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  • 401.
    Buchegger, Sonja
    EPFL.
    A Robust Reputation System for Peer-to-Peer and Mobile Ad-hoc Networks2004In: Proceedings of Third Workshop on Economics of Peer-to-Peer Systems (P2PEcon), 2004, 2004Conference paper (Refereed)
  • 402.
    Buchegger, Sonja
    EPFL.
    Coping with Misbehavior in Mobile Ad-hoc Networks2004Doctoral thesis, monograph (Other academic)
    Abstract [en]

    n this work, we address the question of how to enable a system to operate despite the presence of misbehavior. Specifically, in a mobile ad-hoc network, how can we keep the network functional for normal nodes when other nodes do not route and forward correctly? Node misbehavior due to selfish or malicious reasons or faulty nodes can significantly degrade the performance of mobile ad-hoc networks. Existing approaches such as economic incentives or secure routing by cryptographic means alleviate some of the problems, but not all. For instance, nodes can still forward packets on bogus routes. We propose a protocol called CONFIDANT (Cooperation Of Nodes --- Fairness In Dynamic Ad-hoc NeTworks) to cope with misbehavior. It enables nodes to detect misbehavior by first-hand observation and use of second-hand information provided by other nodes. The view a node has about the behavior of another node is captured in a reputation system, which is used to classify nodes as misbehaving or normal. Once a misbehaving node is detected, it is isolated from the network. Reputation systems can, however, be tricked by the spread of false reputation ratings, be it false accusations or false praise. Simple solutions such as exclusively relying on one`s own direct observations have drawbacks, as they do not make use of all the information available. To solve this problem, we propose a fully distributed reputation system that can cope with false information and effectively use second-hand information in a safe way. Our approach is based on a modified Bayesian estimation and classification procedure. In our approach, each node maintains a reputation rating and a trust rating about all other nodes it cares about. Reputation ratings capture the quality of the behavior of a node as an actor in the network performing routing and forwarding tasks. From time to time first-hand reputation information is exchanged with others; using a modified Bayesian approach we designed, second-hand reputation information is only accepted if it is compatible with the current reputation rating. Reputation ratings are only slightly modified by accepted information. Trust ratings capture the quality of a node as an actor in the reputation system and reflect whether the reported first hand information summaries published by node are likely to be true. Trust ratings are updated based on the compatibility of second-hand reputation information with prior reputation ratings. We enable node redemption and prevent the sudden exploitation of good reputation built over time by introducing reputation fading. Data is entirely distributed, the reputation and trust value of a node is the collection of ratings maintained by others. We use simulation to evaluate and demonstrate the performance. We found that CONFIDANT can keep the network performance high even when up to half of the network population misbehaves. We show that our approach of using second-hand information significantly speeds up the detection of misbehaving nodes while keeping the number of false positives and negatives negligibly low.

  • 403.
    Buchegger, Sonja
    Deutsche Telekom Laboratories, TU Berlin.
    Economics of Self-Organized Networks2009Other (Refereed)
  • 404.
    Buchegger, Sonja
    et al.
    Deutsche Telekom Laboratories, TU Berlin.
    Chuang, John
    UC Berkeley.
    Economics-Informed Network Design2007Conference paper (Refereed)
  • 405.
    Buchegger, Sonja
    et al.
    Deutsche Telekom Laboratories, TU Berlin.
    Chuang, John
    UC Berkeley.
    Encouraging Cooperation Among Network Entities2007In: Cognitive Wireless Networks: Concepts, Methodologies and Visions / [ed] Frank Fitzek, Marcos Katz, Springer, 2007, p. 87-107Chapter in book (Refereed)
  • 406.
    Buchegger, Sonja
    et al.
    Deutsche Telekom Laboratories, TU Berlin.
    Krishnamurthy, Sudha
    Deutsche Telekom Laboratories, TU Berlin.
    Sensor Network Economics2007In: Handbook on Sensor Networks / [ed] Yang Xiao, Hui Chen, Frank H. Li, World Scientific, 2007, p. 835-852Chapter in book (Refereed)
  • 407.
    Buchegger, Sonja
    et al.
    EPFL.
    Le Boudec, Jean-Yves
    EPFL.
    Self-Policing Mobile Ad-hoc Networks2004In: Handbook on Mobile Computing, CRC Press, 2004, p. 395-413Chapter in book (Refereed)
  • 408.
    Buchegger, Sonja
    et al.
    EPFL.
    Tissieres, Cedric
    EPFL.
    Le Boudec, Jean-Yves
    EPFL.
    A Test-Bed for Misbehavior Detection in Mobile Ad-hoc Networks: How Much can Watchdogs Really Do?2004In: SIXTH IEEE WORKSHOP ON MOBILE COMPUTING SYSTEMS AND APPLICATIONS, PROCEEDINGS, 2004, p. 102-111Conference paper (Refereed)
    Abstract [en]

    Several misbehavior detection and reputation systems have been proposed for mobile ad-hoc networks, relying on direct network observation mechanisms, so-called watchdogs. While these approaches have so far only been evaluated in simulations and restricted to selfish packet dropping, we are interested in the capabilities of a watchdog detection component in a real network. In this paper we present our test-bed implementation of misbehavior detection. Following an evaluation of both the feasibility and detectability of attacks on routing and forwarding in the Dynamic Source Routing (DSR) protocol, we present the design of our test-bed. In order to add detection capabilities, we extend the concept of passive acknowledgment by mechanisms for partial dropping, packet modification, and fabrication detection. We combine DSR with Netfilter and APE to enable detection. We implement both attackers and detection and show their feasibility and limitations.

  • 409.
    Bude, Cristian
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Kervefors Bergstrand, Andreas
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Internet of Things: Exploring and Securing a Future Concept2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Internet of Things (IoT) is a concept that encompasses various objects and methods of communication to exchange information. Today IoT is more a descriptive term of a vision that everything should be connected to the internet. IoT will be fundamental in the future because the concept opens up opportunities for new services and new innovations. All objects will be connected and able to communicate with each other, while they operate in unprotected environments. This later aspect leads to major security challenges.

    Today, IoT is in great need of standardization and clear architectures that describe how this technology should be implemented and how IoT devices interact with each other in a secure manner. The security challenges are rooted in the technology and how information is acquired and manipulated by this technology. This thesis provides an introduction to what the IoT is and how it can be used as well as some of the threats that IoT may face in regards to information security. In addition, the thesis provides the reader with some suggestions about how to potentially solve the fundamental need for authentication and secure communications. The solutions presented are based on both contemporary solutions and technologies that are under development for the future. Contemporary solutions are based on security protocols such as IPSec and DTLS. These protocols are being used in an environment that extends across the Internet and into a 6LoWPAN network. The proposed authentication solution has been developed based on a public key infrastructure and trust models for certificate management.

    As future work, the thesis presents several research areas where this thesis can be used as a basis. These specialization areas include further analysis of vulnerabilities and an implementation of the proposed solutions.

  • 410.
    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.

  • 411.
    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.

  • 412.
    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.

  • 413. 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.

  • 414.
    Butun, Ismail
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Pereira, Nuno
    Polytechnic Institute of Porto, Porto, Portugal .
    Gidlund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Analysis of LoRaWAN V1.1 Security2018In: Proceedings of the 4th ACM MobiHoc Workshop on Experiences with the Design and Implementation of Smart Objects (SMARTOBJECTS '18)., ACM Digital Library, 2018Conference paper (Refereed)
    Abstract [en]

    LoRa and the LoRaWAN specification is a technology for Low Power Wide Area Networks (LPWAN) designed to allow connectivity for connected objects, such as remote sensors. Several previous works revealed various weaknesses regarding the security of LoRaWAN v1.0 (the official 1st draft) and these led to improvements included in LoRaWAN v1.1, released on Oct 11, 2017. In this work, we provide the first look into the security of LoRaWAN v1.1. We present an overview of the protocol and, importantly, present several threats to this new version of the protocol. Besides, we propose our own ramification strategies for the mentioned threats, to be used in developing next version of LoRaWAN. The threats presented were not previously discussed, they are possible even within the security assumptions of the specification and are relevant for practitioners implementing LoRa-based applications as well researchers and the future evolution of the LoRaWAN specification.

  • 415. Byamukama, Maximus
    et al.
    Nannono, Janet Nakato
    Ruhinda, Kabonire
    Pehrson, Björn
    KTH.
    Nsabagwa, Mary
    Akol, Roselyn
    Olsson, Robert
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Bakkabulindi, Geoffrey
    Kondela, Emmanuel
    Design Guidelines for Ultra-low Power Gateways in Environment Monitoring Wireless Sensor Networks2017In: 2017 IEEE AFRICON / [ed] Cornish, D R, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1472-1478Conference paper (Refereed)
    Abstract [en]

    We explore techniques that can be used to reduce the power consumption of gateways in wireless sensor networks deployed in environment monitoring applications, such as Automatic Weather Stations (AWS). The challenge is the deployment of these networks in locations that are far from a consistent power source, such as a national grid. Such stations must be autonomous and power consumption must be minimized. We present test scenarios illustrating the impact of the suggested techniques. We explore hardware and software based methods of power reduction, assess the impact of each, the constraints to be expected and how to overcome them. We then provide a reference implementation of a gateway in which we integrate these techniques. We show that power consumption can be reduced by 48 - 85% when comparing best and worst case scenarios. The reference implementation we provide consumes 27mW at 3V.

  • 416.
    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.

  • 417.
    Bång, Karl-Lennart
    et al.
    Transportforskningskommissionen.
    Lindkvist, Anders
    Transportforskningskommissionen.
    Kan elektroniska informations- och reglersystem underlätta vägtrafiken?1982Report (Other academic)
  • 418.
    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.

  • 419.
    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.

  • 420.
    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.

  • 421.
    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.

  • 422.
    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.

  • 423.
    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.

  • 424.
    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.

  • 425.
    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[.]

  • 426.
    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.

  • 427. 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.

  • 428.
    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.

  • 429.
    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.

  • 430.
    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.

  • 431.
    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)
  • 432.
    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.

  • 433.
    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)
  • 434.
    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

  • 435.
    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.

  • 436.
    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.

  • 437.
    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

  • 438.
    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)
  • 439.
    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

  • 440.
    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.

  • 441.
    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.

  • 442.
    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.

  • 443.
    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.

  • 444.
    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)
  • 445.
    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

  • 446.
    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.

  • 447.
    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.

  • 448.
    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.

  • 449.
    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.

  • 450.
    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.

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