04 June 2005

What is DMB and why is it trying to crawl into my ear?

Finding references to digital multimedia broadcasting (DMB) is easy; there's been a plethora of new products released with the format (Google News search, Technorati), and already it's assumed I know what it is (Insert exasperated expletives here). Well, thanks be to the Almighty and In-Stat, I do ("DMB in Korea," Jan '05; PDF). Basically DMB is a type of media transmission format developed in Korea based in part on the European Digital Audio Broadcasting (DAB) initiative. I won't go into Eureka 147 and its development, except to mention that the MP2 and MP3 audio formats emerged from this research project. In the USA, DAB has been hampered by the competing formats (TSSF).* In Japan and Korea, DAB has been overtaken by DMB.

One virtue of DAB is that radio receivers in a car or airplane don't need to be retuned as one moves from point to point; also, reception is consistently high. The signal is transmitted either by satellite or by terrestrial stations; this is also true for DMB (T-DMB for terrestrial; S-DMB for satellite).

DMB was an initiative launched by Korea around 2002, and quickly adopted by Japan. Both national initiatives favored S-DMB, which involves less up-front investment. The InStat report intimates that the initiative was taken by industrial associations in the RoK, and taken up by counterparts in Japan. DMB differs from DAB mainly in the compression formats, which are essentially higher density. As a result, DMB-configured devices can operate in a more crowded environment than DAB devices can, and the types of data are more varied.

A drawback of DMB seems to be costs of implementation. In order to implement T-DMB outside of greater Seoul, for example, all television transmission has to be digitized; analog transmissions interfere with T-DMB signals. In fact, this changeover was part of the original plan, since Korean wireless and wideband usage is the highest in the world.In my next post, I'll discuss the cultural effects of DMB.

*Curiously, US laws make it far costlier to run a radio station in digital format than in analog format. According to the Wikipedia article linked above, if a song is transmitted using analog technology, then the station pays a royalty to ASCAP, BMI, or SESAC (which represent the songwriters); if the song is transmitted digitally, then RIAA (which represents the performers) must also get a cut. It's rather astonishing how prohibitive US laws are against new consumer technologies generally.


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