Showing papers by "Carsten Griwodz published in 1999"

Multicast for Savings in Cache-based Video Distribution

Abstract: Internet video-on-demand (VoD) today streams videos directly from server to clients, because re-distribution is not established yet. Intranet solutions exist but are typically managed centrally. Caching may overcome these management needs, however existing web caching strategies are not applicable because they work in different conditions. We propose movie distribution by means of caching, and study the feasibility from the service providers' point of view. We introduce the combination of our reliable multicast protocol LCRTP for caching hierarchies combined with our enhancement to the patching technique for bandwidth friendly True VoD, not depending on network resource guarantees.

Position paper: Internet VoD cache server design

Abstract: 2. INTRODUCTION Internet VoD today is dominated by systems like the Real G2 System [ 131 supporting various low bandwidth formats. The length and especially the quality of current video clips are very limited, and not applicable at all for commercial VoD. One of the major limitations is the necessity to stream the video clip directly from a central server to each client individually, because re-distribution is not established yet. Intranet solutions have existed for a while, they use distributed systems but are typically managed from a central site.

Distributed media server for the support of multimedia teaching

Abstract: One major problem of using multimedia material in lecturing is the trade-off between actuality of the content and quality of the presentations. A frequent need for content refreshment exists, but high quality presentations can not be authored by the individual teacher alone at the required rate. Several past and current projects have had the goal of developing so-called learning archives, a variation of digital libraries. On demand, these deliver material with limited structure to students. For lecturing, these systems provide just as insufficient service as the unreliable WWW. Based on our system HyNoDe [HYN97] we address these issues in our distributed media server built of 'medianodes.' We add content management that addresses teachers' needs and provide guaranteed service for connected as well as disconnected operation of their presentation systems. Medianode aims at a scenario for non-real-time, shared creation and modification of presentations and presentation elements. It provides user authentication, administrative roles and authorization mechanisms. It requires an understanding of consistency, versioning and alternative content tailored to lecturing. To allow for predictable presentation quality, medianode provides application level QoS supporting alternative media and alternative presentations. Viable presentation tracks are dynamically generated based on user requests, user profiles and hardware profiles. For machines that are removed from the system according to a schedule, the systems guarantees availability of consistent, complete tracks of selected presentations at disconnect time. In this paper we present the scope of the medianode project and afterwards its architecture, following the realization steps.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Objects with self-reflecting object relevance functions

Abstract: The invention relates to objects within a computer-system said objects comprise object data and the invention relates to a specification of an object-specific, self-reflecting relevance-function associated with the objects. The specification of the relevance-function allows an object-exploiter to evaluate an object-relevance at a certain point in time without inspecting the object-data.

Data object for computer system has self-reflecting object relevance function examined by user for determining relevance of data object

Abstract: The data object, which is loaded in the memory of a computer system, is provided with an object-specific self-reflecting relevance function, supplied to the object user for evaluating the object relevance at a given time point, without the object data being inspected. An Independent claim for an object management method is also included.

Life-Cycle Considerations for Wide-Area Distribution of Multimedia Data

Abstract: Various applications for world-wide multimedia object distribution arise currently as more and more companies integrate streamed continuous media elements in their web pages and as TV broadcasters add computer programs and data to their video streams.Currently, the streams that can be found on the web have only very small data volume, but as network capacities increase, the data volume mat is used by applications will also be increased. TV applications have a lack of networking support and are unable to give feedback to the sender. In the future the integration of computer networks, telephony and broadcast networks will achieve a functional integration of these two worlds.