-Forest, a former military training field which is now used as a recreation area. The poll consists of a number of questions about the visitor’s activities, age, opinions etc, and a map on which the visitor has drawn his or her path through the forest. Source data is a database containing poll answers, and the original maps with the drawn information. The task is partly to investigate if the maps can be batch-digitalized through scanning and vectorization, and partly to normalize the database.

    A method for digitalizing has been developed and tested on a selection of the maps. The method consists of a number of steps, including image processing, classification and vectorization. According to lack of batch-possibilities in the used GIS software, macros have been created by programming in VBA. The method works well on the selected maps and the conclusion is that it is possible to digitalize the drawn lines automatically. However, there are some shortages regarding accuracy and usability. Furthermore, the selection is relatively small and some adjustments on the settings for classification and vectorization might be necessary when applying the method on a larger part of the data.

    The database has been normalized as far as reasonable with consideration of performance and usability. To enable reliable searches, several attributes has been interpreted and modified through categorization and classification.

    The result is a geodatabase consisting of all poll answers, and the selected data from the digitalization test. To show how the database can be used, two simple examples of analyses have been made.

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  • 102.
    Alaqra, Ala
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Pettersson, John
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Centre for HumanIT (from 2013).
    Wästlund, Erik
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013).
    Stakeholders’ Perspectives on Malleable Signatures in a Cloud-based eHealth Scenario2016In: Proceedings of the International Symposium on Human Aspects of Information Security & Assurance / [ed] Nathan Clarke & Steven Furnell, 2016, p. 220-230Conference paper (Refereed)
    Abstract [en]

    In this paper, we discuss end user requirements that we elicited for the use of malleable signatures in a Cloud-based eHealth scenario. The concept of a malleable signature, which is a privacy enhancing cryptographic scheme that enables the redaction of personal information from signed documents while preserving the validity of the signature, might be counter- intuitive to end users as its functionality does not correspond to the one of a traditional signature scheme. A qualitative study via a series of semi-structured interviews and focus groups has been conducted to understand stakeholders’ opinions and concerns in regards to the possible applications of malleable signatures in the eHealth area, where a medical record is first digitally signed by a doctor and later redacted by the patient in the cloud. Results from this study yielded user requirements such as the need for suitable metaphors and guidelines, usable templates, and clear redaction policies. 

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  • 103.
    Alaqra, Ala Sarah
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    The Wicked Problem of Privacy: Design Challenge for Crypto-based Solutions2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Data privacy has been growing in importance in recent years, especially with the continuous increase of online activity. Researchers study, design, and develop solutions aimed at enhancing users’ data privacy. The wicked problem of data privacy is a continuous challenge that defies straightforward solutions. Since there are many factors involved in data privacy, such as technological, legal, and human aspects, we can only aim at mitigating rather than solving this wicked problem. Our aim was to focus on human aspects for designing usable crypto-based privacy-enhancing solutions.  In this thesis, we followed a user centered design method by using empirical qualitative means for investigating user’s perceptions and opinions of our solutions. Most of our work has focused on redactable signatures in the cloud context within the eHealth use-case. Redactable signatures are  a privacy enhancing scheme allowing to remove parts of a signed document by a specified party for achieving data minimization without invalidating the respective signature.

    We mainly used semi-structures interviews and focus groups in our investigations. Our results yielded key HCI considerations as well as guidelines of different means for supporting the design of future solutions.

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  • 104.
    Alaqra, Ala Sarah
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Tinkering the Wicked Problem of Privacy: Design Challenges and Opportunities for Crypto-based Services2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Data privacy has been growing in importance in recent years, especially with the constant increase of online activity. Consequently, researchers study, design, and develop solutions aimed at enhancing users' data privacy. The wicked problem of data privacy is a dynamic challenge that defies straightforward solutions. Since there are many factors involved in data privacy, such as technological, legal, and human aspects, we can only aim at mitigating rather than solving this wicked problem.

    Our aim was to explore challenges and opportunities with a focus on human aspects for designing usable crypto-based privacy-enhancing technologies (PETs). Mainly, there were three PETs in the cloud context included in our studies: malleable signatures, secret sharing, and homomorphic encryption. Based on the three PETs, services were developed within European research projects that were the scope of our user studies. We followed a user-centered design approach by using empirical qualitative and quantitative means for collecting study data. Our results and tinkering conveyed (i) analysis of different categories of user's perspectives, mental models, and trade-offs, (ii) user requirements for PET services, and (iii) user interface design guidelines for PET services. In our contributions, we highlight considerations and guidelines for supporting the design of future solutions.

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  • 105.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Framner, Erik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Enhancing Privacy Controls for Patients via a Selective Authentic Electronic Health Record Exchange Service: Qualitative Study of Perspectives by Medical Professionals and Patients2018In: Journal of Medical Internet Research, E-ISSN 1438-8871, Vol. 20, no 12, article id e10954Article in journal (Refereed)
    Abstract [en]

    Background: Patients' privacy is regarded as essential for the patient-doctor relationship. One example of a privacy-enhancing technology for user-controlled data minimization on content level is a redactable signature. It enables users to redact personal information from signed documents while preserving the validity of the signature, and thus the authenticity of the document. In this study, we present end users' evaluations of a Cloud-based selective authentic electronic health record (EHR) exchange service (SAE-service) in an electronic health use case. In the use case scenario, patients were given control to redact specified information fields in their EHR, which were signed by their doctors with a redactable signature and transferred to them into a Cloud platform. They can then selectively disclose the remaining information in the EHR, which still bears the valid digital signature, to third parties of their choice. Objective: This study aimed to explore the perceptions, attitudes, and mental models concerning the SAE-service of 2 user roles: signers (medical professionals) and redactors (patients with different technical knowledge) in Germany and Sweden. Another objective was to elicit usability requirements for this service based on the analysis of our investigation. Methods: We chose empirical qualitative methods to address our research objective. Designs of mock-ups for the service were used as part of our user-centered design approach in our studies with test participants from Germany and Sweden. A total of 13 individual walk-throughs or interviews were conducted with medical staff to investigate the EHR signers' perspectives. Moreover, 5 group walk-throughs in focus groups sessions with (N=32) prospective patients with different technical knowledge to investigate redactor's perspective of EHR data redaction control were used. Results: We found that our study participants had correct mental models with regard to the redaction process. Users with some technical models lacked trust in the validity of the doctor's signature on the redacted documents. Main results to be considered are the requirements concerning the accountability of the patients' redactions and the design of redaction templates for guidance and control. Conclusions: For the SAE-service to be means for enhancing patient control and privacy, the diverse usability and trust factors of different user groups should be considered.

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  • 106.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Chalmers University of Technology, Sweden.
    Karegar, Farzaneh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Transparency of Privacy Risks Using PIA Visualizations2023In: HCI for Cybersecurity, Privacy and Trust: 5th International Conference, HCI-CPT 2023, Held as Part of the 25th HCI International Conference, HCII 2023, Copenhagen, Denmark, July 23–28, 2023, Proceedings / [ed] Moallem Abbas, Cham: Springer, 2023, p. 3-17Conference paper (Refereed)
    Abstract [en]

    Privacy enhancing technologies allow the minimization of risks to online data. However, the transparency of the minimization process is not so clear to all types of end users. Privacy Impact Assessments (PIAs) is a standardized tool that identifies and assesses privacy risks associated with the use of a system. In this work, we used the results of the PIA conducted in our use case to visualize privacy risks to end users in the form of User Interface (UI) mock ups. We tested and evaluated the UI mock-ups via walkthroughs to investigate users' interests by observing their clicking behavior, followed by four focus group workshops. There were 13 participants (two expert groups and two lay user groups) in total. Results reveal general interests in the transparency provided by showing the risks reductions. Generally, although participants appreciate the concept of having detailed information provided about risk reductions and the type of risks, the visualization and usability of the PIA UIs require future development. Specifically, it should be tailored to the target group's mental models and background knowledge.

    The full text will be freely available from 2024-07-10 14:55
  • 107.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kane, Bridget
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Wearable devices and measurement data: An empirical study on ehealth and data sharing2020In: Proceedings - IEEE Symposium on Computer-Based Medical Systems, Institute of Electrical and Electronics Engineers (IEEE), 2020, p. 443-448Conference paper (Refereed)
    Abstract [en]

    The development of medical applications and services is growing but is hampered by security and privacy concerns and a lack of trust by users. This interview study with 29 users of wearable devices reports perspectives on privacy concerns towards sharing of measured data in general, and measured stress data in the workplace. Participants consider stress data to be sensitive (73%), and report that privacy protection is a requirement for both the technology and the workplace. Sharing behavior is shown to be strongly coupled with clear purposes and incentives. Sharing measured fitness data is accepted (72%), and sharing stress measured data for the common good (48%), despite privacy concerns. Over half mistrust the technology not to leak data. Technology solutions should provide clear and sound purposes for storing, sharing, and processing measured data, as well as provide assurances from workplace and cloud.

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  • 108.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kane, Bridget
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Machine Learning–Based Analysis of Encrypted Medical Data in the Cloud: Qualitative Study of Expert Stakeholders’ Perspectives2021In: JMIR Human Factors, E-ISSN 2292-9495, Vol. 8, no 3, p. 1-15, article id e21810Article in journal (Refereed)
    Abstract [en]

    Background:Third-party cloud-based data analysis applications are proliferating in electronic health (eHealth) because of the expertise offered and their monetary advantage. However, privacy and security are critical concerns when handling sensitive medical data in the cloud. Technical advances based on “crypto magic” in privacy-preserving machine learning (ML) enable data analysis in encrypted form for maintaining confidentiality. Such privacy-enhancing technologies (PETs) could be counterintuitive to relevant stakeholders in eHealth, which could in turn hinder adoption; thus, more attention is needed on human factors for establishing trust and transparency.

    Objective:The aim of this study was to analyze eHealth expert stakeholders’ perspectives and the perceived tradeoffs in regard to data analysis on encrypted medical data in the cloud, and to derive user requirements for development of a privacy-preserving data analysis tool.

    Methods:We used semistructured interviews and report on 14 interviews with individuals having medical, technical, or research expertise in eHealth. We used thematic analysis for analyzing interview data. In addition, we conducted a workshop for eliciting requirements.

    Results:Our results show differences in the understanding of and in trusting the technology; caution is advised by technical experts, whereas patient safety assurances are required by medical experts. Themes were identified with general perspectives on data privacy and practices (eg, acceptance of using external services), as well as themes highlighting specific perspectives (eg, data protection drawbacks and concerns of the data analysis on encrypted data). The latter themes result in requiring assurances and conformance testing for trusting tools such as the proposed ML-based tool. Communicating privacy, and utility benefits and tradeoffs with stakeholders is essential for trust. Furthermore, stakeholders and their organizations share accountability of patient data. Finally, stakeholders stressed the importance of informing patients about the privacy of their data.

    Conclusions:Understanding the benefits and risks of using eHealth PETs is crucial, and collaboration among diverse stakeholders is essential. Assurances of the tool’s privacy, accuracy, and patient safety should be in place for establishing trust of ML-based PETs, especially if used in the cloud.

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  • 109.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Karegar, Farzaneh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Chalmers University of Technology, Sweden.
    Structural and functional explanations for informing lay and expert users: the case of functional encryption2023In: Proceedings on Privacy Enhancing Technologies, E-ISSN 2299-0984, Vol. 2023, no 4, p. 359-380Article in journal (Refereed)
    Abstract [en]

    Usable explanations of privacy-enhancing technologies (PETs) help users make more informed privacy decisions, but the explanations of PETs are generally geared toward individuals with more technical knowledge. To explain functional encryption (FE) to experts and laypersons, we investigate structural and functional explanations and explore users' interests and preferences, as well as how they affect users' comprehension and decisions about sharing data. To this end (with an EU-based population), we conducted four focus groups, in combination with walk-throughs, with 13 participants in the first study, followed by an online survey with 347 experts and 370 laypersons. Both explanations were considered useful in fulfilling the different needs of participants interested in the privacy policy information. Participants, regardless of their expertise, trusted and were more satisfied with the structural explanation. However, functional explanations had a higher contribution to all participants' comprehension. We, therefore, recommend combining both types of explanations for a usable privacy policy.

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  • 110.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013). Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Khumalo, Akhona
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Swedish Recreational Businesses Coping with COVID-19 Using Technologies2022In: HCI International 2022 Posters: 24th International Conference on Human-Computer Interaction, HCII 2022 Virtual Event, June 26 – July 1, 2022 Proceedings, Part III / [ed] Constantine Stephanidis; Margherita Antona; Stavroula Ntoa, Springer, 2022, p. 349-357Conference paper (Refereed)
    Abstract [en]

    Restrictions imposed on societies across the world due to the COVID-19 pandemic have had direct and indirect consequences to the public’s health and well-being. Unlike many countries, Sweden’s restrictions were significantly milder. Businesses offering recreational services provide activities that are important to the well-being of the public. This study explores the status and perspectives of 34 Swedish businesses that provide recreational activities during COVID-19 and the role of technology on recreational services. Results show that businesses comply with guidelines and recommendations, have trust in the government despite lack of sufficient support, and have special considerations for youth. Technology was significant in aiding businesses to cope with COVID-19. Trends reported are: adoption of new remote technologies, increase of digital tools use, offerings of online services, and openness to new solutions.

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  • 111.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Kitkowska, Agnieszka
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Impact of Intrinsic Factors and COVID-19 Pandemic on the Use of Technology2021Conference paper (Refereed)
    Abstract [en]

    The unprecedented pandemic of the infectious coronavirus disease (COVID-19) is still ongoing. Considering the limitations and restrictions imposed by COVID-19, we explored the role of technology and the extent of usage by end-users. In our online survey, we investigated users’ perspectives on their use of technologies in different contexts (e.g., work, entertainment), taking into consideration intrinsic factors such as health consciousness, perceived social isolation, and pandemic-related concerns. Results from 218 respondents show a significant increase in technology use in all investigated contexts after the pandemic occurred. Moreover, the results suggest that different factors may contribute to such increases, depending on the context. It appears that perceived social isolation, concerns about the pandemic, and tracking have the most prominent influence on different use of technology. Furthermore, open-ended responses include beneficial opportunities, concerns & consequences, and behavioral transformations & adaptations due to COVID-19. Our findings provide insights for designing and developing new technologies, especially for communication and entertainment, to support users’ needs during a pandemic.

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  • 112.
    Alaqra, Ala Sarah
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Wästlund, Erik
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013). Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Social and Psychological Studies (from 2013).
    Reciprocities or Incentives?: Understanding Privacy Intrusion Perspectives and Sharing Behaviors2019In: HCI for Cybersecurity, Privacy and Trust: First International Conference, HCI-CPT 2019, Held as Part of the 21st HCI International Conference, HCII 2019, Orlando, FL, USA, July 26–31, 2019, Proceedings / [ed] Abbas Moallem, Cham, Switzerland: Springer, 2019, p. 355-370Conference paper (Refereed)
    Abstract [en]

    The importance and perception of privacy varies from one context to the other. However, everyone values his or her privacy to a certain extent. The subjectivity of that value, attitudes, and behaviors would depend on different entangling factors. It is important to understand the motivation that influences human behavior, whether to protect or share their information. In this paper, we aim at understanding the boundaries of privacy, factors influencing information sharing behavior including experiences (reciprocities of privacy), and efforts taken to protect one’s data. We collected data using quantitative (survey/quiz) and qualitative means (focus groups). In the survey/quiz, our results showed that intrusion experience and awareness have a significant correlation between sharing of data. Furthermore, our focus groups results yielded details on influencing factors for privacy reciprocities and tradeoffs. We discuss our results in terms of privacy incentives and factors influencing the sharing behavior of their information. Finally, we highlight the complexity of behavior where intrinsic and extrinsic motivations could clash and result in a dilemma such as the privacy paradox phenomenon. © 2019, Springer Nature Switzerland AG.

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  • 113.
    Alaqra, Ala(a)
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Groß, Thomas
    Newcastle University, UK.
    Lorünser, Thomas
    Austrian Institute of Technology, Austria.
    Slamanig, Daniel
    Graz University of Technology, Austria.
    Signatures for Privacy, Trust and Accountability in the Cloud: Applications and Requirements2015In: Privacy and Identity Management. Time for a Revolution?: 10th IFIP WG 9.2, 9.5, 9.6/11.7, 11.4, 11.6/SIG 9.2.2 International Summer School, Edinburgh, UK, August 16-21, 2015, Revised Selected Papers / [ed] David Aspinall, Jan Camenisch, Marit Hansen, Simone Fischer-Hübner, Charles Raab, Springer Publishing Company, 2015, Vol. 476, p. 79-96Conference paper (Refereed)
    Abstract [en]

    This paper summarises the results of a workshop at the IFIP Summer School 2015 introducing the EU Horizon 2020 project PRISMACLOUD, that is, Privacy and Security Maintaining Services in the Cloud. The contributions of this summary are three-fold. Firstly, it provides an overview to the PRISMACLOUD cryptographic tools and use-case scenarios that were presented as part of this workshop. Secondly, it distills the discussion results of parallel focus groups. Thirdly, it summarises a ``Deep Dive on Crypto'' session that offered technical information on the new tools. Overall, the workshop aimed at outlining application scenarios and eliciting end-user requirements for PRISMACLOUD.

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    IFIP2015
  • 114.
    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
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Karlsson, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    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: demo2016In: 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, p. 85-86Conference paper (Refereed)
    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.

  • 115.
    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
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Karlsson, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    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 networks2017In: MobiCom '17 Proceedings of the 23rd Annual International Conference on Mobile Computing and Networking, New York: Association for Computing Machinery (ACM), 2017, p. 70-78Conference paper (Refereed)
    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

  • 116.
    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
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Karlsson, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    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 MONROE2016In: 2016 IEEE International Symposium on a World of Wireless, Mobile, and Multimedia Networks (WoWMoM), Red Hook: IEEE, 2016Conference paper (Refereed)
    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.

  • 117. Albert, Lars
    et al.
    Fredriksson, Odd
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Information Systems and Project Management.
    Effektivisering av golvbranschen. En studie av struktur och lönsamhet samt några idéer till förändringar1986Report (Refereed)
  • 118.
    Alcalá-Marín, Sergi
    et al.
    Universidad Carlos Iii de Madrid, ESP.
    Raman, Aravindh
    Telefonica Research, ESP.
    Wu, Weili
    Northwestern University, USA.
    Lutu, Andra
    Telefonica Research, ESP.
    Bagnulo, Marcelo
    University Carlos Iii of Madrid, ESP.
    Alay, Özgü
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). University of Oslo, NOR.
    Bustamante, Fabián
    Northwestern University, USA.
    Global Mobile Network Aggregators: Taxonomy, Roaming Performance and Optimization2022In: MobiSys 2022 - Proceedings of the 2022 20th Annual International Conference on Mobile Systems, Applications and Services, Association for Computing Machinery (ACM), 2022, p. 183-195Conference paper (Refereed)
    Abstract [en]

    A new model of global virtual Mobile Network Operator (MNO) - the Mobile Network Aggregator (MNA) - has recently been gaining significant traction. MNAs provide mobile communications services to their customers by leveraging multiple MNOs, and connecting through the one that best match their customers’ needs at any point in time (and space). MNAs naturally provide optimized global coverage by connecting through local MNOs across the different geographic regions they provide service. In this paper, we dissect the operations of three MNAs, namely, Google Fi, Twilio and Truphone. We perform measurements using the three selected MNAs to assess their performance for three major applications, namely, DNS, web browsing and video streaming. We benchmark their performance comparing it to the one of a traditional MNO. We find that even MNAs provide some delay penalty compared to the service accessed through the local MNOs in the geographic area where the user is roaming, they can significantly improve performance compared to traditional roaming model of the MNOs (e.g. home routed roaming). Finally, in order to fully quantify the potential benefits that can be realized using the MNA model, we perform a set of emulations by deploying both control and user plane functions of open-source 5G implementations in different locations of AWS, and measure the potential gains.

  • 119.
    Al-Dulaimy, A.
    et al.
    Mälardalen University.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Papadopoulos, A. V.
    Mälardalen University.
    Nolte, T.
    Mälardalen University.
    LOOPS: A Holistic Control Approach for Resource Management in Cloud Computing2021In: ICPE 2021 - Proceedings of the ACM/SPEC International Conference on Performance Engineering, Association for Computing Machinery (ACM), 2021, p. 117-124Conference paper (Refereed)
    Abstract [en]

    In cloud computing model, resource sharing introduces major benefits for improving resource utilization and total cost of ownership, but it can create technical challenges on the running performance. In practice, orchestrators are required to allocate sufficient physical resources to each Virtual Machine (VM) to meet a set of predefined performance goals. To ensure a specific service level objective, the orchestrator needs to be equipped with a dynamic tool for assigning computing resources to each VM, based on the run-Time state of the target environment. To this end, we present LOOPS, a multi-loop control approach, to allocate resources to VMs based on the service level agreement (SLA) requirements and the run-Time conditions. LOOPS is mainly composed of one essential unit to monitor VMs, and three control levels to allocate resources to VMs based on requests from the essential node. A tailor-made controller is proposed with each level to regulate contention among collocated VMs, to reallocate resources if required, and to migrate VMs from one host to another. The three levels work together to meet the required SLA. The experimental results have shown that the proposed approach can meet applications' performance goals by assigning the resources required by cloud-based applications.

  • 120.
    Al-Dulaimy, Auday
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Itani, Wassim
    Beirut Arab University, Lebanon.
    Shamseddine, Maha
    Beirut Arab University, Lebanon.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Privacy-Aware Job Submission in the Cloud2019In: 2019 2nd IEEE Middle East and North Africa COMMunications Conference, MENACOMM 2019, IEEE, 2019Conference paper (Refereed)
    Abstract [en]

    The services offered by cloud computing are provided to individuals and organizations by varied shared resources which are forming the hardware layer of cloud data centers. Cloud users do not deal or interact directly with those resources, instead, they deal with the virtualized version of them, in other words, users deal with the virtualization layer which conceals to a great extent the specifics of the physical hardware layer. Based on the virtualization concept, more than one virtual machine can be co-hosted on the same physical machine. In spite of the wide range of benefits, co-hosting virtual machines on the same host comes with privacy and security threats. From one side, cloud providers are serving the virtual machines without being aware of their contents. On the other side, once cloud users submit their jobs to be serviced in the cloud, they lose their control on their jobs' sensitive information. Thus, cloud users' hesitation from moving to the cloud is logical since their sensitive jobs' content leakage or misuse is possible, especially when cloud services are not designed with privacy considerations. This paper proposes an approach to make the jobs with sensitive information more secure when submitted to the cloud environment. The core idea of the approach is to request the inclusion of the privacy specification of a set of one or more provider services in the Service Level Agreement contract.

  • 121.
    Al-Dulaimy, Auday
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Itani, Wassim
    University of Houston Victoria, USA..
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Shamseddine, Maha
    Beirut Arab University, LBN..
    BWSLICER: A bandwidth slicing framework for cloud data centers2020In: Future generations computer systems, ISSN 0167-739X, E-ISSN 1872-7115, Vol. 112, p. 767-784Article in journal (Refereed)
    Abstract [en]

    Bandwidth allocation is an important and influential factor in enhancing the performance of the data centers' nodes. In this paper we propose bwSlicer, a framework for bandwidth slicing in cloud data centers, that sheds light on the virtues of effective dynamic bandwidth allocation on improving the system performance and energy efficiency. Three algorithms are investigated to deal with this issue. In the first algorithm, called Fair Bandwidth Reallocation (FBR), two virtual machines co-hosted on the same node conditionally exchange bandwidth slices based on their requirements. The second algorithm, called Required Bandwidth Allocation (RBA), periodically monitors the co-hosted virtual machines and adds/removes bandwidth slices for each of them based on their bandwidth utilization. The third algorithm, called Divide Bandwidth Reallocation (DBR), divides the bandwidth of the virtual machine into slices once it finishes its execution, and distributes the slices among the co-hosted running virtual machines according to a specific policy. The proposed bandwidth slicing algorithms are emulated in a virtualized networking environment using the Mininet network emulator. The emulation results demonstrated a promising improvement ratio in execution time and energy consumption reaching up to 30%. These results present a call for action for further research into bandwidth slicing and reallocation as a viable complement to other energy-saving techniques for enhancing the energy consumption in cloud data centers.

  • 122.
    Al-Dulaimy, Auday
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Sharma, Yogesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Gokan Khan, Michel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Introduction to edge computing2020In: Edge Computing: Models, technologies and applications / [ed] Javid Taheri; Shuiguang Deng, Institution of Engineering and Technology, 2020Chapter in book (Refereed)
    Abstract [en]

    Edge computing is the model that extends cloud computing services to the edge of the network. This model aims to move decision-making operations as close as possible to data sources since it acts as an intermediate layer connecting cloud data centres to edge devices/sensors. Transferring all the data from the network edge to the cloud data centres for processing may create a latency problem and outstrip the network's bandwidth capacity. To resolve this issue, it might be best to process data closer to the devices/sensors. This chapter will take a deep dive into edge computing, its applications, and the existing challenges related to this model.

  • 123.
    Al-Dulaimy, Auday
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Hoseiny Farahabady, M. R.
    University of Sydney, AUS.
    Deng, S.
    Zhejiang University, CHN.
    Zomaya, A.
    University of Sydney, AUS.
    MultiScaler: A Multi-Loop Auto-Scaling Approach for Cloud-Based Applications2020In: IEEE Transactions on Cloud Computing, ISSN 2168-7161Article in journal (Refereed)
    Abstract [en]

    Cloud computing offers a wide range of services through a pool of heterogeneous Physical Machines (PMs) hosted on cloud data centers, where each PM can host several Virtual Machines (VMs). Resource sharing among VMs comes with major benefits, but it can create technical challenges that have a detrimental effect on the performance. To ensure a specific service level requested by the cloud-based applications, there is a need for an approach to assign adequate resources to each VM. To this end, we present our novel Multi-Loop Control approach, called MultiScaler , to allocate resources to VMs based on the Service Level Agreement (SLA) requirements and the run-time conditions. MultiScaler is mainly composed of three different levels working closely with each other to achieve an optimal resource allocation. We propose a set of tailor-made controllers to monitor VMs and take actions accordingly to regulate contention among collocated VMs, to reallocate resources if required, and to migrate VMs from one PM to another. The evaluation in a VMware cluster have shown that the MultiScaler approach can meet applications performance goals and guarantee the SLA by assigning the exact resources that the applications require. Compared with sophisticated baselines, MultiScaler produces significantly better reaction to changes in workloads even under the presence of noisy neighbors.

  • 124.
    Alfredsson, Rebecka
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science.
    Multipath transport protocol offloading2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Recently, we have seen an evolution of programmable network devices, where it is possible to customize packet processing inside the data plane at an unprecedented level. This is in contrast to traditional approaches, where networking device functionality is fixed and defined by the ASIC and customers need to wait possibly years before the vendors release new versions that add features required by customers. The vendors in the industry have adapted and the focus has shifted to offering new types of network devices, such as the SmartNIC, IPU, and DPU. Another major paradigm shift in the networking area is the shift towards protocols that encrypt parts of headers and contents of packets such as QUIC. Also, many devices such as smart phones have support for multiple access networks, which requires efficient multipath protocols to leverage the capabilities of multiple networks at the same time.

    However, when using protocols inside the network that requires encryption such as QUIC or multipath QUIC, packet processing operations for the en/decryption process are very resource intensive. Consequently, network vendors and operators are in need to accelerate and offload crypto operations to dedicated hardware in order to free CPU cycles for business critical operations. Therefore, the aim of this study is to investigate how multipath QUIC can be offloaded or hardware accelerated in order to reduce the CPU utilization on the server.

    Our contributions are an evaluation of frameworks, programming languages and hardware devices in terms of crypto offloading functionality. Two packet processing offloading prototypes were designed using the DPDK framework and the programming language P4. The design using DPDK was implemented and evaluated on a BlueField 2 DPU. The offloading prototype handles a major part of the packet processing and the crypto operations in order to reduce the load of the user application running on the host. A evaluation show that the throughput when using larger keys are only slightly decreased. The evaluation gives important insights in the need of crypto engines and/or CPUs with high performance when offloading.

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  • 125.
    Alfredsson, Rebecka
    et al.
    Karlstad University.
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Vestin, Jonathan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Pieskä, Marcus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Amend, Markus
    Deutsche Telekom, DEU.
    Accelerating a Transport Layer based 5G Multi-Access Proxy on SmartNIC2022In: Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22), Würzburgs universitet , 2022, p. 4-Conference paper (Other academic)
    Abstract [en]

    Utilizing multiple access technologies such as 5G,4G, and Wi-Fi within a coherent framework is currentlystandardized by 3GPP within 5G ATSSS. Indeed, distributingpackets over multiple networks can lead to increased robustness,resiliency and capacity. A key part of such a framework isthe multi-access proxy, which transparently distributes packetsover multiple paths. As the proxy needs to serve thousands ofcustomers, scalability and performance are crucial for operatordeployments. In this paper, we leverage recent advancementsin data plane programming, implement a multi-access proxybased on the MP-DCCP tunneling approach in P4 and hardwareaccelerate it by deploying the pipeline on a smartNIC. Thisis challenging due to the complex scheduling and congestioncontrol operations involved. We present our pipeline and datastructures design for congestion control and packet schedulingstate management. Initial measurements in our testbed showthat packet latency is in the range of 25 μs demonstrating thefeasibility of our approach.

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  • 126.
    Alfredsson, Stefan
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science.
    A Cross-Layer Perspective on Transport Protocol Performance in Wireless Networks2012Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Communication by wireless technologies has seen a tremendous growth in the last decades. Mobile phone technology and wireless broadband solutions are rapidly replacing the last-hop wireline connectivity for telephones and Internet access.  Research has, however, shown that Internet traffic can experience a performance degradation over wireless compared to wired networks.  The inherent properties of radio communication lead to a higher degree of unreliability, compared to communication by wire or fiber.  This can result in an increased amount of transmission errors, packet loss, delay and delay variations, which in turn affect the performance of the main Internet transport protocols TCP and UDP.  This dissertation examines the cross-layer relationship between wireless transmission and the resulting performance on the transport layer. To this end, experimental evaluations of TCP and UDP over a wireless 4G downlink system proposal are performed.  The experiment results show, in a holistic scenario, that link-level adaptive modulation, channel prediction, fast persistent link retransmissions, and channel scheduling, enables the transport protocols TCP and UDP to perform well and utilize the wireless link efficiently.  Further, a novel approach is proposed where a modified TCP receiver can choose to accept packets that are corrupted by bit errors. Results from network emulation experiments indicate that by accepting and acknowledging even small amounts of corrupted data, a much higher throughput can be maintained compared to standard TCP.

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  • 127.
    Ali Khorshid, Namo
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Säkerhet och användbarhet ur användarnas perspektiv: En tematisk innehållsanalys av användarnas recensioner till betalningsapparna Apple Pay och Google Pay på capterra.se2022Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    I takt med utvecklingen av att allt fler enheter är ihopkopplade och det ökade användandet av applikationer som lagrar persondata är säkerhet en aspekt som måste implementeras av utvecklare och som användarna behöver förstå sig bättre på. Samtidigt är smarta enheter och applikationer designade för att vara lätta att använda och för att vara funktionella är det utmanande att förena faktorerna användbarhet och säkerhet på en acceptabel nivå. Denna balans är särskilt intressant att undersöka när det dessutom gäller betalningsappar då historiskt har konsumenter velat att en betalning genomförs säkert, smidigt och bekvämt. Betalningsapparna medger köp av varor utan användning av kontanter och används av över två miljarder människor globalt där Apple Pay och Google Pay är de två globala betalningsapplikationerna. Denna studie har till syfte att belysa användarnas syn på faktorerna användbarhet och säkerhet hos betalningsapparna Apple Pay och Google Pay.

    Data om användarnas recensioner till de två utvalda betalningsapplikationerna har inhämtats från online-marknadsförsäljaren capterra.se, som fungerar som mellanhand mellan köpare och teknikleverantörer inom mjukvaruindustrin. För att uppnå syftet inom ramen för uppsatsens storleksbegränsning har uppsatsens undersökningsområde avgränsats till att behandla data om användares recensioner till betalningsapplikationerna Apple Pay respektive Google Pay, lagda av användare med minst två års användarlängd.

    En kvalitativ metod i form av en tematisk innehållsanalys har använts som metod för att analysera de ovan nämnda recensionerna vilket har utgått från tvåhundra recensioner för Apple Pay respektive hundrasextiofem recensioner på Google Pay. I enlighet med metoden för tematisk analys har jag gått igenom de valda recensionernas rubrik och innehåll för de två valda applikationerna för att sedan analysera och identifiera kännetecken och särdrag i dess data. Slutligen har datamaterialet organiserats och grupperats för att identifiera tema för att relatera till syftet och frågeställningarna.

    Slutsatsen av studien visar att användarna lyfter följande teman i sina recensioner: Integritet, Sekretess, Tillgänglighet, Användarvänligt, Tillfredsställanede och Effektivitet. De tre förstnämnda teman är i denna studie kopplade till säkerhetsfaktorn och resterande tre teman är kopplade till faktorn användbarhet. Den procentuella andelen av teman kopplad till säkerhet är 31% och till användbarhet 69% som omnämnts i recensionerna för Apple Pay. För Google Pay är motsvarande siffra 27% respektive 73%. Detta innebär att användarna lyfter användbarhetsfaktorn mer än säkerhetsfaktorn i sina recensioner. Trots användarnas fokus på användbarhet är säkerhet inte en obetydlig faktor.

    Inga avsevärda skillnader föreligger bland recensionerna utifrån de två studerade faktorerna mellan de två utvalda betalningsapplikationerna Apple Pay respektive Google Pay.

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  • 128.
    Ali, Nour
    et al.
    Brunel University, London, UK.
    Baker, Sean
    University of Limerick, Ireland.
    O’Crowley, Ross
    Red Orkid Limited, Dublin, Ireland.
    Herold, Sebastian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Buckley, Jim
    University of Limerick, Ireland.
    Architecture consistency: State of the practice, challenges and requirements2018In: Empirical Software Engineering, ISSN 1382-3256, E-ISSN 1573-7616, Vol. 23, no 1, p. 224-258Article in journal (Refereed)
    Abstract [en]

    Architecture Consistency (AC) aims to align implemented systems with their intended architectures. Several AC approaches and tools have been proposed and empirically evaluated, suggesting favourable results. In this paper, we empirically examine the state of practice with respect to Architecture Consistency, through interviews with nineteen experienced software engineers. Our goal is to identify 1) any practises that the companies these architects work for, currently undertake to achieve AC; 2) any barriers to undertaking explicit AC approaches in these companies; 3) software development situations where practitioners perceive AC approaches would be useful, and 4) AC tool needs, as perceived by practitioners. We also assess current commercial AC tool offerings in terms of these perceived needs. The study reveals that many practitioners apply informal AC approaches as there are barriers for adopting more formal and explicit approaches. These barriers are: 1) Difficulty in quantifying architectural inconsistency effects, and thus justifying the allocation of resources to fix them to senior management, 2) The near invisibility of architectural inconsistency to customers, 3) Practitioners’ reluctance towards fixing architectural inconsistencies, and 4) Practitioners perception that huge effort is required to map the system to the architecture when using more formal AC approaches and tools. Practitioners still believe that AC would be useful in supporting several of the software development activities such as auditing, evolution and ensuring quality attributes. After reviewing several commercial tools, we posit that AC tool vendors need to work on their ability to support analysis of systems made up of different technologies, that AC tools need to enhance their capabilities with respect to artefacts such as services and meta-data, and to focus more on non-maintainability architectural concerns.

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  • 129.
    Ali Shah, Usman
    et al.
    University of Engineering and Technology at Peshawar, Pakistan.
    Yousaf, Suhail
    University of Engineering and Technology at Peshawar, Pakistan.
    Ahmad, Iftikhar
    University of Engineering and Technology at Peshawar, Pakistan.
    Ur Rehman, Safi
    Karakoram International University, Pakistan.
    Ahmad, Muhammad Ovais
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Accelerating Revised Simplex Method using GPU-based Basis Update2020In: IEEE Access, E-ISSN 2169-3536, Vol. 8, p. 52121-52138Article in journal (Refereed)
    Abstract [en]

    Optimization problems lie at the core of scientific and engineering endeavors. Solutions to these problems are often compute-intensive. To fulfill their compute-resource requirements, graphics processing unit (GPU) technology is considered a great opportunity. To this end, we focus on linear programming (LP) problem solving on GPUs using revised simplex method (RSM). This method has potentially GPU-friendly tasks, when applied to large dense problems. Basis update (BU) is one such task, which is performed in every iteration to update a matrix called basis-inverse matrix. The contribution of this paper is two-fold. Firstly, we experimentally analyzed the performance of existing GPU-based BU techniques. We discovered that the performance of a relatively old technique, in which each GPU thread computed one element of the basis-inverse matrix, could be significantly improved by introducing a vectorcopy operation to its implementation with a sophisticated programming framework. Second, we extended the adapted element-wise technique to develop a new BU technique by using three inexpensive vector operations. This allowed us to reduce the number of floating-point operations and conditional processing performed by GPU threads. A comparison of BU techniques implemented in double precision showed that our proposed technique achieved 17.4% and 13.3% average speed-up over its closest competitor for randomly generated and well-known sets of problems, respectively. Furthermore, the new technique successfully updated basisinverse matrix in relatively large problems, which the competitor was unable to update. These results strongly indicate that our proposed BU technique is not only efficient for dense RSM implementations but is also scalable.

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  • 130.
    Ali, Usman
    et al.
    Sapienza University of Rome, Italy.
    Caso, Giuseppe
    Ericsson AB, Kista, Sweden.
    De Nardis, Luca
    Sapienza University of Rome, Italy.
    Kousias, Konstantinos
    Simula Research Laboratory, Norway.
    Rajiullah, Mohammad
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Alay, Özgü
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). University of Oslo, Norway.
    Neri, Marco
    Rohde & Schwarz, Italy..
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Di Benedetto, Maria-Gabriella
    Sapienza University of Rome, Italy.
    Data-Driven Analysis of Outdoor-to-Indoor Propagation for 5G Mid-Band Operational Networks2022In: Future Internet, E-ISSN 1999-5903, Vol. 14, no 8, p. 1-27, article id 239Article in journal (Refereed)
    Abstract [en]

    The successful rollout of fifth-generation (5G) networks requires a full understanding of the behavior of the propagation channel, taking into account the signal formats and the frequencies standardized by the Third Generation Partnership Project (3GPP). In the past, channel characterization for 5G has been addressed mainly based on the measurements performed on dedicated links in experimental setups. This paper presents a state-of-the-art contribution to the characterization of the outdoor-to-indoor radio channel in the 3.5 GHz band, based on experimental data for commercial, deployed 5G networks, collected during a large scale measurement campaign carried out in the city of Rome, Italy. The analysis presented in this work focuses on downlink, outdoor-to-indoor propagation for two operators adopting two different beamforming strategies, single wide-beam and multiple synchronization signal blocks (SSB) based beamforming; it is indeed the first contribution studying the impact of beamforming strategy in real 5G networks. The time and power-related channel characteristics, i.e., mean excess delay and Root Mean Square (RMS) delay spread, path loss, and K-factor are studied for the two operators in multiple measurement locations. The analysis of time and power-related parameters is supported and extended by a correlation analysis between each pair of parameters. The results show that beamforming strategy has a marked impact on propagation. A single wide-beam transmission leads, in fact, to lower RMS delay spread and lower mean excess delay compared to a multiple SSB-based transmission strategy. In addition, the single wide-beam transmission system is characterized by a smaller path loss and a higher K-factor, suggesting that the adoption of a multiple SSB-based transmission strategy may have a negative impact on downlink performance.

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  • 131. Ali Yahiya, Tara
    et al.
    Chaouchi, Hakima
    Kassler, Andreas
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT.
    Pujolle, Guy
    Seamless Interworking of WLAN and WMAN Wireless Networks2006Conference paper (Refereed)
    Abstract [en]

    Future network environments will be heterogeneous and mobile terminals will have the opportunity to dynamically select among many different access technologies. Therefore, it is important to provide service continuity in case of vertical handovers when terminals change the access technology. Two important wireless access technologies are WLAN (Wireless Local Access Networks) and WMAN (Wireless Metropolitan Access Networks) networks. In this paper, we address several challenges related to a seamless integration of those technologies. We highlight important aspects for designing a WLAN/WMAN interworking architecture and we address important Quality of Service (QoS) issues for such interworked systems like degree of QoS support provided by the technologies, QoS mapping and signalling for vertical handover. By formulating several interworking scenarios, where WLAN users with ongoing voice, video and data sessions hand over to WMAN, we study QoS and performance issues and analyse feasibility of seamless session continuity through simulations

  • 132.
    Alizadeh Noghani, Kyoomars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Service Migration in Virtualized Data Centers2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Modern virtualized Data Centers (DCs) require efficient management techniques to guarantee high quality services while reducing their economical cost. The ability to live migrate virtual instances, e.g., Virtual Machines (VMs), both inside and among DCs is a key operation for the majority of DC management tasks that brings significant flexibility into the DC infrastructure. However, live migration introduces new challenges as it ought to be fast and seamless while at the same time imposing a minimum overhead on the network. In this thesis, we study the networking problems of live service migration in modern DCs when services are deployed in virtualized environments, e.g., VMs and containers. In particular, this thesis has the following main objectives: (1) improving the live VM migration in Software-Defined Network (SDN) enabled DCs by addressing networking challenges of live VM migration, and (2) investigating the trade-off between the reconfiguration cost and optimality of the Service Function Chains (SFCs) placement after the reconfiguration has been applied when SFCs are composed of stateful Virtual Network Functions (VNFs).

    To achieve the first objective, in this thesis, we use distinctive characteristics of SDN architectures such as their centralized control over the network to accelerate the network convergence time and address suboptimal routing problem. Consequently, we enhance the quality of intra- and inter-DC live migrations. Furthermore, we develop an SDN-based framework to improve the inter-DC live VM migration by automating the deployment, improving the management, enhancing the performance, and increasing the scalability of interconnections among DCs.

    To accomplish the second objective, we investigate the overhead of dynamic reconfiguration of stateful VNFs. Dynamic reconfiguration of VNFs is frequently required in various circumstances, and live migration of VNFs is an integral part of this operation. By mathematically formulating the reconfiguration costs of stateful VNFs and developing a multi-objective heuristic solution, we explore the trade-off between the reconfiguration cost required to improve a given placement and the degree of optimality achieved after the reconfiguration is performed. Results show that the cost of performing the reconfiguration operations required to realize an optimal VNF placement might hamper the gain that could be achieved.

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  • 133.
    Alizadeh Noghani, Kyoomars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Towards Seamless Live Migration in SDN-Based Data Centers2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Live migration of Virtual Machines (VMs) has significantly improved the flexibility of modern Data Centers (DCs). Ideally, live migration ought to be seamless which in turn raises challenges on how to minimize service disruption and avoid performance degradation. To address these challenges, a comprehensive support from the underlying network is required. However, legacy DC networks fall short to help as they take a reactive approach to live migration procedure. Moreover, the complexity and inflexibility of legacy DC networks make it difficult to deploy, manage, and improve network technologies that DC providers may need to use for migration.

    In this thesis, we explore the application of Software Defined Networking (SDN) paradigm for making live VM migration more seamless. Exploiting the characteristics of SDN such as its centralized view on network states, we contribute to the body of knowledge by enhancing the quality of intra- and inter-DC live migration. Firstly, for intra-DC migration, we provide an SDN-based solution which minimizes the service disruption by employing OpenFlow-based resiliency mechanisms to prepare a DC network for migration proactively. Secondly, we improve the inter-DC live migration by accelerating the network convergence through announcing the migration in the control plane using MP-BGP protocol. Further, our proposed framework resolves the sub-optimal routing problem by conducting the gateway functionality at the SDN controller. Finally, with the ultimate goal of improving the inter-DC migration, we develop an SDN-based framework which automates the deployment, improves the management, enhances the performance, and increases the scalability of interconnections among DCs.

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  • 134.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ghazzai, Hakim
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    A Generic Framework for Task Offloading in mmWave MEC Backhaul Networks2018In: 2018 IEEE Global Communications Conference (GLOBECOM), IEEE, 2018, p. 1-7Conference paper (Refereed)
    Abstract [en]

    With the emergence of millimeter-Wave (mmWave) communication technology, the capacity of mobile backhaul networks can be significantly increased. On the other hand, Mobile Edge Computing (MEC) provides an appropriate infrastructure to offload latency-sensitive tasks. However, the amount of resources in MEC servers is typically limited. Therefore, it is important to intelligently manage the MEC task offloading by optimizing the backhaul bandwidth and edge server resource allocation in order to decrease the overall latency of the offloaded tasks. This paper investigates the task allocation problem in MEC environment, where the mmWave technology is used in the backhaul network. We formulate a Mixed Integer NonLinear Programming (MINLP) problem with the goal to minimize the total task serving time. Its objective is to determine an optimized network topology, identify which server is used to process a given offloaded task, find the path of each user task, and determine the allocated bandwidth to each task on mmWave backhaul links. Because the problem is difficult to solve, we develop a two-step approach. First, a Mixed Integer Linear Program (MILP) determining the network topology and the routing paths is optimally solved. Then, the fractions of bandwidth allocated to each user task are optimized by solving a quasi-convex problem. Numerical results illustrate the obtained topology and routing paths for selected scenarios and show that optimizing the bandwidth allocation significantly improves the total serving time, particularly for bandwidth-intensive tasks.

  • 135.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Hernandez Benet, Cristian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Marotta, Antonio
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Jestin, Patrick
    Ericsson AB, Sweden.
    Srivastava, Vivek V.
    Ericsson AB, Sweden.
    Automating Ethernet VPN deployment in SDN-based Data Centers2017In: 2017 Fourth International Conference on Software Defined Systems (SDS)., IEEE, 2017, p. 61-66Conference paper (Refereed)
    Abstract [en]

    Layer 2 Virtual Private Network (L2VPN) is widely deployed in both service provider networks and enterprises. However, legacy L2VPN solutions have scalability limitations in the context of Data Center (DC) interconnection and networking which require new approaches that address the requirements of service providers for virtual private cloud services. Recently, Ethernet VPN (EVPN) has been proposed to address many of those concerns and vendors started to deploy EVPN based solutions in DC edge routers. However, manual configuration leads to a time-consuming, error-prone configuration and high operational costs. Automating the EVPN deployment from cloud platforms such as OpenStack enhances both the deployment and flexibility of EVPN Instances (EVIs). This paper proposes a Software Defined Network (SDN) based framework that automates the EVPN deployment and management inside SDN-based DCs using OpenStack and OpenDaylight (ODL). We implemented and extended several modules inside ODL controller to manage and interact with EVIs and an interface to OpenStack that allows the deployment and configuration of EVIs. We conclude with scalability analysis of our solution.

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  • 136.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Hernandez Benet, Cristian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    SDN helps volume in Big Data2018In: Big Data and Software Defined Networks / [ed] Javid Taheri, London: IET Digital Library, 2018, 1, p. 185-206Chapter in book (Refereed)
    Abstract [en]

    Both Big Data and SDN are described in detail in previous chapters. This chapter investigates how SDN architecture can leverage its unique features to mitigate the challenges of Big Data volume. Accordingly, first, we provide an overview of Big Data volume, its effects on the underlying network, and mention some potential SDN solutions to address the corresponding challenges. Second, we elaborate more on the network-monitoring, traffic-engineering, and fault-tolerant mechanisms which we believe they may help to address the challenges of Big Data volume. Finally, this chapter is concluded with some open issues.

  • 137.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Reconfiguration of Service Function Chains: Trade-off between Optimality and Effort2019In: Proceedings of the 30th European conference on operational research, Euro 2019, 23-26 June, Dublin, Ireland., 2019Conference paper (Refereed)
  • 138.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    SDN Enhanced Ethernet VPN for Data Center Interconnect2017In: 2017 IEEE 6th International Conference on Cloud Networking (CloudNet) / [ed] Maga, D, IEEE, 2017, p. 77-82Conference paper (Refereed)
    Abstract [en]

    Ethernet Virtual Private Network (EVPN) is an emerging technology that addresses the networking challenges presented by geo-distributed Data Centers (DCs). One of the major advantages of EVPN over legacy layer 2 VPN solutions is providing All-Active (A-A) mode of operation so that the traffic can truly be multi-homed on Provider Edge (PE) routers. However, A-A mode of operation introduces new challenges. In the case where the Customer Edge (CE) router is multi-homed to one or more PE routers, it is necessary that only one of the PE routers should forward Broadcast, Unknown unicast, and Multicast (BUM) traffic into the DC. The PE router that assumes the primary role for forwarding BUM traffic to the CE device is called the Designated Forwarder (DF). The proposed solution to select the DF in the EVPN standard is based on a distributed algorithm which has a number of drawbacks such as unfairness and intermittent behavior. In this paper, we introduce a Software-Defined Networking (SDN) based architecture for EVPN support, where the SDN controller interacts with EVPN control plane. We demonstrate how our solution mitigates existing problems for DF selection which leads to improved EVPN performance.

  • 139.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Sankar Gopannan, Prem
    Ericsson, USA.
    EVPN/SDN Assisted Live VM Migration between Geo-Distributed Data Centers2018In: 4th IEEE Conference on Network Softwarization (NetSoft), IEEE, 2018, p. 105-113Conference paper (Refereed)
    Abstract [en]

    Live Virtual Machine (VM) migration has significantly improved the flexibility of modern Data Centers (DC). However, seamless live migration of a VM between geo-distributed DCs faces several challenges due to difficulties in preserving the network configuration after the migration paired with a large network convergence time. Although SDN-based approaches can speed up network convergence time, these techniques have two limitations. First, they typically react to the new topology by installing new flow rules once the migration is finished. Second, because the WAN is typically not under SDN control, they result in sub-optimal routing thus severely degrading the network performance once the VM is attached at the new location.

    In this paper, we identify networking challenges for VM migration across geo-distributed DCs. Based on those observations, we design a novel long-haul VM migration scheme that overcomes those limitations. First, instead of reactively restoring connectivity after the migration, our SDN-based approach proactively restores flows across the WAN towards the new location with the help of EVPN and VXLAN overlay technologies. Second, the SDN controller accelerates the network convergence by announcing the migration to other controllers using MP-BGP control plane messages. Finally, the SDN controller resolves the sub-optimal routing problem that arises as a result of migration implementing a distributed anycast gateway. We implement our approach as extensions to the OpenDaylight controller. Our evaluation shows that our approach outperforms existing approaches in reducing the downtime by 400 ms and increasing the application performance up to 12 times.

  • 140.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    On the Cost-Optimality Trade-off for Service Function Chain Reconfiguration2019Conference paper (Refereed)
    Abstract [en]

    Optimal placement of Virtual Network Functions (VNFs) in virtualized data centers enhances the overall performance of Service Function Chains (SFCs) and decreases the operational costs for mobile network operators. Maintaining an optimal placement of VNFs under changing load requires a dynamic reconfiguration that includes adding or removing VNF instances, changing the resource allocation of VNFs, and re-routing corresponding service flows. However, such reconfiguration may lead to notable service disruptions and impose additional overhead on the VNF infrastructure, especially when reconfiguration entails state or VNF migration. On the other hand, not changing the existing placement may lead to high operational costs. In this paper, we investigate the trade-off between the reconfiguration of SFCs and the optimality of the resulting placement and service flow (re)routing. We model different reconfiguration costs related to the migration of stateful VNFs and solve a joint optimization problem that aims to minimize both the total cost of the VNF placement and the reconfiguration cost necessary for repairing a suboptimal placement. Numerical results show that a small number of reconfiguration operations can significantly reduce the operational cost of the VNF infrastructure; however, too much reconfiguration may not pay off should heavy costs be involved.

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    Cloudnet-2019
  • 141.
    Alizadeh Noghani, Kyoomars
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Öhlen, Peter
    Ericsson AB.
    Curescu, Calin
    Ericsson AB.
    On the Cost-Optimality Trade-off for Fast Service Function Chain ReconfigurationManuscript (preprint) (Other academic)
    Abstract [en]

    Optimal placement of Virtual Network Functions (VNFs) in data centers enhances the overall performance of Service Function Chains (SFCs) and decreases the operational costs for mobile network operators. In order to cope with changes in demands, VNF instances may be added or removed dynamically, resource allocations may be adjusted, and servers may be consolidated. To maintain an optimal placement of SFC under changing conditions, dynamic reconfiguration is required including the migration of VNFs and the re-routing of service flows. However, such reconfiguration may lead to notable service disruptions and can be exacerbated when reconfiguration entails state or VNF migration, both imposing additional overhead on the VNF infrastructure. On the other hand, not changing the placement may lead to a suboptimal operation, servers and links may become congested or underutilized, leading to high operational costs. In this paper, we investigate the trade-off between the reconfiguration of SFCs and the optimality of the resulting placement and service flow routing. We model reconfiguration costs related to the migration of stateful VNFs and solve a joint optimization problem that aims to minimize both the total cost of the new placement and the reconfiguration cost necessary to achieve it. We also develop a fast multi-objective genetic algorithm that finds near-optimal solutions for online decisions. Our numerical evaluations show that a small number of reconfiguration operations can significantly reduce the operational cost of the VNF infrastructure. In contrast, too much reconfiguration may not pay off due to high costs. We believe that our work is an important tool that helps network provider to plan a good reconfiguration strategy for their service chains.

  • 142.
    Al-Khalaf, Bara
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School.
    Medborgarnas behov av vad som kommuniceras på kommunens Facebook sida: En fallstudie på Grums kommun och Karlstads kommun2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sociala medier ger oss en möjlighet att kommunicera med varandra och sprida information till tusentals människor samtidigt. Idag använder båda privatpersoner och organisationer sig av sociala medier, även kommuner finns idag på sociala medier för bland annat sprida information och kommunicera med medborgarna. Syftet med denna uppsats är att ta reda på medborgarnas önskemål om vad kommunen bör använda Facebook till/hur. Men även ta reda om det stämmer överrens med vad kommunen publicerar idag eller inte. Detta ger kommunen en bild av vad medborgaren är intresserade av att se på deras Facebooksida.Studien baseras på två metoder, den ena metoden är en webbaserad enkätundersökning där 32 deltagare från Karlstads universitet besvarar frågorna med egna ord. Frågorna i enkäten är fördefinerade och hjälper med att besvara uppsatsens syfte. Den andra metoden är en liten dataanalys av Karlstads och Grums kommuns Facebook sida för att kartlägga vad kommunerna publicerar idag. Undersökningen visar att medborgaren är intresserade av att se mer information om vad som händer i kommunen, om olika event och hur kommunen jobbar. Medborgaren vill också ta del av de olika besluten som tas i kommunen. Kommunen publicerar idag till vis del det medborgaren är intresserad av men medborgaren vill att kommunen visar mer delaktighet, att svara och delta aktivt i kommentarerna som medborgaren ger på kommunens inlägg.

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  • 143.
    Allansson, Robin
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Yang, Vittcki
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Comparing Model- and Delay-based Congestion Controls in a Kubernetes Cluster2024Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today's society is heavily influenced by the use of cloud-based services and the internet as a whole. This is causing higher demand for stable networks and maximized efficiency inside the cloud industry. The direction the cloud-based industry went was to maximize their hardware using virtualization. To make this happen they had two options one being virtual machines and the other which grew more common were containers. Kubernetes and Docker are top candidates for virtualized environments which also raises the question of whether the current network protocol is up to speed, TCP Cubic has been the standard network protocol in Linux kernels since 2006 but there are newer protocols that challenge the old standard mainly TCP BBR which was announced by Google 2016. The current situation between the explosive growth of network-based applications and the older network-based protocol that was not designed for this type of traffic which begs the question, is the current standard keeping up to the task? Is the virtualization causing an impact on the traffic flow and is the older protocol worth it compared to the newer protocol produced by Google? In this thesis we are going to investigate the impact on performance, particularly delay and throughput, of the mentioned network protocols. This will be done by running a Docker container in a Kubernetes cluster to have a virtualized environment while being able to compare it to a standard test instance outside of the virtualized container. When the instances are set up there will be traffic generated by the use of iperf, netem and socket statistics to get the data needed to compare and evaluate. The experiment that was performed showed an array of different results. When it came to the main questions that were investigated it was concluded that the TCP protocols BBR and Cubic were not affected by virtualization to the point that it was harmful to use them within Kubernetes, likewise it was concluded during the experiment that when introducing packet loss as a variable the protocols expect differently as theory dictated, TCP cubic handles package loss more aggressively which leads it to have a lower throughput compared to BBR that quickly tries to resume with the speed it had before a packet was lost. So to summarize the experiment, Kubernetes negatively effects both TCP protocols but it is minuscule enough that it will not cause issues when using virtualized environments. When it comes to the two protocols it is shown that BBR handles package loss better than Cubic but both protocols provide a similar throughput when the connection is stable. 

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  • 144.
    Allawerdi, Rabii
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Gamers and non-gamers preferences ofcrossmodal AI assistants: A remote explorative study on the uncanny2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Technological advancements have allowed the design of more realistic virtual characters, for example, in-game development; meanwhile, researchers argue that more realism is not always suitable. As an explorative pilot study, this thesis investigates the uncanny among human-like agents and intelligent systems with human-like attributes. The thesis focuses on the uncanny theories to understand whether Mori's Uncanny Valley (UV) or Tinwell's Uncanny wall (UW) is more suitable when designing with a user-centred approach. The study facilitated two remote focus group workshops consisting of seven participants to understand the participant's expectations, needs and desires of existing and future AI technology. The participants consisted of two target groups, gamers and non-gamers, in order to understand if exposure to AI leads to adoptability of the technology. The participants described their perspectives and needs of existing AI assistants, and their preferences of human-like cross modality such as voice and avatar for future assistants. The research activities resulted in insights and four themes: rejection of existing assistant technology, productivity and task management, expectations of future AI assistants and balancing human-likeness. Findings show that participants reject existing assistant technologies, as old tangible habits, social norms, and incompatibility prevent the adoption of existing assistant technology. While both gamers and non-gamers seek a balance between generic robotics and pure human likeness, none of the participants fully adopted the idea of human likeness as it generates uncanny feelings.

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  • 145. Allman, Mark
    et al.
    Avrachenkov, Konstatin
    Ayesta, Urtzi
    Blanton, Josh
    Hurtig, Per
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science.
    Early Retransmit for TCP and SCTP2008Other (Other (popular science, discussion, etc.))
    Abstract [en]

    This document proposes a new mechanism for TCP and SCTP that can be used to recover lost segments when a connection's congestion window is small. The "Early Retransmit" mechanism allows the transport to reduce, in certain special circumstances, the number of duplicate acknowledgments required to trigger a fast retransmission. This allows the transport to use fast retransmit to recover packet losses that would otherwise require a lengthy retransmission timeout.

  • 146.
    Alm, Anton
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Internet of Things mesh network: Using the Thread networking protocol2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis summarizes my project in setting up a Thread network. The idea of this project was presented by the company ÅF in Karlstad, Sweden. ÅF wishes to upgrade their current demonstrator for IoT. The current demonstrator includes Azure Cloud component, Raspberry Pi, Bluetooth and Arduino components. The upgrade includes implementing Thread technology together with Thread verified hardware from Nordic semiconductor and the Raspberry Pi Foundation.

    Thread is an IoT mesh networking protocol that was released year 2014. Compared to Bluetooth it offers IP communication (including IPv6) combined with higher reliability, performance and security. The process of installing, compiling and configuring the Thread network is explained.

    The result is an operational thread network that has sensor devices sending data to an HTTP web server, where the data is stored and monitored. Though, there are many improvements and functions that can be implemented to make this demonstrator more appealing.

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    ThreadMeshNetwork
  • 147.
    Almgren, Mats
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Hansen, Erik
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Coridendro: Ett verktyg för att grafiskt åskådliggöra incidensen av malignt melanom inom olika släkter2006Independent thesis Basic level (professional degree), 10 points / 15 hpStudent thesis
    Abstract [en]

    The county council of Värmland is taking part in a larger project which in general consists of surveying malign melanoma within different families. Counties in Sweden are following-up on patients suffering from malign melanoma, which is likely to have inheritable causes. When a suspected heritable malign melanoma is found an investigation is started. A pedigree is drawn, describing the propositus’ family.

    Every individual in the pedigree is represented by a symbol. The appearance of this symbol is determined by: unhealthy/healthy, diseased/alive, man/woman. When the individuals have been identified and the according symbols drawn, the symbols are connected by lines representing kinship.

    Today the pedigrees are drawn by hand using pen and paper. This is a time consuming task and the appearance differ depending on who is drawing the pedigree.

    The result of our problem-analysis is a graphical software tool. On a drawing area the user may draw the symbols on predefined locations. The tool also allows for symbols to be connected with lines. Symbols are connected through selecting a start-symbol and an end-symbol.

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    FULLTEXT01
  • 148. Almén, Örjan
    et al.
    Malmén, Emma
    Framgångsfaktorer och fallgropar vid implementation av webbhandel: - En fallstudie av fyra företag i Värmland2012Student thesis
    Abstract [sv]

    E-handeln ökar stadigt enligt flera gjorda undersökningar, och fler och fler företag ansluter sig till elektronisk handel och framförallt webbhandel. Att införa e-handel kan ge många positiva effekter på företag genom en ökad kundkrets, minskade kostnader för lagerhållning och administrativt arbete. Vi har valt att undersöka olika faktorer som kan påverka en lyckad Implementation av e-handel, och detta har gjorts dels genom att söka i litteratur och artiklar samt att vi genomfört en fallstudie på fyra olika företag i Värmland. Vår studie bygger på en teoretisk och en empirisk del och vi har funnit flera framgångsfaktorer och fallgropar, som kan påverka implementationen av e-handel. Vi har genom fallstudierna identifierat att tre av de fyra företagen redan innan implementationen av webbhandel haft en befintlig kundkrets, vilket de ansåg vara en framgångsfaktor, något som vi däremot inte funnit i teorin. Det finns också tydliga fördelar med ett färdigintegrerat affärssystem, men som vi heller inte identifierat i de studerade källorna. En av de identifierade fallgroparna är att om kommunikationen med sin systemleverantör är undermålig kan det leda till längre utvecklingstid och missförstånd.

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    fulltext
  • 149.
    Alonso, Nils
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Olsson, Jesper
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Providing a Solution for Configuration of Linux end-hosts in Time-Sensitive Networks2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Time-critical networks of various types are widely used in fields such as industrial automation. Many of these time-critical networking solutions are proprietary and closed, which can make them costly to work with. An alternative to these legacy solutions is Time-Sensitive Networking. Time Sensitive Networking, or TSN, is an open standard for time-critical communication over Ethernet hardware and protocols. Compared to proprietary and closed legacy solutions, a TSN can be easier to set up. There is still however a challenge in configuring a TSN since the configuration process is hardware dependent. This thesis sets out to ease the configuration process, making it more user-friendly by providing a tool for the generation of end-host configurations. Currently, no such readily available tool exists for configuration of Linux end-hosts in TSNs. This is done by implementing extensions to the incomplete TSN configuration middleware DETD to a state where it is a suitable solution to this problem. The extensions made to DETD consist of implementing support for configuring listener streams, adding the ability to configure the TAPRIO queueing discipline, and adding support for an additional network interface card in the form of the Intel I210. To verify the functionality of these extensions a simple testbed using two real-time Linux machines is used.

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    Providing a Solution for Configuration of Linux end-hosts in Time- Sensitive Networks
  • 150.
    Alsarhan, Qusay
    et al.
    University of Duhok, IRQ.
    Ahmed, Bestoun S.
    Ceske Vysoke Uceni Technicke v Praze, CZE.
    Bures, Miroslav
    Ceske Vysoke Uceni Technicke v Praze, CZE.
    Zamli, Kamal
    Universiti Malaysia Pahang, MYS.
    Software module clustering: an in-depth literature analysis2022In: IEEE Transactions on Software Engineering, ISSN 0098-5589, E-ISSN 1939-3520, Vol. 48, no 6, p. 1905-1928Article in journal (Refereed)
    Abstract [en]

    Software module clustering is an unsupervised learning method used to cluster software entities (e.g., classes, modules, or files) of similar features. The obtained clusters may be used to study, analyze, and understand the structure and behavior of the software entities. Implementing software module clustering with optimal results is challenging. Accordingly, researchers have addressed many aspects of software module clustering in the last decade. Thus, it is essential to present research evidence that has been published in this area. In this study, 143 research papers that examined software module clustering from well-known literature databases were extensively reviewed to extract useful data. The obtained data were then used to answer several research questions regarding state-of-the-art clustering approaches, applications of clustering in software engineering, clustering process, clustering algorithms, and evaluation methods. Several research gaps and challenges in software module clustering are discussed in this paper to provide a useful reference for researchers in this field.

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