An architecture for real time multimedia communication system

The purpose of this work is to examine and exploit the potential of the coordination paradigm to act as the main communication and synchronization mechanism between components forming a distributed multimedia environment and exhibiting real-time properties. Towards this purpose, we have developed a mechanism for coordinating the distributed execution of components, as these are defined by the Multimedia System Services Architecture (MSSA). Our coordination environment uses the control-driven approach to coordination, namely the model IWIM and the associated language Manifold. In the process we show how Manifold can be used to realize object communication and synchronization of MSSA components and we present a methodology of combining a software architecture such as MSSA with a coordination language such as Manifold. We illustrate our approach by means of a suitable example.

Technology, Management and Applications, 2002

Distributed multimedia applications are characterized by timing constraints and endto-end quality of service (QoS) requirements, and, therefore need efficient management mechanisms to respond to transient changes in the load or the availability of the resources. This chapter presents a real-time distributed multimedia framework, based on the Common Object Request Broker Architecture (CORBA), that provides resource management and Quality of Service (QoS) for CORBA applications. The framework consists of multimedia components and resource management components. The multimedia components produce multimedia streams, and combine multimedia streams generated by individual sources into a single stream to be received by the users. The resource management components provide QoS guarantees during multimedia transmissions based on information obtained from monitoring the usage of the system's resources.

Proceedings Third IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (ISORC 2000) (Cat. No. PR00607), 2000

In this paper we highlight major technical requirements for designing and developing future distributed multimedia information system using Internet technology. The key requirements of this system are t o a llow users to access and search and to communicate multimedia documents consisting of text, audio, video, and image. We emphasize the role of object-oriented technology for information management and real-time communication protocols to guarantee QoS. We present a r eference a r chitecture for Web-based r eal-time distributed multimedia system which integrates enabling technologies including real-time streaming, multimedia indexing and searching, and distributed object management.

1999

Real-time systems and Multimedia systems have been developed separately for along time. The vocabularies are different, but some concepts are similar and it seems now useful to analuse and compare these systems in order to define more generic or common solutions and understanding. The applications characteristics, the operating system mechanisms and the modelling techniques are analysed for both of these systems.

Proceedings - Euromicro Conference on Real-Time Systems, 2000

This paper describes a methodology for the development of real-time systems and shows its application to the modeling, analysis and implementation of distributed multimedia systems. The methodology is centered on Communicating Real-Time State Machines as the modeling language and is supported by a Java toolset (jCRSM). The latter provides a graphical environment for editing, testing, debugging and Java code generation of a prototyped system. Multimedia systems are particular real-time systems which normally do not have hard deadlines to fulfill but only soft deadlines concerning the achievement of a user-defined level of quality of service. For instance, timing QoS parameters refer to jitter, skew and endto-end delay, which are to be kept bounded throughout a multimedia session. QoS constraints are monitored by assertions on the recorded timestamped event histories. The paper reports some experimental results of a modeled remote multimedia presentation system.

1998

In this paper we present a general framework for the real-time transmission ofinteractive media, i.e. media involving user interaction. Examples of interactive media areshared whiteboards, Java animations and VRML worlds. By identifying and supporting thecommon aspects of this media class the framework allows the development of genericservices for network sessions involving the transmission of interactive media. Examples aremechanisms for late

International Journal of Internet Protocol Technology, 2009

Emerging distributed multimedia systems such as Telemedicine, Tele-Conference and IPTV, deal with simultaneous geographically distributed sources by transmitting heterogeneous data, such as text, images, graphics, video and audio. The preservation of temporal relations that consider different data types and simultaneous distributed sources is an open research area. Although several works try to specify and execute at runtime distributed temporal multimedia scenarios, they are far from resolving the problem. This paper proposes a synchronization mechanism to be used at runtime in distributed multimedia systems. One original aspect of the present work is that we avoid the use of a common reference by executing all possible multimedia temporal relations according to their causal dependencies. We emulate the mechanism considering a wide area network environment and using MPEG-4 encoders. The emulation results show that our mechanism is effective in reducing the intermedia synchronization error that can exist. The present work does not require previous knowledge of when, nor for how long, the media involved of a temporal scenario is executed.

Lecture Notes in Computer Science, 2003

This paper combines work done in the areas of Artificial Intelligence, Multimedia Systems and Coordination Programming to derive a framework for Distributed Multimedia Systems based on asynchronous timed computations expressed in a certain coordination formalism. More to the point, we propose the development of multimedia programming frameworks based on the declarative logic programming setting and in particular the framework of object-oriented timed concurrent constraint programming (OO-TCCP). The real-time extensions that have been proposed for the concurrent constraint programming framework are coupled with the object-oriented and inheritance mechanisms that have been developed for logic programs yielding an integrated declarative environment for multimedia objects modelling, composition and synchronisation. Furthermore, we show how the framework can be implemented in the general purpose coordination language Manifold, without the need for using special architectures or real-time languages.

Transactions on edutainment IV, 2010

2005

2000

The transmission of related multimedia data causes problems because of their very large size and continuous nature. Unlike the majority of the existing solutions for transmitting continuous media, which use connectionless protocols, we propose one that uses a connection-oriented protocol (TCP/IP). An object-oriented approach is used to build both server and client, allowing easier system debugging and expansion. We implemented a buffering mechanism which allows us to continue playing for a period when the network load increases. Multithreading is used to solve some problems which require concurrent solutions.

Multimedia Tools and Applications, 1995

This paper presents the Distributed InterProcess Communication System (DIPCS) as a framework for managing communication in a distributed multimedia system. Within DIPCS, connection level management is provided through a novel distributed process group model called ADP-Group communication. The ADP-Group paradigm defines a new type of group message passing, called qos-reliable. Qos-reliable semantics are appropriate to controlling real-time multimedia communication, by allowing a spectrum of performance and reliability specifications to co-exist within one group. DIPCS also provides an abstract programming model of multimedia devices, easing control of a heterogeneous multimedia system. Distributed multimedia applications can be rapidly developed using simple group operation primitives. We show how ADP-Group message delivery semantics can be directly mapped into an efficient Integrated Services Network support policy.

… and Systems, 1999. …, 1999

In this paper we present a general framework for the transmission of interactive media with real-time characteristics, ie media involving user interaction. By identifying and supporting the common aspects of interactive media the framework allows the ...

1991

In this paper we describe ongoing work in protocol support for distributed multimedia applications. This work concerns the provision of suitable transport mechanisms to convey multimedia information (text, and digital voice and video) between multimedia workstations in a distributed system. There are two parts to the Lancaster multimedia work. First, we have developed an abstract model for multimedia communications that is based on the use of streams; and second, we have built an experimental system on which to test the implementation of protocols based on this model. This paper reports on both aspects of the Lancaster work, describing the results so far and identifying areas to be investigated further.