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  • 701.
    Channakeshava, Karthik
    et al.
    Virginia Tech, Blacksburg, Virginia.
    Phanse, Kaustubh
    DaSilva, Luiz A.
    Virginia Tech, Blacksburg, Virginia.
    Ravindran, Binoy
    Virginia Tech, Blacksburg, Virginia.
    Midkiff, Scott F.
    Virginia Tech, Blacksburg, Virginia.
    Jensen, E. Douglas
    MITRE Corporation, Bedford, MD.
    IP quality of service support for soft real-time applications2005In: Proceedings - RTN 2005, 4th Intl. Workshop on Real-Time Networks (formerly RTLIA: Palma de Mallorca, Spain, July 5, 2005 ; satellite event to ECRTS 2005, 6 - 8 July, Palma de Mallorca, Spain / [ed] Jörg Kaiser, Magdeburg: Otto-von-Guericke Univ , 2005Conference paper (Refereed)
    Abstract [en]

    To obtain acceptable timeliness performance for emerging large-scale distributed real-time control applications operating in large IP internetworks, a scalable quality of service (QoS) architecture is needed. In this paper, we propose a scalable QoS architecture (abbreviated as RTQoS) in support of real-time systems, one that implements real-time scheduling at end-hosts and stateless QoS in the core routers. We address challenges and explore potential benefits achieved by integrating network services with real-time systems, through the use of a network testbed. Experimental evaluation demonstrates the RTQoS architecture as a promising approach for soft real-time applications that are subject to time/utility function time constraints and utility accrual optimality criteria.

  • 702.
    Parviainen, Roland
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Large scale and mobile group communication systems2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis examines different attributes of large scale group communication systems such as scalability, security and mobility by studying two different prototype systems - mIR (multicast Interactive Radio) and MES (Mobile E-meeting Services). mIR is a system for large scale real-time music distribution, designed as an interactive radio system for the Internet. MES is a collection of tools for improving the use of e-meeting and video conferencing tools in a mobile environment. The mIR prototype has been used to study scalability and security. Scalability in mIR concerns how to support as many users as possible without degrading the experience. This is achieved using IP multicast together with algorithms that limits the bandwidth usage regardless of the number of users. The work on security have focused on copy prevention through digital watermarking. By adding a unique watermark, i.e. a fingerprint, to each media copy a pirated copy can be traced back to a specific user, which can act as a deterrent. The thesis shows how we can combine the different goals of fingerprinting and IP-multicast while still maintaining the scalability features of multicast. Many issues need to be considered if e-meetings and video conferencing will become widespread and popular. Scalability and security, discussed in the first part of the thesis are two examples, and the second part of the thesis tries to address a third issue: mobility. In particular we are interested in enabling access to an e-meeting in a mobile environment, where we often have difficult conditions such as bad network connections, the user only have access to the Internet through a web browser or the available devices are small and limited. In many cases it is currently impossible to participate in an e-meeting when you're not in the office. The prototype system developed in the second part of the thesis aims to enable participation from any location and device that have some sort of Internet connection. We try to achieve this by allowing a mobile user to access an e-meeting session from a web browser or from a Java enabled mobile phone. Further, the system makes it possible to review missed events in an e-meeting as it is likely that there are many times where no Internet connection at all is available. The general style of work has been prototype driven with a goal of creating usable prototypes - i.e. the prototypes should be easy to deploy and it should be possible to use and test the prototypes daily. Most the prototypes described in this thesis have indeed been deployed and have seen daily use.

  • 703.
    Brännström, Robert
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Zaslavsky, Arkady
    Maintaining gateway connectivity in multi-hop ad hoc networks2005In: Proceedings: the IEEE Conference on Local Computer Networks, 30th anniversary : Sydney, Australia, November 15 - 17, 2005, Los Alamitos, Calif: IEEE Computer Society Press , 2005, p. 682-689Conference paper (Refereed)
    Abstract [en]

    The need for maintaining gateway connectivity in an ad hoc access network is vital considering the 80/20 ratio of Internet traffic. There are several proposals of how to integrate gateway forwarding strategies but they all rely on the route discovery procedure of reactive routing protocols. We propose a proactive approach to avoid the delay of the route discovery process. Mobile IP is often suggested to handle macro mobility and we use the advertisements periodically sent by the gateway to update routing tables in the ad hoc network. Since advertisements may arrive to a mobile host through multiple paths, it is important to keep track of the best path to each gateway. We demonstrate the use of a proposed dynamic metric and how to handle location of correspondent hosts. A simulation study demonstrates the usefulness and efficiency of our approach.

  • 704. Kristiansson, Johan
    et al.
    Scholl, Jeremiah
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Managing bandwidth in multimedia applications using a market-based middleware2005In: Management of Multimedia Networks and Services: 8th International Conference on Management of Multimedia Networks and Services, MMNS 2005, Barcelona, Spain, October 24-26, 2005. Proceedings / [ed] Jordi Dalmau Royo, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2005, p. 216-227Conference paper (Refereed)
    Abstract [en]

    This paper presents an application-layer middleware that applies a microeconomic model to help multimedia applications utilize available bandwidth in a way that maximizes the user’s net benefit. The key components are a bandwidth broker that puts the supply of available bandwidth on a virtual market residing inside the application, and utility functions for each media, which are used to calculate their relative gain to the user at each bandwidth level. Basic supply and demand principles are used where the broker raises a virtual price if the total demand from all media exceeds the available supply, or lowers the price if demand is lower than the available supply. The advantage of the middleware is that it allows problems related to network management (usually affecting the supply) and human computer interaction (usually affecting demand) to be researched and integrated separately into an application and combined to leverage bandwidth in the best possible way. As a proof of concept, a prototype has been built by integrating the middleware into Marratech Pro, a commercially available e-meeting application. The paper presents experimental results using this prototype

  • 705.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Zaslavsky, Arkady
    M-mip: extended mobile ip to maintain multiple connections to overlapping wireless access networks2005In: Networking - ICN 2005: 4th International Conference on Networking, Reunion Island, France, April 17 - 21, 2005; / [ed] Pascal Lorenz, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2005, p. 204-213Conference paper (Refereed)
    Abstract [en]

    In future wireless access networks, connectivity to wired infrastructure will be provided through multiple access points with possibly different capabilities and utilization. The demand for increased network performance requires the ability to predict the best overall performance of those access points and to switch access point when the performance changes. Then there is the demand for mobility between networks with maintained connectivity which requires the ability to switch the point of attachment. We propose Multihomed Mobile IP, enabling performance discovery at the networks layer and the capability to decide what AP to use. Mobile IP support is needed to allow mobile hosts to move between networks with maintained connectivity. Multihomed Mobile IP enables mobile hosts to register multiple care-of addresses at the home agent, to enhance the performance of wireless network connectivity. This article describes a simulator evaluation of multihomed Mobile IP.

  • 706.
    Brännström, Robert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Network-layer mobility in wireless ad hoc access networks2005Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis proposes and discusses solutions to enable network-layer mobility in wireless ad hoc access networks. The deployment of wireless access networks has made them ubiquitous and current research strives to make them pervasive. Users having wireless access to wired IP networks and the Internet are driving the demand for mobile and heterogeneous solutions. To enable all kinds of mobility in heterogeneous All-IP networks there are many issues to be solved. This thesis focuses on network-layer mobility and connectivity of wireless multi-hop ad hoc networks to the Internet. In a wireless environment with overlapping service areas, mobile hosts need to select which gateway(s) to use to access the wireless infrastructure. The signal-to-noise ratio of an access point, which is part of a wireless LAN, does not reflect the number of attached hosts or the traffic between them. The throughput of the access point could be low while the signal is strong. At the same time an access point with weaker signal could allow higher throughput. In ad hoc routing, hop count is the most common metric and the selection of a route to a gateway is affected by the same utilization problem. This could lead to a situation where a short route is used by more hosts and performing worse than a longer route serving fewer hosts. This thesis proposes and discusses solutions to calculating network-layer metrics and using them in gateway selection and handover decisions. To enable connectivity of a mobile ad hoc network (MANET) to the Internet, a gateway must support the wired single-hop and wireless multi-hop approaches. To deploy network-layer mobility in a MANET, the Mobile IP protocol needs to be adapted for the multi-hop environment. A MANET enables connectivity to more than one gateway at a time and combined with multihoming it provides seamless handover between subnets. The gateway selection and handover decisions are complicated by the multihoming capabilities. This thesis proposes and discusses solutions to deploying multihomed mobility into MANETs and thereby handling multi-hop gateway discovery, registration of multiple gateways and tunneling to selected gateway(s). Traffic patterns in wired LANs generally follow the 80/20 ratio of Internet destined vs. local traffic. The same traffic patterns generally hold true for wireless hosts. Therefore it is important to maintain the route to the gateway for the Internet destined traffic. This thesis proposes and discusses a solution to maintaining gateway connectivity in MANETs by installing routes to gateways using advertisements. Deciding the locality of a peer and setting up the forwarding route differs between single-hop and multi-hop networks. In single-hop networks a source matches the destination prefix with its own to decide what forwarding policy to use. Local traffic is sent directly to the destination with the link- layer protocol while global traffic is forwarded to a default gateway. In multi-hop networks the ad hoc routing protocol finds the route to a destination either proactively or on-demand. This thesis proposes and discusses a solution to deciding on the mobile host destination locality in a MANET.

  • 707. Drugge, Mikael
    et al.
    Hallberg, Josef
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Parnes, Peter
    Relieving the medical workers' daily work through wearable and pervasive computing2005In: ICE2005: the 11th International Conference on Concurrent Enterprising : integrated engineering of products, services and organisations, Munich, Germany 20-22 June 2005, Nottingham: Centre for concurrent enterprising, University of Nottongham , 2005Conference paper (Refereed)
    Abstract [en]

    We intend to relieve the daily work at care-centers, allowing medical workers to focus on the patients and their needs. This goal can be achieved by employing technology that automate and simplify tasks previously requiring tedious interventions, giving more time for the important human to human interaction. For any technology to become accepted by the medical workers, we must ensure that it is highly natural and unobtrusive, without interfering with their caregiving. By studying the medical workers’ daily work, we can draw conclusions on what problems they encounter, allowing us to develop prototypes which can be deployed and used at the care-centers. In doing this, we can proceed to study the acceptance and usability of our proposed solution, and see whether and how it solves the problem. In this position paper, we present our current and future research in wearable and pervasive health-care.

  • 708.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Zaslavsky, Arkady
    Running variance metric for evaluating performance of wireless ip networks in the mobilecity testbed2005In: Proceedings: First International Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities : Trento, Italy, February 23 - 25, 2005 / [ed] Roberto Battiti, Los Alamitos, Calif: IEEE Computer Society Press , 2005, p. 120-127Conference paper (Refereed)
    Abstract [en]

    This paper proposes and analyzes a Running Variance Metric performance measurement of wireless local area networks and its formal aspects. Our approach evaluates the performance of wireless local area networks in infrastructure mode as well as in ad hoc mode. The Running Variance Metric is used to discover relative traffic loads of available access-points/gateways at the network layer in order to provide connectivity to the wired network. The paper discusses a simulation study. The simulation results demonstrate the usefulness and efficiency of the Running Variance Metric to evaluate the utilization of available access-points/gateways. It is also shown that this metric can be used for hop-analysis in multi-hop ad hoc wireless networks.

  • 709. Kristiansson, Johan
    et al.
    Hallberg, Josef
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Svensson, Sara
    Luleå tekniska universitet.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Parnes, Peter
    Supporting automatic media resource selection using context-awareness2005In: The Third International Conference on Advances in Mobile Multimedia: (MoMM2005), September 19-21, 2005, Kuala Lumpur, Malaysia / [ed] G. Kotsis, Die Österreichische Computer Gesellschaft, 2005Conference paper (Refereed)
    Abstract [en]

    In a world of ubiquitous media resources, such as cameras, displays, microphones, provided by a wide variety of multimedia systems, there is a need for automatic resource selection which seamlessly utilizes the best available communication tool from a user perspective. This paper therefore presents an algorithm which uses context-awareness to support automatic media resource selection. The algorithm takes advantage of an abstract classification of privacy, quality, and cost in order to compare media resources to user’s preferences. As a proof of concept implementation, the algorithm has been incorporated into an e-meeting application called Marratech.

  • 710.
    Scholl, Jeremiah
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Technology for supporting informal communication in multimedia conferencing systems2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This dissertation presents work on designing multimedia conferencing systems that better support informal communication among groups. In this case the term “informal” refers to the ability of the system to support unplanned communication and side conversations between members of the group. This contrasts from the classical goal of video-conferencing systems, which was to support room-to-roommeetings between participants at scheduled intervals. The work in the dissertation includes problems related to computer communication and human computer interaction in order to achieve this goal. More specifically, work in the field of computer communication is presented on how to design multimedia systems that use available network resources more efficiently so that a larger number of end users can be supported. This problem of scalability is important when trying to support informal communication because the room-to-room model of deployment is viewed as the primary reason why classical conferencing systems could not support side conversations between participants. Thus, while it may be an option to pack a large number of participants into a few conferencing rooms for a formal meeting, informal communication is better achieved when each participant can join from their own conferencing client. Other work in the field of human computer interaction deals with various usability issues related to improving the flow of unplanned communication. This includes work on the visualization of file systems in order to make it easier for users to locate shared files when coordination and planning on the structure of the file system has not taken place. It also includes user studies that focus on identifying new requirements and new design goals for supporting spontaneous communication. In addition, some interdisciplinary work is also included that seeks to make it easier to unify research in computer communication and human computer interaction so that network resources may be allocated to the various functions in these applications while giving the user the most benefit. A variety of methods are used to investigate the problems including the design and testing of prototypes and algorithms and studies of users in laboratory and naturalistic settings.

  • 711.
    Tscholl, Michael
    et al.
    University College London.
    McCarthy, John
    University College London.
    Scholl, Jeremiah
    The effect of video-augmented chat on collaborative learning with cases2005In: Computer supported collaborative learning 2005: the next 10 years! : proceedings of the International Conference on Computer Supported Collaborative Learning 2005, Taipei, May 30-June 4, 2005 / [ed] Timothy D Koschmann; Dan Suthers; Tak-Wai Chan, Mahwah, N.J: Lawrence Erlbaum Associates, Incorporated , 2005, p. 682-686Conference paper (Refereed)
    Abstract [en]

    Efficient learning with cases requires discussion on the facts of the case as well as on their meaning. We investigated the focus (factual vs. abstract) of a case-based learning discussion when video was added to a chat-based learning system. Students whose first experience includes high-quality video, focus significantly more on abstract knowledge than students first exposed to chat-only or chat + low-quality video. We also found that these students expressed a preference for face-to-face discussion. We conclude that video may improve learning where discussions on abstract and concrete knowledge are important.

  • 712.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    The future of Internet based conferencing: ubiquitous human group communication2005Conference paper (Other academic)
    Abstract [en]

    In the modern world where many companies and groups are distributed there is a strong need for tools that support distributed work, yet very few companies actually use more than phones and email for their daily collaborative work. If they need to meet physically, they travel long distances wasting resources in the form of time, money on travel, pollution from their transports and mostly they are not available for interaction with their other colleagues. The latter creates stress for both the traveler and the persons in her/his organization that need to interact with the traveler to get their work done as smoothly as possible. At the same time the need for distributed work increases with the possibility for having work forces distributed over large geographical areas. Employees work more from their home and on the road today than they did just a decade ago and personal experience show that allowing employees to work in a more relaxed environment as their home minimizes stress symptoms, and increases life quality. One such support tool is e-meetings where users can interact in real-time using high-quality audio, video, text chat, shared whiteboard, shared applications and co-web browsing.

  • 713. Parviainen, Roland
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A web based history tool for multicast e-meeting sessions2004In: 2004 IEEE International Conference on Multimedia and Expo: June 27 - 30, 2004, Taipei, Taiwan, Piscataway NJ: IEEE Communications Society, 2004, p. 511-514Conference paper (Refereed)
    Abstract [en]

    This paper presents a web based history tool for multicast based e-meeting systems. The tool allow users to see past events and activity graphs of current and past sessions. Video snapshots are stored when events are reported, making it possible to quickly get an overview of the history of a session. This tool has several uses such as a quick and easily accessible way to improve group awareness, monitoring and review of meetings and lectures.

  • 714.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Zaslavsky, Arkady
    Agent selection strategies in wireless networks with multihomed mobile ip2004In: Service Assurance with Partial and Intermittent Resources: First International Workshop, SAPIR 2004, Fortaleza, Brazil, August 1-6, 2004. Proceedings / [ed] Petre Dini; Pascal Lorenz; José Neuman DeSouza, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2004, p. 197-206Conference paper (Refereed)
    Abstract [en]

    Mobile IP is a proposed standard for mobility management in IP networks. With today’s emerging possibilities within wireless broadband communication, mobility within networks will increase. New applications and protocols will be created and Mobile IP is important to this development, since Mobile IP support is needed to allow mobile hosts to move between networks with maintained connectivity. This article describes multihomed Mobile IP enabling mobile hosts to register multiple care-of addresses at the home agent, to enhance the performance of wireless network connectivity. A prototype is described and a simulator evaluation shows the performance of our approach.

  • 715. Kristiansson, Johan
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Application-layer mobility support for streaming real-time media2004In: Broadband wireless - the time is now: 2004 IEEE Wireless Communications and Networking Conference, WCNC 2004 ; 21 - 25 March 2004, Atlanta, GA, USA, Piscataway, NJ: IEEE Communications Society, 2004, Vol. 1, p. 268-273Conference paper (Refereed)
    Abstract [en]

    This paper presents an UDP-based socket extension called the resilient mobile socket (RMS), which provides application-layer mobility support by encapsulating other sockets into a new aggregated socket abstraction. Encapsulated sockets can then be added or removed without disturbing running applications. RMS also provides a method for soft handovers where several encapsulated sockets are used simultaneously during a handover. As a proof of concept, a working prototype has been built by integrating RMS with Marratech Pro, a commercially available e-meeting application. This prototype has been used to evaluate RMS and to investigate how GSM audio quality is affected by handovers. The result from the investigation shows that soft handovers can be executed without loosing packets or causing extra latency, while a hard handover in average took around 200 ms to complete. This indicates that proactive handovers and redundancy are important, but that more work must he done to predict disconnections.

  • 716.
    Nilsson, Marcus
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Communication, with and through wearable computers2004Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents research on wearable computers and their usage in communication. The wearable computer is looked upon as a tool for communication between people but also on how it can be used in communication with the environment. A wearable computer has been built with ordinary computer parts and devices available in well-equipped computer stores. This wearable computer is used in this thesis and has both video and audio capabilities and wireless network for communication with people and equipment over distance. The setup has then been used to study the effect of using wearable computer in activities involving communication with people and other equipment. This thesis presents some ways that a wearable computer can be used when considering communication. The user can become a beacon of knowledge sharing the knowledge of people connected to her through the network with people that are collocated with her. She could also become a tool for other people to explore and experience places where they are not located at the moment so called telepresence. It could be said that this is possible with equipment that is available today, but what differences the usage of wearable computer is the possibility to do these activities while still being active in what happens around the user. As the wearable computer should be easy to wear and interact with, the roll as a knowledge beacon or telepresence provider can become almost invisible for the user and other collocated people. To make these rolls as invisible as possible great care must be taken into the interaction between the wearable computer and the user, but also the interaction the user does through the wearable computer with other equipment. When being active as one or both of these rolls the user will mostly be involved in tasks that do not directly involve the wearable computer. When the wearable computer then needs the attention of the user it may have to interrupt the user's current task. This interruption should be done so that the decrease in performance of the user can be kept to a minimum. It is also of equal importance not to only consider the performance but also the experienced stress, which should also be kept to a minimum. A user study is presented in this thesis that explores some of the possible ways to interrupt a wearable computer and analyses what way is preferred when considering both objective and subjective data. In this thesis a novel interaction method called "Eventcasting" is also presented to decrease the time needed to focus on the wearable computer when doing simple tasks with the environment. This is so that interruption on the primary task can be even more minimized and the rolls as a knowledge beacon and telepresence provider can be as invisible as possible.

  • 717.
    Kristiansson, Johan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Creating always-best-connected multimedia applications for the 4:th generation wireless systems2004Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes an application-layer framework for managing network connectivity in the 4th-generation wireless systems, which will consist of overlapping heterogeneous networks. If multiple access networks are present, users will have a choice to access the Internet through the “best” available network. The main problem today is that different wireless networks are not particularly integrated and users are in most cases forced to manually interact with the system when switching between networks. The work presented in this thesis addresses this challenge and describes a framework for managing IP mobility while considering competing connection speeds and pricing models. By using an application-layer mobility scheme, called the Resilient Mobile Socket (RMS), the thesis shows how applications can manage handovers and seamlessly migrate data streams between different networks. Moreover, by using a method called Competition based Soft Handovers (CSHM), the thesis demonstrates how handovers can be automatically triggered to the network currently offering the least packet losses and end-to-end delay. Finally, the thesis proposes bandwidth broker to manage network connectivity and share bandwidth effectively between multiple media within an application. As a proof of concept several prototypes have been built into the commercial e-meeting application Marratech Pro. The thesis presents real-life results from exploratory experiments using these prototypes.

  • 718.
    Hallberg, Josef
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Svensson, Sara
    Luleå tekniska universitet.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Enhanced Experience of Sport Events2004Other (Other academic)
    Abstract [en]

    This paper describes a system where Internet-enabled sensor technology was integrated into a context information platform to give viewers of sport events an enriched media experience. The system was developed as a proof of concept and was evaluated during real-life use at the Vasaloppet cross-country ski event. Using Bluetooth wireless ad-hoc networking and GPRS technology, sensor data was transmitted from contestants to a context information platform, which in turn presented the sport event viewer with a personalized, context-aware view.

  • 719.
    Hallberg, Josef
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Svensson, Sara
    Luleå tekniska universitet.
    Östmark, Åke
    Lindgren, Per
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Enriched media-experience of sport events2004In: Proceedings: Sixth IEEE Workshop on Mobile Computing Systems and Applications, WMCSA 2004 : 2 - 3 December 2004, Windermere, Cumbria, United Kingdom, Los Alamitos, Calif: IEEE Communications Society, 2004, p. 2-9Conference paper (Refereed)
    Abstract [en]

    This paper describes a system where Internet-enabled sensor technology was integrated into a context-aware platform to give viewers of sport events an enriched media experience. The system was developed as a proof of concept and was evaluated during real-life use at the Vasaloppet cross-country ski event. Using Bluetooth wireless ad-hoc networking and GPRS technology, sensor data was transmitted from contestants to the context-aware platform Alipes, which in turn presented the sport event viewer with a personalized, context-aware view. In this paper we discuss the system architecture and integration of components. The system was evaluated both from technical and user perspectives, where the evaluation results confirm our approach to be technically feasible and that the system provide an enriched media-experience for the majority of viewers.

  • 720. Drugge, Mikael
    et al.
    Nilsson, Marcus
    Luleå tekniska universitet.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Parnes, Peter
    Eventcasting with a wearable computer2004In: Proceedings, 24th International Conference on Distributed Computing Systems workshops: 23 - 24 March 2004, Hachioji, Tokyo, Japan / [ed] Nian-Feng Tzeng, Los Alamitos, Calif: IEEE Computer Society Press , 2004, p. 408-413Conference paper (Refereed)
    Abstract [en]

    Traditionally, interaction methods for wearable computers have focused on input to the computer itself, yet little has been done when it comes to allowing interaction with the surrounding environment. Pervasive computing, on the other hand, offers access to computational power from any place all the time, yet most interaction techniques utilize either physical hardware or monitoring of the user in order to receive input. This paper presents a novel form of interaction by which a wearable computer user can interact with and control a pervasive computing environment in a natural and intuitive manner. Using sensors, the user can be allowed to literally "throw" events into the environment as a way of interacting with devices and computers

  • 721. Drugge, Mikael
    et al.
    Nilsson, Marcus
    Luleå tekniska universitet.
    Parviainen, Roland
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Experiences of using wearable computers for ambient telepresence and remote interaction2004In: Proceedings of the ACM SIGMM 2004 workshop on effective telepresence ETP 2004: Toward seamless remote interaction and experience, IEEE Communications Society, 2004, p. 2-11Conference paper (Refereed)
    Abstract [en]

    We present our experiences of using wearable computers for providing an ambient form of telepresence to members of an e-meeting. Using a continuously running e-meeting session as a testbed for formal and informal studies and observations, this form of telepresence can be investigated from the perspective of remote and local participants alike. Based on actual experiences in real-life scenarios, we point out the key issues that prohibit the remote interaction from being entirely seamless, and follow up with suggestions on how those problems can be resolved or alleviated. Furthermore, we evaluate our system with respect to overall usability and the different means for an end-user to experience the remote world

  • 722.
    Bladh, Thomas
    et al.
    Luleå tekniska universitet.
    Carr, David
    Luleå tekniska universitet.
    Scholl, Jeremiah
    Extending tree-maps to three dimensions: a comparative study2004In: Computer Human Interaction: 6th Asia Pacific Conference, APCHI 2004, Rotorua, New Zealand, June 29-July 2, 2004. Proceedings / [ed] M. Masoodian; S. Jones; B. Rogers, Encyclopedia of Global Archaeology/Springer Verlag, 2004, p. 50-59Conference paper (Refereed)
    Abstract [en]

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

  • 723.
    Bladh, Thomas
    et al.
    Luleå tekniska universitet.
    Carr, David
    Luleå tekniska universitet.
    Scholl, Jeremiah
    Extending tree-maps to three dimensions: a comparative study2004Report (Other academic)
    Abstract [en]

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

  • 724. Drugge, Mikael
    et al.
    Nilsson, Marcus
    Luleå tekniska universitet.
    Liljedahl, Urban
    Parviainen, Roland
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Methods for interrupting a wearable computer user2004In: Proceedings: Eighth IEEE International Symposium on Wearable Computers, ISWC 2004 : 31 October - 3 November 2004, Arlington, Virginia, Los Alamitos, Calif: IEEE Communications Society, 2004, p. 150-157Conference paper (Refereed)
    Abstract [en]

    A wearable computer equipped with a head-mounted display allows its user to receive notifications and advice that is readily visible in her field of view. While needless interruption of the user should be avoided, there are times when the information is of such importance that it must demand the user’s attention. As the user is mobile and likely interacts with the real world when these situations occur, it is important to know in what way the user can be notified without increasing her cognitive workload more than necessary. To investigate ways of presenting information without increasing the cognitive workload of the recipient, an experiment was performed testing different approaches. The experiment described in this paper is based on an existing study of interruption of people in human-computer interaction, but our focus is instead on finding out how this applies to wearable computer users engaged in real world tasks.

  • 725.
    DaSilva, Luiz
    et al.
    Virginia Polytechnic Institute and State University.
    Midkiff, Scott
    Virginia Polytechnic Institute and State University.
    Park, Jahng
    Virginia Polytechnic Institute and State University.
    Phanse, Kaustubh
    Lin, Tao
    Virginia Polytechnic Institute and State University.
    Hadjichristofi, George
    Virginia Polytechnic Institute and State University.
    Davis, Davis, Nathaniel
    Virginia Polytechnic Institute and State University.
    Network mobility and protocol interoperability in ad hoc networks2004In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 42, no 11, p. 88-96Article in journal (Refereed)
    Abstract [en]

    The integration of various network-level functions, including routing, management, and security, is critical to the efficient operation of a mobile ad hoc network. In this article we focus on network mobility (rather than node mobility), implying the movement of entire subnetworks with respect to one another, while individual users initially associated with one such subnetwork may also move to other domains. One example is a battlefield network that includes ships, aircraft, and ground troops. In this "network of networks", subnets (e.g. shipboard networks) may be interconnected via a terrestrial mobile wireless network (e.g., between moving ships). We discuss the design and implementation of a new ad hoc routing protocol, a suite of solutions for policy-based network management, and approaches for key management and deployment of IPsec in a MANET. These solutions, in turn, are integrated with real-time middleware, a secure radio link, and a topology monitoring tool. We briefly describe each component of the solution, and focus on the challenges and approaches to integrating these components into a cohesive system to support network mobility. We evaluate the effectiveness of the system through experiments conducted in a wireless ad hoc testbed.

  • 726. Kristiansson, Johan
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Providing seamless mobility with competition based soft handover management2004In: Management of Multimedia Networks and Services: 7th IFIP/IEEE International Conference, MMNS 2004, San Diego, CA, USA, October 3-6, 2004. Proceedings / [ed] John Vicente; David Hutchison, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2004, p. 295-307Conference paper (Refereed)
    Abstract [en]

    As host mobility and radio interference in wireless networks cause packet losses and delays, it is difficult to develop useful mobile real-time media applications. This paper describes a new handover strategy for end-to-end mobility called Competition based Soft Handover Management (CSHM). During a handover, redundant packet streams are sent through multiple connections which are later merged into one stream when received by the other end-point. As each network connection competes with other connections in contributing to the merged packet stream, the handover process can be viewed as a competition. As a proof of concept, CSHM has been implemented in Resilient Mobile Socket, RMS, an application-layer mobility scheme and used together with Marratech Pro, which is a commercially available e-meeting application. By using this prototype, the paper shows that it is possible to minimize redundant packets as well as decrease packet losses during handovers.

  • 727.
    Elf, Stefan
    et al.
    Luleå tekniska universitet.
    Scholl, Jeremiah
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Schemes for user-interest controlled video bandwidth adaptation in a collaborative workspace environment2004In: 2004 IEEE International Conference on Multimedia and Expo, Piscataway, NJ: IEEE Communications Society, 2004, p. 197-200Conference paper (Refereed)
    Abstract [en]

    In this paper, bandwidth-sharing schemes, controlled by user-interest, are presented as an approach to efficient use of resources in a collaborative workspace environment. Two schemes for group videoconferencing are presented and evaluated. Monitoring of user-behavior and message passing to adapt video bandwidth allocation to user needs are key features of both schemes, in which each user's client reports interest in other users to enable them to determine their relative importance. Experimental results using a prototype implementation to sample user-behavior show that one scheme is better suited for high, and the other for low bandwidth-limit scenarios. Measurements also show that the message passing does not add a substantial amount of bandwidth.

  • 728.
    Nilsson, Marcus
    et al.
    Luleå tekniska universitet.
    Drugge, Mikael
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Sharing experience and knowledge with wearable computers2004Conference paper (Refereed)
    Abstract [en]

    Wearable computer have mostly been looked on when used in isolation. But the wearable computer with Internet connection is a good tool for communication and for sharing knowledge and experience with other people. The unobtrusiveness of this type of equipment makes it easy to communicate at most type of locations and contexts. The wearable computer makes it easy to be a mediator of other people knowledge and becoming a knowledgeable user. This paper describes the experience gained from testing the wearable computer as a communication tool and being the knowledgeable user on different fairs.

  • 729. Parviainen, Roland
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    The MIM web gateway to IP multicast e-meetings2004In: Multimedia Computing and Networking 2004: 21 - 22 January 2004, San Jose, California, USA ; proceedings of Electronic imaging, science and technology, Bellingham, Wash: SPIE - International Society for Optical Engineering, 2004, p. 225-236Conference paper (Refereed)
    Abstract [en]

    As video conferencing and e-meeting systems are used more and more on the Internet and in businesses it becomes increasingly important to be able to participate from any computer at any location. Often this is impossible, since these systems requires often special software that are not available everywhere or impossible to install for administrative reasons. Many locations also lack the necessary network infrastructure such as IP multicast. This paper presents a WWW gateway system that enables users to participate using only a standard web browser. The design and architecture of the system are described and performance tests that show the scalability of the system are also presented.

  • 730.
    Drugge, Mikael
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Wearable computer interaction issues in mediated human to human communication2004Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis explores the use of wearable computers as mediators for human to human communication. The user of a wearable computer can deliver live video, audio and commentary from a remote location, allowing local participants to experience it and interact with people on the other side. In this way, knowledge and information can be shared over a distance, passing through the owner of the wearable computer who acts as a mediator. One of the main problems of today is that the virtual world offered by wearable computers can become too immersive, thereby distancing its user from interactions in the real world. At the same time, the very same immersion serves to let the user sense the remote participants as being there, accompanying and communicating through the virtual world. The key here is to get the proper balance between the real and the virtual worlds; remote participants should be able to experience a distant location through the user, while the user should similarly experience their company in the virtual world.

  • 731.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Zaslavsky, Arkady
    A multihoming approach to mobile IP2003In: Swedish National Computer Networking Workshop - Proceedings: SNCNW 2003, Stockholm, 2003Conference paper (Other academic)
    Abstract [en]

    Mobile IP is the standard for mobility management in IP networks. With today's emerging possibilities within wireless broadband communication, mobility within networks will increase. New applications and protocols will be created and Mobile IP is important to this development, since Mobile IP support can be used to allow mobile hosts to move between networks with maintained connectivity. This article describes multihomed Mobile IP enabling mobile hosts to register multiple care-of addresses at the home agent, to enhance the performance of wireless network connectivity. Flows can be load-balanced between care-of addresses to achieve a more reliable connectivity. A prototype is also described.

  • 732.
    Elf, Stefan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Application semantics for cost-effective media distribution2003Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Public use of the Internet increases as wideband connections become pervasive and applications suitable for media distribution grow popular. Group collaboration applications have attracted interest during recent years. Wireless connectivity and business applications also furthers a need for reliable communication protocols. Multicast is a driving force for new applications involving one-to-many as well as many-to-many user scenarios like lecturing, discussions, and collaborative work. In some applications guaranteed delivery of every packet is not crucial, while in other this is a requirement. Error handling in reliable protocols can present a substantial challenge already in a homogeneous environment. Including a plethora of end-user terminal types with widely varying resources it becomes even more challenging. Protocols and applications must therefore be able to handle receiver and network link heterogeneity. The thesis addresses some of the challenges facing the applications in this field, related to multicast and unicast alike. Although the obstacles each of them must overcome may differ, there are similarities with regards to possible solutions with respect to error handling or resource allocation. Error handling protocols are proactive or reactive. Proactive protocols transmit redundant information along with the original information, enabling the receivers to repair lost packets without feedback to the sender. Reactive protocols rely either on positive or negative feedback from the receivers in order to establish reliability. According to a definition of semantic reliability the reliability concept can be interpreted in terms of application semantics. It is proposed to view reliable multicast as a special case of semantically reliable multicast and to implement a dynamically configurable transport layer with an error-handling rule set that can be configured from the application or even from the sender in- session. It is also proposed to make use of the application's knowledge of specific semantics to improve on the recovery of lost packets, congestion handling, or resource allocation. The thesis also presents a bandwidth-sharing scheme for video in group collaboration using application semantics in the form of user hints. The presence of such events is made available to all senders via message passing between session members. As information relating to a user's interest in another user is conveyed, the sender may increase its use of resources on the expense of other senders. A scheme is proposed and a prototype implementation and experimental results are presented.

  • 733.
    Elf, Stefan
    et al.
    Luleå tekniska universitet.
    Scholl, Jeremiah
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Applying user-behavior to bandwidth adaptations in collaborative workspace applications and video conferencing2003Report (Other academic)
    Abstract [en]

    A bandwidth-sharing scheme for group video conferencing is presented in this paper. The key features of the scheme are the monitoring of user behavior and message passing, which are used by each client in order to identify and report their interest in other group members. Each video sender operates on the information about other users ' interest in order to adjust the sender's own frame rate, resolution, and ultimately bandwidth consumption in an attempt to satisfy the current interests of the receivers as well as the overall bandwidth constraints of the session. A general framework, an initial prototype, and a bandwidth allocation algorithm are presented together with experimental results. The experiences from the prototype have prompted refinements to the bandwidth-allocation algorithm that will be important for future implementations. We also conclude that the necessary messaging will not add a significant amount of bandwidth.

  • 734.
    Schefström, Dick
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Distance- Spanning Technology.
    Architecture of a mobile Internet2003In: Proceedings of the 36th Annual Hawaii International Conference on System Sciences: HICSS ´03, IEEE Communications Society, 2003, p. 150-Conference paper (Refereed)
    Abstract [en]

    In this paper, we outline the next major evolution of the Internet architecture, where support for mobility is not the exception but the typical case. We show which parts of the Internet architecture needs to be extended, how they interact, and why they are needed. We point out the suitability of especially license free radio access equipment not only technically, but as a well harmonizing piece in the non-centralized and distributed way that Internet grows. We show that a wired Internet supporting mobility drastically changes the market situation in the mobile and wireless sector, possibly to a level where special mobile operators are not needed. We show that this leads to a situation where wireless and mobile access is just as inexpensive as its wired counterpart

  • 735. Scholl, Jeremiah
    et al.
    Elf, Stefan
    Luleå tekniska universitet.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Efficient workspaces through semantic reliability2003In: 10th International Conference on Telecommunications: ICT 2003, Piscataway, NJ: IEEE Communications Society, 2003, p. 1099-1104Conference paper (Refereed)
    Abstract [en]

    Transport level protocols typically provide “best-effort” data delivery where no attempts are made to recover lost packets, or “reliable” data delivery where techniques are used to ensure that all data sent out eventually reaches the receiver(s). However, it has been suggested that some applications will perform better when using dynamically configurable reliability based on application level semantics. A general framework has been created with the intent of delivering this type of semantic reliability to a wide variety of applications, but to date little research has been done to demonstrate how any applications can benefit from the use of such a framework. This paper addresses this problem in that it discusses semantic reliability in the context of collaborative workspaces.

  • 736. Drugge, Mikael
    et al.
    Nilsson, Marcus
    Luleå tekniska universitet.
    Kristiansson, Johan
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Experiences from mobile e-meetings with the borderland wearable computer2003Report (Other academic)
    Abstract [en]

    People are presented with an increasing number of opportunities to communicate regardless of location as wireless network connectivity becomes more prevalent. Questions that arise are in what form this communication is and what challenges it poses? Can the experience of group communication be enhanced so that a feeling of actual presence can be conveyed? Can we enable participants to experience the world from another person's perspective? We believe so, in this paper we discuss our experiences of group communication when using a wearable computer that is always connected to the network.

  • 737. Drugge, Mikael
    et al.
    Nilsson, Marcus
    Luleå tekniska universitet.
    Kristiansson, Johan
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Experiences of conveying knowledge in borderland2003Report (Other academic)
    Abstract [en]

    One of humankind's most basic needs is that of being able to communicate with other people. As wireless network connectivity becomes more prevalent, factors such as physical location and situation diminish in significance for deciding when and how such communication can take place. What happens when a user is given this freedom to utilize the network regardless of time and place? Questions that arise are how different media can enrich communication and what challenges it poses. Can we enable other users to experience the world from another person's perspective? Can we expand it beyond pure communication and allow other more novel uses to emerge? Can we use this as a way of conveying knowledge in real-time to those in need of it? We believe so, in this paper we discuss our experiences of mobile communication when using a wearable computer that is always connected to the best network available.

  • 738.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Extending global IP connectivity for ad hoc networks2003In: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 24, no 2-4, p. 221-250Article in journal (Refereed)
    Abstract [en]

    Ad hoc networks have thus far been regarded as stand-alone networks without assumed connectivity to wired IP networks and the Internet. With wireless broadband communications and portable devices with appropriate CPU, memory and battery performance, ad hoc connectivity will become more feasible and demand for global connectivity through ad hoc networking is likely to rapidly grow. In this paper we propose an algorithm and describe a developed prototype for connectivity between an ad hoc network running the ad hoc on-demand distance-vector protocol and a wired IP network where mobile IP is used for mobility management. Implementation issues and performance metrics are also discussed.

  • 739.
    Nilsson, Marcus
    et al.
    Luleå tekniska universitet.
    Drugge, Mikael
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    In the borderland between wearable computers and pervasive computing2003Report (Other academic)
    Abstract [en]

    In this paper we will show the ideas that are the foundation for the Borderland architecture. We have looked at two views of how researchers are thinking about computers in the future, wearable computers and pervasive computing. Wearable computers is the view where the user is wearing a computer and by that augment the user's view on his environment with additional digital information. Wearable computers have their strength in that they mostly do not have any requirements on the environment and that the user is in control of his integrity and security. In the pervasive computing view the digital representation of reality is in the physical environment itself. There are few requirements on the user for him to be able to use this digital augmented environment. There is also no restriction of what can be used in this environment as everything can be used for digital representation. We can see that the problems in one view are often the strengths in the other view. We believe that by combining these views into one we can use the strength of both areas and in that solve some of the problems involved in these two research areas. In this paper we present some of the problems we see in this combined view and also some ideas to solutions that we will evaluate in future work.

  • 740.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Integration of ad hoc network and IP network capabilities for mobile hosts2003In: 10th International Conference on Telecommunications: ICT 2003 ; February 23 - March 1, 2003, Sofitel Coralia Maeva Beach Hotel, Tahiti, Papeete, French Polynesia, Piscataway, NJ: IEEE Communications Society, 2003, Vol. 1, p. 482-489Conference paper (Refereed)
    Abstract [en]

    Mobility of user devices connecting to the Internet is of major interest in today’s research in networking. Users with portable devices, like laptops and personal digital assistants (PDA), connecting to foreign networks in the Internet want the same functionality as when connected to the home network, as well as accessibility through the home IP address. Ad hoc networking is also of major importance for connectivity between communicating mobile hosts without backbone infrastructure and for connectivity to access points. For the users as well as for the applications, network mobility should be transparent. The usage of the ad hoc network or the wired IP network should also be managed by the networking software and hidden from applications and users. In this paper we propose and describe an integrated connectivity solution and its software implementation between an ad hoc network running the Ad Hoc On- Demand Distance-Vector Protocol and a wired IP network where Mobile IP is used for mobility management. With the usage of ad hoc networking, a mobile host will be able to use multiple foreign networks to enhance the communication performance. A proposal to multihomed Mobile IP is presented to achieve this.

  • 741.
    Synnes, Kåre
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Nord, James
    Luleå tekniska universitet.
    Parnes, Peter
    Location privacy in the Alipes platform2003In: Proceedings of the 36th Annual Hawaii International Conference on System Sciences: : 6 - 9 January 2003, Big Island, Hawaii / [ed] Ralph H. Sprague, Los Alamitos, Calif: IEEE Communications Society, 2003Conference paper (Refereed)
    Abstract [en]

    An increasing number systems use contextual information about their users. Such contextual information can be used to design applications that survey usage and adapt thereafter, or simply just use context information to optimize presentation. Context information could therefore be used to create applications for the benefit of the users of the system, but the same information could cause serious violations of personal integrity if misused. Locality may be the most widely used, but also the most sensitive contextual information. The Alipes platform makes it easy to create location-based services while enforcing user privacy and integrity. The platform handles privacy through rules that describe how and under what circumstances a user’s context may be distributed to other users, for example rules describing limitations concerning the user’s context, a certain time period, the number of queries and the type of applications. This paper presents how location privacy is enforced in the Alipes platform.

  • 742. Parviainen, Roland
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Mobile instant messaging2003In: 10th International Conference on Telecommunications: ICT 2003 ; February 23 - March 1, 2003, Sofitel Coralia Maeva Beach Hotel, Tahiti, Papeete, French Polynesia, Piscataway, NJ: IEEE Communications Society, 2003, p. 425-430Conference paper (Refereed)
    Abstract [en]

    In this paper we describe a Mobile Instant Messaging system, MIM, designed for mobile environments. During design of mobile applications several new problems and possibilities have to be considered that do not exist with applications targeted at desktop PCs. One example of an application not designed for a mobile environment is current, very popular, instant messaging systems such as ICQ, AIM and MSN messenger. We describe why current systems are not suitable in a mobile environment and present our architecture for a new system, MIM, and show various implementations for different mobile devices such as PDAs, wearable computers and mobile phones.

  • 743. Kristiansson, Johan
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Mobility support for collaborative real-time applications2003Report (Other academic)
    Abstract [en]

    Today we are approaching a truly connected and wireless world where users can be always connected by switching between different carriers and providers. This paper presents an architecture which enables mobile media applications to operate across a wide range of wireless networks, gracefully handle network failures and share environmental information, such as packet loss-rate or available bandwidth with remote peers. The architecture is evaluated using a commercially available E-meeting application, Marratech Pro by seamlessly switching between three carriers; LAN, WLAN and GRPS.

  • 744.
    Åhlund, Christer
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Multihoming with mobile IP2003In: High-Speed Networks and Multimedia Communications: 6th IEEE International Conference ; proceedings / HSNMC 2003, Estoril, Portugal, July 23 - 25, 2003 / [ed] Mário Marques Freire, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2003, p. 235-243Conference paper (Refereed)
    Abstract [en]

    Mobile IP is the standard for mobility management in IP networks. With today’s emerging possibilities within wireless broadband communication, mobility within networks will increase. New applications and protocols will be created and Mobile IP is important to this development, since Mobile IP support is needed to allow mobile hosts to move between networks with maintained connectivity. This article describes multihomed Mobile IP enabling mobile hosts to register multiple care-of addresses at the home agent, to enhance the performance of wireless network connectivity. Flows can be loadbalanced between care-of addresses to achieve a more reliable connectivity. A prototype is also described.

  • 745.
    Scholl, Jeremiah
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Network and user-level traffic adaptation for collaborative-workspace applications2003Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Collaborative workspace applications based on IP-multicast offer a scalable solution for computer supported human-to-human communication. Although Internet-wide multicast access is not a reality, multicast deployment is steadily increasing on subnets, such as corporate and campus networks. Over the past few years this has allowed these applications to begin making headway into work and educational environments. One of the primary drawbacks that the current generation of these applications suffer from is that they generally use simple data transport protocols, which leads to inefficient use of network resources. The primary reason for this is that while a great deal of progress has been made in the area of multicast transport, additional work is needed that can put this research in the context of real-world requirements and usage scenarios, which will enable effective application-level-framing. The work in this thesis focuses on this problem, in that it discusses data transport in the context of a specific industrial collaborative-workspace and shows how improvements can be made in terms of data recovery and bandwidth adaptation, which will save network resources and improve the quality of media reception experienced by users. Thus, an industrial partner, Marratech AB, which specializes in collaborative workspaces, was consulted throughout the work conducted in the thesis and was valuable in helping identify real-world requirements for the protocols and ideas presented. In addition, prototyping relating to the work has been built into Marratech software. The thesis explores the two primary areas of data transport in this context, these being reliability and bandwidth adaptation. In the area of reliability the thesis explores how to generate the necessary feedback for data recovery in a novel and efficient way that does not interfere with calculations for available bandwidth, which is a drawback that many other reliable multicast protocols suffer from. In addition, the thesis explores how to integrate data semantics into the recovery process in order to minimize unnecessary packet retransmissions and control traffic. In the area of bandwidth adaptation, the feedback scheme mentioned above is used in order to adapt the bandwidth consumption of reliable media, such as whiteboards and shared web-browsers, to levels that are ''friendly'' with traditional TCP-based applications. In addition, a bandwidth sharing scheme for the video-streams used in collaborative workspaces is presented that identifies the most important senders in the session and allocates them with a larger share of the session bandwidth.

  • 746.
    Hallberg, Josef
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Nilsson, Marcus
    Luleå tekniska universitet.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Positioning with Bluetooth2003In: 10th International Conference on Telecommunications: ICT 2003 ; February 23 - March 1, 2003, Sofitel Coralia Maeva Beach Hotel, Tahiti, Papeete, French Polynesia, Piscataway, NJ: IEEE Communications Society, 2003, p. 954-958Conference paper (Refereed)
    Abstract [en]

    This paper presents an evaluation of Bluetooth positioning in a general positioning platform. Proceeding the evaluation a Bluetooth based positioning system was implemented in order to complement the theoretical evaluation with empirical tests. Three different ways of positioning with Bluetooth have been developed. With a registered positioning service a Bluetooth device has an active role in the positioning task as it sends a position on request. A Bluetooth device can also take a more passive role in a positioning task, where the unique address of the device is used by a connected device to look up respective position in a database. It is also possible to forward a position gained from the positioning platform using the peer to peer characteristics in Bluetooth. This paper does also contain a discussion on the theoretical time requirements for a positioning system based on Bluetooth. Empirical tests show that these requirements hold.

  • 747.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Secure inclusion of phones into online e-meetings2003In: Management of Multimedia Networks and Services: 6th IFIP/IEEE international conference ; proceedings ; [augmented by a Workshop on End-to-End Monitoring Techniques and Services (E2EMON)] / [ed] Alan Marshall, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2003, p. 396-408Conference paper (Refereed)
    Abstract [en]

    Online Internet based e-meetings for synchronous communication is becoming more and more common and the need for secure communication is a strong requirement from both corporate and private users. At the same time not all users can always be available via the Internet and as phones (fixed and mobile) are still the dominant communication method there is a need for general inclusion of phones into online e-meetings, without compromising the security of the online session. This paper presents an architecture supporting three different scenarios for including normal phones into e-meetings, and at the same time keeping the security of the session intact. It is also shows how an e-meeting portal is used for simple inclusion of phones into e-meetings even if the inviting client is behind a NAT gateway or a firewall.

  • 748. Parviainen, Roland
    et al.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Supporting E-meetings on Java capable mobile phones2003Report (Other academic)
    Abstract [en]

    In this paper we discuss different methods for providing group awareness to participants of e-meeting software using small, limited devices connected with limited networks such as a mobile phone. Currently small devices such as mobile phones are getting more advanced and capable of running custom software such as small Java applications while at the same time the available wireless networks are getting more pervasive and faster making it possible to connect to the Internet from anywhere, from almost any device. We describe the limitations of our target devices and methods to overcome these limitations for each media and present an implementation of some of these methods using an existing commercial e-meeting system.

  • 749. Scholl, Jeremiah
    et al.
    Elf, Stefan
    Luleå tekniska universitet.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    User-interest driven video adaptation for collaborative workspace applications2003In: Group Communications and Charges: technology and business models ; 5th COST 264 International Workshop on Networked Group Communications, and 3rd International Workshop on Internet Charging and QoS Technologies, proceedings / [ed] Burkhard Stiller, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2003, p. 3-12Conference paper (Refereed)
    Abstract [en]

    This paper presents a bandwidth sharing scheme for group video conferencing. The key features of the scheme are the monitoring of implicit user-hints and message passing, which are used by each client in order to identify and report their interest in other group members. Information about user interest is then used by each video sender in order to adjust their frame-rate, resolution, and ultimately bandwidth consumption in an attempt to satisfy the current interests of the receivers. A general framework and initial prototype are presented together with experimental results.

  • 750.
    James, Nord
    et al.
    Luleå tekniska universitet.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Parnes, Peter
    An architecture for location aware applications2002In: Proceedings of the 35th Annual Hawaii International Conference on System Sciences: 7 - 10 January 2001 [i.e. 2002], Big Island, Hawaii / [ed] Ralph H. Sprague, Los Alamitos, Calif: IEEE Communications Society, 2002, p. 3805-3810Conference paper (Refereed)
    Abstract [en]

    This paper presents an architecture for location aware applications, where positioning sources such as GPS, WaveLAN and Bluetooth devices can be seamlessly interchanged and combined to achieve a more accurate positioning service with a higher availability. The architecture also supports peer-to-peer communication to allow clients to interchange position information over a network such as Bluetooth or WaveLAN. This enables a user to use other users position sources if their clients are close enough. The position information can be used directly by an application or be combined with habitual and other contextual information to achieve more personalized applications. A generic positioning protocol for interchange of position information between position sources and client applications, and different techniques for merging of position information are presented. The interfaces to the platform are also discussed. The paper finally touches on privacy issues and outlines a schema for handling positioning information by user controlled contracts

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