Digital Multimedia Broadcasting

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For other uses, see DMB.

Digital Multimedia Broadcasting (DMB) is a digital radio transmission system for sending multimedia (radio, TV, and datacasting) to mobile devices such as mobile phones. This technology was first developed in South Korea under the national IT project and the world's first official DMB broadcast started in South Korea in 2005, although trials were available much earlier. It can operate via satellite (S-DMB) or terrestrial (T-DMB) transmission. DMB is based on the Eureka 147 Digital Audio Broadcasting (DAB) standard, and has some similarities with the main competing mobile TV standard, DVB-H.

Like DAB, T-DMB is made for transmissions on radio frequency bands band III (VHF) and L (UHF), mainly for terrestrial and satellite, respectively. Because the United States and Canada still allocate the first band as for television broadcasting (VHF channels 7 to 13) and the United States reserves the L band for military applications, DMB is still unavailable in North America. Qualcomm's MediaFLO is a proprietary system used there instead. In Japan, 1seg is the standard, using ISDB.

T-DMB uses MPEG-4 Part 10 (H.264) for the video and MPEG-4 Part 3 BSAC or HE-AAC V2 for the audio. The audio and video is encapsulated in MPEG-2 TS. The stream is RS encoding and the parity word is 16 bytes length. There is convolutional interleaving made on this stream, then the stream is broadcast in data stream mode on DAB. In order to diminish the channel effects such as fading and shadowing, DMB modem uses OFDM-4DPSK modulation. A single-chip T-DMB receiver is also provided by an MPEG-2 transport stream demultiplexer. DMB has several applicable devices such as mobile phone, portable TV, PDA and telematics devices for automobiles.

T-DMB is an ETSI standard (TS 102 427 and TS 102 428).

Contents

[edit] Deployment

Currently, DMB is being put into use in a number of countries, although mainly used in South Korea.

[edit] South Korea - The Leader

In 2005, South Korea started S-DMB and T-DMB service on May 1 and December 1, respectively. [1] [2]

As of December 2006, T-DMB service in South Korea consists of, 11 TV channels, 25 radio channels, and 8 data channels. These are broadcast on six multiplexes in the VHF band on TV channels 8 and 12 (6MHz faster).

As of April 2006, S-DMB service in South Korea consists of 11 TV channels and 25 radio channels and 3 data channels.

S-DMB service in South Korea is provided on a subscription basis through TU Media and is accessible throughout the country. T-DMB service is provided free of charge, but access is limited in selected regions.

Around one million receivers have been sold as of June 2006. Receivers are integrated in car navigation systems, mobile phones, portable media players, laptop computers and digital cameras.

Today, South Korea has Full T-DMB serviced that include JSS(Jpeg Slide Show),DLS(Dynamic Label Segment),BWS, and TPEG.

[edit] Europe and some other countries

Some T-DMB trials are currently planned or available around Europe and other countries:

  • Following the lead of South Korea, Germany's 'Mobiles Fernsehen Deutschland' launched the commercial T-DMB service "Watcha" in June 2006, in time for the World Cup 2006, marketed together with Samsung's P900 DMB Phone, the first DMB Phone in Europe.
  • France is currently running a trial in Paris.
  • Indonesia is currently running a trial in Jakarta.
  • NRK is currently running a trial in Trondheim, Norway.
  • Italy is currently running a trial in some areas.
  • China is planning to do DMB service during the 2008 Olympics.

[edit] See also

[edit] External links

[edit] Official

[edit] Other


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