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  • 51.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Granlund, Daniel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Elkotob, Muslim
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Bandwidth efficient mobility management for heterogeneous wireless networks2010Ingår i: 2010 7th IEEE Consumer Communications and Networking Conference: Las Vegas, Nevada, USA : 9-12 January, 2010, Piscataway, N.J: IEEE Communications Society, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    An important feature of the upcoming fourth generation wireless networks is support for heterogeneous radio access technologies in combination with an all-IP type of overall architecture. Operators and users will benefit from a smooth technology transition leveraging existing investments and use a variety of access technologies simultaneously. This paper describes and evaluates an innovative mobility management scheme in such an environment. It does not require any changes to the IP stack in the mobile node and does not introduce any additional overhead to the payload traffic over air interfaces. Furthermore, it does not add any signaling overhead and outperforms existing mobility management schemes for heterogeneous environments in terms of bandwidth consumption. The architecture uses a make-before-break principle for vertical handovers and bidirectional tunneling using various tunneling mechanisms connecting mobile nodes through access networks to a home network. Also, it proposes a packet inspection routine for timely handover execution in the home network. The architecture is evaluated both through analytical calculations and experiments using a voice over IP traffic model.

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  • 52.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Granlund, Daniel
    Åhlund, Christer
    M4: MultiMedia Mobility Manager: a seamless mobility management architecture supporting multimedia applications2007Ingår i: Proceedings of the 6th International Conference on Mobile and Ubiquitous Multimedia: December 12 - 14, 2007, Oulu, Finland / [ed] Timo Ojala, Red Hook, NY: Curran Associates, Inc., 2007, s. 6-13Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, a proof-of-concept and a software architecture, M4 (MultiMedia Mobility Manager), is presented. In short, M4 is offering seamless mobility management to multimedia appli­cations using a variety of wireless access networks. First, M4 is built on multihomed Mobile IP building on the principle of soft handovers. Second, network selection in M4 is based on a network layer metric combining round-trip times and jitter in round-trip times. Third, the end-user can enter its own preferences on network selection through a policy-based extension to the proposed network selection algorithm.The proposed architecture is evaluated in a live heterogeneous networking environment where handover performance is studied in detail. In addition, user-perceived quality of experience for Voice over IP using the M4 software architecture has been studied. Last, downloads of large amount of data using a combination of high and low capacity wireless networks in M4 were studied.Results indicate that the architecture as a whole and the proposed algorithms perform well. M4 can thus be seen as an imple­mentation of the "Always Best Connected" vision.

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  • 53.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Hallberg, Josef
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Project: PERvasive Computing and COMmunications for sustainable development2015Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 54.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Hossain, Mohammad Shahadat
    University of Chittagong, Department of Computer Science and Engineering, University of Chittagong.
    Heterogeneous Wireless Sensor Networks for Flood Prediction Decision Support Systems2015Ingår i: 2015 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS): 6th IEEE INFOCOM International Workshop on Mobility Management in the Networks of the Future World, Piscataway, NJ: IEEE Communications Society, 2015, s. 133-137Konferensbidrag (Refereegranskat)
    Abstract [en]

    Recent advancements in the fields of sensor equipment and wireless sensor networks have opened the window of opportunity for many innovative applications. In this paper, we propose a new architecture for building decision support systems using heterogeneous wireless sensor networks. The architecture is built around standard hardware and existing wireless sensor networks technology. We show the effectiveness of the proposed architecture by applying it to a flood prediction scenario.

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  • 55.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Hossain, Mohammad Shahadat
    University of Chittagong, Department of Computer Science and Engineering, University of Chittagong.
    Smart Risk Assessment Systems using Belief-rule-based DSS and WSN Technologies2014Ingår i: 2014 4th International Conference on Wireless Communications, Vehicular Technology, Information Theory and Aerospace and Electronic Systems, VITAE 2014: Co-located with Global Wireless Summit, Aalborg, Denmark 11-14 May 2014, Piscataway, NJ: IEEE Communications Society, 2014, artikel-id 6934397Konferensbidrag (Refereegranskat)
    Abstract [en]

    Smart risk assessment systems are becoming more and more important in the society. If the chances of reducing and managing certain risks are increased, the impacts can be controlled and reduced significantly. This article surveys different belief-rule-based decision support systems and various wireless sensor network technologies that can be used in collaboration to build interesting risk assessment applications. We propose a model for building such an environment and describe a potential application of our proposed model for assessing flood risks in a case study.

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  • 56.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Hossain, Mohammad Shahadat
    University of Chittagong.
    Thapa, Devinder
    Department of Information Systems, University of Agder.
    Zander, Pär-Ola
    Department of Communication and Psychology, Aalborg University.
    A Novel Framework of an Expert System by integrating Capability Approach and BRB to Evaluate E-Government Services2015Ingår i: Proceedings of eChallenges e-2015 Conference / [ed] Paul Cunningham; Miriam Cunningham, IIMC International Information Management Corporation Ltd , 2015, s. 1-12, artikel-id 68Konferensbidrag (Refereegranskat)
    Abstract [en]

    Capability approach is hard to operationalize and capabilities are sometimes difficult to reduce into the individual level. We describe our approach to solve these problems paired with an adequate ICT infrastructure and believe that the impact of concrete eGovernment services will become more visible and available. Citizens can inspect it, professionals can target their re-engineering on failure cases, learn from best cases, and researchers can compare different types of eGovernment. The solving of operationalisation will also strengthen the capability approach, by extending its scope from macro theory towards more easy application on the institutional and organizational levels.

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  • 57.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Johansson, Dan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Mobile e-services using HTML52012Ingår i: Proceedings of the 37th IEEE Conference on Local Computer Networks Workshops (LCN Workshops): 6th IEEE Workshop On User MObility and VEhicular Networks / [ed] Tom Pfeifer; Anura Jayasumana; Damla Turgut, Piscataway, NJ: IEEE Computer Society Press , 2012, s. 814-819Konferensbidrag (Refereegranskat)
    Abstract [en]

    New mobile networks and new devices like smartphones and tablets are rapidly changing opportunities for public sector units delivering smart, mobile e-services to their citizens. Moreover, the upcoming HTML5 standard allows for cross-device and cross-browser support making service development and deployment much more easier than before at lower costs. This paper analyzes the most important features of HTML5, CSS3, and WebGL and their applicability for mobile e-services in the public sector. Also, we present a novel architecture for mobile e-services using HTML5, mashups, and RESTful web APIs as important building blocks.

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  • 58.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Kafle, Ved
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Disaster-resilient mobile network architecture2014Ingår i: Proceedings of the 2014 IEEE 11th Annual Consumer Communications & Networking Conference, Piscataway, NJ: IEEE Communications Society, 2014, s. 359-364Konferensbidrag (Refereegranskat)
    Abstract [en]

    Conventional cellular networks are likely to get disturbed easily when a natural disaster (earthquake, tsunami, flooding, etc.) hits an area because of their centralized control and high-power requirements. To address this issue, we propose a new mobile network architecture having distributed controls and ad-hoc configurations. This architecture exploits the locally available resources such as frequency spectrum and lively nodes to reconfigure the network and provide emergency services. We present its design and use cases.

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  • 59.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Lundahl, Carl-Gustav
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Lundmark, Martin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Nordvik, Enar
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Pantze, Anna
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Förslag till handlingsplan för utveckling av LTU Skellefteå: Att synas med stolthet2008Rapport (Övrigt vetenskapligt)
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  • 60.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Lövf, Eva
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknologi.
    Studenters upplevelser av distansundervisning: en fallstudie2008Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Artikeln presenterar resultat från en studie av studenters upplevelser vid införande av modern videokonferensteknik i undervisningen. Studien omfattar 40 studenter vid fyra kurser. Resultaten indikerar att universitet och högskolor, förutom kostnadsbesparingar, lätt kan engagera specialistkompetens i kurser, erbjuda undervisning utanför campus och underlätta studentens självstudier. I sin bästa form uppnås både rums- och tidsoberoende. Samtidigt indikerar resultaten att det finns utrymme för förbättringar vid undervisning via videokonferenssändningar, främst i interaktionen mellan student och lärare. Oavsett lärarens pedagogik, ämnets inriktning och studenternas vana vid modern teknik så föredrog 39 av de 40 studenterna i undersökningen att ha en lärare på plats. Till viss del kan detta förklaras av teknikproblem, som delvis åtgärdats under kursernas genomförande, men även av att lärarna inte anpassat sin pedagogik fullt ut. Vår bedömning är att om rätt pedagogik används kan både kommunikation och interaktion fungera mycket bra och vara en utmärkt undervisningsform även om lärare och student inte befinner sig på samma plats.Vi föreslår att lärarna som sänder föreläsningarna ges tillfälle att interagera mer med studenterna, både synkront och asynkront, vilket kräver att kurserna planeras på annat sätt än vid traditionell campus-undervisning. Vidare föreslår vi att studenter på annan ort regelbundet erbjuds separata tillfällen för att diskutera och ställa frågor till läraren och gärna träffas fysiskt. Avslutningsvis föreslår vi att en särskild ämneskunnig producent, s.k. e-moderator, engageras parallellt med lärarens undervisning, för att stöda studenterna som följer föreläsningarna genom att besvara deras frågor. Alternativt kan en e-moderator uppmärksamma läraren på relevanta frågor som dyker upp, så att en utökad interaktion uppnås.

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  • 61.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Mostafa, Seraj Al Mahmud
    Luleå tekniska universitet.
    Islam, Raihan Ul
    Luleå tekniska universitet.
    Mobile VoIP user experience in LTE2011Ingår i: Proceedings of The 36th IEEE Conference on Local Computer Networks (LCN): 5th IEEE Workshop On User MObility and VEhicular Networks, IEEE Computer Society Press , 2011, s. 789-792Konferensbidrag (Refereegranskat)
    Abstract [en]

    3GPP Long-term Evolution (LTE) systems being deployed are fast gaining market shares. High data rates (approaching 100 Mbit/s in the downlink direction and 50 Mbit/s for uplink connections) and small delays are attractive features of LTE. Spectrum flexibility also makes deployment easy on various frequency bands in different parts of the world. However, as LTE offers packet switched services only, mobile broadband connectivity has become the dominant LTE application so far. This paper studies user-perceived quality of service for a mobile Voice over IP (VoIP) application in LTE. Results were achieved using the OPNET Modeler simulation environment.

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  • 62.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Rondeau, Éric
    University of Lorraine.
    Kor, Ah-Lian
    School of Computing, Creative Technologies and Engineering, Leeds Beckett University.
    Johansson, Dan
    Umeå University, Department of Informatics.
    Sustainable Mobile Computing and Communications2017Ingår i: Mobile Information Systems, ISSN 1574-017X, Vol. 2017, artikel-id 1098264Artikel i tidskrift (Övrigt vetenskapligt)
  • 63.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Sarker, ANM. Zaheduzzaman
    Luleå tekniska universitet.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Multihomed mobile IPv6: OPNET simulation of network selection and handover timing in heterogeneous networking environments2007Ingår i: Proceedings of the Eleventh Annual OPNET Technology Conference: OPNETWORK 2007, 2007Konferensbidrag (Refereegranskat)
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  • 64.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT. Luleå tekniska universitet, Institutionen för system- och rymdteknik, Digitala tjänster och system.
    Tan, Hwee-Pink
    Singapore Management University, Singapore.
    LCN 2019 Message from the TPC Chairs2019Ingår i: 2019 IEEE 44th Conference on Local Computer Networks (LCN) / [ed] Karl Andersson, Hwee-Pink Tan, Sharief Oteafy, IEEE, 2019, s. i-iKonferensbidrag (Övrigt vetenskapligt)
  • 65.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Ul Islam, Raihan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Hossain, Md. Shahadat
    Chittagong University, Chittagong, Bangladesh.
    Project: A belief-rule-based DSS to assess flood risks by using wireless sensor networks2015Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 66.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    You, Ilsun
    Soonchunhyang University, Chungcheongnam-do, Republic of Korea.
    Palmieri, Francesco
    University of Salerno, Fisciano (SA), Italy.
    Security and Privacy for Smart, Connected, and Mobile IoT Devices and Platforms2018Ingår i: Security and Communication Networks, ISSN 1939-0114, E-ISSN 1939-0122, Vol. 2018, s. 1-2, artikel-id 5346596Artikel i tidskrift (Övrigt vetenskapligt)
  • 67.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    You, Ilsun
    Soonchunhyang University, Asan, Republic of Korea.
    Rahmani, Rahim
    Stockholm University, Stockholm, Sweden.
    Sharma, Vishal
    Soonchunhyang University, Asan, Republic of Korea.
    Secure Computation on 4G/5G Enabled Internet-of-Things2019Ingår i: Wireless Communications & Mobile Computing, ISSN 1530-8669, E-ISSN 1530-8677, Vol. 2019, artikel-id 3978193Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    The rapid development of Internet-of-Things (IoT) techniques in 4G/5G deployments is witnessing the generation of massive amounts of data which are collected, stored, processed, and presented in an easily interpretable form. Analysis of IoT data helps provide smart services such as smart homes, smart energy, smart health, and smart environments through 4G and 5G technologies. At the same time, the threat of the cyberattacks and issues with mobile internet security is becoming increasingly severe, which introduces new challenges for the security of IoT systems and applications and the privacy of individuals thereby. Protecting IoT data privacy while enabling data availability is an urgent but difficult task.

    Data privacy in a distributed environment like IoT can be attained through secure multiparty computation. An emerging area of potential applications for secure computation is to address privacy concerns in data aggregation and analysis to match the explosive growth of the amount of IoT data. However, the inherent complexity of IoT systems really complicates the design and deployment of efficient, interoperable, and scalable secure computation mechanisms. As a result, there is an increasing demand for the development of new secure computation methods and tools which can fill in the gap between security and practical usage in IoT.

    The scope of this special issue is in line with recent contributions from academia and industry on the recent activities that tackle the technical challenges making computing secure on 4G/5G enabled Internet-of-Things. For the current issue, we are pleased to introduce a collection of papers covering a range of topics such as securely verifiable remote erasure schemes, multiuser identification algorithms, privacy-preserving shared storage, situational aware threat assessment, authorized client-side deduplication in cloud storage, radio environment map construction, analysis of the vulnerabilities of connected car environments, combat pollution attacks in 5G multihop networks, automatically traceback RDP-based targeted ransomware attacks, multiresolution face recognition through virtual faces generation, anonymous communication via anonymous identity-based encryption, and Secure Storage and Retrieval of IoT Data.

  • 68.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    A mobility management scheme for heterogeneous environments supporting vehicular speeds using a policy-based approach2008Ingår i: Proceedings of the 5th International Workshop Conference on Performance Modelling and Evaluation of Heterogeneous Networks: (HET-NETs), 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today, handsets and terminals are typically equipped with multiple radio interfaces. Meanwhile, various types of access networks using different radio technologies are being deployed all over the world. Also, there is a strong trend towards All-IP-Networks following the principle "Everything over IP", and "IP over everything". This development is leading researchers into the area of heterogeneous networking and overlay topologies.This paper focuses on mobility management issues related to such an environment supporting vehicular speeds of users using a policy-based approach and a network-layer metric for access network selection.A Mobile IP-based architecture is proposed where mobility bindings are sent periodically at a frequency depending on the speed of the user also taking variations in the network-layer metric into account and the overall signaling cost. The architecture is designed with a focus on minimizing packet losses and timely handling of vertical hand-overs.

  • 69.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    An architecture for seamless mobility management in various types of applications using a combination of MIP and SIP2006Ingår i: Proceedings of Swedish National Computer Networking Workshop 2006: sponsored by IEEE VT/COM Sweden : October 26-27, 2006, Luleå University of Technology, Luleå: Luleå tekniska universitet, 2006, s. 33-36Konferensbidrag (Refereegranskat)
    Abstract [en]

    In the future, mobile users will have the possibility to use a variety of wireless access networks simultaneously making the vision "Always best connected" come true. The Internet Protocol (IP) will most likely be the least common divisor allowing service providers to deploy services in a unified way regardless of access network type (being wired or wireless). The 3GPP-led development of the IP Multimedia Subsystem (IMS) is a promising step towards the vision. However, there are a number of obstacles along this way forward. Various deployment difficulties related to already installed base of user and infrastructure equipment and service providers protecting their old investments are the most common obstacles. In addition to those reasons, somewhat conservative regulatory authorities, short-comings in digital rights management, multiple standardization bodies proposing non-aligned solutions, as well as non-uniformed and non-optimized use of radio spectrum do not improve the speed of change.Our research is performed within the area of seamless real-time multimedia distribution in heterogeneous wireless access networks with a user-centric and end-to-end system approach. Having proposed various extensions to Mobile IP (MIP) including multihoming and port-based handling of flows, as well as solutions for global connectivity in ad hoc networks we now present a combined architecture using both MIP and Session Initiation Protocol (SIP) for mobility management where MIP is used for TCP connections and SIP is used for UDP traffic carrying real-time multimedia streams of data.

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  • 70.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Mobile mediator control function-an IEEE 802.21-based mobility management and access network selection model2009Ingår i: Proceedings of the 18th ICT-Mobile Summit / [ed] Paul Cunningham; Miriam Cunningham, IIMC International Information Management Corporation , 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes a combined network and application layer access network decision model for multimedia applications in heterogeneous networking environments. It builds on previous work of a network layer based metric used in combination with multihomed Mobile IP and introduces a mechanism for applications to interact with the mobility management system in the mobile node. This way, applications executing in the mobile node can decide either to take access network decisions on their own or to let the network layer handle mobility management tasks automatically based on default decision criterion decided by the end-user.An extended architecture based on previous work and the upcoming IEEE 802.21 standard for media-independent handover services is presented. The control plane, named "Mobile Mediator Control Function", offers a set of events and commands through an additional service access point. Results from a scenario with a Voice over IP application running in the proposed environment simulated in OPNET Modeler are presented.

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  • 71.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Optimized access network selection in a combined WLAN/LTE environment2011Ingår i: Wireless personal communications, ISSN 0929-6212, E-ISSN 1572-834X, Vol. 61, nr 4, s. 739-751Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multimode terminals equipped with multiple radio access technologies are becoming increasingly popular. At the same time, network operators and service providers seek opportunities to deliver seamless services cost effectively, leveraging a variety of radio access technologies using both licensed and unlicensed spectrum. In order to standardize the operations of such complex environments 3GPP is currently working on IP flow mobility and mobile data offload solutions. This article proposes and evaluates a new access network selection procedure in such a combined WLAN/LTE environment. The proposed solution takes not only parameters available in the mobile node and its current and candidate access networks into account, but performs an optimization on the heterogeneous wireless network level as well. An optimization model based on an approximate solution to the well-known bin packing problem is presented. Also, there is a signaling scheme for distribution handling presented. Results from simulations performed in OPNET Modeler show improvements compared to basing handover decisions on locally available information only.

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  • 72.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Projekt: Hybrinet@Skellefteå2007Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Projektet Hybrinet@Skellefteå studerar effektiv multimediedistribution i heterogena nätverksmijöer

  • 73.
    Andersson, Karl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Gukhool, Balkrishna Sharma
    Electrical and Computer Engineering Department, Sherbrooke University.
    Cherkaoui, Soumaya
    Electrical and Computer Engineering Department, Sherbrooke University.
    Mobility management for highly mobile users and vehicular networks in heterogeneous environments2008Ingår i: 2008 IEEE 33rd Conference on Local Computer Networks: [LCN 2008] ; Montreal, AB, Canada, 14 - 17 October 2008, Piscataway, NJ: IEEE Communications Society, 2008, s. 593-599Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the recent developments in wireless networks, different radio access technologies are used in different places depending on capacity in terms of throughput, cell size, scalability etc. In this context, mobile users, and in particular highly mobile users and vehicular networks, will see an increasing number and variety of wireless access points enabling Internet connectivity. Such a heterogeneous networking environment needs, however, an efficient mobility management scheme offering the best connection continuously. In this paper, a mobility management architecture focusing on efficient network selection and timely handling of vertical and horizontal hand-overs is proposed. The solution is based on Mobile IP where hand-over decisions are taken based upon calculations of a metric combining delay and delay jitter. For efficiency reasons, the frequency of binding updates is dynamically controlled, depending on speed and variations in the metric. The dynamic frequency of binding updates helps the timely discovery of congested access points and cell edges so as to allow efficient hand-overs that minimize packet drops and hand-over delays.Results show that the overall signaling cost is decreased and changes in networking conditions are detected earlier compared to standard Mobile IP.

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  • 74.
    Araujo, Victor
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Mitra, Karan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Saguna, Saguna
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Performance evaluation of FIWARE: A cloud-based IoT platform for smart cities2019Ingår i: Journal of Parallel and Distributed Computing, ISSN 0743-7315, E-ISSN 1096-0848, Vol. 132, s. 250-261Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As the Internet of Things (IoT) becomes a reality, millions of devices will be connected to IoT platforms in smart cities. These devices will cater to several areas within a smart city such as healthcare, logistics, and transportation. These devices are expected to generate significant amounts of data requests at high data rates, therefore, necessitating the performance benchmarking of IoT platforms to ascertain whether they can efficiently handle such devices. In this article, we present our results gathered from extensive performance evaluation of the cloud-based IoT platform, FIWARE. In particular, to study FIWARE’s performance, we developed a testbed and generated CoAP and MQTT data to emulate large-scale IoT deployments, crucial for future smart cities. We performed extensive tests and studied FIWARE’s performance regarding vertical and horizontal scalability. We present bottlenecks and limitations regarding FIWARE components and their cloud deployment. Finally, we discuss cost-efficient FIWARE deployment strategies that can be extremely beneficial to stakeholders aiming to deploy FIWARE as an IoT platform for smart cities.

  • 75.
    Arfizurrahmanl, Mohammad
    et al.
    International Islamic University Chittagong, Chittagong, Bangladesh.
    Ahmad,
    International Islamic University Chittagong, Chittagong, Bangladesh.
    Hossain, Mohammad Shahadat
    University of Chittagong Chittagong, Bangladesh.
    Haque, Mohammad Ahsanul
    Radio Analyzer Aalborg, Denmark.
    Andersson, Karl
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Real-time non-intrusive driver fatigue detection system using belief rule-based expert system2021Ingår i: Journal of Internet Services and Information Security (JISIS), ISSN 2182-2069, E-ISSN 2182-2077, Vol. 11, nr 4, s. 44-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a non-intrusive system for detecting driver fatigue in real-time. To determine the level of fatigue the system uses various visual features, namely head nodding, eye closure duration and yawning. A state-of-the-art facial landmark detector ’IntraFace’ has been adopted to determine the eye state, mouth state and head pose estimation. However, different forms of uncertainties such as vagueness, imprecision, ambiguity and incompleteness are involved in calculating these visual parameters. Therefore, a Belief Rule-Based Expert System (BRBES) is employed, which has the ability to handle the uncertainties. The information of the visual parameters is sent to BRBES as input to determine the level of fatigue. An optimal learning model has been developed to improve the performance and accuracy of the BRBES. A comparison between the system and the fuzzy rulebased expert system has been carried out. The system generates more effective and reliable results than the fuzzy rule-based expert system.

  • 76.
    Backman, Ylva
    et al.
    Luleå tekniska universitet, Institutionen för hälsa, lärande och teknik, Pedagogik, språk och ämnesdidaktik.
    Gardelli, Viktor
    Luleå tekniska universitet, Institutionen för hälsa, lärande och teknik, Pedagogik, språk och ämnesdidaktik.
    Parnes, Peter
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Game technologies to assist learning of communication skills in dialogic settings for persons with aphasia2021Ingår i: International Journal: Emerging Technologies in Learning, ISSN 1868-8799, E-ISSN 1863-0383, Vol. 16, nr 03, s. 190-205Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Persons with aphasia suffer from a loss of communication ability as a consequence of a brain injury. While rare, a small strand of research indicates effectiveness of dialogic interventions for communication development for persons with aphasia, but a vast amount of research studies shows its effectiveness for other target groups. In this paper, we describe the main parts of the hitherto technological development of an application named Dialogica that is (i) aimed at facilitating increased communicative participation in dialogic settings for persons with aphasia and other communication disorders, (ii) based on computer game technology as well as on theory in dialogic education and argumentation theory, and (iii) designed for mobile devices with larger screens.

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  • 77.
    Bai, Emilien
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Synnes, Kåre
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    A Reward System for Collaborative Care of Elderly based on Distributed Ledger Technologies2017Ingår i: UBICOMM 2017: The Eleventh International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies / [ed] Timothy Arndt, Evgeny Pyshkin, Martin Ruskowski, Aliane Loureiro Krassmann, Hiroaki Higaki, IARA , 2017, s. 46-55Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents the design and implementation of a reward system for collaborative care of elderly based on distributed ledger technologies. The work is motivated by the demographic change, where an aging population consequently increases the need for care. This causes a great tension in our society, as care resources become increasingly constrained, both regarding costs and availability of care staff. Much of the daily care of the elderly is today done by family members (spouses, children) and friends, often on a voluntarily basis, which adds to the tension. The core idea of this work is to help broaden the involvement of people in caring for our elderly, enabled by a system for collaborative care. The proposed system benefits from recent advances in distributed ledger technologies, which similarly to digital currencies, are build on the ability for mutual agreements between people who do not know each other. The system also benefits from recent gamification techniques to motivate people to collaborate on a larger scale through performing simple daily tasks. The system builds on rewards automatically given when these smart contracts are fulfilled, a gamification technique that is believed to maintain motivation of the volunteers. In this paper, we thus describe a reward system designed to connect elderly and volunteers by mutual agreements implemented as smart contracts. 

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  • 78.
    Bai, Emilien
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Synnes, Kåre
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Supporting Collaborative Care of Elderly through a Reward System based on Distributed Ledger Technologies2018Ingår i: International Journal on Advances in Life Sciences, E-ISSN 1942-2660, Vol. 10, nr 1-2, s. 90-102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper discusses supporting collaborative care of elderly through a reward system based on distributed ledger technologies. The design and implementation of such a reward system that connect elderly and volunteers by mutual agreements involve technologies such as smart contracts and blockchains. The work is motivated by the demographic change, where an aging population consequently increases the need for care. This causes a great tension in our society, as care resources become increasingly constrained, both regarding costs and availability of care staff. Much of the daily care of the elderly is today done by family members (spouses, children) and friends, often on a voluntarily basis, which adds to the tension. The core idea of this work is to help broaden the involvement of people in caring for our elderly, enabled by a system for collaborative care. The proposed system benefits from recent advances in distributed ledger technologies, which similarly to digital currencies, are build on the ability for mutual agreements between people who do not know each other. The system also benefits from recent gamification techniques to motivate people to collaborate on a larger scale through performing simple daily tasks. The proposed system benefits from inherent distributed ledger technologies advantages, such as a high level of decentralization, thus a high availability, and strong data consistency. These advantages make it interesting to develop the possible links between blockchains and the outside world to allow for a higher level of automation and distribution of services such as collaborative care. New models for distributed ledger technologies, such as Iota tangles or the Swirld platform, may however scale and perform better than blockchains. These should thus be considered for a full implementation and test of the system. In summary, this paper presents a novel framework and prototype implementation of a reward system supporting collaborative care of elderly, that is based on distributed ledger technologies.

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  • 79.
    Bansal, Shubham
    et al.
    NEC Laboratories Europe, Heidelberg.
    Schmidt, Mischa
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Energy Disaggregation Methods for Commercial Buildingsusing Smart Meter and Operational data2017Ingår i: The Workshops of the Thirty-First AAAI Conference on Artificial Intelligence: Artificial Intelligence for Smart Grids and Smart Buildings, AI Access Foundation , 2017, s. 325-329Konferensbidrag (Refereegranskat)
    Abstract [en]

    One of the key information pieces in improving energy efficiency of buildings is the appliance level breakdown of energy consumption. Energy disaggregation is the process of obtaining this breakdown from a building level aggregate data using computational techniques. Most of the current research focuses on residential buildings, obtaining this information from a single smart meter and often relying on high frequency data. This work is directed at commercial buildings equipped with building management and automation systems providing low frequency operational and contextual data. This paper presents a machine learning method to disaggregate energy consumption of the building using this operational data as input features. Experimental results on two publicly available datasets demonstrate the effectiveness of the approach, which surpasses existing methods. For all but one appliance of House 2 of the publicly available REDD dataset, improvements in normalized error in assigned power range between 20% (Lighting) and 220% (Stove). For another dataset from an educational facility in Singapore, disaggregation accuracy of 92% is reported for the facility’s cooling system.

  • 80.
    Baqer Mollah, Muhammad
    et al.
    Jahangirnagar University.
    Azad, Md. Abul Kalam
    Jahangirnagar University.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Secure Data Sharing and Searching at the Edge of Cloud-Assisted Internet of Things2017Ingår i: IEEE Cloud Computing, E-ISSN 2325-6095, Vol. 4, nr 1, s. 34-42, artikel-id 7879139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Over the last few years, smart devices are able to communicate with each other and with Internet/cloud from short to long range. As a consequence, a new paradigm is introduced called Internet of Things (IoT). However, by utilizing cloud computing, resource limited IoT smart devices can get various benefits like offload data storage and processing burden at cloud. To support latency sensitive, real-time data processing, mobility and high data rate IoT applications, working at the edge of the network offers more benefits than cloud. In this paper, we propose an efficient data sharing scheme that allows smart devices to securely share data with others at the edge of cloud-assisted IoT. In addition, we also propose a secure searching scheme to search desired data within own/shared data on storage. Finally, we analyze the performance based on processing time of our proposed scheme. The results demonstrate that our scheme has potential to be effectively used in IoT applications

  • 81.
    Baqer Mollah, Muhammad
    et al.
    Department of Computer Science and Engineering, Jahangirnagar University, Dhaka.
    Kalam Azad, Md. Abul
    Department of Computer Science and Engineering, Jahangirnagar University, Dhaka.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Security and privacy challenges in mobile cloud computing: Survey and way ahead2017Ingår i: Journal of Network and Computer Applications, ISSN 1084-8045, E-ISSN 1095-8592, Vol. 84, s. 38-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The rapid growth of mobile computing is seriously challenged by the resource constrained mobile devices. However, the growth of mobile computing can be enhanced by integrating mobile computing into cloud computing, and hence a new paradigm of computing called mobile cloud computing emerges. In here, the data is stored in cloud infrastructure and the actual execution is shifted to cloud environment so that a mobile user is set free from resource constrained issue of existing mobile devices. Moreover, to avail the cloud services, the communications between mobile devices and clouds are held through wireless medium. Thus, some new classes of security and privacy challenges are introduced. The purpose of this survey is to present the main security and privacy challenges in this field which have grown much interest among the academia and research community. Although, there are many challenges, corresponding security solutions have been proposed and identified in literature by many researchers to counter the challenges. We also present these recent works in short. Furthermore, we compare these works based on different security and privacy requirements, and finally present open issues.

  • 82.
    Baraër, Christophe
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Phanse, Kaustubh
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Nykvist, Johan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Birsa, Luka
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    ExPLoIT: exploiting past location information and transitivity for positioning in mobile sensor networks2007Ingår i: 2nd International Conference on Communication Systems Software and Middleware, 2007: COMSWARE 2007 ; 7 - 12 Jan. 2007, Bangalore, India, Piscataway, NJ: IEEE Communications Society, 2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present a novel distributed range-free technique called ExPLoIT for estimating geographical location of sensor nodes in mobile sensor networks. ExPLoIT is the first positioning technique that exploits location information at regular nodes in addition to using seeds. The key idea is the notion of confidence that a node has in its location estimate which can be used by other nodes for localization. Using Monte Carlo integration, a node estimates its current location and confidence based on its past location and the location information it receives from its neighbors. Node mobility is exploited to transitively localize the network. Our extensive simulation study shows that our proposal outperforms three other state-of-the-art range-free localization techniques under a wide range of conditions. The strength of ExPLoIT is that it is robust to irregular radio propagation, arbitrary seed and node density, and stochastic seed and node mobility; no special hardware is necessary at sensor nodes.

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  • 83.
    Batalla, Jordi Mongay
    et al.
    National Institute of Telecommunications, Warsaw University of Technology.
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Gajewski, Mariusz
    National Institute of Telecommunications, Poland..
    Secure Smart Homes: Opportunities and Challenges2017Ingår i: ACM Computing Surveys, ISSN 0360-0300, E-ISSN 1557-7341, Vol. 50, nr 5, s. p75:1-75:32Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Smart Home concept integrates smart applications in the daily human life. In recent years, Smart Homes have increased security and management challenges due to the low capacity of small sensors, multiple connectivity to the Internet for efficient applications (use of big data and cloud computing) and heterogeneity of home systems, which require inexpert users to configure devices and micro-systems. This article presents current security and management approaches in Smart Homes and shows the good practices imposed on the market for developing secure systems in houses. At last, we propose future solutions for efficiently and securely managing the Smart Homes

  • 84.
    Bauer, Martin
    et al.
    NEC Laboratories Europe.
    Dobre, Dan
    NEC Laboratories Europe.
    Santos, Nuno
    NEC Laboratories Europe.
    Schmidt, Mischa
    NEC Laboratories Europe, NEC Europe Ltd., Heidelberg.
    Scalable Processing of Geo-tagged Data in the Cloud2012Ingår i: NEC Technical Journal, ISSN 1880-5884, Vol. 7, nr 2, s. 97-101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The explosive growth of the mobile internet calls for scalable infrastructures capable of processing large amounts of mobile data with predictable response times. We have developed a scalable system supporting continuous geoqueries over geo-tagged data streams in the cloud. The experimental results confirm that our system scales, both in the number of supported geo-queries and throughput.

  • 85.
    Beattie, Mark
    et al.
    Computer Science Research Institute and School of Computing and Mathematics, University of Ulster.
    Hallberg, Josef
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Nugent, Chris D.
    University of Ulster. School of Computing and Mathematics, University of Ulster, Computer Science Research Institute, University of Ulster.
    Synnes, Kåre
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Cleland, Ian
    University of Ulster. School of Computing and Mathematics.
    Lee, Sungyoung
    Ubiquitous Computing Laboratory, Kyung Hee University, Seocheon-dong, Giheung-gu.
    A Collaborative Patient-Carer Interface for Generating Home Based Rules for Self-Management2015Ingår i: Smart Homes and Health Telematics: 12th International Conference, ICOST 2014, Denver, CO, USA, June 25-27, 2014, Revised Papers / [ed] Cathy Bodine; Sumi Helal; Tao Gu; Mounir Mokhtari, New York: Encyclopedia of Global Archaeology/Springer Verlag, 2015, s. 93-102Konferensbidrag (Refereegranskat)
    Abstract [en]

    The wide spread prevalence of mobile devices, the decreasing costs of sensor technologies and increased levels of computational power have all lead to a new era in assistive technologies to support persons with Alzheimer’s disease. There is, however, still a requirement to improve the manner in which the technology is integrated into current approaches of care management. One of the key issues relating to this challenge is in providing solutions which can be managed by non-technically orientated healthcare professionals. Within the current work efforts have been made to develop and evaluate new tools with the ability to specify, in a non-technical manner, how the technology within the home environment should be monitored and under which conditions an alarm should be raised. The work has been conducted within the remit of a collaborative patient-carer system to support self-management for dementia. A visual interface has been developed and tested with 10 healthcare professionals. Results following a post evaluation of system usability have been presented and discussed.

  • 86.
    Belyakhina, Tamara
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Zaslavsky, Arkady
    CSIRO, Melbourne.
    Mitra, Karan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Saguna, Saguna
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Jayaraman, Prem Prakash
    Swinburne University of Technology, Melbourne.
    DisCPAQ: Distributed Context Acquisition and Reasoning for Personalized Indoor Air Quality Monitoring in IoT-Based Systems2017Ingår i: Internet of Things, Smart Spaces, and Next Generation Networks and Systems: 17th International Conference, NEW2AN 2017, 10th Conference, ruSMART 2017, Third Workshop NsCC 2017, St. Petersburg, Russia, August 28–30, 2017, Proceedings / [ed] Galinina O., Andreev S., Balandin S., Koucheryavy Y., Cham: Springer, 2017, s. 75-86Konferensbidrag (Refereegranskat)
    Abstract [en]

    The rapidly emerging Internet of Things supports many diverse applications including environmental monitoring. Air quality, both indoors and outdoors, proved to be a significant comfort and health factor for people. This paper proposes a smart context-aware system for indoor air quality monitoring and prediction called DisCPAQ. The system uses data streams from air quality measurement sensors to provide real-time personalised air quality service to users through a mobile app. The proposed system is agnostic to sensor infrastructure. The paper proposes a context model based on Context Spaces Theory, presents the architecture of the system and identifies challenges in developing large scale IoT applications. DisCPAQ implementation, evaluation and lessons learned are all discussed in the paper.

  • 87. Bengtsson, Johan
    et al.
    Andersson, Karl
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Parnes, Peter
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Nyström, Jimmy
    Nyström, Nicklas
    Project: COnnected Media and Presence from European Institute of Technology2014Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 88.
    Bera, Samaresh
    et al.
    Computer Science and Engineering Department, Indian Institute of Technology, Kharagpur, 721302, India..
    Misra, Sudip
    Computer Science and Engineering Department, Indian Institute of Technology, Kharagpur, 721302, India..
    Vasilakos, Athanasios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Software-Defined Networking for Internet of Things: a Survey2017Ingår i: IEEE Internet of Things Journal, ISSN 2327-4662, Vol. 4, nr 6, s. 1994-2008Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Internet of things (IoT) facilitates billions of devices to be enabled with network connectivity to collect and exchange real-time information for providing intelligent services. Thus, IoT allows connected devices to be controlled and accessed remotely in the presence of adequate network infrastructure. Unfortunately, traditional network technologies such as enterprise networks and classic timeout-based transport protocols are not capable of handling such requirements of IoT in an efficient, scalable, seamless, and cost-effective manner. Besides, the advent of software-defined networking (SDN) introduces features that allow the network operators and users to control and access the network devices remotely, while leveraging the global view of the network. In this respect, we provide a comprehensive survey of different SDN-based technologies, which are useful to fulfill the requirements of IoT, from different networking aspects – edge, access, core, and data center networking. In these areas, the utility of SDN-based technologies is discussed, while presenting different challenges and requirements of the same in the context of IoT applications. We present a synthesized overview of the current state of IoT development. We also highlight some of the future research directions and open research issues based on the limitations of the existing SDN-based technologies.

  • 89.
    Bergvall-Kåreborn, Birgitta
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Broberg, Anders
    Umeå universitet.
    Lassinantti, Josefin
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Davoli, Lorenzo
    Umeå universitet.
    Kuenen, Stoffel
    Umeå universitet.
    Palmquist, Lena
    Umeå universitet.
    Parnes, Peter
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Ståhlbröst, Anna
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Synnes, Kåre
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Wennberg, Paula
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    User toolkits for citizen-centric mobild service innovation2012Ingår i: eChallenges e-2012 Conference Proceedings / [ed] Paul Cunningham; Miriam Cunningham, IIMC International Information Management Corporation , 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Around the world, there is an ongoing shift from en economy focusing on product development to an economy with focus on digital service development. An ongoing initiative in Europe to support this shift is the Internet of Services (IoS) which strives for a situation where everything that is needed to use a software is available as a service. The aim of this paper is to present a toolkit that non-programmers can use develop their own innovative mobile services. This environment strives to put forth a situation where technologies are made available as components that easily can be composed into a mobile services by just about anyone. This has tremendous impact on the feasibility of citizen-centric services where citizens create apps based on their current needs in their contemporary situation.

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  • 90.
    Berhane, Welderufael Tesfay
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Aleksy, Markus
    ABB Corporate Research.
    Andersson, Karl
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Lehtola, Marko
    ABB Corporate Research.
    Mobile computing application for industrial field service engineering: a case for ABB service engineers2013Ingår i: Proceedings of the 38th IEEE Conference on Local Computer Networks Workshops (LCN Workshops): 7th IEEE Workshop On User MObility and VEhicular Networks / [ed] Damla Turgut; Nils Aschenbruck; Jens Tölle, Piscataway, NJ: IEEE Computer Society Press , 2013, s. 188-193Konferensbidrag (Refereegranskat)
    Abstract [en]

    The increasing digitalization of our daily lives is gaining a new momentum recently in what is called the post- desktop era of computing. This wide spread in digitalization is made possible by the introduction of handy devices specifically of mobile phones, laptop computers, smartphones, and tablets. This new trend in shaping up technological advancement presents new opportunities for mobile information presentation, processing, and synthesis in different spheres of application such as providing industrial field services engineering support. Industrial field service engineers execute sets of work orders on daily basis plans. These work order executions demand the availability of digital information anywhere anytime to process them faster. This paper presents a scenario where the newly emerging Smartphone features such as augmented reality, audio/video processing, and near field communication sensing can be used to develop a prototype that supports industrial field service engineers in the contemporary field service engineering taskforces. It employs real world use-cases and carrying out quantitative prototype usability test analysis.

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  • 91.
    Bezerra, Nibia Souza
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Ferreira Maciel, Tarcisio
    Federal University of Ceará.
    M. Lima, Francisco Rafael
    Federal University of Ceará.
    Sousa Jr., Vicente A.
    Federal University of Rio Grande do Norte.
    Interference Aware Resource Allocation with QoS Guarantees in OFDMA/SC-FDMA2018Ingår i: Journal of Communication and Information Systems, ISSN 1980-6604, Vol. 33, nr 1, s. 124-128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efficient Radio Resource Allocation (RRA) is of utmost importance for achieving maximum capacity in mobile networks. However, the performance assessment should take into account the main constraints of these networks. This letter presents important enhancements to RRA algorithms proposed in [1]. Prior work [1] ignores some important system constraints such as the impact of inter-cell interference and granularity of frequency allocation blocks. Here we show the performance degradation when these system constraints are assumed on the algorithms in [1] as well as propose some improvements on these algorithms in order to achieve better performance.

  • 92.
    Bezerra, Nibia Souza
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Wang, Min
    Network Architecture and Protocols Research, Ericsson .
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Nordberg, Mats
    Network Architecture and Protocols Research, Ericsson .
    Schelén, Olov
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    RACH performance in massive machine-type communications access scenario2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the increasing number of devices performing Machine-Type Communications (MTC), mobile networks are expected to encounter a high load of burst transmissions. One bottleneck in such cases is the Random Access Channel (RACH) procedure, which is responsible for the attachment of devices, among other things. In this paper, we performed a rich-parameter based simulation on RACH to identify the procedure bottlenecks. A finding from the studied scenarios is that the Physical Downlink Control Channel (PDCCH) capacity for the grant allocation is the main limitation for the RACH capacity rather than the number of Physical Random Access Channel (PRACH) preambles. Guided by our simulation results, we proposed improvements to the RACH procedure and to PDCCH.

  • 93.
    Bezerra, Nibia Souza
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Saguna, Saguna
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    de Sousa Jr., Vicente A.
    Communication Engineering Department (DCO), Federal University of Rio Grande do Norte (UFRN), Rio Grande do Norte, Brazil.
    Propagation Model Evaluation for LoRaWAN: Planning Tool Versus Real Case Scenario2019Ingår i: IEEE 5th World Forum on Internet of Things, IEEE, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    LoRa has emerged as a prominent technology for the Internet of Things (IoT), with LoRa Wide Area Network (LoRaWAN) emerging as a suitable connection solution for smartthings. The choice of the best location for the installation of gateways, as well as a robust network server configuration, are key to the deployment of a LoRaWAN. In this paper, we present an evaluation of Received Signal Strength Indication (RSSI) values collected from the real-life LoRaWAN deployed in Skellefteå, Sweden, when compared with the values calculatedby a Radio Frequency (RF) planning tool for the Irregular Terrain Model (ITM), Irregular Terrain with Obstructions Model (ITWOM) and Okumura-Hata propagation models. Five sensors are configured and deployed along a wooden bridge, with different Spreading Factors (SFs), such as SF 7, 10 and 12. Our results show that the RSSI values calculated using the RF planning tool for ITWOM are closest to the values obtained from the real-life LoRaWAN. Moreover, we also show evidence that the choice of a propagation model in an RF planning tool has to be made with care, mainly due to the terrain conditions of the area where the network and the sensors are deployed.

  • 94.
    Bezerra, Nibia Souza
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Åhlund, Christer
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Saguna, Saguna
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    de Sousa Jr., Vicente A.
    Federal University of Rio Grande do Norte (UFRN).
    Temperature Impact in LoRaWAN: A Case Study in Northern Sweden2019Ingår i: Sensors, E-ISSN 1424-8220, Vol. 19, nr 20, artikel-id 4414Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    LoRaWAN has become popular as an IoT enabler. The low cost, ease of installation and the capacity of fine-tuning the parameters make this network a suitable candidate for the deployment of smart cities. In northern Sweden, in the smart region of Skellefteå, we have deployed a LoRaWAN to enable IoT applications to assist the lives of citizens. As Skellefteå has a subarctic climate, we investigate how the extreme changes in the weather happening during a year affect a real LoRaWAN deployment in terms of SNR, RSSI and the use of SF when ADR is enabled. Additionally, we evaluate two propagation models (Okumura-Hata and ITM) and verify if any of those models fit the measurements obtained from our real-life network. Our results regarding the weather impact show that cold weather improves the SNR while warm weather makes the sensors select lower SFs, to minimize the time-on-air. Regarding the tested propagation models, Okumura-Hata has the best fit to our data, while ITM tends to overestimate the RSSI values.

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  • 95.
    Biswas, Munmun
    et al.
    BGC Trust University Bangladesh,Department of Computer Science and Engineering,Bidyanagar, Chandanaish,Bangladesh.
    Chowdury, Mohammad Salah Uddin
    BGC Trust University Bangladesh,Department of Computer Science and Engineering,Bidyanagar, Chandanaish,Bangladesh.
    Nahar, Nazmun
    BGC Trust University Bangladesh,Department of Computer Science and Engineering,Bidyanagar, Chandanaish,Bangladesh.
    Hossain, Mohammad Shahadat
    University of Chittagong University,Department of Computer Science and Engineering,Bangladesh,4331.
    Andersson, Karl
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    A Belief Rule Base Expert System for staging Non-Small Cell Lung Cancer under Uncertainty2019Ingår i: BECITHCON 2019: 2019 IEEE International Conference on Biomedical Engineering, Computer and Information Technology for Health (BECITHCON), IEEE, 2019, s. 47-52Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Non small cell Lung cancer (NSCLC) is one of the most well-known types of Lung cancer which is reason for cancer related demise in Bangladesh. The early detection stage of NSCLC is required for improving the survival rate by taking proper decision for surgery and radiotherapy. The most common factors for staging NSCLC are age, tumor size, lymph node distance, Metastasis and Co morbidity. Moreover, physicians' diagnosis is unable to give more reliable outcome due to some uncertainty such as ignorance, incompleteness, vagueness, randomness, imprecision. Belief Rule Base Expert System (BRBES) is fit to deal with above mentioned uncertainty by applying both Belief Rule base and Evidential Reasoning approach. Therefore, this paper represents the architecture, development and interface for staging NSCLC by incorporating belief rule base as well as evidential reasoning with the capability of handling uncertainty. At last, a comparative analysis is added which indicate that the outcomes of proposed expert system is more reliable and efficient than the outcomes generated from traditional human expert as well as Support Vector Machine (SVM) or Fuzzy Rule Base Expert System (FRBES).

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  • 96. Bittencourt, Roberto Almeida
    et al.
    Carr, David
    Luleå tekniska universitet.
    A method for asynchronous web-based lecture delivery2001Ingår i: Impact on engineering and science education: conference proceedings / FIE 2001, 31st Annual Frontiers in Education Conference, IEEE Communications Society, 2001Konferensbidrag (Refereegranskat)
    Abstract [en]

    Computer-based distance education has been growing enormously in recent years due to advances in key technologies: telecommunications, computer technology, graphical user interfaces, and the Internet. Distance education materials can be presented either synchronously, creating the illusion of a classroom on the computer, or asynchronously, allowing the students access-on-demand. We describe the development of a system to solve part of the asynchronous education problem - delivery of pre-recorded multimedia lectures via a web browser. We built a demonstration system using off-the-shelf technology making it possible to make presentations using commercial tools and to display them on standard systems. We designed the system with lectures composed of "slides" accompanied by audio commentary. These presentations can be delivered via lowspeed modem links - an important consideration in places without a well-developed infrastructure. We also believe that computer-based education is often so complicated to use that operation interferes with education. In order to avoid this, we evaluated a prototype system to obtain feedback about difficulties in operation and to correct them.

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  • 97.
    Bladh, Thomas
    et al.
    Luleå tekniska universitet.
    Carr, David A.
    Luleå tekniska universitet.
    Scholl, Jeremiah
    Luleå tekniska universitet.
    Extending tree-maps to three dimensions: a comparative study2004Ingår i: Computer Human Interaction: 6th Asia Pacific Conference, APCHI 2004, Rotorua, New Zealand, June 29-July 2, 2004. Proceedings / [ed] M. Masoodian; S. Jones; B. Rogers, Springer, 2004, s. 50-59Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents StepTree, an information visualization tool designed for depicting hierarchies, such as directory structures. StepTree is similar to the hierarchy-visualization tool, Treemap, in that it uses a rectangular, space-filling methodology, but differs from Treemap in that it employs three-dimensional space, which is used to more clearly convey the structural relationships of the hierarchy. The paper includes an empirical study comparing typical search and analysis tasks using StepTree and Treemap. The study shows that users perform significantly better on tasks related to interpreting structural relationships when using StepTree. In addition, users achieved the same performance with StepTree and Treemap when doing a range of other common interpretative and navigational tasks.

    Ladda ner fulltext (pdf)
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  • 98.
    Bladh, Thomas
    et al.
    Luleå tekniska universitet.
    Carr, David
    Luleå tekniska universitet.
    Scholl, Jeremiah
    Extending tree-maps to three dimensions: a comparative study2004Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This paper presents StepTree, an information visualization tool designed for depicting hierarchies, such as directory structures. StepTree is similar to the hierarchy-visualization tool, Treemap, in that it uses a rectangular, space-filling methodology, but differs from Treemap in that it employs threedimensional space, which is used to more clearly convey the structural relationships of the hierarchy. The paper includes an empirical study comparing typical search and analysis tasks using StepTree and Treemap. The study shows that users perform significantly better on tasks related to interpreting structural relationships when using StepTree. In addition, users achieved the same performance with StepTree and Treemap when doing a range of other common interpretative and navigational tasks.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 99.
    Bodin, Ulf
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Schelén, Olov
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Vemmervik, Claes
    Operax AB.
    End-to-End QoS control architectures from a wholesale and retail perspective: benefits and challenges2006Konferensbidrag (Refereegranskat)
    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 100.
    Bohli, Jens-Mathias
    et al.
    NEC Laboratories Europe.
    Kurpatov, Roman
    NEC Laboratories Europe.
    Schmidt, Mischa
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Selective Decryption of Outsourced IoT Data2015Ingår i: 2015 IEEE 2nd World Forum on Internet of Things (WF-IoT): Milan, Italy, 14-16 Dec, 2015, Piscataway, NJ: IEEE Communications Society, 2015, s. 739-744Konferensbidrag (Refereegranskat)
    Abstract [en]

    Outsourcing of IoT-data is a common concept when using third-party services, e.g. an external building management service is given access to the building's sensor measurements. However, the measurements captured from building systems often need to be protected from unauthorized access, because they are linked to persons, processes or business secrets, and therefore data protection requirements apply. Nevertheless, due to the large data volumes, external storage is desirable from a business perspective. We propose the concept of a Security Broker based on symmetric encryption schemes. It offers a key management scheme to flexibly create short decryption keys for time intervals or specific ranges of measurement values. We further show how the scheme can be generalized or a combination of the schemes can be applied. We implemented a prototype in Java and analyzed its performance. The evaluation proved the mechanism's applicability for mainstream applications running on off-the-shelf computing equipment.

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