New Digital Broadcasting Services

New Digital Broadcasting Services

Abstract

Broadcasting Corporation and Stanford UniversityRecently, many countries are launching, or going to launch NEW digital broadcasting services. These new digitals services have big advance from legacy digital services: High Definition TV or HDTV and Multimedia Interactive Presentation. In last December, Japan launched this kind of new digital satellite broadcasting as the first launcher in the world. In my presentation, the features and mechanisms of this new Japanese digital satellite broadcasting from the technical viewpoint will be described. The presentation will be focused on newly developed and standardized technologies for the broadcasting system, such as hierarchical transmission system, multimedia coding scheme and software download toward the receiver. Hierarchical transmission system was developed to cope with large rain attenuation of satellite downlink in Ku band. Reception antenna of individual household is typically 17 inches or less in diameter. Under large rain attenuation, traditional digital services works digitally: clear picture or service shutdown. This technique brings graceful degradation to improve service continuity. This is very useful not to miss a very important scene of the program, such as touchdown of the football game, and for emergency broadcast.Multimedia Interactive Presentation provides text and graphic information on TV screen.

This technique adds not only a flavor of web to TV, but also Program-related information that is TV centric interactive services. Coding scheme of this Multimedia Presentation, named BML (Broadcast Markup Language), was developed based on XHTML. Special enhancements to W3C standards and ECMAScript are applied to enable content manipulation only by Remote Controller and broadcast specific features such as access to Program Guide data. A modem installed in a receiver returns enables two- way interaction between viewers and broadcasters. These new digital receivers carry embedded computers for handling protocols, displaying the multimedia contents, and system control. For future service enhancements, the receiver provides one-way software download mechanism, which returns no information to software providers. A new system software including common data, such as Genre Code or Broadcasters Logo, is downloaded automatically by the similar way to timer program recording on VCR. Schedule notification information is transmitted to a receiver to program a timer inside a receiver.