Compact Disc (CD) Starts Penetration of Digital Technology
The fact that any information can be transmitted using the two digits of 1 and 0 was elucidated by Shannon’s information theory in 1948. The introduction of digital technology to the world’s broadcasting media started with development of the PCM recorder in 1967 and other devices. The beginning of the 1980’s was when a new medium, the compact disk (CD), replaced the vinyl disk record medium, thanks to its excellent sound quality and operability. How digital technology can best be utilized in broadcasting has become one of the most significant research topics along with HDTV development.

“Integrated Services Digital Broadcasting (ISDB)”
In 1982, STRL proposed a future digital broadcasting called “Integrated Services Digital Broadcasting (ISDB).” This was an entirely new idea concerning broadcasting services in which all the data including video/sound/textual data/still pictures would be transmitted as digital signals on a single radio wave. Research on ISDB later became a subject of study at the CCIR (Comité Consultatif Internatiponal des Radio-Communications ) (later ITU-R), making the concept acceptable on a global scale.

Digital BS Begins Operation
Near the end of the 20th century, on December 1, 2000, digital BS broadcasting commenced services in Japan. Digital broadcasters included NHK and commercial key broadcasters in Tokyo.
This digital broadcasting was the first ISDB concept to be realized. It provides highly functional, versatile services that far exceed the capabilities of conventional TV. These include high-quality picture/sound digital HDTV programming, 5.1 channel surround stereo, various kinds of data broadcast, interactive programming using a remote control device, an Electronic Program Guide (EPG), a Conditional Access System (CAS) function, and a download function to update the software of the receivers. In particular, the data broadcasting of ISDB together with HDTV provides much more information in comparison with the conventional terrestrial teletext broadcasting, in addition to enhanced service. The services now available include “Anytime News,” a local weather forecast service selectable by postal zip code, and a stock price quotation service.

Toward Real-time, Storage, Interactive Services
ISDB is just the first act of the upcoming digital broadcasting revolution. Digitalization laid a foundation for television viewers to move from “watching TV” to “using TV.”
Future digitialzation of terrestrial TV broadcasting will provide high picture quality, high functionality services to mobile and portable receivers as well as to fixed receivers. ISDB, through implementation of the home server system, will make the dream that any viewer can obtain desired information at anytime and anywhere a reality.

1. Original ISDB concept
2. Digital satellite broadcasting and digital compression/transmission technology