DAVIC (Digital Audio Visual Council)

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DAVIC (Digital Audio Visual Council) is a non-profit-making association which has charged itself with the task of promoting broadband digital services. The goals of DAVIC are declared as “…to identify, select augment, develop and obtain the endorsement by formal standards bodies of specifications of interfaces, protocols and architectures of digital audio-visual applications and services”.To enable the development of its specifications, DAVIC has developed the following philosophy [1]:

  1. Tools and not systems. DAVIC’s goal of providing interoperability across applications eliminates the definition of a system, instead, non-system-specific components, or ‘tools’, are defined which still guarantee interoperability.
  2. Relocation of tools. Tools should be usable in a variety of different systems and also in different parts of the same system. Therefore, they are defined so that they can be relocated when relocation is technically possible.
  3. One functionality, one tool. Where possible tools are defined to be unique.
  4. Specify the minimum. Because DAVIC has to satisfy a multi-industry constituency it is essential that only the very minimum that is required for interoperability be specified.

Figure 4 shows the general DAVIC system. It includes the Content Provider System connected to the Service Provider System by the CPS-SPS Delivery System, and the Service Consumer System connected to the Service Provider System by the SPS-SCS Delivery System. [1]

General DAVIC System
Figure 4 - General DAVIC system.

There are five information flows used to control the data flows. In Figure 4, these are indicated by the horizontal lines. From top to bottom, these information flows are numbered as [2]:

  • S1: Principal services layer peer flow for the transfer of audio, video and data from the server to the set-top unit.
  • S2: Application services layer peer flow for the control of the application.
  • S3: Session/transport services layer peer flow for the connection control of a session.
  • S4: Network services layer peer flow for the connection of the network and routing through the network.

The S5 information flow is for the administration of the network elements, e.g. network management, and occurs with the delivery system itself.