The Experts below are selected from a list of 68718 Experts worldwide ranked by ideXlab platform
Martin Mauve - One of the best experts on this subject based on the ideXlab platform.
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Recording and playing back Interactive Media streams
IEEE Transactions on Multimedia, 2005Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:Recording systems and Media servers for networked audio and video streams have become an important part of today's Internet. In contrast to this, only a few recording and playback solutions currently exist for the data streams of Interactive Media applications (e.g., shared whiteboards and distributed virtual environments). So far these solutions are application-specific: individual algorithms and implementations are required for each application that is to be recorded. In this paper, we are proposing generic algorithms for the recording and playback of Interactive Media streams. These algorithms are based on a common model for the class of Interactive Media. They enable full random access to recordings by initializing the replaying applications with the required state information (e.g., the current slide in a recorded presentation). We have implemented these algorithms in the Interactive Media on Demand (IMoD) system. In order to interpret the semantics of an Interactive Media stream, the system requires that the Real-Time Application-Level Protocol for Distributed Interactive Media (RTP/I) protocol is used for the framing of the transmitted data. Any application using RTP/I can be recorded directly using the system without any modification. Interactive Media streams not using RTP/I can be recorded using the generic recording algorithms. However, they require an adaptation of the system so that it is able to extract a minimal set of information from the application-level protocol of these streams. In addition to the generic recording algorithms, we present the architecture and major design considerations of the system and discuss the experiences gained from recording different Interactive Media applications.
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ACM MultiMedia - Interactive Media on demand: generic recording and replay of Interactive Media streams
Proceedings of the ninth ACM international conference on Multimedia - MULTIMEDIA '01, 2001Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:In this demonstration we present a generic recording service for distributed Interactive Media, i.e., Media which allow a distributed group of users to interact with the medium itself. Typical examples of this Media class are shared whiteboard systems, distributed virtual environments and networked computer games. By defining an abstract model and an application level protocol we were able to develop the first generic recording service for arbitrary distributed Interactive Media. This service is called Interactive Media on Demand (IMoD), and it is able to record and replay all applications that are based on the RTP/I protocol. In particular it allows random access to the recorded Media streams. We demonstrate the IMoD system by recording and replaying a shared whiteboard, a networked computer game and a 3D telecooperation application.
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consistency control for distributed Interactive Media
ACM Multimedia, 2001Co-Authors: Jürgen Vogel, Martin MauveAbstract:In this paper we present a generic consistency control service for distributed Interactive Media, i.e. Media which allow a distributed group of users to interact with the medium itself. Consistency control is vital to these Media since they typically require that a local copy of the medium's state be maintained by each user's application. Our service helps the applications to keep the local state copies consistent. The main characteristics of this service are as follows: a significant number of inconsistencies are prevented by using a mechanism called local lag. Inconsistencies that cannot be prevented are repaired by an improved timewarp algorithm that can be executed locally without burdening the network or the applications of other users. Exceptional situations and consistency during late-join situations are supported by a consistent state request mechanism. Moreover, the service also supports the application in detecting intention conflicts between the actions of distinct users. The major part of this functionality is based on a Media model and the application level protocol for distributed Interactive Media (RTP/I) and can thus be reused by arbitrary RTP/I-based applications. In order to demonstrate the feasibility of our approach and to evaluate its performance we have integrated the generic consistency service into a shared whiteboard system.
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rtp i toward a common application level protocol for distributed Interactive Media
IEEE Transactions on Multimedia, 2001Co-Authors: Martin Mauve, Volker Hilt, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:Distributed Interactive Media are Media that involve communication over a computer network as well as user interactions with the medium itself. Examples of this kind of Media are shared whiteboard presentations and networked computer games. One key problem of this Media class is that a large amount of common functionality is currently redesigned and redeveloped for each single medium. In order to solve this problem we present a Media model and an application level protocol called RTP/I. Derived from the experience gained with audio and video transmission using RTP, RTP/I is defined as a new protocol framework which reuses many aspects of RTP while it is thoroughly adapted to meet the demands of distributed Interactive Media. By identifying and supporting the common aspects of distributed Interactive Media RTP/I allows the reuse of key functionality in form of generic services. Furthermore RTP/I makes it possible for applications of different vendors to interact with each other in a standardized way.
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consistency in replicated continuous Interactive Media
Conference on Computer Supported Cooperative Work, 2000Co-Authors: Martin MauveAbstract:In this paper we investigate how consistency can be ensured for replicated continuous Interactive Media, i.e., replicated Media which change their state in reaction to user initiated operations as well as because of the passing of time. Typical examples for this Media class are networked computer games and distributed VR applications. Existing approaches to reach consistency for replicated discrete Interactive Media are briefly outlined and it is shown that these fail in the continuous domain. In order to allow a thorough discussion of the problem, a formal definition of the term consistency in the continuous domain is given. Based on this definition we show that an important tradeoff relationship exists between the responsiveness of the medium and the appearance of short-term inconsistencies. Until now this tradeoff was not taken into consideration for consistency in the continuous domain, thereby severely limiting the consistency related fidelity for a large number of applications. We show that for those applications the fidelity can be significantly raised by voluntarily decreasing the responsiveness of the medium. This concept is called local lag. It enables the distribution of continuous Interactive Media that are more vulnerable to short-term inconsistencies than, e.g., battlefield simulations. We prove that the concept of local lag is valid by describing how local lag was successfully used to ensure consistency in a 3D telecooperation application.
Wolfgang Effelsberg - One of the best experts on this subject based on the ideXlab platform.
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Recording and playing back Interactive Media streams
IEEE Transactions on Multimedia, 2005Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:Recording systems and Media servers for networked audio and video streams have become an important part of today's Internet. In contrast to this, only a few recording and playback solutions currently exist for the data streams of Interactive Media applications (e.g., shared whiteboards and distributed virtual environments). So far these solutions are application-specific: individual algorithms and implementations are required for each application that is to be recorded. In this paper, we are proposing generic algorithms for the recording and playback of Interactive Media streams. These algorithms are based on a common model for the class of Interactive Media. They enable full random access to recordings by initializing the replaying applications with the required state information (e.g., the current slide in a recorded presentation). We have implemented these algorithms in the Interactive Media on Demand (IMoD) system. In order to interpret the semantics of an Interactive Media stream, the system requires that the Real-Time Application-Level Protocol for Distributed Interactive Media (RTP/I) protocol is used for the framing of the transmitted data. Any application using RTP/I can be recorded directly using the system without any modification. Interactive Media streams not using RTP/I can be recorded using the generic recording algorithms. However, they require an adaptation of the system so that it is able to extract a minimal set of information from the application-level protocol of these streams. In addition to the generic recording algorithms, we present the architecture and major design considerations of the system and discuss the experiences gained from recording different Interactive Media applications.
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ACM MultiMedia - Interactive Media on demand: generic recording and replay of Interactive Media streams
Proceedings of the ninth ACM international conference on Multimedia - MULTIMEDIA '01, 2001Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:In this demonstration we present a generic recording service for distributed Interactive Media, i.e., Media which allow a distributed group of users to interact with the medium itself. Typical examples of this Media class are shared whiteboard systems, distributed virtual environments and networked computer games. By defining an abstract model and an application level protocol we were able to develop the first generic recording service for arbitrary distributed Interactive Media. This service is called Interactive Media on Demand (IMoD), and it is able to record and replay all applications that are based on the RTP/I protocol. In particular it allows random access to the recorded Media streams. We demonstrate the IMoD system by recording and replaying a shared whiteboard, a networked computer game and a 3D telecooperation application.
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rtp i toward a common application level protocol for distributed Interactive Media
IEEE Transactions on Multimedia, 2001Co-Authors: Martin Mauve, Volker Hilt, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:Distributed Interactive Media are Media that involve communication over a computer network as well as user interactions with the medium itself. Examples of this kind of Media are shared whiteboard presentations and networked computer games. One key problem of this Media class is that a large amount of common functionality is currently redesigned and redeveloped for each single medium. In order to solve this problem we present a Media model and an application level protocol called RTP/I. Derived from the experience gained with audio and video transmission using RTP, RTP/I is defined as a new protocol framework which reuses many aspects of RTP while it is thoroughly adapted to meet the demands of distributed Interactive Media. By identifying and supporting the common aspects of distributed Interactive Media RTP/I allows the reuse of key functionality in form of generic services. Furthermore RTP/I makes it possible for applications of different vendors to interact with each other in a standardized way.
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RTP/I : an application level real-time protocol for distributed Interactive Media
2000Co-Authors: Martin Mauve, Volker Hilt, Jürgen Vogel, Christoph Kuhmünch, Werner Geyer, Wolfgang EffelsbergAbstract:This document specifies RTP/I, an application level real-time protocol for distributed Interactive Media. Typical examples of distributed Interactive Media are shared whiteboards, networked computer games and distributed virtual environments. RTP/I defines a standardized framing for the transmission of data and provides mechanisms that are universally needed for this Media class. Thereby RTP/I enables the development of reusable functionality and generic services that can be employed for multiple distributed Interactive Media. Examples for this kind of functionality are the ability to record sessions, to support late coming participants, and to provide security services. RTP/I is a protocol that follows the ideas of application level framing and integrated layer processing. It has been designed to be independent of the underlying network and transport layers. To a large extend RTP/I has been inspired by the real-time transport protocol (RTP), which is used for continuous non-Interactive Media. This document is intended to stimulate the discussion on how to transport distributed Interactive Media over the Internet. There exists an RTP/I mailing list. Instructions on how to subscribe to this list can be found at the RTP/I homepage (http://www.informatik.uni-mannheim.de/informatik/pi4/projects/ RTPI/index.html). Feedback on this document should be addressed to the RTP/I mailing list or directly to the authors.
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IDMS - A Generic Scheme for the Recording of Interactive Media Streams
Interactive Distributed Multimedia Systems and Telecommunication Services, 1999Co-Authors: Volker Hilt, Martin Mauve, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:Interactive Media streams with real-time characteristics, such as those produced by shared whiteboards, distributed Java applets or shared VRML viewers, are rapidly gaining importance. Current solutions to the recording of Interactive Media streams are limited to one specific application (e.g. one specific shared whiteboard). In this paper we present a generic recording service that enables the recording and playback of this new class of Media. To facilitate the generic recording we have defined a profile for the Real-Time Transport Protocol (RTF) that covers common aspects of the Interactive Media class in analogy to the profile for audio and video. Based on this profile we introduce a generalized recording service that enables the recording and playback of arbitrary Interactive Media.
Volker Hilt - One of the best experts on this subject based on the ideXlab platform.
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Recording and playing back Interactive Media streams
IEEE Transactions on Multimedia, 2005Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:Recording systems and Media servers for networked audio and video streams have become an important part of today's Internet. In contrast to this, only a few recording and playback solutions currently exist for the data streams of Interactive Media applications (e.g., shared whiteboards and distributed virtual environments). So far these solutions are application-specific: individual algorithms and implementations are required for each application that is to be recorded. In this paper, we are proposing generic algorithms for the recording and playback of Interactive Media streams. These algorithms are based on a common model for the class of Interactive Media. They enable full random access to recordings by initializing the replaying applications with the required state information (e.g., the current slide in a recorded presentation). We have implemented these algorithms in the Interactive Media on Demand (IMoD) system. In order to interpret the semantics of an Interactive Media stream, the system requires that the Real-Time Application-Level Protocol for Distributed Interactive Media (RTP/I) protocol is used for the framing of the transmitted data. Any application using RTP/I can be recorded directly using the system without any modification. Interactive Media streams not using RTP/I can be recorded using the generic recording algorithms. However, they require an adaptation of the system so that it is able to extract a minimal set of information from the application-level protocol of these streams. In addition to the generic recording algorithms, we present the architecture and major design considerations of the system and discuss the experiences gained from recording different Interactive Media applications.
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ACM MultiMedia - Interactive Media on demand: generic recording and replay of Interactive Media streams
Proceedings of the ninth ACM international conference on Multimedia - MULTIMEDIA '01, 2001Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:In this demonstration we present a generic recording service for distributed Interactive Media, i.e., Media which allow a distributed group of users to interact with the medium itself. Typical examples of this Media class are shared whiteboard systems, distributed virtual environments and networked computer games. By defining an abstract model and an application level protocol we were able to develop the first generic recording service for arbitrary distributed Interactive Media. This service is called Interactive Media on Demand (IMoD), and it is able to record and replay all applications that are based on the RTP/I protocol. In particular it allows random access to the recorded Media streams. We demonstrate the IMoD system by recording and replaying a shared whiteboard, a networked computer game and a 3D telecooperation application.
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rtp i toward a common application level protocol for distributed Interactive Media
IEEE Transactions on Multimedia, 2001Co-Authors: Martin Mauve, Volker Hilt, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:Distributed Interactive Media are Media that involve communication over a computer network as well as user interactions with the medium itself. Examples of this kind of Media are shared whiteboard presentations and networked computer games. One key problem of this Media class is that a large amount of common functionality is currently redesigned and redeveloped for each single medium. In order to solve this problem we present a Media model and an application level protocol called RTP/I. Derived from the experience gained with audio and video transmission using RTP, RTP/I is defined as a new protocol framework which reuses many aspects of RTP while it is thoroughly adapted to meet the demands of distributed Interactive Media. By identifying and supporting the common aspects of distributed Interactive Media RTP/I allows the reuse of key functionality in form of generic services. Furthermore RTP/I makes it possible for applications of different vendors to interact with each other in a standardized way.
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ACM MultiMedia - A generic late-join service for distributed Interactive Media
Proceedings of the eighth ACM international conference on Multimedia - MULTIMEDIA '00, 2000Co-Authors: Jürgen Vogel, Volker Hilt, Martin Mauve, Werner Geyer, Christoph KuhmünchAbstract:In this paper we present a generic late-join service for distributed Interactive Media, i.e, networked Media which involve user interactions. Examples for distributed Interactive Media are shared whiteboards, networked computer games and distributed virtual environments. The generic late-join service allows a latecomer to join an ongoing session. This requires that the shared state of the medium is transmitted from the old participants of the session to the latecomer in an efficient and scalable way. In order to be generic and useful for a broad range of distributed Interactive Media, we have implemented the late-join service based on the Real Time Application Level Protocol for Distributed Interactive Media (RTP/I). All applications which employ this protocol can also use the generic late-join service. Furthermore the late-join service can be adapted to the specific needs of a given application by specifying policies for the late-join process. Applications which do use a different application level protocol than RTP/I may still use the concepts presented in this work. However, they will not be able to profit from our RTP/I based implementation.
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An application developer's perspective on reliable multicast for distributed Interactive Media
ACM SIGCOMM Computer Communication Review, 2000Co-Authors: Martin Mauve, Volker HiltAbstract:In this paper we investigate which characteristics reliable multicast services should have in order to be appropriate for use by distributed Interactive Media applications such as shared whiteboards, networked computer games, or distributed virtual environments. We take a close look at the communication requirements of these applications and at existing approaches to realize reliable multicast. Based on this information we deduce which reliable multicast transport protocols are appropriate for the different aspects of distributed Interactive Media. Furthermore we discuss how the application program interface of a reliable multicast service should be designed in order to support the development of applications for distributed Interactive Media.
Christoph Kuhmünch - One of the best experts on this subject based on the ideXlab platform.
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rtp i toward a common application level protocol for distributed Interactive Media
IEEE Transactions on Multimedia, 2001Co-Authors: Martin Mauve, Volker Hilt, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:Distributed Interactive Media are Media that involve communication over a computer network as well as user interactions with the medium itself. Examples of this kind of Media are shared whiteboard presentations and networked computer games. One key problem of this Media class is that a large amount of common functionality is currently redesigned and redeveloped for each single medium. In order to solve this problem we present a Media model and an application level protocol called RTP/I. Derived from the experience gained with audio and video transmission using RTP, RTP/I is defined as a new protocol framework which reuses many aspects of RTP while it is thoroughly adapted to meet the demands of distributed Interactive Media. By identifying and supporting the common aspects of distributed Interactive Media RTP/I allows the reuse of key functionality in form of generic services. Furthermore RTP/I makes it possible for applications of different vendors to interact with each other in a standardized way.
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ACM MultiMedia - A generic late-join service for distributed Interactive Media
Proceedings of the eighth ACM international conference on Multimedia - MULTIMEDIA '00, 2000Co-Authors: Jürgen Vogel, Volker Hilt, Martin Mauve, Werner Geyer, Christoph KuhmünchAbstract:In this paper we present a generic late-join service for distributed Interactive Media, i.e, networked Media which involve user interactions. Examples for distributed Interactive Media are shared whiteboards, networked computer games and distributed virtual environments. The generic late-join service allows a latecomer to join an ongoing session. This requires that the shared state of the medium is transmitted from the old participants of the session to the latecomer in an efficient and scalable way. In order to be generic and useful for a broad range of distributed Interactive Media, we have implemented the late-join service based on the Real Time Application Level Protocol for Distributed Interactive Media (RTP/I). All applications which employ this protocol can also use the generic late-join service. Furthermore the late-join service can be adapted to the specific needs of a given application by specifying policies for the late-join process. Applications which do use a different application level protocol than RTP/I may still use the concepts presented in this work. However, they will not be able to profit from our RTP/I based implementation.
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RTP/I : an application level real-time protocol for distributed Interactive Media
2000Co-Authors: Martin Mauve, Volker Hilt, Jürgen Vogel, Christoph Kuhmünch, Werner Geyer, Wolfgang EffelsbergAbstract:This document specifies RTP/I, an application level real-time protocol for distributed Interactive Media. Typical examples of distributed Interactive Media are shared whiteboards, networked computer games and distributed virtual environments. RTP/I defines a standardized framing for the transmission of data and provides mechanisms that are universally needed for this Media class. Thereby RTP/I enables the development of reusable functionality and generic services that can be employed for multiple distributed Interactive Media. Examples for this kind of functionality are the ability to record sessions, to support late coming participants, and to provide security services. RTP/I is a protocol that follows the ideas of application level framing and integrated layer processing. It has been designed to be independent of the underlying network and transport layers. To a large extend RTP/I has been inspired by the real-time transport protocol (RTP), which is used for continuous non-Interactive Media. This document is intended to stimulate the discussion on how to transport distributed Interactive Media over the Internet. There exists an RTP/I mailing list. Instructions on how to subscribe to this list can be found at the RTP/I homepage (http://www.informatik.uni-mannheim.de/informatik/pi4/projects/ RTPI/index.html). Feedback on this document should be addressed to the RTP/I mailing list or directly to the authors.
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IDMS - A Generic Scheme for the Recording of Interactive Media Streams
Interactive Distributed Multimedia Systems and Telecommunication Services, 1999Co-Authors: Volker Hilt, Martin Mauve, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:Interactive Media streams with real-time characteristics, such as those produced by shared whiteboards, distributed Java applets or shared VRML viewers, are rapidly gaining importance. Current solutions to the recording of Interactive Media streams are limited to one specific application (e.g. one specific shared whiteboard). In this paper we present a generic recording service that enables the recording and playback of this new class of Media. To facilitate the generic recording we have defined a profile for the Real-Time Transport Protocol (RTF) that covers common aspects of the Interactive Media class in analogy to the profile for audio and video. Based on this profile we introduce a generalized recording service that enables the recording and playback of arbitrary Interactive Media.
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A General Framework and Communication Protocol for the Real-Time Transmission of Interactive Media
1998Co-Authors: Martin Mauve, Volker Hilt, Christoph Kuhmünch, Wolfgang EffelsbergAbstract:In this paper we present a general framework for the real-time transmission of Interactive Media, i.e. Media involving user interaction. Examples of Interactive Media are shared whiteboards, Java animations and VRML worlds. By identifying and supporting the common aspects of this Media class the framework allows the development of generic services for network sessions involving the transmission of Interactive Media. Examples are mechanisms for late join and session recording. The proposed framework is based on the Real-Time Transport Protocol (RTP) which is widely used in the Internet for the real-time transmission of audio and video. Using the experience gained through the framework for audio and video, our work consists of three important parts: the definition of a protocol profile, the instantiation of this profile for specific Media, and the development of generic services. The profile captures those aspects that are common to the class of Interactive Media. A single medium must instantiate this profile by providing Media-specific information in the form of a payload type definition. Based on the profile, generic services can be developed for all Interactive Media. In this paper we focus on the description of the profile for the real-time transmission of Interactive Media. We then present the main ideas behind a generic recording service. Finally we show how multi-user VRML and distributed Interactive Java animations can instantiate the profile.
Jürgen Vogel - One of the best experts on this subject based on the ideXlab platform.
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Recording and playing back Interactive Media streams
IEEE Transactions on Multimedia, 2005Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:Recording systems and Media servers for networked audio and video streams have become an important part of today's Internet. In contrast to this, only a few recording and playback solutions currently exist for the data streams of Interactive Media applications (e.g., shared whiteboards and distributed virtual environments). So far these solutions are application-specific: individual algorithms and implementations are required for each application that is to be recorded. In this paper, we are proposing generic algorithms for the recording and playback of Interactive Media streams. These algorithms are based on a common model for the class of Interactive Media. They enable full random access to recordings by initializing the replaying applications with the required state information (e.g., the current slide in a recorded presentation). We have implemented these algorithms in the Interactive Media on Demand (IMoD) system. In order to interpret the semantics of an Interactive Media stream, the system requires that the Real-Time Application-Level Protocol for Distributed Interactive Media (RTP/I) protocol is used for the framing of the transmitted data. Any application using RTP/I can be recorded directly using the system without any modification. Interactive Media streams not using RTP/I can be recorded using the generic recording algorithms. However, they require an adaptation of the system so that it is able to extract a minimal set of information from the application-level protocol of these streams. In addition to the generic recording algorithms, we present the architecture and major design considerations of the system and discuss the experiences gained from recording different Interactive Media applications.
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ACM MultiMedia - Interactive Media on demand: generic recording and replay of Interactive Media streams
Proceedings of the ninth ACM international conference on Multimedia - MULTIMEDIA '01, 2001Co-Authors: Volker Hilt, Martin Mauve, Jürgen Vogel, Wolfgang EffelsbergAbstract:In this demonstration we present a generic recording service for distributed Interactive Media, i.e., Media which allow a distributed group of users to interact with the medium itself. Typical examples of this Media class are shared whiteboard systems, distributed virtual environments and networked computer games. By defining an abstract model and an application level protocol we were able to develop the first generic recording service for arbitrary distributed Interactive Media. This service is called Interactive Media on Demand (IMoD), and it is able to record and replay all applications that are based on the RTP/I protocol. In particular it allows random access to the recorded Media streams. We demonstrate the IMoD system by recording and replaying a shared whiteboard, a networked computer game and a 3D telecooperation application.
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consistency control for distributed Interactive Media
ACM Multimedia, 2001Co-Authors: Jürgen Vogel, Martin MauveAbstract:In this paper we present a generic consistency control service for distributed Interactive Media, i.e. Media which allow a distributed group of users to interact with the medium itself. Consistency control is vital to these Media since they typically require that a local copy of the medium's state be maintained by each user's application. Our service helps the applications to keep the local state copies consistent. The main characteristics of this service are as follows: a significant number of inconsistencies are prevented by using a mechanism called local lag. Inconsistencies that cannot be prevented are repaired by an improved timewarp algorithm that can be executed locally without burdening the network or the applications of other users. Exceptional situations and consistency during late-join situations are supported by a consistent state request mechanism. Moreover, the service also supports the application in detecting intention conflicts between the actions of distinct users. The major part of this functionality is based on a Media model and the application level protocol for distributed Interactive Media (RTP/I) and can thus be reused by arbitrary RTP/I-based applications. In order to demonstrate the feasibility of our approach and to evaluate its performance we have integrated the generic consistency service into a shared whiteboard system.
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ACM MultiMedia - A generic late-join service for distributed Interactive Media
Proceedings of the eighth ACM international conference on Multimedia - MULTIMEDIA '00, 2000Co-Authors: Jürgen Vogel, Volker Hilt, Martin Mauve, Werner Geyer, Christoph KuhmünchAbstract:In this paper we present a generic late-join service for distributed Interactive Media, i.e, networked Media which involve user interactions. Examples for distributed Interactive Media are shared whiteboards, networked computer games and distributed virtual environments. The generic late-join service allows a latecomer to join an ongoing session. This requires that the shared state of the medium is transmitted from the old participants of the session to the latecomer in an efficient and scalable way. In order to be generic and useful for a broad range of distributed Interactive Media, we have implemented the late-join service based on the Real Time Application Level Protocol for Distributed Interactive Media (RTP/I). All applications which employ this protocol can also use the generic late-join service. Furthermore the late-join service can be adapted to the specific needs of a given application by specifying policies for the late-join process. Applications which do use a different application level protocol than RTP/I may still use the concepts presented in this work. However, they will not be able to profit from our RTP/I based implementation.
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RTP/I : an application level real-time protocol for distributed Interactive Media
2000Co-Authors: Martin Mauve, Volker Hilt, Jürgen Vogel, Christoph Kuhmünch, Werner Geyer, Wolfgang EffelsbergAbstract:This document specifies RTP/I, an application level real-time protocol for distributed Interactive Media. Typical examples of distributed Interactive Media are shared whiteboards, networked computer games and distributed virtual environments. RTP/I defines a standardized framing for the transmission of data and provides mechanisms that are universally needed for this Media class. Thereby RTP/I enables the development of reusable functionality and generic services that can be employed for multiple distributed Interactive Media. Examples for this kind of functionality are the ability to record sessions, to support late coming participants, and to provide security services. RTP/I is a protocol that follows the ideas of application level framing and integrated layer processing. It has been designed to be independent of the underlying network and transport layers. To a large extend RTP/I has been inspired by the real-time transport protocol (RTP), which is used for continuous non-Interactive Media. This document is intended to stimulate the discussion on how to transport distributed Interactive Media over the Internet. There exists an RTP/I mailing list. Instructions on how to subscribe to this list can be found at the RTP/I homepage (http://www.informatik.uni-mannheim.de/informatik/pi4/projects/ RTPI/index.html). Feedback on this document should be addressed to the RTP/I mailing list or directly to the authors.
