The Digital Audio-Visual Council (DAVIC) has approved for publication the DAVIC 1.0 technical specification to support a wide range of applications using emerging digital technologies, such as broadcasting, video-on-demand, tele-shopping and other interactive services. This is the first global end-to-end Multimedia specification that supports content and hardware interoperability.

This specification embodies agreements reached by some 350 engineers from 25 countries representing more than 200 companies during a 5 day meeting in Berlin hosted by Deutsche Telekom.

The goal of DAVIC is to promote global standards for broadband digital services using a variety of delivery media such as optical fiber, cable or satellite, ensuring compatibility and interoperability on a world-wide basis. This will be advantageous to all parties - equipment manufacturers, network operators, content producers, service providers and most importantly consumers.

Leonardo Chiariglione, the President of DAVIC, said: "This is the first set of specifications that have ever allowed players from a broad spectrum of industries, worldwide, to interconnect seamlessly to provide the next generation of audio-visual services that everyone wants. I would like to congratulate the DAVIC membership for producing this comprehensive specification on time."

DAVIC is a not-for-profit organisation registered in Geneva, Switzerland that works closely with international bodies, such as the ISO/IEC/ITU and the ATM Forum.

DAVIC 1.0 embodies eleven chapters of detailed specifications defining the service provider systems, the delivery systems and the customer electronics necessary to provide enriched consumer oriented applications based on digital television.

The 1996 DAVIC workplan includes interoperability events, an extensive coordination with Internet and additional tools to include new areas, such as MMDS (microwave multi-point distribution service).

Copies of specifications, fourth call for proposals and procedures to respond can be obtained from DAVIC secretariat. The secretariat should also be the initial contact for press enquiries.

DAVIC secretariat :

DAVIC specifications are intended to define unambiguously a complete end-to-end system capable of providing a wide range of services which include digital broadcasting, video on demand and highly-interactive applications such as home shopping. The specifications are complete in that they define all system components, including set-top unit, delivery systems and servers, from the physical level all the way through to the application level. The nature of specifications is such that systems built in accordance with it will not only provide the required functionality but can also be constructed of elements which are interchangeable on a world-wide basis. Such world-wide inter-operability is essential in stimulating the development of applications which can be offered to the public on a global basis. Additionally the specifications are so constructed that a multi-vendor environment is enabled and individual vendors are empowered to develop their own unique implementations of system components.

Because DAVIC specifications are at the forefront of a rapidly developing field, the need for rapid deployment has to be balanced against the possibility of introducing new technology in the future. Therefore DAVIC specifications define the technical "tools" whose use allows the provision of functionalities required by digital audio-visual systems and the applications that make use of it. Tools are usually associated with grades that determine the level of performance of a given tool, e.g. mono/stereo/multichannel audio, TV/HDTV, or bandwidth of a return channel. As time goes on more grades of tools or brand new tools can be introduced. The toolkit nature of DAVIC specifications would lead to too many incompatible instances of subsystems if not accompanied by the definition of groupings of tools with associated grades - called profiles. Profiles are defined so as to minimise their number yet be able to span a broad range of uses.

Specifications contain a general description of functionalities, the reference model of the entire system and of its functional components, all protocols and modulation schemes used in the different parts of the system, the precise definition of reference points and interfaces, and the adopted profiles.

Among the key agreements documented by the specifications are the modulation schemes needed for delivery of information encoded according to DAVIC specifications on hybrid fiber coax (HFC), fiber to the curb (FTTC), satellite and twisted pairs at both long and short ranges. Protocols adopted by DAVIC include elements of MPEG-2, the DSM-CC (Digital Storage Media Command and Control, part 6 of MPEG-2), the RPC (Remote Procedure Call) defined by OMG (Object Management Group) UNO (Universal Network Object) with IIOP/GIOP, AAL5 (ATM Adaptation Layer) and Q.2931 for ATM signalling.

Specifications can be downloaded from the DAVIC server:

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