With rapid innovations in MPEG2 technology, data volume had been reduced to just 22 Mbps by 1998. One relay aboard the broadcast satellite transmits at a bandwidth of 34.5 MHz with a transmission speed of around 51 Mbps. In other words, two channels each carrying a 22 Mbps HDTV signal just barely fit in the bandwidth transmitted by one relay. The four relays allocated to Japan, then, result in eight HDTV channels. The developments in digital compression technology are what made multi-channel HDTV broadcasts over DBS digital television possible.
Viewers are especially interested in and excited about high-quality HDTV broadcasts.
Broadcasts of movies with 5.1 channel audio, which makes viewers feel like they are inside the movie, and broadcasts of high-quality dramas, documentaries and sports events produced with HDTV broadcasting equipment are gaining a devoted following. NHK's channels, including surface wave broadcasting and analog DBS broadcasting as well as digital DBS, are supported entirely by viewer fees. The other five digital channels connected to major private broadcasting corporations, however, are currently broadcasting free programming supported by advertising income. However, because digital DBS television is not yet received by many households, the stations cannot expect a plentiful influx of advertising income and thus inevitably the budget available for producing programs is limited. Consequently, the private channels are mainly broadcasting television shopping programs and quiz programs, which take advantage of the bi-directionality aspect of digital broadcasting.