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  • 51.
    Jonsson, Magnus
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Nilsson, Kenneth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    A fiber-optic interconnection concept for scaleable massively parallel computing1995Inngår i: Proceedings of the Second International Conference on Massively Parallel Processing Using Optical Interconnections: October 23 - 24, 1995, San Antonio, Texas, Piscataway, NJ.: IEEE , 1995, s. 313-320Konferansepaper (Fagfellevurdert)
    Abstract [en]

    One of the most important features of interconnection networks for massively parallel computer systems is scaleability. The fiber-optic network described in this paper uses both wavelength division multiplexing and a configurable ratio between optics and electronics to gain an architecture with good scaleability. The network connects distributed modules together to a huge parallel system where each node itself typically consists of parallel processing elements. The paper describes two different implementations of the star topology, one uses an electronic star and fiber optic connections, the other is purely optical with a passive optical star in the center. The medium access control of the communication concept is presented and some scaleability properties are discussed involving also a multiple-star topology.

  • 52.
    Jonsson, Magnus
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Olin, Ulf
    Optical interconnection technology in switches, routers and optical cross connects2000Rapport (Annet vitenskapelig)
    Abstract [en]

    The performance of data- and telecommunication equipment must keep up with the increasing network speed. Moreover, to allow more input and output ports on such equipment, the internal interconnection complexity often grows exponentially with the number of ports. Therefore, new interconnection technologies to be used internally in the equipment are needed. Optic interconnection technology is a promising alternative and a lot of work has been done. In this report, a number of optical and optoelectronic interconnection architectures are reviewed, especially from a data- and telecommunication equipment point-of-view. Three kinds of systems for adoption of optical interconnection technology are discussed: (i) optical cross connects (OXCs), (ii) switches and routers with some kind of burst switching, and (iii) switches and routers which redirect traffic on the packet or cell level. The reviewed interconnection technologies and architectures are discussed according to their suitability of adoption in the three mentioned systems.

    The annex summarises manufacturers of devices required for optical interconnects and backplanes, and needs for optical interconnection technology in future Ericsson systems.

  • 53.
    Jonsson, Magnus
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Svensson, Bertil
    Chalmers University of Technology, Gothenburg, Sweden.
    On inter-cluster communication in a time-deterministic WDM star network1997Inngår i: Proc. 2nd Workshop on Optics and Computer Science (WOCS), Geneva, Switzerland, Apr. 1, 1997, 1997, s. 10-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Future real-time applications requiring massively parallel computer systems also put high demands on the interconnection network. By connecting several WDM star clusters by a backbone star, forming a star-of-stars network, we get a modular high-bandwidth network. In this paper we show how to achieve time-deterministic packet switched communication in such networks, even for inter-cluster communication. An analysis of how the deterministic latency and node bandwidth vary with design parameters is presented. We also propose a general clock-synchronization scheme, improving the worst-case latency with up to 33 percentages.

  • 54.
    Jonsson, Magnus
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Taveniku, Mikael
    Chalmers University of Technology.
    Åhlander, Anders
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Fiber-ribbon pipeline ring network for high-performance distributed computing systems1997Inngår i: Proceedings of the Third International Symposium on Parallel Architectures, Algorithms, and Networks, 1997. (I-SPAN '97), IEEE, 1997, s. 138-143Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a high-bandwidth ring network built up with fiber-ribbon point-to-point links. The network has support for both packet switched and circuit switched traffic. Very high throughputs can be achieved in the network due to pipelining, i.e., several packets can be traveling through the network simultaneously but in different segments of the ring. The network can be built today using fiber-optic off-the-shelf components. The increasingly good price/performance ratio for fiber-ribbon links indicates a great success potential for the proposed kind of networks. We also present a massively parallel radar signal processing system with exceptionally high demands on the communication network. An aggregated throughput of tens of Gb/s is needed in this application, and this is achieved with the proposed network.

  • 55.
    Jonsson, Magnus
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Åhlander, Anders
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Taveniku, Mikael
    Chalmers University of Technology.
    Svensson, Bertil
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Time-deterministic WDM star network for massively parallel computing in radar systems1996Inngår i: Proceedings of the Third International Conference on Massively Parallel Processing Using Optical Interconnections: October 27-29, 1996, Maui, Hawaii / [ed] Allan Gottlieb, Los Alamitos, California: IEEE Computer Society Press , 1996, s. 85-93Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In massively parallel computer systems for embedded real-time applications there are normally very high bandwidth demands on the interconnection network. Other important properties are time-deterministic latency and services to guarantee that deadlines are met. In this paper we analyze how these properties vary with the design parameters for a passive optical star network, specifically when used in a massively parallel radar signal processing system. The aggregated bandwidth and computational power of the radar system are approximately 45 Gb/s and 100 GOPS, respectively. The analysis is focused on the medium access control protocol, called TD-TWDMA, for the time and wavelength multiplexed network. It is concluded that the proposed network is very well suited to this kind of signal-processing applications. We also present a new distributed slot-allocation algorithm with real-time properties.

  • 56. Ku, Bih-Yuan
    et al.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Report on Rail Conference and Wireless Communications: [VTS News]2011Inngår i: IEEE Vehicular Technology Magazine, ISSN 1556-6072, Vol. 6, nr 3, s. 111-117Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The 2011 Joint Rail Conference (JRC) was held in Pueblo, Colorado, on March 16-18, 2011, immediately after the Association of American Railroads Research Review. The conference started with a technical tour of TTCi. The highlights of the technical tour were two on-site presentations on a full-scale train impact test and the field test of the positive train control (PTC) system. The tour attendees were given the opportunity to take a close look at the energy-absorption devices and sensors installed at various locations of the test car. The PTC presentation was held at the communications and train control (C&TC) test bed at the TTCi test track, which is the only CT&C test bed in North America. The 2012 Joint Rail Conference (JRC) will be held in Philadelphia in April 2012, and the IEEE Vehicular Technology Society (VTS) Land Transportation Division (LTD) will take the lead in the planning of the major technical forum onrail engineering in North America.

  • 57.
    Kunert, Kristina
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Architectures and Protocols for Performance Improvements of Real-Time Networks2010Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    When designing architectures and protocols for data traffic requiring real-time services, one of the major design goals is to guarantee that traffic deadlines can be met. However, many real-time applications also have additional requirements such as high throughput, high reliability, or energy efficiency. High-performance embedded systems communicating heterogeneous traffic with high bandwidth and strict timing requirements are in need of more efficient communication solutions, while wireless industrial applications, communicating control data, require support of reliability and guarantees of real-time predictability at the same time. To meet the requirements of high-performance embedded systems, this thesis work proposes two multi-wavelength high-speed passive optical networks. To enable reliable wireless industrial communications, a framework in­corporating carefully scheduled retransmissions is developed. All solutions are based on a single-hop star topology, predictable Medium Access Control algorithms and Earliest Deadline First scheduling, centrally controlled by a master node. Further, real-time schedulability analysis is used as admission control policy to provide delay guarantees for hard real-time traffic.

    For high-performance embedded systems an optical star network with an Arrayed Waveguide Grating placed in the centre is suggested. The design combines spatial wavelength re­use with fixed-tuned and tuneable transceivers in the end nodes, enabling simultaneous transmis­sion of both control and data traffic. This, in turn, permits efficient support of heterogeneous traf­fic with both hard and soft real-time constraints. By analyzing traffic dependencies in this mul­tichannel network, and adapting the real-time schedulability analysis to incorporate these traffic dependencies, a considerable increase of the possible guaranteed throughput for hard real-time traffic can be obtained.

    Most industrial applications require using existing standards such as IEEE 802.11 or IEEE 802.15.4 for interoperability and cost efficiency. However, these standards do not provide predict­able channel access, and thus real-time guarantees cannot be given. A framework is therefore de­veloped, combining transport layer retransmissions with real-time analysis admission control, which has been adapted to consider retransmissions. It can be placed on top of many underlying communication technologies, exemplified in our work by the two aforementioned wireless stan­dards. To enable a higher data rate than pure IEEE 802.15.4, but still maintaining its energy saving properties, two multichannel network architectures based on IEEE 802.15.4 and encompassing the framework are designed. The proposed architectures are evaluated in terms of reliability, utiliza­tion, delay, complexity, scalability and energy efficiency and it is concluded that performance is enhanced through redundancy in the time and frequency domains.

  • 58.
    Kunert, Kristina
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Fibre-Optic AWG Networks Supporting Real-Time Communication in High-Performance Embedded Systems2008Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    High-performance embedded systems communicating heterogeneous traffic with high bandwidth and strict timing requirements are in need of more efficient communication solutions. This thesis proposes two multi-wavelength passive optical networks able to meet these demands. The networks are based upon a single-hop star topology with an Arrayed Waveguide Grating (AWG) placed in the centre. The intended application areas for the two networks are short range embedded communication systems like System Area Networks (SANs) and router architectures with electronic queuing. The AWG’s attractive property of spatial wavelength reuse, as well as the combination of fixed-tuned and tuneable transceivers in the end nodes, enables simultaneous control and data traffic transmission. This, in turn, makes it possible to support heterogeneous traffic with both hard and soft real-time constraints.

    Additionally, two Medium Access Control (MAC) protocols, one for each network solution, are developed. Traffic scheduling is centrally controlled by a node, the protocol processor, residing together with the AWG in a hub. All nodes use Earliest Deadline First (EDF) scheduling and communicate with the protocol processor through physical control channels. A case study, including simulations, in the field of Radar Signal Processing (RSP) and simulations using periodic real-time traffic are conducted for the two application areas respectively, showing very good results. Further, a deterministic real-time analysis is conducted to provide throughput and delay guarantees for hard real-time traffic and an increase in guaranteed traffic is achieved through an analysis of existing traffic dependencies in a multichannel network. Simulation results incorporating the traffic dependency analysis indicate a considerable increase in the possible guaranteed throughput of hard real-time traffic.

  • 59.
    Kunert, Kristina
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Improving the scheduling analysis of hard real-time traffic by analyzing traffic dependencies2008Rapport (Annet vitenskapelig)
    Abstract [en]

    Support for hard real-time traffic requires throughput guarantees for packets with timing constraints. The deterministic analysis available for real-time communication has its origin in the area of task scheduling in real-time systems and has been mapped onto the communication context. Mapping uniprocessor scheduling techniques directly on a multichannel network with the possibility of concurrent transmissions, however, introduces pessimism to the analysis. This paper presents an approach of successfully increasing the amount of possible guarantees by analyzing traffic interdependencies. By taking into account those traffic interdependencies and integrating concurrent transmissions into the analysis, the amount of throughput guarantees can be increased considerably as shown in our simulations.

  • 60.
    Kunert, Kristina
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES). Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES). Mälardalen University, Västerås, Sweden.
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Bilstrup, Urban
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Deterministic real-time medium access for cognitive industrial radio networks2012Inngår i: 2012 9th IEEE International Workshop Factory Communication Systems: WFWC 2012, Proceedings / [ed] Thomas Nolte & Andreas Willig, Piscataway: IEEE Press, 2012, s. 91-94Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Industrial communication often has to work in an environment where other networks or radiation create different levels of interference for the data traffic. Additionally, industrial applications often demand predictable real-time performance of the network. One way of trying to utilise the available frequencies in an effective manner is to include cognitive functionality in the network. We present a medium access control protocol for a cognitive radio network, providing deterministic medium access for heterogeneous traffic and dynamic spectrum allocation. Spectrum sensing abilities in the nodes open up for the possibility of increasing successful data transmissions, and a real-time analysis framework provides upper-bounded medium access delay in order to guarantee timely treatment of hard real-time traffic. © 2012 IEEE.

  • 61.
    Kunert, Kristina
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Weckstén, Mattias
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Algorithm for the choice of topology in reconfigurable networks with real-time support2007Rapport (Annet vitenskapelig)
    Abstract [en]

    Many future embedded systems are likely to contain System-on-Chip solutions with on-chip networks, and to achieve high aggregated throughputs in these networks, a switched topology can be used. For further performance improvements, the topology can be adapted to application demands, either when designing the chip or by run-time reconfiguration between different predefined application modes. In this report, we describe an algorithm for the choice of topology in, e.g., packet-switched on-chip networks, considering the real-time demands in terms of throughput and delay often put on such systems. To further address possible real-time demands, we include a feasibility analysis to check that the application, when mapped onto the system, will behave in line with its real-time demands. With input information about the traffic characteristics, our algorithm creates a topology and generates routing information for all logical traffic channels. In a case study, we show that our algorithm results in a topology that can outperform the use of state of the art topologies for high-performance computer architectures. Although we have targeted for reconfigurable Network-on-Chip architectures, the algorithm can also be used for other systems. Our algorithm gives the opportunity for topology choice at design stage, both for static network topologies and for reconfigurable network topologies that can be reconfigured during run-time.

  • 62.
    Kunert, Kristina
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Weckstén, Mattias
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Algorithm for the choice of topology in reconfigurable on-chip networks with real-time support2007Inngår i: Proceedings of the 2nd international conference on Nano-Networks, Bryssels: ICST (Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering) , 2007, s. 1-7Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Many future embedded systems are likely to contain System-on-Chip solutions with on-chip networks and in order to achieve high aggregated throughputs in these networks, a switched topology can be used. For further performance improvements, the topology can be adapted to application demands, either when designing the chip or by run-time reconfiguration between different predefined application modes. In this paper, we present an algorithm for the choice of topology in, e.g., on-chip networks, considering realtime demands in terms of throughput and delay often put on such systems. To further address possible real-time demands, we include a feasibility analysis to check that the application, when mapped onto the system, will behave in line with its real-time demands. With input information about traffic characteristics, our algorithm creates a topology and generates routing information for all logical traffic channels. In a case study, we show that our algorithm results in a topology that can outperform the use of state of the art topologies for high-performance computer architectures.

  • 63.
    Larsson, Tony
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    A Two Level Approach to the Design of Software for Cooperating Embedded Systems2009Inngår i: 7th IEEE International Conference on Industrial Informatics, 2009. INDIN 2009, IEEE Press, 2009, s. 721-728Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper proposes an architecture concept to the design of software, for embedded systems and cooperating embedded systems, aimed to simplify not only design but also reuse and reconfigurability. The concept is targeted at software for recurring signal processing and control tasks common in industrial embedded supervision and control applications. An important part of the architecture concept is that the design work is partitioned and described at two major levels. The first level is focused on definition of data structures and reentrant data mapping functions to be supported by a restricted use of an existing programming language. The second level, i.e. the system level, focuses on structural and behavioral concerns including: component encapsulation, connection of actions and components via ports. This level, also handling delays, triggers and actors, is supported by a system modeling language. The thus partitioned approach makes the different design and engineering concerns well separated which simplifies both analysis and verification of functional and time behavioral correctness, compared to if they are mixed and intertwined into each other. Another gain with the proposed architecture concept is that the number of operating system (OS) threads and associated overhead needed to share the processor or a set of processors in a distributed or multi-core case is minimized.

  • 64.
    Lerchbaumer, Peter
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Ochoa, Alejandro
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Test environment design for wireless vehicle communications2007Inngår i: The 66th IEEE Vehicular Technology Conference, 2007. VTC-2007 Fall, Piscataway, NJ: IEEE Press, 2007, s. 2214-2218Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The integration of new wireless technologies with vehicle computing systems has opened the doors for new fields of applications such as intelligent transportation systems. Vehicular ad hoc networks emerge as the technical basis in solutions aiming to improve road safety and efficiency as well as driving comfort. This paper discusses different factors that influence the performance of wireless vehicle communication systems and proposes a general design for the construction of a test environment for these systems. A comprehensive list of different parameters that affect the system performance is compiled. Next, these parameters are analyzed and quantified to serve as guidelines when establishing and designing components of a suitable test environment. This test environment should provide a platform that enables researchers and engineers to identify possible bottlenecks in the network functionality as well as allowing test, assessment and verification of as many of the relevant parameters involved in the ad hoc communication as possible.

  • 65.
    Lidström, Kristoffer
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Cooperative Safety Based on Shared Conventions2008Konferansepaper (Annet vitenskapelig)
  • 66.
    Lidström, Kristoffer
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Larsson, Tony
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Act normal: using uncertainty about driver intentions as a warning criterion2009Inngår i: Proceeding 16th World Congress on Intelligent Transportation Systems, 2009, s. 8-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cooperative safety using vehicle-to-vehicle and vehicle-to-infrastructure communication enables warning systems to take into account more detailed and longer range information than previously possible. Due to the increased prediction horizon tactical concepts such as traffic rules and driver intentions must be modelled in addition to short term kinematics traditionally used in driver alert systems. We propose a cooperative warning system that models such concepts using artificial potential fields taking into account multiple route-choice hypotheses. The system is being implemented on the hardware and software platform of the European CVIS project and will be used to evaluate the feasibility of using the history of route-choice estimates as an indicator of unpredictable driver behaviour.

  • 67.
    Lind, Christoffer
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Green, Jonas
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Ingvarsson, Thomas
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Movement sensor using image correlation on a multicore platform2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The purpose of this study was to investigate the possibility to measure speed of a vehicle usingimage correlation. It was identified that a new solution of measuring the speed of a vehicle, astoday’s solution does not give the True Speed Over Ground, would open up possibilities of highprecision driving applications. It was also the intention to evaluate the performance of theproposed algorithm on a multicore platform. The study was commissioned by HalmstadUniversity.The investigation of image correlation as a method to measure speed of a vehicle was conductedby applying the proposed algorithm on a sequence of images. The result was compared toreference points in the image sequence to confirm the accuracy. The performance of the multicoreplatform was measured by counting the clock cycles it took to perform one measurement cycle ofthe algorithm.It was found out that using image correlation to measure speed has a positional accuracy of closeto a half percent. The results also revealed that one measurement cycle of the algorithm could beperformed in close to half a millisecond and the achieved parallel utilization of the multicoreplatform was close to eighty-seven percent.It was concluded that the algorithm performed well within the limit of acceptance. A conclusionabout the performance was that low execution time of a measurement cycle makes it possible toexecute the algorithm at a frequency of eighteen hundred Hertz. With a frequency that high, incombination with the camera settings proposed in the thesis, the algorithm would be able tomeasure speeds close to one thousand one hundred kilometers per hour.The authors recommend that future work should be focused on investigating the cameraparameters to be able to optimize both the memory and computational requirements of theapplication. It is also recommended to look closer at the algorithm and the possibilities ofdetecting transversal and angular changes as it would open up for other application areas,requiring more than just the speed.

  • 68.
    Mahmood, Ali
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Böhm, Annette
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Wireless Sensor Networks for Surveillance Applications - A Comparative Survey of MAC Protocols2008Inngår i: Proceedings - The 4th International Conference on Wireless and Mobile Communications, ICWMC 2008, Piscataway, NJ.: IEEE Press, 2008, s. 399-403Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless sensor nodes are made up of small electronic devices which are capable of sensing, computing and transmitting data from harsh physical environments. These sensor nodes depend on batteries for energy, which get depleted at a fast rate because of the computation and communication operations these nodes have to perform. A well designed MAC (Medium Access Control) protocol can prolong the network life. Aset of previously reported MAC layer protocols has abilities to achieve some energy efficiency. In this paper, we first describe some assumptions made for the specific application area of surveillance applications. Then, we compare a set of MAC protocols in terms of their suitability to be used in wireless sensor networks for this type of applications. In addition to energy efficiency, keeping the delays reasonably low is a crucial factor when sensing and reporting an event. © 2008 IEEE.

  • 69.
    Mecklenbräuker, Christoph
    et al.
    Vienna University of Technology, Vienna, Austria.
    Bernadó, Laura
    FTW Forschungszentrum Telekommunikation Wien, Vienna, Austria.
    Klemp, Oliver
    BMW Forschung und Technik, Munich, Germany.
    Kwoczek, Andreas
    Volkswagen AG, Wolsburg, Germany.
    Paier, Alexander
    Vienna University of Technology, Vienna, Austria.
    Schack, Moritz
    Technische Universität Braunschweig, Braunschweig, Germany.
    Sjöberg, Katrin
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Ström, Erik G.
    Chalmers University of Technology, Gothenburg, Sweden.
    Tufvesson, Fredrik
    Lund University, Lund, Sweden.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Zemen, Thomas
    FTW Forschungszentrum Telekommunikation Wien, Vienna, Austria.
    Vehicle-to-Vehicle Communications2012Inngår i: Pervasive Mobile and Ambient Wireless Communications: Cost Action 2100 / [ed] Roberto Verdone & Alberto Zanella, London: Springer London, 2012, s. 577-608Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    This chapter discusses major results and conclusions from Special Interest Group C bringing together various aspects of mobile to mobile communication from all working groups. Vehicle-to-vehicle communication scenarios are emphasized. Traffic telematics applications are currently under intense research and development for making transportation safer, more efficient, and cleaner. Communication systems which provide “always on” connectivity at data rates between 1 and 10 Mb/s to highly mobile surface traffic (cars and trains) are urgently required for developing traffic telematics applications and services. Currently much attention is given to advanced active safety, but the application area also ranges to improved navigation mechanisms and infotainment services. mobile to mobile communications need to be reliable and trusted: Drivers in cars which are equipped with vehicle to vehicle communications need to rely on the accuracy and timeliness of the exchanged data. Automotive manufacturers, road authorities, broadcast companies, and telecom providers are the key players in the value chain for such future systems. These communication systems provide an extended information horizon to warn the driver or the vehicular systems of potentially dangerous situations in an early phase.

  • 70.
    Miorandi, Daniele
    et al.
    CREATE-NET 38100 Trento, Italy.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Vitturi, Stefano
    Italian National Research Council I-35131 Padova, Italy.
    Willig, Andreas
    Technical University of Berlin 10587 Berlin, Germany.
    Guest editorial: Special section on wireless technologies in factory and industrial automation – part I2007Inngår i: IEEE Transactions on Industrial Informatics, ISSN 1941-0050, Vol. 3, nr 2, s. 95-98Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The three papers in this special section focus on wireless technologies in factory and industrial automation. The papers which appear in this second part cover everything from protocol design and evaluation to the design and assessment of system-level solutions for wireless sensor networks in industrial automation.

  • 71.
    Miorandi, Daniele
    et al.
    CREATE-NET 38100 Trento, Italy.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Vitturi, Stefano
    Italian National Research Council I-35131 Padova, Italy.
    Willig, Andreas
    Technical University of Berlin 10587 Berlin, Germany.
    Guest editorial: Special section on wireless technologies in factory and industrial automation – part II2007Inngår i: IEEE Transactions on Industrial Informatics, ISSN 1941-0050, Vol. 3, nr 3, s. 189-190Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The three papers in this special section focus on wireless technologies in factory and industrial automation. The papers which appear in this second part cover everything from protocol design and evaluation to the design and assessment of system-level solutions for wireless sensor networks in industrial automation.

  • 72.
    Morsi Mahmod, Mohamed
    et al.
    University of Twente, Center for Transport Studies, The Netherlands.
    Khalil, Issam
    Ericsson AB, Branch Office Sudan, Sudan.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Nygren, Niclas
    Volvo Technology Corporation, Transport, Information and Communication, Sweden.
    Wireless strategies for future and emerging ITS applications2008Inngår i: 15th World Congress on Intelligent Transport Systems: New York, USA, November 16-20, 2008 : ITS connections, saving time, saving lives, New York: World Congress on Intelligent Transport Systems (ITS), 2008, s. 12-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Within the Intelligent Transportation Systems (ITS) field, many applications of a diverse nature are considered and thus their communication requirements differ significantly. This makes it difficult for one wireless carrier to support all or most of these applications. Therefore, we have complied a list of communication requirements for future ITS applications and used it to analyze different ITS applications as well as different wireless carriers. Accordingly, the applications can be grouped into different requirements profiles with recommended wireless carriers assigned to each profile. The concept of profiling can also be used to classify the applications according to their non-technical requirements and hence accelerate their future deployment by encouraging involved stakeholders to make the most common requirements available. It can also be useful when developing a roadmap for deployment of future ITS applications defining which application will most likely be implemented first.

  • 73.
    Nilsson, Björn
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Bengtsson, Lars
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Bilstrup, Urban
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Wiberg, Per-Arne
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Towards an Energy Efficient Protocol for Active RFID2006Inngår i: International Symposium on Industrial Embedded Systems, 2006. IES '06, Piscataway, N.J.: IEEE Press, 2006, s. 1-4Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The use of radio frequency identification systems (RFID) is growing rapidly. Today, mostly "passive" RFID systems are used because no onboard energy source is needed on the transponders. However, "active " RFID with onboard power source gives a new range of opportunities not possible with passive systems. To obtain energy efficiency in an active RFID system a protocol should be designed that is optimized with energy in mind. This paper describes the on-going work of defining and evaluating such a protocol. The protocol's performance in terms of energy efficiency, aggregated throughput, delay, and number of air collisions is evaluated and compared to that of the medium-access layer in 802.15.4 Zigbee, and also to a commercially available protocol from Free2move.

  • 74.
    Nilsson, Björn
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Bengtsson, Lars
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    A snoozing frequency binary tree protocol2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we describe and evaluate anenhanced version of an active RFID wake-up and tag IDextraction radio communication protocol. The enhancedprotocol further reduces the transponders’ power consumption(prolonging their battery lifetime). The protocol uses afrequency binary tree method for extracting the identificationnumber of each transponder. This protocol is enhanced byextending it with a framed slotted medium access controlmethod which decreases the number of activations of eachtransponder during tag ID extractions. Using this medium accessmethod, the average number of transponder activations isdecreased with a factor of 2.5 compared to the original protocol.The resulting increase in ID read-out delay is 0.9%, on average.

  • 75.
    Nilsson, Emil
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Nilsson, Björn
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Bengtsson, Lars
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Svensson, Bertil
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Wiberg, Per-Arne
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Bilstrup, Urban
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    A low power-long range active RFID-system consisting of active RFID backscatter transponders2010Inngår i: 2010 IEEE International Conference on RFID-Technology and Applications (RFID-TA), Piscataway, N.J.: IEEE Press, 2010, s. 26-30Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we present a novel active radio frequency identification system consisting of transponders with low complexity, low power consumption, and long system reading range. The transponder’s low complexity and small circuit integration area indicate that the production cost is comparable to the one of a passive tag. The hardware keystone is the transponder’s radio wake-up transceiver, which is a single oscillator with very low power consumption. The communication protocol, based on frequency signalling binary tree, contributes to the low complexity of the tag architecture. More than 1500 tags can be read per second. The average transponder ID read-out delay is 319 ms when there are 1000 transponders within reach of the interrogator. The calculated expected life time for a transponder is estimated to be almost three years.

  • 76.
    Nilsson, Emil
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Nilsson, Björn
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Järpe, Eric
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    A Pharmaceutical Anti-counterfeiting Method Using Time Controlled Numeric Tokens2011Inngår i: 2011 IEEE International Conference on RFID-Technologies and Applications, Piscataway, NJ: IEEE Press, 2011, s. 335-339Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An anti-counterfeit and authentication method usingtime controlled numeric tokens enabling a secure logistic chain ispresented. Implementation of the method is illustrated with apharmaceutical anti-counterfeit system. The method uses activeRFID technology in combination with product seal. Authenticityis verified by comparing time controlled ID-codes, i.e. numerictokens, stored in RFID tags and by identical numeric tokensstored in a secure database. The pharmaceutical products areprotected from the supplier to the pharmacist, with thepossibility to extend the authentication out to the end customer.The ability of the method is analyzed by discussion of severalpossible scenarios. It is shown that an accuracy of 99.9% tellingthe customer she has an authentic product is achieved by the useof 11-bit ID-code strings.

  • 77.
    Ourique de Morais, Wagner
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Lundström, Jens
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Wickström, Nicholas
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    A Database-Centric Architecture for Home-Based Health Monitoring2013Inngår i: Ambient Assisted Living and Active Aging: 5th International Work-Conference, IWAAL 2013, Carrillo, Costa Rica, December 2-6, 2013, Proceedings / [ed] Christopher Nugent, Antonio Coronato, José Bravo, Heidelberg, Germany: Springer, 2013, Vol. 8277, s. 26-34Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Traditionally, database management systems (DBMSs) have been employed exclusively for data management in infrastructures supporting Ambient Assisted Living (AAL) systems. However, DBMSs provide other mechanisms, such as for security, dependability, and extensibility that can facilitate the development, use, and maintenance of AAL applications. This work utilizes such mechanisms, particularly extensibility, and proposes a database-centric architecture to support home-based healthcare applications. An active database is used to monitor and respond to events taking place in the home, such as bed-exits. In-database data mining methods are applied to model early night behaviors of people living alone. Encapsulating the processing into the DBMS avoids transferring and processing sensitive data outside of database, enables changes in the logic to be managed on-the-fly, and reduces code duplication. As a result, such an approach leads to better performance and increased security and privacy, and can facilitate the adaptability and scalability of AAL systems. An evaluation of the architecture with datasets collected in real homes demonstrated the feasibility and flexibility of the approach.

  • 78.
    Ourique de Morais, Wagner
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Lundström, Jens
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Wickström, Nicholas
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Active In-Database Processing to Support Ambient Assisted Living Systems2014Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 14, nr 8, s. 14765-14785Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As an alternative to the existing software architectures that underpin the development of smart homes and ambient assisted living (AAL) systems, this work presents a database-centric architecture that takes advantage of active databases and in-database processing. Current platforms supporting AAL systems use database management systems (DBMSs) exclusively for data storage. Active databases employ database triggers to detect and react to events taking place inside or outside of the database. DBMSs can be extended with stored procedures and functions that enable in-database processing. This means that the data processing is integrated and performed within the DBMS. The feasibility and flexibility of the proposed approach were demonstrated with the implementation of three distinct AAL services. The active database was used to detect bed-exits and to discover common room transitions and deviations during the night. In-database machine learning methods were used to model early night behaviors. Consequently, active in-database processing avoids transferring sensitive data outside the database, and this improves performance, security and privacy. Furthermore, centralizing the computation into the DBMS facilitates code reuse, adaptation and maintenance. These are important system properties that take into account the evolving heterogeneity of users, their needs and the devices that are characteristic of smart homes and AAL systems. Therefore, DBMSs can provide capabilities to address requirements for scalability, security, privacy, dependability and personalization in applications of smart environments in healthcare.

  • 79.
    Ourique de Morais, Wagner
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Mayr, Matthias
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE). Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
    Wickström, Nicholas
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Philippsen, Roland
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Ambient Intelligence and Robotics: complementing one another to support Ambient Assisted Living2014Inngår i: IAS-13: The 13th International Conference on Intelligent Autonomous Systems: July 15-19, 2014: Padova and Venice, Italy: Proceedings of Workshops and Tutorials / [ed] Jangmyung Lee, Philippe Martinet, Marcus Strand, Stefano Ghidoni & Matteo Munaro, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This work combines a database-centric architecture, which supports Ambient Intelligence (AmI) for Ambient Assisted Living, with a ROS-based mobile sensing and interaction robot. The role of the active database is to monitor and respond to events in the environment and the robot subscribes to tasks issued by the AmI system. The robot can autonomously perform tasks such as to search for and interact with a person. Consequently, the two systems combine their capabilities and complement the lack of computational, sensing and actuation resources.

  • 80.
    Ourique de Morais, Wagner
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Wickström, Nicholas
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    A lightweight method for detecting sleep-related activities based on load sensing2014Inngår i: SeGAH 2014: IEEE 3rd International Conference on Serious Games and Applications for Health, Red Hook, NY: Curran Associates, Inc., 2014, artikkel-id 7067080Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Current practices in healthcare rely on expensive and labor-intensive procedures that are not adequate for future healthcare demands. Therefore, alternatives are required to complement or enhance healthcare services, both at clinical and home settings. Hospital and ordinary beds can be equipped with load cells to enable load sensing applications, such as for weight and sleep assessment. Beds with such functionalities represent a tangible alternative to expensive and obtrusive routines for sleep assessment, such as polysomnography. A finite-state machine is proposed as a lightweight on-line method to detect sleep-related activities, such as bed entrances and exits, awakenings, wakefulness, and sleep atonia. The proposed approach is evaluated with a dataset collected in real homes of older people receiving night-time home care services.

  • 81.
    Ourique de Morais, Wagner
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Wickström, Nicholas
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    A "Smart Bedroom" as an Active Database System2013Inngår i: Proceedings – 9th International Conference on Intelligent Environments, IE 2013, Los Alamitos, CA: IEEE Computer Society, 2013, s. 250-253, artikkel-id 6597820Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Home-based healthcare technologies aim to enable older people to age in place as well as to support those delivering care. Although a number of smart homes exist, there is no established method to architect these systems. This work proposes the development of a smart environment as an active database system. Active rules in the database, in conjunction with sensors and actuators, monitor and respond to events taking place in the home environment. Resource adapters integrate heterogeneous hardware and software technologies into the system. A 'Smart Bedroom' has been developed as a demonstrator. The proposed approach represents a flexible and robust architecture for smart homes and ambient assisted living systems. © 2013 IEEE.

  • 82.
    Pignaton de Freitas, Edison
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Heimfarth, Tales
    Federal University of Rio Grande do Sul, Institute of Informatics, Porto Alegre, Brazil.
    Allgayer, Rodrigo Schmidt
    Federal University of Rio Grande do Sul, Electrical Engineering Department, Porto Alegre, Brazil.
    Wagner, Flavio Rech
    Federal University of Rio Grande do Sul, Institute of Informatics, Porto Alegre, Brazil.
    Larsson, Tony
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Pereira, Carlos Eduardo
    Federal University of Rio Grande do Sul, Electrical Engineering Department, Porto Alegre, Brazil.
    Ferreira, Armando Morado
    Military Institute of Engineering, Defense Engineering Graduate Program, Rio de Janeiro, Brazil.
    Coordinating aerial robots and unattended ground sensors for intelligent surveillance systems2010Inngår i: International Journal of Computers, ISSN 1841-9836, E-ISSN 1841-9844, Vol. 5, nr 1, s. 52-70Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sensor networks are being used to implement different types of sophisticated emerging applications, such as those aimed at supporting ambient intelligence and surveillance systems. This usage is enhanced by employing sensors with different characteristics in terms of sensing, computing and mobility capabilities, working cooperatively in the network. However, the design and deployment of these heterogeneous systems present several issues that have to be handled in order to meet the user expectations. The main problems are related to the nodes' interoperability and the overall resource allocation, both inter and intra nodes. The first problem requires a common platform that abstracts the nodes' heterogeneity and provides a smooth communication, while the second is handled by cooperation mechanisms supported by the platform. Moreover, as the nodes are supposed to be heterogeneous, a customizable platform is required to support both resource rich and poorer nodes. This paper analyses surveillance systems based on a heterogeneous sensor network, which is composed by lowend ground sensor nodes and autonomous aerial robots, i.e. Unmanned Aerial Vehicles (UAVs), carrying different kinds of sensors. The approach proposed in this work tackles the two above mentioned problems by using a customizable hardware platform and a middleware to support interoperability. Experimental results are also provided.

  • 83.
    Pignaton de Freitas, Edison
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Heimfarth, Tales
    Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Pereira, Carlos Eduardo
    Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Morado Ferreira, Armando
    Defense Engineering Graduate Program, Military Institute of Engineering, Rio de Janeiro, Brazil.
    Wagner, Flavio Rech
    Institute of Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
    Larsson, Tony
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Multi-Agent Support in a Middleware for Mission-Driven Heterogeneous Sensor Networks2011Inngår i: Computer journal, ISSN 0010-4620, E-ISSN 1460-2067, Vol. 54, nr 3, s. 406-420Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The emerging applications using sensor network technologies constitute a new trend requiring several different devices to work together and partly autonomously. However, the integration and coordination of heterogeneous sensors in these emerging systems is still a challenge, especially when the target application scenario is susceptible to constant changes. The setup and adaptation of these systems are challenging, considering that their nodes are distributed and must respect operational constraints, such as energy consumption. Due to the dynamicity of the scenarios in which they are deployed and the nature of their operations these systems require autonomous decisions that have to be taken without any human operator intervention. This paper presents a reflective middleware that supports heterogeneous sensor networks deployed in dynamic scenarios. This middleware presents specific handling of users’ requirements by representing them as missions that must be accomplished by the network. These missions are then translated to network parameters and activities that are distributed to network nodes by means of the autonomous reasoning that takes into account network nodes’ capabilities and environment conditions. A multi-agent framework is proposed to provide the necessary support for missions’ dissemination and for the required reasoning to allow autonomous behaviour related to mission allocation and network adaptation.

  • 84.
    Pignaton de Freitas, Edison
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Heimfarth, Tales
    Computer science department, Federal university of Lavras, Lavras, Brazil.
    Wagner, Flávio Rech
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Ferreira, Armando Morado
    Defense Engineering Graduate Program, Military Institute of Engineering, Brazil.
    Pereira, Carlos Eduardo
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Larsson, Tony
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Geo-aware Handover of Mission Agents Using Opportunistic Communication in VANET2010Inngår i: Smart Spaces and Next Generation Wired/Wireless Networking: Proceedings / [ed] Sergey Balandin, Roman Dunaytsev and Yevgeni Koucheryavy, Berlin: Springer Berlin/Heidelberg, 2010, Vol. 6294, s. 365-376Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper explores geographical location awareness to support software agent mobility in ad hoc networks. The idea is to evaluate the concept of opportunistic communication to perform agent migration and mobility among nodes (handover), in an infrastructureless vehicular ad-hoc network (VANET). The application of this idea can support a number of applications, and one of particular interest is a “virtual sensor network” composed of software agents that implement missions in the form of sensing services, which use the available resources provided by the physical nodes, i.e. physical sensor devices, computing platforms and communication devices. A case study is presented together with simulations results to assess the efficiency of the proposed approach.

  • 85.
    Pignaton de Freitas, Edison
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Heimfarth, Tales
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Wehrmeister, Marco Aurélio
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Rech Wagner, Flávio
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Morado Ferreia, Armando
    Military Institute of Engineering, Brazil.
    Pereira, Carlos Eduardo
    Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
    Larsson, Tony
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Using a Link Metric to Improve Communication Mechanisms and Real-Time Properties in an Adaptive Middleware for Heterogeneous Sensor Networks2009Inngår i: Advances in Information Security and Assurance: Third International Conference and Workshops, ISA 2009, Seoul, Korea, June 25-27, 2009; proceedings, Berlin: Springer Berlin/Heidelberg, 2009, s. 422-431Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents middleware mechanisms to support real-time services in heterogeneous sensor networks, focusing on the evaluation of link metrics. Heterogeneous sensor networks require specific QoS (quality of service) guarantees in order to allow the coordination and cooperation among the different nodes that compose the system. In order to improve QoS, one of the first steps is to enhance the usage of the communication links, aiming at a more reliable and efficient message exchange. In this paper, key middleware features to address this concern are presented, in which a focus is given on the use of a link metric that, as part of a protocol, is used to optimize the message forwarding in relay communications across the network. Additionally, preliminary results are also presented.

  • 86.
    Rasmussen, Lars K.
    et al.
    Institute for Telecommunications Research, University of South Australia, Adelaide, Australia.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Brännström, Fredrik
    Dept. Signals and Systems, Chalmers University of Technology, Gothenburg, Sweden.
    Concatenated systems and cross-layer design2006Inngår i: Proceedings, 7th Australian Communications Theory Workshop 2006: 1-3 February 2006, The University of Western Australia, Perth, Australia / [ed] Leif W. Hanlen, Sarah J. Johnson, and Paul D. Teal, Piscataway, NJ: IEEE Press, 2006, s. 80-86Konferansepaper (Fagfellevurdert)
    Abstract [en]

    With high data rate wireless communications networks, new applications relying on high quality audio, video or control become viable. Examples of such applications are remote tele-medicine, collision avoidance systems, and audio/video entertainment at CD/DVD quality. These applications all demand high data rates, but have different quality-of-service (QoS) requirements in terms of reliability and latency. Currently, mobile communications networks have only limited provisions for QoS implementation and control. The conventional functionality separation in network design may be inhibiting effective implementation of guaranteed QoS. In this paper, we propose and review a system design paradigm based on concatenated system models and iterative signal processing. The novelty of the paradigm is to propagate methodologies of physical layer design across disciplinary boundaries within wireless network design in a bottom-up cross-layer approach. The paper is tutorial in nature, promoting the new view through presenting a series of examples of successful application of concatenated systems design from the physical and link layers. The purpose of the paper is to inspire new research directions.

  • 87.
    Sjöberg Bilstrup, Katrin
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Predictable and Scalable Medium Access Control for Vehicular Ad Hoc Networks2009Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This licentiate thesis work investigates two medium access control (MAC) methods, when used in traffic safety applications over vehicular ad hoc networks (VANETs). The MAC methods are carrier sense multiple access (CSMA), as specified by the leading standard for VANETs IEEE 802.11p, and self-organizing time-division multiple access (STDMA) as used by the leading standard for transponders on ships. All vehicles in traffic safety applications periodically broadcast cooperative awareness messages (CAMs). The CAM based data traffic implies requirements on a predictable, fair and scalable medium access mechanism. The investigated performance measures are channel access delay, number of consecutive packet drops and the distance between concurrently transmitting nodes. Performance is evaluated by computer simulations of a highway scenario in which all vehicles broadcast CAMs with different update rates and packet lengths. The obtained results show that nodes in a CSMA system can experience unbounded channel access delays and further that there is a significant difference between the best case and worst case channel access delay that a node could experience. In addition, with CSMA there is a very high probability that several concurrently transmitting nodes are located close to each other. This occurs when nodes start their listening periods at the same time or when nodes choose the same backoff value, which results in nodes starting to transmit at the same time instant. The CSMA algorithm is therefore both unpredictable and unfair besides the fact that it scales badly for broadcasted CAMs. STDMA, on the other hand, will always grant channel access for all packets before a predetermined time, regardless of the number of competing nodes. Therefore, the STDMA algorithm is predictable and fair. STDMA, using parameter settings that have been adapted to the vehicular environment, is shown to outperform CSMA when considering the performance measure distance between concurrently transmitting nodes. In CSMA the distance between concurrent transmissions is random, whereas STDMA uses the side information from the CAMs to properly schedule concurrent transmissions in space. The price paid for the superior performance of STDMA is the required network synchronization through a global navigation satellite system, e.g., GPS. That aside since STDMA was shown to be scalable, predictable and fair; it is an excellent candidate for use in VANETs when complex communication requirements from traffic safety applications should be met.

  • 88.
    Sjöberg, Katrin
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Karedal, Johan
    Dept. of Electrical and Information technology, Lund University.
    Moe, Marie
    Q-Free ASA, Trondheim, Norway.
    Kristiansen, Øyvind
    Q-Free ASA, Trondheim, Norway.
    Søråsen, Runar
    Q-Free ASA, Trondheim, Norway.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Tufvesson, Fredrik
    Dept. of Electrical and Information technology, Lund University.
    Evensen, Knut
    Q-Free ASA, Trondheim, Norway.
    Ström, Erik
    Dept. of Signals and Systems, Chalmers University of Technology.
    Measuring and using the RSSI of IEEE 802.11p2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The scalability of intelligent transport systems (ITS) applications is difficult to test in a field operational test (FOT) due to the high number of ITS equipped vehicles required. Therefore, computer simulations for evaluating different wireless communication technologies for ITS different applications can serve as a complement. In this paper we present results from lab measurements conducted on the CVIS hardware platform equipped with the upcoming standard IEEE 802.11p. We have measured the packet error rate versus the signal-to-noise ratio (SNR) for different packet lengths. This lab measurement is the first step towards an outdoor measurement campaign which also considers interference. The outdoor measurements will then be fed into a computer simulator together with a realistic channel model for evaluating the scalability of VANETs in a highway scenario.

  • 89.
    Sjöberg, Katrin
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Ström, Erik G.
    Chalmers Technical University, Gothenbur, Sweden.
    Delay and interference comparison of CSMA and self-organizing TDMA when used in VANETs2011Inngår i: IWCMC 2011: the 7th International Wireless Communications & Mobile Computing Conference, Istanbul, Turkey, July 4-8, 2011 / [ed] IEEE, New York, NY: IEEE Press, 2011, s. 1488-1793Konferansepaper (Fagfellevurdert)
    Abstract [en]

    IEEE 802.11p is the proposed wireless technology for communication between vehicles in a vehicular ad hoc network (VANET) aiming to increase road traffic safety. In a VANET, the network topology is constantly changing, which requires distributed self-organizing medium access control (MAC) algorithms, but more importantly the number of participating nodes cannot be restricted. This means that MAC algorithms with good scalability are needed, which can fulfill the concurrent requirements on delay and reliability from road traffic safety applications. The MAC method of IEEE 802.11p is a carrier sense multiple access (CSMA) scheme, which scales badly in terms of providing timely channel access for a high number of participating nodes. We therefore propose using another MAC method: selforganizing time division multiple access (STDMA) with which all nodes achieve timely channel access regardless of the number of participating nodes. We evaluate the performance of the two MAC methods in terms of the MAC-to-MAC delay, a measure which captures both the reliability and the delay of the delivered data traffic for a varying number of vehicles. The numerical results reveal that STDMA can support almost error-free transmission with a 100 ms deadline to all receivers within 100 m, while CSMA suffers from packet errors. Moreover, for all considered cases, STDMA offers better reliability than CSMA.

  • 90.
    Sjöberg, Katrin
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Ström, Erik G.
    Chalmers University of Technology.
    How severe is the hidden terminal problem in VANETs when using CSMA and STDMA?2011Inngår i: IEEE Vehicular Technology Conference (VTC Fall) / [ed] IEEE, Piscataway, N.J.: IEEE conference proceedings, 2011, s. 1-5Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The hidden terminal problem is often said to be the major limiting performance factor in vehicular ad hoc networks. In this article we propose a definition of the hidden terminal problem suitable for broadcast transmissions and proceed with a case study to find how the packet reception probability is affected by the presence of hidden terminals. Two different medium access control methods; carrier sense multiple access (CSMA) from IEEE 802.11p and self-organizing time division multiple access (STDMA), are subject of investigation through computer simulations of a highway scenario with a Nakagami fading channel model. The results reveal that the presence of hidden terminals does not significantly affect the performance of the two MAC protocols. STDMA shows a higher packet reception probability for all settings due to the synchronized packet transmissions.

  • 91.
    Sjöberg-Bilstrup, Katrin
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Ström, Erik G.
    Dept. Signals and Systems, Chalmers University of Technology.
    Scalability issues of the MAC methods STDMA and CSMA of IEEE 802.11p when used in VANETs2010Inngår i: 2010 IEEE International Conference on Communications Workshops (ICC), Cape Town, South Africa: IEEE Computer Society, 2010, s. 1-5Konferansepaper (Fagfellevurdert)
    Abstract [en]

     

    Position messages will be the foundation for many emerging traffic safety applications based on wireless communications. These messages contain information about the vehicle’s position, speed, direction, etc. and are broadcasted periodically by each vehicle. The upcoming IEEE 802.11p standard, intended for vehicle unpredictable behavior of its medium access control (MAC) scheme, which imply that traffic safety applications cannot be supported satisfactorily when the network load increases. We study the MAC mechanism within IEEE 802.11p being a carrier sense multiple access (CSMA) algorithm and compare it with a self-organizing time division multiple access (STDMA) scheme when used for broadcasting periodic position messages in a realistic highway scenario. We investigate their scalability in terms of the number of vehicles that the VANET can support using metrics such as channel access delay, probability of concurrent transmissions and interference distance. The results show that STDMA outperforms CSMA of 802.11p even when the network is not saturated.

     

  • 92.
    Svensson, Bertil
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Ul-Abdin, Zain
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Using a CSP based programming model for reconfigurable processor arrays2008Inngår i: International Conference on Reconfigurable Computing and FPGAs, 2008. ReConFig '08, Los Alamitos, California: IEEE Computer Society, 2008, s. 343-348Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The growing trend towards adoption of flexible and heterogeneous, parallel computing architectures has increased the challenges faced by the programming community. We propose a method to program an emerging class of reconfigurable processor arrays by using the CSP based programming model of occam-pi. The paper describes the extension of an existing compiler platform to target such architectures. To evaluate the performance of the generated code, we present three implementations of the DCT algorithm. It is concluded that CSP appears to be a suitable computation model for programming a wide variety of reconfigurable architectures.

  • 93.
    Uhlemann, Elisabeth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Communication requirements of emerging cooperative driving systems2011Inngår i: 2011 IEEE International Conference on Consumer Electronics (ICCE) / [ed] Institute of Electrical and Electronics Engineers, Piscataway, N.J.: IEEE Computer Society, 2011, s. 281-282Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Traffic safety applications relying on cooperative systems are currently being considered by several research projects worldwide. An important question is if existing wireless technologies can meet the communication requirements from this emerging field of applications? Part of the answer to this question is that the communication requirements depend on what is actually communicated and how this information is used by and presented to the driver. The data traffic from realizations based on "cooperative awareness" or on "hazard warnings" are very different. This article discusses the communication requirements of some typical traffic safety applications and how these requirements are affected by different realizations.

  • 94.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Aulin, T.M.
    Department of Computer Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Rasmussen, L.K.
    Department of Computer Engineering, Chalmers University of Technology, Gothenburg, Sweden & Institute for Telecommunications Research, University of South Australia, Mawson Lakes, Australia.
    Wiberg, Per-Arne
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Concatenated hybrid ARQ - a flexible scheme for wireless real-time communication2002Inngår i: Eighth IEEE Real-Time and Embedded Technology and Applications Symposium: proceedings : September 25-27, 2002, San Jose, California, Los Alamitos, Calif.: IEEE Computer Society Press , 2002, s. 35-44, artikkel-id 1137379Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The concept of deadline dependent coding (DDC) has previously been suggested by the authors for maximizing the probability of delivering the required information before a given deadline in a wireless communication system.. In this paper, these principles are further developed using concatenated codes with iterative decoding, providing a new level of flexibility and robustness for DDC protocols. The strategy of DDC is to combine different coding and decoding methods with automatic repeat request (ARQ) techniques in order to fulfill the application requirements within a wireless realtime communication system. These requirements are formulated as two quality of service (QoS) parameters: deadline (tDL) and probability of correct delivery before the deadline (Pd), leading to a probabilistic view of realtime communication. An application can negotiate these QoS parameters with the DDC protocol, thus creating a flexible and fault-tolerant scheme.

  • 95.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Aulin, Tor M.
    Department of Computer Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Rasmussen, Lars K.
    Department of Computer Engineering, Chalmers University of Technology, Gothenburg, Sweden & Institute for Telecommunications Research, University of South Australia, Mawson Lakes, SA, Australia.
    Wiberg, Per-Arne
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Packet combining and doping in concatenated hybrid ARQ schemes using iterative decoding2003Inngår i: The IEEE Wireless Communications and Networking, 2003. WCNC 2003. 2003 IEEE, Piscataway, NJ: IEEE , 2003, s. 849-854Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We consider serially concatenated block codes in a hybrid ARQ scheme using iterative decoding. The extrinsic information generated in the iterative decoding process is saved and used when a retransmission is decoded. Two different strategies are examined; one using the extrinsic information only in the very first iteration, whereas the other uses it in all subsequent iterations until another retransmission arrives. The latter can be seen as turbo or concatenated code combining whereas the former, where the extrinsic information is used only once may be seen as code doping, providing an alternative perspective. The strategy of saving the extrinsic information is also compared to traditional type-III, equal gain diversity combining. Using the extrinsic information from previous retransmission is shown to improve performance not only in terms of bit error rate but also in terms of throughput and convergence speed and requires only negligible additional decoder complexity. The performance of this strategy is however not as good as simple equal gain combining. As a consequence, the investigated schemes are not competitive alternatives, however, the code doping procedure can be used in conjunction with traditional diversity combining schemes, improving further on convergence speed.

  • 96.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Nolte, Thomas
    Mälardalen University.
    Scheduling relay nodes for reliable wireless real-time communications2009Inngår i: IEEE Conference on Emerging Technologies & Factory Automation, 2009. ETFA 2009, Piscataway, NJ: IEEE Press, 2009, s. 1-3Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We consider wireless relay networks for use in industrial applications with strict requirements on both timely and reliable communications. Frequently, more than one suitable relay node is available for retransmitting an erroneous packet. However, if commercially available transceivers are to be used; concurrent transmissions will result in collisions. Further, in a typical industrial network, there may be several data packets that need to travel from source to destination during the same time period. Consequently, relay nodes need to be scheduled to data packets and time instances such that as many packets as possible can be received at their destinations with as high reliability as possible before their respective deadlines. Our goal is thus to increase the data reliability in industrial wireless networks, while respecting real-time deadlines.

  • 97.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Nygren, Niclas
    Volvo Technology.
    Cooperative systems for traffic safety: Will existing wireless access technologies meet the communications requirements?2009Inngår i: Proceedings of the 16th World Congress on Intelligent Transport Systems (ITS), Stockholm: World Congress on Intelligent Transport Systems (ITS), 2009, s. 8-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Traffic safety applications relying on cooperative systems are currently being considered by several research projects worldwide. An important question is if existing wireless technologies can meet the communication requirements from this emerging field ofvapplications? Part of the answer to the question is that the communication requirements depend on implementation. The data traffic from realizations based on “cooperative awareness” or on “hazard warnings” are very different. This article discusses the communication requirements of some typical traffic safety applications, how these requirements are affected by different realizations and finally what is required from a wireless access technology to support these applications.

  • 98.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Rasmussen, Lars K.
    University of South Australia.
    Analytical approach for maximizing the average code rate of incremental redundancy schemes2005Inngår i: Asia-Pacific Conference on Communications, 2005, Piscataway, N.J.: IEEE Press, 2005, s. 481-485Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An analytical design procedure for maximizing the average code rate of incremental redundancy retransmission schemes is presented. Union bounds are used as the tool to select good puncturing patterns and to obtain bounds on frame error rate for the punctured codes. This, in turn, is used for determining the optimal packet size of each retransmission, so that the average code rate is maximized.

  • 99.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Rasmussen, Lars K.
    University of South Australia.
    Incremental redundancy deadline dependent coding for efficient wireless real-time communications2005Inngår i: IEEE Conference on Emerging Technologies and Factory Automation, 2005, Piscataway, N.J.: IEEE Press, 2005, s. 417-424Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The concept of deadline dependent coding (DDC) has been demonstrated as a promising design approach for efficient and reliable real-time communications over wireless channels. The main idea behind the concept of DDC is to make all components of the communication protocol deadline dependent, tailoring the channel code and the retransmission protocol to the specific real-time constraints. The DDC framework allows critical reliability and timing constraints to be readily evaluated as a function of available system resources. Concatenated coding and iterative decoding within retransmission protocols enables additional flexibility and new adaptive design options. Here, we introduce an incremental redundancy retransmission scheme in conjunction with concatenated coding and show that this further improves the DDC scheme.

  • 100.
    Uhlemann, Elisabeth
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Rasmussen, Lars K.
    Chalmers University of Technology.
    Grant, Alex J.
    University of South Australia.
    Wiberg, Per-Arne
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Inbyggda system (CERES).
    Optimal Incremental-redundancy strategy for type-II hybrid ARQ2003Inngår i: ISIT 2003 Yokohama: 2003 IEEE International Symposium on Information Theory : proceedings : Pacifico Yokohama, Yokohama, Japan, June 29-July 4, 2003, Piscataway, N.J.: IEEE , 2003, s. 448-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Given a type-II hybrid ARQ scheme, we propose a general solution to find the optimal partitioning of n-k parity bits over at most M transmissions. The solution is in terms of maximizing the average code rate for a given puncturing pattern.

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