Multimedia Application Categories

  Multimedia applications can be subdivided into different categories, each making particular demands for support on the operating system or runtime environment. Husemann [Hus96, p. 14--16,] suggests three application categories:

• Information Systems.  The main purpose of such systems is to provide information for one or several users. The requested information is typically stored in databases or media archives.
  Examples are electronic publishing, online galleries or weather information systems.
• Remote Representation.  By means of a remote representation system a user can take part in or monitor events at a remote location.
  Important examples are distance conferencing or lecturing, virtual reality, or remote robotic agents.
• Entertainment.  This major application area of multimedia technology is strongly oriented towards audio and video data.
  Example entertainment applications are digital television, video on demand, distributed games or interactive television.

User interaction possibilities are a more technical classification criterion favoured by Heinrichs [Hei96, p. 5--6,]:

• Interactive Services.  Interactive services permit the user to select the transmitted information. These services can be be further subdivided into:
  • Conversational Services.  Services with real-time demands and no relevant buffering, like video conferencing or video surveillance.
  • Messaging Services.  Services with temporary storing, like multimedia mail.
  • Retrieval Services.  Information services interactively presenting previously stored information from a database or media collection, for example tele shopping or hospital information systems.
• Distribution Services.  Distribution services transmit information from a central source to a potentially unknown set of receivers. There are two subcategories that differ in the control possibilities granted the users:
  • Services without User Control. Services characterised by having one central sender that broadcasts information to all participating users, for example digital television broadcasting.
  • Services with User Control. Services allowing the user to choose from the distributed information.