Resource management in networked multimedia systems

F-76058 LE HAVRE CEDEX Ö×ØÒÒÑѺÄÄ×ØÒÒÑÑÐÐØØ×ÐºÖ RÉSUMÉ. Les applications multimédia gèrent des volumes importants de données. L'exploita-tion de ces données doit se faire en respectant les contraintes temporelles permettant de lire les paquets vidéo avec une certaine fluidité. Lorsque les contraintes temporelles ne sont pas respectées, la qualité de service fournie aux utilisateurs diminue. Partant du constat qu'il existe des similarités entre les applications multimédia et les SGBD temps réel, notre approche con-siste à exploiter les travaux concernant la gestion de la qualité de service dans les SGBD temps réel afin de les appliquer aux systèmes multimédia distribués. Dans cet article, nous proposons une nouvelle architecture permettant la gestion efficace des données multimédia et d'améliorer la qualité de service fournie aux clients lors des variations importantes de la charge d'util-isation du système. Notre technique consiste à faire varier la qualité des flux ...

International Seminar on Client/Server Computing, 1995

This paper discusses the client-server computing requirements of networked multimedia services. The client-server programming model has traditionally supported mumerous data applications which can tolerate delay and jitter bounds. The quality of service (QoS) concept is mandatory for multimedia associations since it expresses the application requirements towards the communication subsystem. The application developer should be provided with a mechanism to select and control the QoS parameters applicable to the context of continuous media information transfer. As a consequence, the application programmer easily expresses his requirement for a multimedia multiparty call. At the user perception level diverse QoS parameters are issued which should be interpreted onto specific performance parameters by the communication subsystem. Dynamic management of QoS parameters should be provided either at the association establishment and the data transfer phases. The QoS parameter tuple identifies the entire multimedia association in space (i.e. end-to-end) as well as in time (i.e. during the lifetime of the association). This paper discusses the main weaknesses of existing client-server programming interfaces and proposes the enhancements that should take place to achieve appropriate computing for the development of multimedia networked services in view of new high-speed network technologies. Furthermore, the attractive features of new multimedia multiparty programming interfaces are presented and analysed.

1995

Abstract An open architecture for the distribution of networked multimedia was designed, with the goal being to to allow interoperability between diverse networked multimedia distribution systems built for a range of applications. The approach taken was to use existing standards and technologies as much as possible, especially the World Wide Web and the Internet.

One of the current challenges in multimedia systems is to ensure efficient data transmission between the server and clients. These systems must guarantee to the users a certain quality of service (QoS), by ensuring data accessibility whatever the material and networks conditions are. They also must guarantee information consistency, particularly the respect of temporal constraints in order to obtain a smooth presentation of scenes. In this paper, we propose an architecture obtained by exploiting similarities existing between real-time database systems (RTDBSs) and multimedia systems. Then, we define a method, that we name (m,k)-frame, which allows to control at any moment the number of frames sent to users, by discarding selectively some frames when needed. We, finally, carry out simulations whose results show the best performances of our approach which consists of adapting the QoS to the real conditions, compared both to the application of an already proposed method by other authors (R-(m,k)-firm method) and to the original (m,k)-firm method. This adaptation is done according to the system load, which may become heavy due to network congestion, i.e, dynamic arrival of clients.

1998

The ability of operating system and network infrastructure to provide end-to-end quality of service (QoS) guarantees in multimedia is a major acceptance factor for various distributed multimedia applications due to the temporal audio-visual and sensory information in these applications. Our constraints on the end-to-end guarantees are (1) QoS should be achieved on a general-purpose platform with a real-time extension support, and (2) QoS should be application-controllable.

1994

Presents the basic principles of a general architecture for distributed multimedia applications support over ATM-based networks. The architecture is aimed at providing the services, the mechanisms and the interactions required by multimedia applications. The architecture is based on the quality of service and communication management functions associated to the services it provides

This paper presents a novel network architecture for distributed multimedia systems. The VuNet is a gigabit-per-second desk/local-area ATM network which interconnects general-purpose workstations, network-based multimedia devices and bridges to other networks. During the course of an application, media streams are exchanged between the workstations and devices in a seamless manner. This architecture has several advantages over traditional workstation-centric systems including the ability to share multimedia devices and to reduce the burden of multimedia tasks on the workstation. This paper describes the VuNet philosophy , the VuNet hardware, and presents the results of experiments in which high bit-rate video streams are transported across the system.

The Electrical Engineering Handbook, 2005

The Quality of Service (QoS) concept is of central importance in the context of multimedia systems. Generally, multimedia systems comprise the following functional units: networks, end-to-end protocols, data management systems (DMSs), applications, human-computer interfaces, and operating systems. Obviously, the entire system is influencing QoS that is visible to human users at the human computer interface. However, the relevance of DMS aspects for QoS in multimedia systems has not been broadly recognized. In this paper, we identify QoS characteristics that are visible at the application-DMS interface. Furthermore, we discuss for some QoS characteristics the corresponding mechanisms within DMSs and describe two concrete types of DMSs that aim at QoS support: realtime database systems and multimedia storage servers.

1993

Abstract Applications which require real-time multimedia services [13] face a number of difficult problems in the transmission of multimedia information. Among the most difficult problems are the heterogeneity of end nodes and the heterogeneity of media Quality of Service (QoS) requirements. End nodes typically consist of a computer and number of sensory input and output devices, such as displays, microphones, and cameras. QoS requirements [18] include degrees of reliability, jitter, and delay.

Ibm Systems Journal, 1997

In September 1993, the Canadian Institute for Telecommunications Research, in collaboration with the IBM Toronto Laboratory Centre for Advanced Studies, initiated a major project on Broadband Services. The goal of this major project is to provide the software technologies required for the development of distributed multimedia applications. Of particular interest are \presentational" applications where multimedia documents, stored in database servers, are retrieved by remote users over a broadband network. Emphasis is placed on e ciency and service exibility. By e ciency, w e mean the ability to support many users and many m ultimedia documents. As to service exibility, w e mean the application is able to support a wide range of quality of service requirements from the users, adapt to changing network conditions, and support multiple document t ypes. The research program consists of six constituent projects: multimedia data management, continuous media le server, quality of service negotiation and adaptation, scalable video encoding, synchronization of multimedia data, and project integration. These projects are investigated by a m ulti-disciplinary team from eight institutions across Canada. Multimedia news has been selected as a target application for development, and the results from the various projects have b e e n i n tegrated into a multimedia news prototype. In this paper, the system architecture, research results, and the prototyping e ort, are presented.

2008

In this paper 1, we present a new synchronization strategy for multimedia applications executed in a distributed environment. This strategy makes the timing properties of the system and the quality of the media presentations predictable since one is able to determine analytically whether the timing requirements of each multimediaapplicationwillbe met, and if not, which timing requirements willfail. The proposed synchronization protocol provides deterministic guarantees and service reliability that can’t be compromised by resource contention. Thus, the application can maintain the initial quality of service (QoS) level without encountering unpredictable delays and blocking due to synchronization. 1.

1995

Management and control of multimedia traffic is considered within a scenario characterized by the presence of different network platforms, exhibiting possibly very different features in terms of Quality of Service (QoS). In this framework, the needs for control strategies, acting in the user plane at protocol layers above the transport, is examined, and their goals, possible actions, information bases and location (centralized/decentralized) are discussed. Two specific strategies for QoS control of a multimedia connection involving real time traflc (voice and video) are then introduced; one is based on a backoff procedure at the transmitter, while the other acts upon feedback from the receiver to change some features of the coding algorithm. The joint operation of both control strategies is examined in an experimental environment based on Ethernet networks, interconnected by IP routers.

This paper describes the general problems in providing system software support for multimedia applications. Wespecifically focus on applications which have digital continuous media (DCM) I/O components, and the type of supportthat must be provided by the network software and operating system. DCM applications have large bandwidth and low delay requirements. We discuss network software support to meetthese requirements, such as resource reservation schemes based on parameterized requests for some level of ...

Lecture Notes in Computer Science, 2004

The increase in the bandwidth of wireless channels and the computing power of mobile devices increase the interest in video communications over wireless networks. However, the high error rate and the rapidly changing quality of the radio channels can be devastating for the transport of compressed video. In motion compensated coding, errors due to packet losses are propagated from reference frames to dependant frames causing lasting visual effects. In addition, the bounded playout delay for interactive video limits the effectiveness of retransmission-based error control. In this paper, we propose a mechanism that combines retransmission-based error control with path diversity in wireless networks, to provide different levels of protection to packets according to their importance to the reconstructed video quality. We evaluated the effectiveness of the mechanism under different network conditions. Simulation results show that the mechanism is able to maintain the video quality under different loss rates, with less overhead compared to error control techniques that depend on reference frame updates.