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  • 401.
    Budzisz, Łukasz
    et al.
    Technische Universität Berlin, Berlin, Germany.
    Garcia, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Brunström, Anna
    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.
    Ferrús, Ramon
    Universitat Politècnica de Catalunya, Barcelona, Spain.
    A taxonomy and survey of SCTP research2012In: ACM Computing Surveys, ISSN 0360-0300, E-ISSN 1557-7341, Vol. 44, no 4Article in journal (Refereed)
    Abstract [en]

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

  • 402.
    Bugiel, Sven
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    Ekberg, J. -E
    Implementing an application-specific credential platform using late-launched mobile trusted module2010In: STC '10 Proceedings of the fifth ACM workshop on Scalable trusted computing, 2010, p. 21-30Conference paper (Refereed)
    Abstract [en]

    Contemporary trusted execution environments provide a good foundation for implementing secure user credentials, but these are not properly bound to the application instances that implement their use. This paper introduces a framework for application-specific credentials and provides a prototype implementation using TCG MTM and DRTM technologies. Measurements and a security analysis is presented for the realised architecture.

  • 403.
    Bui, Minh N.
    et al.
    Concordia University.
    Jaumard, Brigitte
    Concordia University.
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Mukherjee, Biswanath
    University of California - Davis.
    Design of a survivable VPN topology over a service provider network2013In: 2013 9th International Conference on the Design of Reliable Communication Networks (DRCN), IEEE conference proceedings, 2013, p. 71-78Conference paper (Refereed)
    Abstract [en]

    Survivability in IP-over-WDM networks has alreadybeen extensively discussed in a series of studies. Up to date,most of the studies assume single-hop working routing of trafficrequests. In this paper, we study the multi layer survivable designof a logical topology in the context of multiple-hop workingrouting for IP layer traffic requests. The design problem iscomposed of two problems which are simultaneously solved:(i) Finding the most efficient or economical multi-hop routingof the IP traffic flows with different bandwidth granularitiesover the logical topology, which involves some traffic grooming,(ii) Ensuring that the logical topology is survivable throughoutan appropriate mapping of the logical links over the physicaltopology, if such a mapping exists.In order to solve such a complex multi layer resilient networkdesign problem, we propose a column generation ILP model. Itallows exploiting the natural decomposition of the problem andhelps devising a scalable solution scheme.We conducted numerical experiments on a German networkwith 50 nodes and 88 physical links. Not only we could solve muchlarger data instances than those published in the literature, butalso observe than multi-hop routing allows a saving of up to 10%of the number of lightpaths, depending on the traffic load.

  • 404. Bulakci, O.
    et al.
    Gutierrez-Estevez, D. M.
    Ericson, M.
    Prasad, A.
    Pateromichelakis, E.
    Calochira, G.
    Belschner, J.
    Arnold, P.
    Moya, F. Sanchez
    Ibrahim, A. M.
    Bronzino, F.
    Čelik, Haris
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Fodor, G.
    An Agile Resource Management Framework for 5G2017In: 2017 IEEE CONFERENCE ON STANDARDS FOR COMMUNICATIONS AND NETWORKING (CSCN), IEEE, 2017, p. 24-29Chapter in book (Other academic)
    Abstract [en]

    This paper presents the design foundations of an agile resource management (RM) framework for the fifth generation (5G) radio access network (RAN) by describing essential building blocks (BBs). Overall, the presented RM framework provides holistic RM solutions that consider and exploit the novel aspects of 5G systems, such as, diverse service requirements, co-existence of multiple air interface (AI) variants (AIVs) in the overall AI, dynamic radio topologies, and novel communication modes. The proposed framework encompasses the following key BBs: Advanced interference management techniques for dense and dynamic deployments; dynamic traffic steering mechanisms that aim to attain the optimum mapping of 5G services to any available resources when and where needed by considering the peculiarities of different AIVs; tight interworking between novel 5G AIVs and evolved legacy AIVs such as Longterm Evolution (LTE); sharing of a common RAN by multiple network slices; RAN moderation techniques to attain energy efficiency gains; and functional extensions in the device measurement context to enable all the above new functionalities. The BBs are analyzed from the perspectives of key findings and RAN design implications.

  • 405.
    Byttner, Anders
    KTH, Superseded Departments, Teleinformatics.
    Internet Telephony using the Session Initiation Protocol2000Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Session Initiation Protocol (SIP) is a highly extensible signaling protocol that provides mechanisms for establishing, modifying, and tearing down Internet telephony calls. Together with other Internet protocols and API’s it can create a flexible, dynamic, and scalable telephony environment, where services can be developed and deployed rapidly and by a wide range of users.

    This report investigates some proposed extensions to SIP and some of the API's that aim to standardize how telephony services can be defined in a SIP enabled network. The report describes some changes and improvements to these proposals and demonstrates how different services can be implemented using them.

  • 406.
    Bång, Karl-Lennart
    et al.
    Transportforskningskommissionen.
    Lindkvist, Anders
    Transportforskningskommissionen.
    Kan elektroniska informations- och reglersystem underlätta vägtrafiken?1982Report (Other academic)
  • 407.
    Böhm, Annette
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Delay-sensitive wireless communication for cooperative driving applications2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cooperative driving holds the potential to considerably improve the level of safety and efficiency on our roads. Recent advances in in-vehicle sensing and wireless communication technology have paved the way for the development of cooperative traffic safety applications based on the exchange of data between vehicles (or between vehicles and road side units) over a wireless link. The access to up-to-date status information from surrounding vehicles is vital to most cooperative driving applications. Other applications rely on the fast dissemination of warning messages in case a hazardous event or certain situation is detected. Both message types put high requirements on timeliness and reliability of the underlying communication protocols.

    The recently adopted European profile of IEEE 802.11p defines two message types,periodic beacons for basic status exchange and event-triggered hazard warnings, both operating at pre-defined send rates and sharing a common control channel. The IEEE 802.11p Medium Access Control (MAC) scheme is a random access protocol that doesnot offer deterministic real-time support, i.e. no guarantee that a packet is granted access to the channel before its deadline can be given. It has been shown that a high number of channel access requests, either due to a high number of communicating vehicles or highdata volumes produced by these vehicles, cannot be supported by the IEEE 802.11p MAC protocol, as it may result in dropped packets and unbounded delays.

    The goal of the work presented in this thesis has therefore been to enhance IEEE 802.11p without altering the standard such that it better supports the timing and reliability requirements of traffic safety applications and provides context-aware andefficient use of the available communication resources in a vehicular network. The proposed solutions are mapped to the specific demands of a set of cooperative driving scenarios (featuring infrastructure-based and infrastructure-free use cases, densely and sparsely trafficked roads, very high and more relaxed timing requirements) and evaluated either analytically, by computer simulation or by measurements and compared to the results produced by the unaltered IEEE 802.11p standard.

    As an alternative to the random MAC method of IEEE 802.11p, a centralized solution isproposed for application scenarios where either a road side unit or a suitable dedicated vehicle is present long enough to take the coordinating role. A random access phase forevent-driven data traffic is interleaved with a collision-free phase where timely channel access of periodic delay-sensitive data is scheduled. The ratio of the two phases isdynamically adapted to the current data traffic load and specific application requirements. This centralized MAC solution is mapped on two cooperative driving applications: merge assistance at highway entrances and platooning of trucks. Further,the effect of a context-aware choice of parameters like send rate or priority settings based on a vehicle’s position or role in the safety application is studied with the goal to reduce the overall number of packets in the network or, alternatively, use the available resources more efficiently. Examples include position-based priorities for the merge assistance use case, context-aware send rate adaptation of status updates in anovertaking warning application targeting sparsely-trafficked rural roads and an efficient dissemination strategy for warning messages within a platoon.

    It can be concluded that IEEE 802.11p as is does not provide sufficient support for the specific timing and reliability requirements imposed by the exchange of safety-criticalreal-time data for cooperative driving applications. While the proper, context-awarechoice of parameters, concerning send rate or priority level, within the limits of the standard, can lead to improved packet inter-arrival rates and reduced end-to-end delays,the added benefits from integrating MAC solutions with real-time support into the standard are obvious and needs to be investigated further.

  • 408.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Co-Existing Periodic Beaconing and Hazard Warnings in IEEE 802.11p-Based Platooning Applications2013In: VANET 2013 - Proceedings of the 10th ACM International Workshop on VehiculAr Inter-NETworking, Systems, and Applications, New York, NY: ACM Press, 2013, p. 99-101Conference paper (Refereed)
    Abstract [en]

    A platoon of trucks driving at the same, mutually agreed speed while keeping a minimum inter-vehicle distance will reduce fuel consumption, enhance transport efficiency as well as improve the safety of other adjacent road users. The European profile of IEEE 802.11p for inter-vehicle communications uses a single 10 MHz control channel dedicated to safety-critical data, shared by periodic status updates, and event-triggered warnings. Coupled with the random access delay inherent to the 802.11p medium access method, the strict timing and reliability requirements of platoon applications are not easily met. To this end, we evaluate the effect of IEEE 802.11p-compliant send rate adaptations and message type prioritizations and the choice of warning dissemination strategy in a platooning scenario. Simulation studies of a platoon of 10-20 vehicles in a busy highway scenario show that a context-aware choice of send rate, priority class and dissemination strategy not only reduces the hazard warning dissemination delay but also has a significant effect on the throughput of periodic beacons.

  • 409.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Uhlemann, Elisabeth
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Co-existing periodic beaconing and hazard warnings in IEEE 802.11p-based platooning applicationsManuscript (preprint) (Other academic)
    Abstract [en]

    A platoon of trucks driving at the same, mutually agreed speed while keeping a minimum inter-vehicle distance will reduce fuel consumption, enhance transport efficiency as well as improve the safety of other adjacent road users. The European profile of IEEE 802.11p for inter-vehicle communications uses a single 10 MHz control channel dedicated to safety-critical data, shared by periodic status updates, CAM (Cooperative Awareness Message), and event-triggered warnings, DENM (Decentralized Environmental Notification Message). Coupled with the random access delay inherent to the 802.11p medium access method, the strict timing and reliability requirements of platoon applications are not easily met. To this end, we evaluate by simulation the effect of IEEE 802.11p-compliant send rate adaptations and message type prioritizations and the choice of warning dissemination strategy on CAM transmissions and DENM dissemination in a platooning scenario. Simulation studies of a platoon of 10-20 vehicles in a busy highway scenario show that the context-aware choice of send rate, priority class and dissemination strategy not only reduce the dissemination delay of DENMs but even has a significant effect on the throughput of CAMs exchanged by platoon members.

  • 410.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Performance comparison of a platooning application using the IEEE 802.11p MAC on the control channel and a centralized MAC on a service channel2013In: 2013 IEEE 9th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), Piscataway, NJ: IEEE Press, 2013, p. 545-552, article id 6673411Conference paper (Refereed)
    Abstract [en]

    Recent advances in cooperative driving hold the potential to significantly improve safety, comfort and efficiency on our roads. An application of particular interest is platooning of trucks, where it has been shown that keeping a minimum inter-vehicle distance results in considerably reduced fuel consumption.This, however, puts high requirements on timeliness and reliability of the underlying exchange of control messages betweenplatoon members. The European profile of IEEE 802.11p, recently adopted by ETSI, defines two message types to this end, periodic beacons for basic cooperative awareness (CAM) and event-triggered decentralized environmental notification messages (DENM), both of which will use one common control channel. IEEE 802.11p employs a random medium access protocol, which may experience excessive delays during high network loads. To mitigate these effects, ETSI standardizes a decentralized congestion control algorithm to, e.g., lower the CAM update frequency during high loads. However, this may prevent proper functionality of a platooning application. In this paper we propose a solution that instead uses a dedicated service channel for platooning applications and compare its performance to standard-compliant IEEE 802.11p inter-platoon communication on the control channel. Service channels typically have less strict requirements on send rates, data traffic types and medium access methods. Our service channel solution combines a random access phase for DENM with a centralized, scheduled access phase for CAM. Using a service channel enables us to guarantee timely channel access for all CAM packets before a specified deadline while still being able to provide a reasonable DENM dissemination delay. © 2013 IEEE.

  • 411.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Uhlemann, Elisabeth
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Performance evaluation of a platooning application using the IEEE 802.11p MAC on a control channel vs. a centralized real-time MAC on a service channelManuscript (preprint) (Other academic)
    Abstract [en]

    Recent advances in cooperative driving hold the potential to significantly improve safety, comfort and efficiency on our roads. An application of particular interest is platooning of trucks, where it has been shown that keeping a minimum inter-vehicle distance results in considerably reduced fuel consumptions. This, however, puts high requirements on timeliness and reliability of the underlying exchange of control messages between platoon members. The European profile of IEEE 802.11p, recently adopted by ETSI, defines two message types to this end, periodic beacons for basic cooperative awareness (CAM) and event-triggered decentralized environmental notification messages (DENM), both using the common control channel. The IEEE 802.11p employs a random medium access protocol, with excessive delays that may prevent proper functionality of a platooning application. To mitigate the effects of this, ETSI standardizes a decentralized congestion control algorithm to, e.g., lower the CAM frequency when needed. Some service channels with less strict requirements on send rates, data traffic types or medium access methods are available. In this paper we compare the performance of decentralized, standard-compliant inter-platoon communication using IEEE 802.11p on the control channel with a solution based on a service channel, which combines a random access phase for DENM with a centralized, scheduled access phase for CAM. A dedicated service channel for platooning applications enables us to always guarantee timely channel access of CAM packets before a specified deadline and our simulations show that this is achieved at very small sacrifices in DENM dissemination delay.

  • 412.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Kunert, Kristina
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Data age based retransmission scheme for reliable control data exchange in platooning applications2015In: 2015 IEEE International Conference on Communication Workshop (ICCW), Piscataway, NJ: IEEE Press, 2015, p. 2412-2418Conference paper (Refereed)
    Abstract [en]

    Recent advances in cooperative driving hold the potential to significantly improve safety, comfort and efficiency on our roads. Platooning of heavy vehicles, where automated or semi-automated driving allows minimal inter-vehicle gaps, has shown considerable reductions in fuel consumption. Although using the same wireless communication technology, a platoon differs from a VANET (Vehicular Ad-hoc NETwork) in several points. It is centralized in its nature, with a well-defined group leader, its topology is fairly stable and it has very challenging requirements on timeliness and reliability of its control data exchange. Therefore, the IEEE 802.11p protocol suite and its recently defined message types do neither support the needs of a platooning application nor take advantage of its properties. A platoons control loop must continuously be fed with fresh data, so the information age is an important parameter to be closely monitored. In this paper, we therefore propose a framework for centralized channel access and retransmission capabilities for safety critical inter-platoon control data based on the data age of earlier received messages. A simulation evaluation compares our solution to a) the decentralized, standard-compliant IEEE 802.11p MAC (Medium Access Control) method, and a time-slotted scheme b) with and c) without retransmissions and shows that the centralized, data age based retransmission scheme clearly outperforms its competitors in terms of maintained data age. © 2015 IEEE.

  • 413.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Lidström, Kristoffer
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Larsson, Tony
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Evaluating CALM M5-based vehicle-to-vehicle communication in various road settings through field trials2010In: Proceedings - Conference on Local Computer Networks, LCN, (2010 12 01): 613-620, Piscataway, N.J.: IEEE Press, 2010, p. 613-620Conference paper (Refereed)
    Abstract [en]

    Future cooperative Intelligent Transport Systems (ITS) applications aimed to improve safety, efficiency and comfort on our roads put high demands on the underlying wireless communication system. To gain better understanding of the limitations of the 5.9 GHz frequency band and the set of communication protocols for medium range vehicle to vehicle (V2V) communication, a set of field trials with CALM M5 enabled prototypes has been conducted. This paper describes five different real vehicle traffic scenarios covering both urban and rural settings at varying vehicle speeds and under varying line-of-sight (LOS) conditions and discusses the connectivity (measured as Packet Reception Ratio) that could be achieved between the two test vehicles. Our measurements indicate a quite problematic LOS sensitivity that strongly influences the performance of V2V-based applications. We further discuss how the awareness of these context-based connectivity problems can be used to improve the design of possible future cooperative ITS safety applications.

  • 414.
    Börjesson, Martin
    KTH, Superseded Departments, Teleinformatics.
    Creation & Deployment of Voice Browsing Services1999Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Making the World Wide Web accessible trough audio interfaces (voice browsing) would provide many benefits. Far more people today have access to phones than have access to computers, further more, cellular phones allow user-mobility. Traditional Interactive Voice Response (IVR) applications have so far been restricted to the POTS network. However, a combination of Internet and IVR technologies could make voice browsing on the WWW possible. IVR services can with many benefits be described with customised markup languages instead of the traditional programming languages that are used today. The services can be published on the web using the same tools as in graphical Web publishing.

    In this paper, existing conversational markup languages are presented and evaluated together with suggestions for improvements. The benefits of the Extensible Markup Language in web publishing are studied with the conclusion that it would provide the best available base a future conversational markup standard.

    Requirements for a voice browser are suggested and possible media platforms are evaluated and discussed. The design of a voice browser is presented and discussed together with experiences gained from an implementation task.

    This paper concludes that voice browsing on the WWW will become a common way of web interaction within a not too distant future. The techniques necessary already exists. The benefits and opportunities that it offers will drive the development of necessary standards as well as the growth of content provide[r]s and users[.]

  • 415.
    Bülow, Jonas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Mobile IP and AAA Services2002Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Networks providing Authentication, Authorization and Accounting services are found all over the world. The number of mobile devices is growing rapidly and the need to have a seamless, user friendly, and stable integration between mobile devices and AAA enabled networks is an important development trend right now.

    This thesis will give an overview of the work taking place in the field of AAA and Mobile IP. Issues when Mobile IP and AAA meet will be discussed.

    The thesis will describe sample tests of a Mobile IP network and a simple test using the forthcoming AAA protocol Diameter.

    Conclusions based on these tests are described along with some obvious future work.

  • 416. Caballero Bayerri, Juan
    et al.
    Malmkvist, Daniel
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Experimental Study of a Network Access Server for a public WLAN access network2002Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Wireless access networks have gained popularity due to the flexibility they allow the user, who is able to move away from his or her desk while still being able to access information. Among the different Wireless LAN standards, the most widespread, by far, is IEEE 802.11.

    Public WLAN access networks are being set up in hotspots, i.e. areas expected to have high demand for bandwidth. Access to the Internet and to corporate networks is provided at these hotspots with limited coverage but high available bandwidth. Airports and hotels have often been the first targeted locations for these hotspots, but conference centres, cafes, and train stations follow. In the near future, any person who owns at least one access point and has a connection to the Internet can become a small operator and offer access to the Internet using these resources.

    Existing solutions for such WLAN access networks lack support for security, flexible accounting, mobility, multiaccess, roaming and user-friendly login. The aim of this Master's Thesis was to study if it was possible to solve these problems and how to integrate all this new functionality into existing public WLAN access networks by building and evaluating a prototype of a public WLAN access network

    System requirements were defined, currently available solutions analysed and a prototype was built. Most of the functionality of the prototype is placed in the Network Access Server, which is the main element providing security, mobility, and accounting.

    Flexible accounting, improvements in security, an easy and fast way to login the user, a feedback module to provide information about the current session and integration of the RADIUS architecture with the Mobile IP distribution have all been implemented.

  • 417.
    Cabarkapa, Dragan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Authorization Architecture for SWoT2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Social Web of Things (SWoT) is a user centric framework which facilitates interaction between software agents deployed on smart things and in the cloud. Software agents deployed on smart things are remotely accessible, host sensitive resources, and often represent high value targets. SWoT currently does not feature adequate security mechanisms which could protect software agents from unauthorized access. In this thesis, we aim to rectify this deficiency by introducing platform independent, exible, and user centric authorization mechanism inSWoT.

    We derive requirements and design of abstract authorization architecture from the preceding seminal work performed in SENSEI project. SENSEI and SWoT share same problem domain, but while SENSEI addresses enterprise use cases SWoT focusses on consumer use cases. This single but fundamental difference motivates adaptations of SENSEI contributions for application in SWoT. To realize concrete authorization architecture we perform extensive study of various authorization solutions. Results of our study indicate that novel User Managed Access (UMA) protocol represents promising solution for SWoT.

    We present the Authorization as a Service solution for SWoT framework, based on UMA protocol. This solution enables users to manage and control communication between software agents deployed on smart things and in the cloud from single centralized location. It also features runtime association of software agents, management, evaluation, and enforcement of access permissions for resources provided by software agents.

  • 418.
    Cambazoglu, Volkan
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Computer Systems. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Protocol, mobility and adversary models for the verification of security2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The increasing heterogeneity of communicating devices, ranging from resource constrained battery driven sensor nodes to multi-core processor computers, challenges protocol design. We examine security and privacy protocols with respect to exterior factors such as users, adversaries, and computing and communication resources; and also interior factors such as the operations, the interactions and the parameters of a protocol.

    Users and adversaries interact with security and privacy protocols, and even affect the outcome of the protocols. We propose user mobility and adversary models to examine how the location privacy of users is affected when they move relative to each other in specific patterns while adversaries with varying strengths try to identify the users based on their historical locations. The location privacy of the users are simulated with the support of the K-Anonymity protection mechanism, the Distortion-based metric, and our models of users' mobility patterns and adversaries' knowledge about users.

    Security and privacy protocols need to operate on various computing and communication resources. Some of these protocols can be adjusted for different situations by changing parameters. A common example is to use longer secret keys in encryption for stronger security. We experiment with the trade-off between the security and the performance of the Fiat–Shamir identification protocol. We pipeline the protocol to increase its utilisation as the communication delay outweighs the computation.

    A mathematical specification based on a formal method leads to a strong proof of security. We use three formal languages with their tool supports in order to model and verify the Secure Hierarchical In-Network Aggregation (SHIA) protocol for Wireless Sensor Networks (WSNs). The three formal languages specialise on cryptographic operations, distributed systems and mobile processes. Finding an appropriate level of abstraction to represent the essential features of the protocol in three formal languages was central.

  • 419.
    Cambazoglu, Volkan
    Uppsala universitet, Avdelningen för datorteknik.
    Protocol, mobility and adversary models for the verification of security2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The increasing heterogeneity of communicating devices, ranging from resource constrained battery driven sensor nodes to multi-core processor computers, challenges protocol design. We examine security and privacy protocols with respect to exterior factors such as users, adversaries, and computing and communication resources; and also interior factors such as the operations, the interactions and the parameters of a protocol.

    Users and adversaries interact with security and privacy protocols, and even affect the outcome of the protocols. We propose user mobility and adversary models to examine how the location privacy of users is affected when they move relative to each other in specific patterns while adversaries with varying strengths try to identify the users based on their historical locations. The location privacy of the users are simulated with the support of the K-Anonymity protection mechanism, the Distortion-based metric, and our models of users' mobility patterns and adversaries' knowledge about users.

    Security and privacy protocols need to operate on various computing and communication resources. Some of these protocols can be adjusted for different situations by changing parameters. A common example is to use longer secret keys in encryption for stronger security. We experiment with the trade-off between the security and the performance of the Fiat–Shamir identification protocol. We pipeline the protocol to increase its utilisation as the communication delay outweighs the computation.

    A mathematical specification based on a formal method leads to a strong proof of security. We use three formal languages with their tool supports in order to model and verify the Secure Hierarchical In-Network Aggregation (SHIA) protocol for Wireless Sensor Networks (WSNs). The three formal languages specialise on cryptographic operations, distributed systems and mobile processes. Finding an appropriate level of abstraction to represent the essential features of the protocol in three formal languages was central.

  • 420.
    Cambazoglu, Volkan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Gutkovas, Ramunas
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Åman Pohjola, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Victor, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Modelling and analysing a WSN secure aggregation protocol: A comparison of languages and tool support2015Report (Other academic)
  • 421.
    Cambazoglu, Volkan
    et al.
    Uppsala universitet, Datorarkitektur och datorkommunikation.
    Gutkovas, Ramunas
    Uppsala universitet, Datalogi.
    Åman Pohjola, Johannes
    Uppsala universitet, Datalogi.
    Victor, Björn
    Uppsala universitet, Datalogi.
    Modelling and analysing a WSN secure aggregation protocol: A comparison of languages and tool support2015Report (Other academic)
    Abstract [en]

    A security protocol promises protection of a significant piece of information while using it for a specific purpose. Here, the protection of the information is vital and a formal verification of the protocol is an essential step towards guaranteeing this protection. In this work, we study a secure aggregation protocol (SHIA) for Wireless Sensor Networks and verify the protocol in three formal modelling tools (Pwb, mCRL2 and ProVerif). The results of formal verification heavily depend on the model specification and the ability of the tools to deal with the model. Among the three tools, there is difference in data representation, communication types and the level of abstraction in order to represent SHIA. ProVerif and mCRL2 are mature and well-established tools, geared respectively towards security and distributed systems; however, their expressiveness constrains modelling SHIA and its security properties. Pwb is an experimental tool developed by the authors; its relative immaturity is offset by its increased expressive power and customisability. This leads to different models of the same protocol, each contributing in different ways to our understanding of SHIA's security properties.

  • 422.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Characterizing broadcast packet losses in IEEE 802.11p/WAVE vehicular networks2011Conference paper (Refereed)
  • 423.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    On the Performance of Beaconing in 802.11p/WAVE Vehicular Ad Hoc Networks2010Conference paper (Refereed)
    Abstract [en]

    Cooperative vehicular applications, like collision avoidance, driver assistance, and cruise control require that vehicles become aware of other vehicles in the surroundings. This cooperative awareness is achieved by beaconing, the exchange of periodical single-hop broadcast short status message that include data about the position, the speed, and the heading of a vehicle. Although several works have studied beaconing techniques both from an analytical point of view and through simulative study, none of the existing works has investigated how beaconing works on top of 802.11p/WAVE (Wireless Access for Vehicular Environment), the upcoming standard intended to deliver both safety and non-safety applications to vehicles on the roads. According to it, safety and control messages are expected to be delivered on a given frequency during a common control channel (CCH) interval set by the WAVE draft standard. The rest of the time, vehicles switch over one of available service channel (SCH) frequencies for non-safety related data exchange. In this paper we discuss and evaluate through numerical results the main effects the WAVE channel switching procedures have on beaconing. © 2010 by IEICE

  • 424.
    Campolo, Claudia
    et al.
    Mediterranea University of Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Mediterranea University of Reggio Calabria, Reggio Calabria, Italy.
    Berthet, Antoine O.
    Gif-sur-Yvette, CNRS-Centrale Supélec-Université Paris Sud, Gif-sur-Yvette, France.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Full-Duplex Radios for Vehicular Communications2017In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 55, no 6, p. 182-189Article in journal (Refereed)
    Abstract [en]

    Recent significant advances in self-interference cancellation techniques pave the way for the deployment of full-duplex wireless transceivers capable of concurrent transmission and reception on the same channel. Despite the promise to theoretically double the spectrum efficiency, full-duplex prototyping in off-the-shelf chips of mobile devices is still in its infancy, mainly because of the challenges in mitigating self-interference to a tolerable level and the strict hardware constraints. In this article, we argue in favor of embedding full-duplex radios in onboard units of future vehicles. Unlike the majority of mobile devices, vehicular onboard units are good candidates to host complex FD transceivers because of their virtually unlimited power supply and processing capacity. Taking into account the effect of imperfect SI cancellation, we investigate the design implications of full-duplex devices at the higher-layer protocols of next-generation vehicular networks and highlight the benefits they could bring with respect to half-duplex devices in some representative use cases. Early results are also provided that give insight into the impact of self-interference cancellation on vehicle-to-roadside communications, and showcase the benefits of FD-enhanced medium access control protocols for vehicle-to-vehicle communications supporting crucial road safety applications.

  • 425.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    To switch or not to switch: Service discovery and provisioning in multi-radio V2R communications2016In: Proceedings of 2016 8th International Workshop on Resilient Networks Design and Modeling (RNDM) / [ed] Magnus Jonsson, Jacek Rak, Arun Somani, Dimitri Papadimitriou & Alexey Vinel, Piscataway: IEEE Press, 2016, p. 281-287, article id 7608299Conference paper (Refereed)
    Abstract [en]

    A rich portfolio of services (e.g., road traffic information, maps download, Internet/cloud access) will be delivered to users on wheels through Vehicular Ad Hoc Networks (VANETs).Most of them will be offered by road-side units (RSUs) sparsely deployed along the roads. The prompt access to such services by passing by vehicles highly relies on the efficiency of service announcement procedures performed by the RSUs. In this paper, we present an analytical framework that models the service discovery and access mechanisms in multi-channel vehicular networks. The model accounts for dual-radio devices under different channel configurations for the delivery of announcements (e.g., on the control channel, on a service channel) and related switching mechanisms. Guidelines are suggested for the setting of service announcements parameters and channel configuration to allow providers to boost service provisioning. © 2016 IEEE.

  • 426.
    Campolo, Claudia
    et al.
    Mediterranea University of Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Mediterranea University of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Understanding Adjacent Channel Interference in Multi-Channel VANETs2014In: 2014 IEEE Vehicular Networking Conference (VNC) / [ed] Falko Dressler, Onur Altintas, Suman Banerjee, Björn Scheuermann & David Eckhoff, Piscataway, NJ: IEEE Press, 2014, p. 101-104, article id 7013316Conference paper (Refereed)
    Abstract [en]

    Multiple channels have been allocated in the 5 GHz spectrum for vehicular communications worldwide, however, due to the limited allocated bandwidth, simultaneous communications occurring over nearby channels may be affected by adjacent channel interference (ACI). Due to ACI, packet reception may be unsuccessful and transmissions may be delayed. In this work, we investigate the ACI phenomena in multichannel vehicular networks to shed light on their effects, with focus on the transmitter-side. To this purpose, a simple analytical model is introduced along with a preliminary evaluation. Suggestions are also provided about the usage of adjacent channels so to minimize side effects on the communication quality. © 2014 IEEE

  • 427.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Understanding the performance of short-lived control broadcast packets in 802.11p/WAVE Vehicular networks2011In: 2011 IEEE Vehicular Networking Conference (VNC) / [ed] Altintas, O., Chen, W., Heijenk, G. J., Dressler, F., Ekici, E., Kargl, F., Shigeno, H., Dietzel, S., Piscataway, NJ: IEEE Press, 2011, p. 102-108Conference paper (Refereed)
  • 428.
    Campolo, Claudia
    et al.
    Università Mediterranea di Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Università Mediterranea di Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Lyamin, Nikita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Service Discovery and Access in Vehicle-to-Roadside Multi-Channel VANETs2015In: 2015 IEEE International Conference on Communication Workshop, Piscataway, NJ: IEEE Press, 2015, p. 2477-2482Conference paper (Refereed)
    Abstract [en]

    A wide portfolio of safety and non-safety services will be provided to drivers and passengers on top of Vehicular Ad Hoc Networks (VANETs).

    Non-safety services are announced by providers, e.g., road-side units (RSUs), on a channel that is different from the one where the services are delivered. The dependable and timely delivery of the advertisement messages is crucial for vehicles to promptly discover and access the announced services in challenging vehicle-to-roadside scenarios, characterized by intermittent and short lived connectivity.

    In this paper, we present an analytical framework that models the service advertisement and access mechanisms in multichannel vehicular networks.

    The model accounts for dual-radio devices, and computes the mean service discovery time and the service channel utilization by considering the disruption periods due to the switching of the RSU from the advertising channel (where announcements are transmitted) to the advertised channel (where services are exchanged), under different channel and mobility conditions. It provides quick insights on parameter settings to allow providers to improve service provisioning. © 2015 IEEE

  • 429.
    Campolo, Claudia
    et al.
    University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Zhang, Yan
    Simula Research Laboratory, Fornebu, Norway.
    Modeling and enhancing infotainment service access in vehicular networks with dual-radio devices2016In: Vehicular Communications, ISSN 2214-2096, Vol. 6, p. 7-16Article in journal (Refereed)
    Abstract [en]

    A dedicated spectrum portion at 5 GHz is available to provide services in vehicular environments (e.g., road safety, traffic efficiency, comfort and infotainment services). The multitude of non-safety critical services offered by roadside and mobile providers can be accessed by vehicles under radio coverage if they listen to the advertisement messages announcing the service configuration parameters and tune to the announced frequency to access the service. Due to intermittent and short connectivity periods, timely and successful advertisements reception is crucial to enable a vehicle accessing available services while it is still connected to the provider.

    In this paper, we design an analytical model of the service advertisement and access procedure for dual-radio vehicular devices. Moreover, we enhance the advertisement phase with a simple technique of message repetition and channel switching coordination, which helps in making vehicles aware of local services promptly coping with channel impairments and collisions. The model flexibly accounts for channel switching, message repetitions, access prioritization, and interference by contending traffic on the channel where service announcements are regularly transmitted. ©2016 Elsevier Inc. All rights reserved.

  • 430.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy.
    Vinel, Alexey
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Zhang, Yan
    Simula Research Laboratory, Fornebu, Norway.
    Modeling Event-Driven Safety Messages Delivery in IEEE 802.11p/WAVE Vehicular Networks2013In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 17, no 12, p. 2392-2395Article in journal (Refereed)
    Abstract [en]

    A stochastic model is designed to assess the delivery performance of event-driven safety messages in IEEE 802.11p/1609.4 vehicular ad-hoc networks (VANETs). The study focuses on the case of a vehicle detecting an unpredictable hazard and broadcasting the alert in the one-hop neighborhood. The model aims at providing quick insights into the impact of the latest WAVE specifications (i.e., traffic differentiation, channel switching) on the delivery of such short-lived alert messages. Results prove that it is accurate in capturing the effect of relevant parameters and show that repeating the alert transmission on the control channel helps to achieve reliable delivery. © 2013 IEEE.

  • 431.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology.
    Zhang, Yan
    Simula Research Laboratory.
    Modeling Prioritized Broadcasting in Multichannel Vehicular Networks2012In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 61, no 2, p. 687-701Article in journal (Refereed)
    Abstract [en]

    Effective data broadcasting is essential in vehicular networks not only for road-safety message dissemination but also to aid routing and cooperative driving applications through periodic beaconing and to spread network initialization advertisements that are mandatory to support infotainment applications. Broadcast data are neither acknowledged nor retransmitted in case of failure, which raises the possibility of frame loss due to channel errors and collisions with multiple simultaneous broadcasts. This paper aims at modeling periodic broadcasting on the control channel of IEEE Std. 802.11p vehicular networks with multichannel architecture. Unlike previous related work, the proposed novel analytical approach accounts for mutual influence among nodes, frequent periodic updates of broadcasted data, standard network advertisement procedures, and 802.11p prioritized channel access with multichannel-related phenomena under various link quality conditions. © 2012 IEEE.

  • 432.
    Campolo, Claudia
    et al.
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Italy.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology.
    Molinaro, Antonella
    Dipartimento di Informatica, Matematica, Elettronica e Trasporti, University Mediterranea of Reggio Calabria, Italy.
    Koucheryavy, Yevgeni
    Department of Communications Engineering, Tampere University of Technology.
    Modeling Broadcasting in IEEE 802.11p/WAVE Vehicular Networks2011In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 15, no 2, p. 199-201Article in journal (Refereed)
    Abstract [en]

    IEEE 802.11p/WAVE (Wireless Access in Vehicular Environments) is an emerging family of standards intended to support wireless access in Vehicular Ad Hoc Networks (VANETs). Broadcasting of data and control packets is expected to be crucial in this environment. Both safety-related and non-safety applications rely on broadcasting for the exchange of data or status and advertisement messages. Most of the broadcasting traffic is designed to be delivered on a given frequency during the control channel (CCH) interval set by the WAVE draft standard. The rest of the time, vehicles switch over to one of available service channels (SCHs) for non-safety related data exchange. Although broadcasting in VANETs has been analytically studied, related works neither consider the WAVE channel switching nor its effects on the VANET performance. In this letter, a new analytical model is designed for evaluating the broadcasting performance on CCH in IEEE 802.11p/WAVE vehicular networks. This model explicitly accounts for the WAVE channel switching and computes packet delivery probability as a function of contention window size and number of vehicles. © 2011 IEEE.

  • 433.
    Campos, Jaime
    Linnaeus University, Faculty of Technology, Department of Informatics. LNU.
    Modelling the Web 2.0 oriented sites for the e-maintenance applications2013In: International congress of condition monitoring and diagnostic engineering management: Congress Proceedings, COMADEM 2013, 11-13 June, Helsiki, 2013, p. 52-57Conference paper (Refereed)
  • 434.
    Campos, Jaime
    Linnaeus University, Faculty of Technology, Department of Informatics.
    The ICT Systems Developments in Maintenance: From Data Processing into Knowledge Driven Approaches2014In: Proceedings of the 15th European conference on Knowledge management, (ECKM 2014): vol. 1-3 / [ed] Vivas C & Sequeira P, Academic Conferences Limited, 2014, p. 182-188Conference paper (Refereed)
    Abstract [en]

    The paper goes through the developments of Information and Communication Technologies (ICTs) in the area of Condition Monitoring (CM) and Maintenance with the aim to understand the current state of the ICTs developments in the area of interest as well as their future prospects. The findings are ordered into a framework, which emphasizes the diverse maturity aspects when it comes to the use of these technologies. The results show that the researchers are working with various ICT applications that are in the different eras of the framework. There are findings that support the last era, i.e. the fourth era, but those findings are fewer. However, the applications that support this last era, even if they are at the primary stage, is the e-maintenance approach especially when the knowledge driven approaches are considered in their applications. The e-maintenance approach apart from its integration capabilities also considers other important aspects such as collaboration, cooperation, and organisational learning as well as companies' strategies such as the condition based maintenance, etc. it is, therefore, important to consider the e-maintenance approach as a facilitator for the entrance into the fourth era, which promises sustainability in the use of the ICTs for the domain of interests as well as higher organizational performance

  • 435.
    Campos, Jaime
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Jantunen, Erkki
    VTT Technical Research Centre of Finland, Finland.
    Baglee, David
    University of Sunderland, UK.
    Fumagalli, Luca
    Politecnico di Milano, Italy .
    Emmanouilidis, Christos
    Cranfield University, UK.
    Gilabert, Eduardo
    Fundación TEKNIKER, Spain.
    Mobile Information Systems in Maintenance Engineering and Asset Management2016In: Journal of Societal Studies, ISSN 2029-2244, Vol. 8, no 2, p. 180-197Article in journal (Refereed)
    Abstract [en]

    The objective of this paper is to provide a profound insight into important characteristics with regard to the integration of mobile technology into the area of industrial maintenance. The aspects highlighted in the paper uncover, for instance, acceptance models and best practices, as well as the financial impact of mobile technologies in the domain of interest. Moreover, the paper pinpoints some important characteristics that impede full integration of these technologies into this area. In addition, the economic benefits and the current situation with regard to mobile integration are highlighted. In addition, relevant literature and theories are analysed and discussed. Furthermore, the industrial integration of mobile technologies is outlined. The results indicate that there is a tendency to place an emphasis on the technical aspects of mobile devices rather than on understanding the organisational context, which affects the integration of mobile technologies into this domain.

    The work provides a thorough understanding of best practices and aspects to consider for the successful integration of mobile technologies in this area. This is because the use of mobile devices enables maintenance staff to gain access to information and services pertaining to the task in hand in real time, as long as some form of network access is provided. Users of these devices thus become mobile actors who dynamically interact with the physical environment in the workplace and support information systems, leading to a faster response to events and improved organizational performance.

  • 436.
    Campos, Jaime
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Jantunen, Erkki
    VTT Technical Research Centre of Finland, Finland.
    Baglee, David
    University of Sunderland, UK .
    Gilabert, Eduardo
    Fundación TEKNIKER, Spain.
    Fumagalli, Luca
    Politecnico di Milano, Italy.
    Emmanouilidis, Christos
    ATHENA Research & Innovation Centre, Greece .
    The Use of Mobile Technologies and Their Economic Benefits in Maintenance2016In: Proceedings of the 10th World Congress on Engineering Asset Management (WCEAM 2015) / [ed] Koskinen, K.T., Kortelainen, H., Aaltonen, J., Uusitalo, T., Komonen, K., Mathew, J., Laitinen, J. (Eds.), Springer, 2016, p. 113-119Conference paper (Refereed)
    Abstract [en]

    The use of mobile devices enables maintenance staff to gain access to information and services relevant to the task in hand in near real time and wherever some form of network access is provided. Essentially, mobile device users become mobile actors who dynamically interact with the physical environment, i.e. workplace, and supporting information systems, leading to faster response to events and an increased performance. This paper provides insight into the acceptance prospects and best practices of the mobile technologies in the area of maintenance. Furthermore, the potential financial impact is discussed as a key driver for the adoption of mobile technologies in the maintenance practice.

  • 437.
    Campos, Jaime
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics. LNU.
    Kortelainen, Juha
    VTT Technical Research Centre of Finland.
    Jantunen, Erkki
    VTT Technical Research Centre of Finland.
    Product Lifecycle Simulation Applying Semantic Data Management2011In: Product Lifecycle Management: Virtual Product Lifecycles for Green Products and Services:Proceedings of the PLM11 conference held at the Eindhoven University of Technology, The Netherlands, 11-13 July 2011 / [ed] Pels, H.J., Bouras, A., & McMahon, C., 2011, p. 455-464Conference paper (Refereed)
    Abstract [en]

    Product lifecycle simulation (PLCS) has been given ever moreattention as the manufacturers are competing with the quality and lifecyclecosts of their products. Especially, the need of companies to try to get a strongposition in providing services for their products and thus to make themselvesless vulnerable to changes in the market has led to high interest in PLCS. Ashort summary of current status of PLCS is presented especially related to thepoor integration of data in product lifecycle management systems and in PLCS.The potential of applying semantic data management to solve these problems isthoroughly discussed in the light of recent development. A basic roadmap howthe above-described problems could be tackled with open software solutions ispresented. Finally, this paper reviews the emergent Web technologies such asthe Semantic Web framework and the Web services.

  • 438.
    Campos, Jaime
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Sharma, Pankaj
    Indian Institute of Technology Delhi, India.
    Jantunen, Erkki
    VTT Technical Research Centre of Finland, Finland.
    Baglee, David
    University of Sunderland, UK.
    Fumagalli, Luca
    Politecnico di Milano, Italy.
    Business Performance Measurements in Asset Management with the Support of Big Data Technologies2017In: Management Systems in Production Engineering, E-ISSN 2450-5781, Vol. 25, no 3, p. 143-149Article in journal (Refereed)
    Abstract [en]

    The paper reviews the performance measurement in the domain of interest. Important data in asset management are further, discussed. The importance and the characteristics of today’s ICTs capabilities are also mentioned in the paper. The role of new concepts such as big data and data mining analytical technologies in managing the performance measurements in asset management are discussed in detail. The authors consequently suggest the use of the modified Balanced Scorecard methodology highlighting both quantitative and qualitative aspects, which is crucial for optimal use of the big data approach and technologies.

  • 439.
    Cao, Le Phuong
    et al.
    KTH, School of Electrical Engineering (EES), Information Science and Engineering. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Information Science and Engineering. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Optimal transmit strategy for MIMO channels with joint sum and per-antenna power constraints2017In: 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), IEEE, 2017, p. 3569-3573Conference paper (Refereed)
    Abstract [en]

    This paper studies optimal transmit strategies for multiple-input multiple-output (MIMO) Gaussian channels with joint sum and per-antenna power constraints. It is shown that if an unconstraint optimal allocation for an antenna exceeds a per-antenna power constraint, then the maximal power for this antenna is used in the constraint optimal transmit strategy. This observation is then used in an iterative algorithm to compute the optimal transmit strategy in closed-form. Finally, a numerical example is provided to illustrate the theoretical results.

  • 440.
    Cao, Wei Qiu
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    A new Content Distribution Network architecture - PlentyCast2004Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Content Distribution Networks have existed for some years. They involve the following problem domains and have attracted attention both in academic research and industry: content replica placement, content location and routing, swarm intelligence, and overlay network self-organization for this type of distributed system. In this project, we propose a novel Content Distribution Network architecture – PlentyCast. This study focuses on improving access latency, network scalability, high content availability, low bandwidth consumption, and improving infrastructure performance for Content Distribution Networks. Outstanding problems such as: Flash crowd, DoS, and difficulty of traffic engineering due to Peer-to-Peer are addressed.

  • 441.
    Carlos, Perez Penichet
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Hermans, Frederik
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Varshney, Ambuj
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Voigt, Thiemo
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Augmenting IoT networks with backscatter-enabled passive sensor tags2016In: Proceedings of the 3rd Workshop on Hot Topics in Wireless, 2016, p. 23-27Conference paper (Refereed)
    Abstract [en]

    The sensing modalities available in an Internet-of-Things (IoT) network are usually fixed before deployment, when the operator selects a suitable IoT platform. Retrofitting a deployment with additional sensors can be cumbersome, because it requires either modifying the deployed hardware or adding new devices that then have to be maintained. In this paper, we present our vision and work towards passive sensor tags: battery-free devices that allow to augment existing IoT deployments with additional sensing capabilities without the need to modify the existing deployment. Our passive sensor tags use backscatter transmissions to communicate with the deployed network. Crucially, they do this in a way that is compatible with the deployed network's radio protocol, and without the need for additional infrastructure. We present an FPGA-based prototype of a passive sensor tag that can communicate with unmodified 802.15.4 IoT devices. Our initial experiments with the prototype support the feasibility of our approach. We also lay out the next steps towards fully realizing the vision of passive sensor tags.

  • 442.
    Carls, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    NGN – Nästa Generations Nätverk (Nätverks- och Riskanalys) för Piteå Kommun2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    My mission has been to technical documentation and identify Piteå Municipality's existing network infrastructure. Everything has been summarized in several different areas: Network Services, Network-related services, Technology, Management/Control and Security. A risk analysis has been developed where I have identified a total of 28 risks and deficiencies in the municipality's existing network infrastructure. 4 risks and deficiencies under Design, 9 risks and deficiencies under Security, 5 risks and deficiencies under Network related services, 2 risks and deficiencies under Network Services, 2 risks and deficiencies under Management/Control and 5 risks and deficiencies under Technology. All risks and deficiencies have been categorized in order of low, medium and high risks and deficiencies of varying action time (0-24 + months). This final report has been the basis for then developing a new future-proof network infrastructure using a Requirements and Vision for the Municipality of Piteå.

  • 443.
    Carlsson, Daniel
    KTH, School of Information and Communication Technology (ICT).
    Dynamics AX in the Cloud: Possibilities and Shortcomings2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The usage of the cloud is rapidly increasing and is something that is of large interest to everyone involved in technology. The purpose of this thesis is to examine the benefits and possible shortcomings of using Microsoft Dynamics AX in the cloud, specifically Microsoft Azure, instead of using local datacenters. This thesis project has been done at Scania IT using their implementation of Dynamics AX.

    This thesis project consists of an extensive literature study regarding both ERP Systems as well as other systems in regards to the cloud. It was decided early on to focus on the new version of Dynamics AX, which currently is only available in the cloud and compare this implementation to the two versions that the majority are using today, AX 2009 and AX 2012. The benefits of AX and Azure both being Microsoft products are clear with the welldesigned integrations and support all the way through the clients to the servers regarding backups and load balancing. It is shown how the developers have to work differently in regards to integrations with outside systems, especially in regards to AX 2009 with the frameworks having changed. The addition of Data Entities mean that the developers can save a lot of time by only needing a reference to the location of the object in the database instead of having to keep track of all the tables themselves.

    The analysis focuses on the differences in four different areas, performance & accessibility, scalability, cost savings as well as security & privacy. The background knowledge that is being used for the analysis primarily comes from the literature study as well as knowledge gained by studying the implementation at Scania today. The result shows that there are clear advantages regarding performance, cost savings and especially accessibility, however it is also clear that laws in a lot of countries still have not caught up with the fact that it is possible to use the cloud for data storage these days. Which in turn means that the best move in the near future for the majority of ERP users would be either a hybrid or private cloud within the borders of the same country.

  • 444.
    Carlsson, Henric
    University of Skövde, School of Informatics.
    Using A Recommender To Influence Consumer Usage2013Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    In this dissertation, the issues of the increased awareness of energy use are considered. Energy technologies are continuously improved by energy retailers and academic researchers. The Smart Grid are soon customary as part of the energy domain. But in order to improve energy efficiency the change must come from the consumers. Consumers should be active decision makers in the Smart Grid domain and therefor a Recommender system suits the Smart Grid and enables customers. Customers will not use energy in the way energy retailers, and politicians advocates instead they will do what fits them. By investigating how a Recommender can be built in the Smart Grid we focus on parameters and information that supports the costumers and enables positive change. An investigation of what customers perceive as relevant is pursued as well as how relevancy can adjust the system. A conceptual model of how to build a Recommender is rendered through a literature review, a group interview and a questionnaire.

  • 445.
    Carlsson, Niklas
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Optimized eeeBond: Energy Efficiency with non-Proportional Router Network Interfaces2016In: PROCEEDINGS OF THE 2016 ACM/SPEC INTERNATIONAL CONFERENCE ON PERFORMANCE ENGINEERING (ICPE'16), ACM Digital Library, 2016, p. 215-223Conference paper (Refereed)
    Abstract [en]

    The recent Energy Efficient Ethernet (EEE) standard and the eBond protocol provide two orthogonal approaches that allow significant energy savings on routers. In this paper we present the modeling and performance evaluation of these two protocols and a hybrid protocol. We first present eeeBond, pronounced ``triple-e bond'', which combines the eBond capability to switch between multiple redundant interfaces with EEE's active/idle toggling capability implemented in each interface. Second, we present an analytic model of the protocol performance, and derive closed-form expressions for the optimized parameter settings of both eBond and eeeBond. Third, we present a performance evaluation that characterizes the relative performance gains possible with the optimized protocols, as well as a trace-based evaluation that validates the insights from the analytic model. Our results show that there are significant advantages to combine eBond and EEE. The eBond capability provides good savings when interfaces only offer small energy savings when in short-term sleep states, and the EEE capability is important as short-term sleep savings improve.

  • 446.
    Carlsson, Robin
    Linköping University, Department of Electrical Engineering, Communication Systems. Linköping University, The Institute of Technology.
    Investigation and Implementation of Coexistence Tool for Antennas2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the increase of the number of radios and antennas on today’s systems, the risk of co-site interference is very high. Intermodulation product and antenna coupling are two common sources of interference. The thesis investigates some features of a radio system, like antenna types, receiver parameters, intermodulation products and isolation, and suggests how this knowledge can be used to minimize the risk of co-site interference. The goal is to maximize the isolation between the antennas, by good frequency planning, the use of filters and taking great care in antenna placement. A first version of an analysis software was developed where transmitters and receivers can be paired and evaluated. An intermodulation product calculator was also implemented, to easily find which products are an issue and where they originate. The goal of the software is to be simple to use and easy to adapt to different setups and situations. It should also be easy to upgrade with new features.

  • 447.
    Carlsson, Stefan
    et al.
    KTH, Superseded Departments, Teleinformatics.
    Halén, Erik
    KTH, Superseded Departments, Teleinformatics.
    Mobile Internet: Content Adaptation for Limited Devices2000Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates how to adapt content on the Web to the limited I/O capabilities of today’s WAP (Wireless Application Protocol) devices and how to translate from HTML to WML (Wireless Markup Language). We also give an overview of WAP and Mobile Internet and a brief analysis of the future of WAP.

    To evaluate different methods of adaptation, two existing Web sites are adapted to WML. Three different methods are tried and evaluated: The first method is a brute force WML re-coding of the site. The second method is an XML based solution that separates the data from the presentation and uses different XSLT (eXtensible Style sheet Language Transformations) style sheets for different devices. The third method uses a proxy that translates a requested page from HTML to WML. The proxy evaluated here is Oracle’s Portal-to-Go in its semi-automated form, i.e. where it is manually pre-configured for every site it adapts.

    An important issue is whether to adapt specifically for each device or whether to use generically written WML for the entire range of WAP devices. Another issue is that a WAP device only can receive a limited amount of information at a time, and this limit varies between different devices.

  • 448.
    Carlsson, Ulrika
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Stenhammar, Marie
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Sociala medier: och kundinteraktion i mindre företag 2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Title: Social Media – And customer interaction in smaller firms

    Seminar date: 2011-06-10

    Course: Information Logistics, D-level.

    Authors: Marie Stenhammar and Ulrika Carlsson

    Advisor: Jaime Campos

    Key words: Social Media, Web 2.0, Co-creation, Viral marketing, Word of Mouth, smaller firms

    Purpose: This paper aims to describe the relevance of social media to smaller firms, the challenges and opportunities they face and what strategies they use, in the interaction with their customers.

    Methodology: The study is qualitative in nature and has an abductive approach. The empirical material consists of in-depth interviews with chosen companies and Internet observations.

    Theoretical perspectives: Social Media, Web 2.0, Co-creation, Viral marketing, Word of Mouth

    Empirical foundation: The study takes its empirical base from in-depth interviews with representatives from the small companies and internet observations connected to these.

    Conclusions: Smaller companies have great interest in social media. They preferably use Facebook, blogs, YouTube and Twitter. Their strategy is mainly to be very active and update their social media regularly. The opinion of the companies is that social media offer several possibilities such as stronger relationships with customers and the ability to collect information about the market.

  • 449.
    Carrara, Elisabetta
    KTH, Superseded Departments, Teleinformatics.
    Wireless Adaptation of a Security Management Protocol Suite1999Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Internet Security is rapidly increasing in importance, as Internet itself is spreading out so fast. The IETF Security working group has defined the "IP Security Protocol Suite", a set of protocols that aim at securing the IP layer, so providing general security services for all kinds of applications.

    The IPSec Protocol Suite is completed by a protocol for key management and key exchange, the "Internet Security Association and Key Management Protocol (ISAKMP)" . It is currently an IETF Proposed Standard for the Internet.

    In this thesis we describe ISAKMP, and also its use together with the Internet Key Exchange (IKE) protocol, as a negotiation and key exchange protocol for IPSec. A general overview of cryptography is also provided, since ISAKMP widely uses modern cryptographic techniques.

    ISAKMP flexibility is at the cost of complexity and increased packet traffic. This should be faced in constrained communications, such as wireless. Therefore, this thesis introduces some proposals for a compressed version of the protocol, trying to reduce the number of handshakes and the number of transmitted bytes without significantly decreasing the security level.

    The model is based on the use of a Proxy, which follows the compressed version of ISAKMP on the side of the  mobile node, and then switches to the original version of the protocol on the wired side with the second peer. Ad-hoc solutions are adopted, and security implications are taken into account.

  • 450. Casati, Fabio
    et al.
    Daniel, Florian
    Dantchev, Guenadi
    Eriksson, Joakim
    Finne, Niclas
    Karnouskos, Stamatis
    Montera, Patricio Moreno
    Mottola, Luca
    Oppermann, Felix Jonathan
    Picco, Gian Pietro
    Quartulli, Antonio
    Römer, Kay
    Spiess, Patrik
    Tranquillini, Stefano
    Voigt, Thiemo
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Towards business processes orchestrating the physical enterprise with wireless sensor networks2012In: ICSE, 2012, p. 1357-1360Conference paper (Refereed)
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